Talk:Theory of relativity/Archive 2
legal right to abortion
"For example, Democratic presidential candidate Barack Obama helped publish an article by liberal law professor Laurence Tribe to apply the relativistic concept of "curvature of space" to promote a broad legal right to abortion."
Unfortunately there is no link to the article in question. It would interest me much what the right to abortion has to do with the alleged curvature of space. Either the space is curved, or it isn't. Neither of both could ever affect my moral convictions.
- This entire section is ridiculous and irrelevant. Clearly the curvature of spacetime was being referred to as a metaphor. Kristkrispies
- Where is the reference to Obama helping publish the article? The current reference points to the JSTOR article abstract, which does not mention Obama's involvement whatsoever. ATang 15:33, 29 May 2008 (EDT)
Paradoxes? Nobel Prize?
Why are these things labeled as paradoxes? The rule is the speed of light IN A VACUUM is constant WITH RESPECT TO INERTIAL FRAME. The variability of c (the speed of light) through a medium is accepted and irrelevant as far as SR is concerned. That is due to the absorption and reemission of photons by atoms as light hits travels through glass (or air or fiber optics cable). Similarly, relativity neither prohibits nor "encourages" a c that varies with the age of the universe. Indeed, the nature of the constant is still a mystery, and it may indeed be dependent on some factors we are unaware of.
If anyone is confused, shoot me an email and I'll either give you a full explanation or point you in the direction of a good resource.
Also, there are several reasons Einstein never received a Nobel Prize for relativity:
-he recieved a prize for the photoelectric effect,which has laid the framework for quantum mechanics (arguably just as important). They may have had qualms over giving two to the same person (they haven't done it yet).
-initially, there was some resistance against it by the old guard of physicists who had wasted their lives pursuing the alternative (and stupid) ether explanation for the nature of c.
-the Nobel committee favors ideas that have practical applications (hence no prize for mathematics), and at the time relativity had none.
-as to why they haven't given him one recently...well, Einstein's dead, and they don't give prizes posthumously. (A sticking point, since the full significance of a theory might only be fully realized generations after its inception).
So saying the Nobel prize hasn't recognized Einstein for relativity is misleading and irrelevant.
And now I'm curious. This article seems to have an anti-relativity bias. Why is relativity unAmerican or unChristian (besides the fact that Einstein was a German Jew)?
And what's up with the Obama reference? I don't think God asks politicians (liberal or conservative) for their opinions when he establishes His natural law. (unsigned by User:QED)
- I looked at your edits for this and found them to be wanting. The information on the Nobel committee is accurate. It's a small part of the article and no specific conclusions are stated from it. I can see why you would believe this is not a slight on relatively, nevertheless it is true as written. In the absense of any counter evidence, such as writings by the Nobel committee explaining this, it should be allowed to stand. Your other point is, temporarily, out of bounds. You may believe that relativity allows for faster than light movement 'virtually', but unless you have a source, it's not going to be included. In other words your conjecture is not going to trump a source that appears to take a neutral position.
- Lastly, do not try to play the minority card again. You aren't Johnny Cochran. The article on Einstein is extensive and written with great respect. I'm assuming you could already have checked it up to see the view on him at CP. Consider this to be your one and only warning in this area. Learn together 17:38, 29 May 2008 (EDT)
- User: Learn together's analysis is superb. The polemic comments above by QED seem to have little relation to the actual entry here, or to science.--Aschlafly 19:13, 29 May 2008 (EDT)
The introduction refers to "a principle which led to the first theory", but as far as I can see, there's no further reference to or explanation of this. What is this referring to?
It's been asked a couple of times above, but not answered as far as I can see: What relevance does Obama's comment have in this article?
Philip J. Rayment 11:54, 31 May 2008 (EDT)
- The reference to "principle" should be to postulates. That's been fixed. The reference to Obama is explained enough, don't you think? It describes political support for the theory, and use (or misuse) of it for political gain.--Aschlafly 18:45, 31 May 2008 (EDT)
- It hasn't been explained on this talk page at all. Harald asked the question above, Kristkrispies added a criticism, and the only reply was from Ed Poor suggesting the section be rewritten. QED asked about it also, and the reply didn't address that point.
- However, rereading the footnote (or did I miss that before?), I can see a very tenuous connection, but not one that warrants it being included in this article. I suggest it be removed. Philip J. Rayment 19:44, 31 May 2008 (EDT)
- Philip, I'm assuming you're referring to the Obama reference. The heading explains it. Political insights are a key part of this site, and explaining political benefit to something is essential to understanding why it is emphasized and/or misrepresented. The theory of relativity is used, or misused, to advance liberal goals, and the Obama reference is an important illustration of that. Would you like to see more examples?--Aschlafly 23:16, 31 May 2008 (EDT)
- Yes, I was referring to the Obama reference. Not, it's actually the opposite of the heading, because it is (mis)using relativity (physics) to support something political, not political support of relativity which is what the heading refers to. And as such, it's only of marginal if any real relevance to an article about relativity. I guess, though, I can see some point in it. That is, it's like an article about comets mentioning that there was a musical group named The Comets; a bit of barely-related trivia, but the sort of thing that Wikipedia and Conservapedia sometimes do (often under the heading of "cultural references"). Philip J. Rayment 02:10, 1 June 2008 (EDT)
- Philip, I'm assuming you're referring to the Obama reference. The heading explains it. Political insights are a key part of this site, and explaining political benefit to something is essential to understanding why it is emphasized and/or misrepresented. The theory of relativity is used, or misused, to advance liberal goals, and the Obama reference is an important illustration of that. Would you like to see more examples?--Aschlafly 23:16, 31 May 2008 (EDT)
I added a bit more information in the introduction to general relativity, because, as written, the article didn't really explain what the idea behind general relativity was. I don't think the edit is perfect, so people are free to tweak it or add more.--Mathoreilly 13:12, 1 July 2008 (EDT)
I also deleted "at infinite speed" from the sentence that said in classical physics light travels at infinite speed in a straight line. In classical physics, light still travels at c (approx 300,000 km/s), as Maxwell or any book on electrodynamics can tell you. In fact, it was this very observation that got people all caught up in the ether theory, because Maxwell's equations made direct reference to the speed of light. Consequently, people assumed that the equations had to be referring to the speed of light with respect to some fixed medium, i.e., the ether. Of course, we all know how well that theory worked out.--Mathoreilly 13:21, 1 July 2008 (EDT)
I removed the sentence about the Nobel prize committee not recognizing SR/GR in the evidence for SR/GR section. Mostly, the sentence just seems out of place with the rest of the section. Also, the reference provided was just a link to the Nobel committee homepage.--Mathoreilly 13:49, 1 July 2008 (EDT)
I removed the last section: time dilation and creation science. If we start including every crackpot scientific theory ever proposed, this page is going to become enormous.--Mathoreilly 14:00, 1 July 2008 (EDT)
- I see you are not around to respond, but including the latest creationary thinking doesn't mean that crackpot theories will be included. Philip J. Rayment 01:01, 16 July 2008 (EDT)
New Edits, Proposed edits
This article needs some major work, and I don't mind diving in and trying to correct some things. I added something on the equivalence principle because the existing information about general relativity was mostly mathematical with no physical insight. I'll try to clean up more when I have more time. --WLink 11:10, 24 July 2008 (EDT)
I also corrected a mistake about force defined in special relativity. The way it was written it wasn't defining a vector. --WLink 11:10, 24 July 2008 (EDT)
Further, I would really like to clean up the experimental evidence section, but there appears to be some contention regarding GPS, so I thought I'd discuss it with other editors here. The GPS definately DOES include some relativistic corrections. Consider the 1996 paper referenced in the article, on page 193 of the journal, page 5 of the article the authors tell us "The GPS operational control system corrects the pseudoranges measured by its monitor stations for the sum of the gravitational and velocity effects." What the article discusses is that the corrections are merely the average corrections, not the full specific velocity/gravitational effects. The article is being used misleadingly to make an unsupported claim. If no one objects in a day or two, I'll make the changes. --WLink 11:10, 24 July 2008 (EDT)
I'd also like to remove the stress on Dicke's theory, as Dicke's theory is basically just an extension of GR. Dicke's theory is still a metric theory of gravity involving curved space time, so most of the discussion of GR should be applicable to Dicke's theory. Dicke's theory should probably be included in another article. Also, the contention that Dicke didn't get a nobel because he proposed an alternative theory needs some supporting information or a citation or I think it should be removed. Again, if no one objects, I'll make the change. --WLink 11:10, 24 July 2008 (EDT)
I also plan, given time, to give a more "layman" style description of GR following my brief discussion on the equivalence principle. For students, diving straight into tensors, geodesics and field equations will most likely obscure the physics. --WLink 11:10, 24 July 2008 (EDT)
Einstein's Cross/Ring and Gravitational Lensing
I think it'd useful to have a picture of gravitational lensing in the proof section. As I'm not an admin, I can't upload it. There's the picture found on wikipedia which is known as "Einstein's Cross," but there are plenty of other examples of gravitational lensing that can be found in the public domain: . I suggest picking a nice looking one and displaying it. I'm personally partial to the double ring found here: . ArnoldFriend 20:43, 19 October 2008 (EDT)
- The images don't add anything new of substantive value. What's really needed here is more explanation about whether twice as much bending of light by relativity is really predicted and shown, compared to the prediction of bending of light by Newton's theory. Most people are misled to think that Newton's theory does not predict the bending of light, when it does.--Aschlafly 20:53, 19 October 2008 (EDT)
- I tried to edit, read it over, reverted it as it wasn't making sense. However, I think there should be something about photons being able to move at speeds other than c in the bit about Newtonian lensing. My phrasing was really poor, thus the self-revert. I may take another crack at this later when I can get the words right.--ArnoldFriend 21:22, 19 October 2008 (EDT)
- The bending of light in Newtonian physics is not a trivial issue. The mass can approach zero and it still bends, for example. How much it bends is debatable, I think.--Aschlafly 21:35, 19 October 2008 (EDT)
- Do you think it'd be a good idea to create a page about the bending of light under Newtonian Dynamics? Most people don't know about this and I think an explanation that's less technical than the linked source might help. ArnoldFriend 15:07, 22 October 2008 (EDT)
Science And Math Facts That Prove Einstein's Blatant Error In His Relativity Theory
With all due respect, but with regard to truth in real science, my writing here is to provide undeniable mathematical and science fact that special relativity is false science. For information this math proof was written on Wikipedia about two years ago and they squelched the truth in science by a vote of 8 to 1, and even though a supposed expert in relativity wrote that the math proofs did in fact prove relativity to be totally wrong, in the end he chose to live a lie and to squelch the truth. In the end you can also squelch truth in real science by determining that truth by the undeniable science and math facts written here or to live according to truth. Either is your choice but squelching will only suppress science facts and true science. So I am going to write the science and math that shows undeniable truth and you can decide. StevenCrum 16:31, 31 October 2008 (EDT)
- A section on "critiques of Einsteinian relativity" would be good. Do you remember the name of the expert? --Ed Poor Talk 12:58, 12 May 2009 (EDT)
More regarding the criticism of LIGO
As a student of physics, I feel myself almost obliged to add something to the discussion regarding LIGO, particularly as I work for a Professor that is part of the LIGO collaboration and have actually attended scientific conferences where the subject is addressed (though to be fair my work with her specifically deals with another one of her collaborations, Borexino).
First, as mentioned in previous discussion, it is indeed true that it was understood that LIGO, like many scientific undertakings, would need to be refined and calibrated before reaching its design sensitivity. To claim the LIGO is a failure before it has reached its design sensitivity is just as ridiculous and ignorant as criticizing any other tool or piece of equipment for not functioning before it is properly calibrated. It isn't like the LIGO collaboration is trying to pull any fast ones on anyone by being secretive about this - just do a Google search for LIGO to bring up their web page, where they discuss the details of this matter.
Secondly, it is true that the "success" of the experiment cannot be known prior to its being conducted, but if it could, what would be the point in conducting the experiment in the first place? Experimentation is a necessary aspect of science because scientific investigation fundamentally deals with the discovery of knowledge not previously known to us, and because it is not known to us, even its ultimate usefulness cannot be known a priori. The rate of observed events under the initial design sensitivity is predicted to be very low, so it would not be very surprising if we did not observe anything until advanced LIGO debuts. Even still, there is a fundamental uncertainty in the rate of events that will be seen. Maxwell was once asked what the usefulness of electromagnetism could ever be, to which he replied "What good is a newborn baby?" I do not believe I need to highlight the usefulness of electromagnetism in the modern world.
Which brings me to my third point, which is the enormous significance LIGO holds in terms of scientific potential. If LIGO is successful, it will revolutionize modern day astronomy by providing a new method for detecting cosmological phenomena. Gravitational radiation would offer another method of "imaging" the heavens, independent of electromagnetic radiation. To say that LIGO would have limited scientific benefit would be a serious rebuke to the field of astronomy in general. Optical astronomy would be coupled with gravitational astronomy as a valuable check on astronomical results attained by optical methods alone. But of course, the fundamental uncertainty we have as to what the observed rate of events will be reflects the fact that we do not know with complete certainty what cosmological objects exist, hence the very reason that LIGO would be useful.
Even more revolutionary would be if LIGO failed to detect gravitational waves. If you only assume the existence of a gravitational field, and that disturbances in that field cannot propagate faster than the speed of light, then by the very definition of wavelike phenomena, you have gravitational waves. Gravitational radiation is a prediction of General Relativity, and as such, were it to be disproved, it would falsify a prediction of a scientific theory. To say that this is not valuable would be to suggest that, for example, Michelson's experiments in search of the aether were not valuable, whereas in reality they gave supporting evidence to the idea that there is indeed no aether. At the very least, the experiment should be able to place certain restrictions on the rate of observed events. If gravitational radiation were not found, and this represented a serious contradiction with the rate of events predicted, it would be ABSOLUTELY ENORMOUS in terms of scientific relevance, and I cannot stress that enough. Something huge, somewhere in our understanding of the world, would have to be revised, be it the idea of the gravitational field, causality itself, etc. As a practicing scientist, I would almost hope that LIGO fails to see gravitational radiation, just because the scientific implications would be so unimaginably radical and weird, and force us to completely reexamine how we perceive the universe. But this subject could be argued until it reaches the realm of some very deep scientific philosophy - scientific theory is generally not viewed as being "completely true" or "completely wrong," but as a method of predicting physical phenomena, which eventually is replaced with a more accurate theory. Newtonian mechanics is not so much wrong, as it is not a good enough approximation in certain specific applications. If you want a metaphor, think about scientific progress as continuing to improve our Taylor expansion of the universe.
Though I suspect given the general tone of this article, somehow the death of GR would also please most of the contributors to this encyclopedia, as if General Relativity, a scientific theory, is somehow inherently a "liberal" idea. I'm sure that when Einstein formulated it, he envisioned it being used by Barack Obama to support a woman's legal right to terminate her pregnancy. Though, I hope for the sake of those contributors that General Relativity is either disproved, or is shown to be a "conservative" idea, because if it does adequately describe our universe, is a "liberal" idea, and God created the universe, then either God is a liberal, or he has a very weird sense of humo(u)r.
Just to get this nonsense out of the way now, I'm a registered independent. I vote, based on all of the relevant information I have been able to attain via what I believe to be credible sources, for whoever I honestly believe will be able to fulfill the duties of the office they seek, and I don't think anyone can ask any more of me than that. If any of this leads some of you to believe that I am incapable of discussing the theory of General Relativity, then I surely and sincerely have nothing but pity for you. --kfratus
- What are you talking about? The article has only one simple sentence about LIGO. Is that sentence correct or not? RSchlafly 13:13, 23 March 2009 (EDT)
- First, if you'll take a closer look at the talk page, you'll notice that there has been a good amount of discussion of the usefulness of LIGO, and that was what I was principally referencing. Secondly, the article in reality contains three sentences that in some way reference LIGO, albeit only one of them by name. The last sentence specifically mentions LIGO, the second sentence is clearly directly referencing LIGO without naming it, and the first claims that research involving the theory of relativity receives a disproportionate amount of funding. I would regard the first of those sentences as a matter of scientific opinion, which I addressed in my comments by pointing out how much impact LIGO could have on the entire astronomy community. The second and third sentences may not be incorrect, so much as they are worded as half truths. LIGO has been unsuccessful, or has failed, to detect graitational waves so far. To assert that LIGO has been unsuccessful in general would be entirely untrue, and is completely dependent on your notion of the "success" of the experiment, which I also addressed - LIGO has indeed managed to reach its target sensitivity, and whether or not they manage to detect gravitational waves, their results will still have a huge impact on the field of physics, which I would consider a successful experiment. --kfratus
- Hopefully, when LIGO disproves so-called "gravity waves", a relativist working on the project will be honest enough to call LIGO what it is. In this way, LIGO may end up being a very, very expensive way of disproving relativity, once and for all.
- I doubt it, though, with all that grant money on the line. BHarlan 23:35, 26 March 2009 (EDT)
- Maybe it is unfair to say that LIGO has been unsuccessful. But what about Gravity Probe B? That experiment seemed like a big expensive flop to me. RSchlafly 02:26, 27 March 2009 (EDT)
- I just want to make sure that the people here criticizing LIGO understand that the frequency range of the gravitational waves it was built to detect predict a variations in spacetime by only a factor of 10^-21. LIGO's longest vacuum tubes are 4km long. So physicists are attempting to measure a change in length approximately 1/2500th the diameter of an atomic nucleus.
- Yes, that is why some people predicted that LIGO would fail. RSchlafly 10:58, 7 April 2009 (EDT)
And to the poster who linked to youtube video of "gravity waves". Those ARE NOT gravity waves. Those are clouds.
- As a passer-by stumbling upon your conversation, I never really meant to end up leaving this many posts, and I apologize if I'm violating your 90/10 rule, or anything like that. But I just wanted to clarify something that I see come up very often. I frequently run into people who have this impression that all scientists are members of some secret organization that is trying to hold knowledge from the public, and that they have their own personal reasons for trying to manipulate the body of scientific knowledge. While I cannot speak for all scientists, any of the ones that I have ever met (myself included), would be absolutely more than happy to welcome more people to our field of study. Most physicists I have met enjoy what they do, and would be very willing to pass their knowledge onto others (and one would have to admit that if we were somehow manipulating the entire body of public knowledge, we'd have to be doing a pretty good job of keeping every single scientist in the entire world quiet about the real truth - not very practical). And with respect to the comments made by BHarlan, I can assure you that most scientists would actually LOVE to disprove general relativity. In many cases, scientists are not famous because they confirm the prediction of a theory, but because they disprove one, thereby radically changing what we know about the world around us. The reason Einstein was so famous was because he disproved the Newtonian picture of the universe, not because he confirmed some prediction of it. But this is just like any other profession - think about it, if a rival of yours was successful in some way, wouldn't you be just dieing to somehow prove them wrong and rub it in their face? Scientists are people too, subject to the same personality traits as everyone else. This is why most physicists feel relatively comfortable with the scientific process - they know that if something is proposed as a theory, there will be a thousand people just itching to prove it wrong, thereby stealing the limelight for themselves. I think that if I ever found a way to disprove relativity, I'd practically have a heart attack out of excitement (and you can be sure I'd get a Nobel prize for it, too). In fact, it is already a well known fact that GR must be wrong at at least some level, because as it is formulated now, it's not compatible with some of the basic tenets of quantum mechanics. Though, I'm still pretty sure we'll see gravity waves, if you want my opinion. Gravity waves are predicted by ideas much more fundamental than GR (aka, the finite speed of light), and so GR could be be wrong, and we could still have gravity waves - as long as you define the propagating influence of gravity as a "wave," and assume that information can't travel faster than the speed of light, then there you have it, really. And with respect to the video of the clouds, those are actually "gravity waves," but of a different sort. The term comes from how the Earth's gravitational field effects atmospheric conditions. So it is the same term for two very different things, which unfortunately may lead to some confusion for some people. And with respect to Gravity Probe B, I admit that I do not know as much about that experiment, and off the top of my head would not really be able to debate it. Though if I remember correctly its data analysis is scheduled to continue into 2010, so I would hesitate to say anything until then (other than the fact that in principle, I find its goals fairly relevant - if you really wanted to test the geometrical nature of GR, you should try to confirm/disprove one of its craziest, most non-intuitive predictions - aka, frame-dragging).
- But I can assure you, I have met plenty of people who are very politically conservative, and believe in gravity waves. In fact, many deeply spiritual people believe that relativity is a sign of God's existence. The basic idea goes that if relativity were not true, there would have to be some preferred reference frame, which would have to be chosen somewhat arbitrarily. But how could a divine creator just make some arbitrary choice like that? Not very elegant, if you ask me. In fact, I have heard that some people actually cry when they finally understand GR, because of what an elegant theory it is. If you want to read more about ideas like that, I definitely suggest Brian Greene's book, "Fabric of the Cosmos." If you want my honest opinion, I have yet to come across anything in my study of physics that I believe is a serious threat to the existence of some intelligent creator. From what I can gather, most physicists don't even concern themselves with such an aim - if God exists, then he exists. Our goal is to study what we can see, and make useful predictions based on that. If it's all just a result of God, then so be it. The only result will be that we've come to know Him a little better through out study of the universe and its workings. --kfratus
- The article hardly says anything about gravity waves. Are you suggesting some change to the article? RSchlafly 12:00, 12 April 2009 (EDT)
The article suggests that Newtonian physics somehow suggest the bending of light, which is impossible according to Newtonian physics. Since a photon has zero mass, it cannot be bent by the force as described by Newton.
- Huh? I thought it was Newton who discovered the bending of light, which occurs as light enters a prism. It is because the various frequencies of light bend by different amounts that we get the rainbox effect (see spectrum). Or I have I totally forgotten my high-school physics and history of science? --Ed Poor Talk 17:00, 19 May 2009 (EDT)
Next point, Newton's action-at-a-distance theory of gravity seems to be taken as fact. The idea that general relativity violates this is used as a point against it. Newton himself stated, and I quote:
"It is inconceivable, that inanimate brute matter should, without the mediation of something else, which is not material, operate upon, and affect other matter without mutual contact; as it must do, if gravitation, ...., be essential and inherent in it. And this is one reason, why I desired you would not ascribe innate gravity to me. That gravity should be innate, inherent, and essential to matter, so that one body may act upon another, at a distance through vacuum, without the mediation of anything else, by and through their action and force may be conveyed from one to another, is to me so great an absurdity, that I believe no man who has in philosophical matters a competent faculty of thinking, can ever fall into it."
Therefor, even the founder of classical mechanics saw action-at-a-distance as problem, so how is it in any way evidence to contradict a well tested theory?
- Oh, ignoring phenomena such as quantum entanglement, are we? --PhyllisS 22:57, 11 May 2009 (EDT)
- Actually, no. The reason that a grand unified theory is necessary is because of the discrepancies of the quantum world and the macro world. Both have been tested, neither conclusively, but evidence is in their favor. All I am saying here is that you can't use this (logically) as a point to disqualify an entire theory. Especially when you use this point when referencing a person (Newton) who had a problem with it.
- Kindly use the signature button (10th from the left above) to "sign" your comments, so we can tell who's saying what.
- Newton assumed nothing; he "feigned no hypotheses." Accordingly, he didn't have "a problem with it." It was his peers who could not accept it. Newton's quote above does not question "action at a distance," but is commenting on the nature of matter.
- Many still refuse to accept action at a distance (and non-locality), as your own viewpoints demonstrate.--Andy Schlafly 23:16, 11 May 2009 (EDT)
- Still refuse? As one of your relatives pointed out, there is some support for it, such as quantum entanglement, but on a large scale (say larger than the what is it now, 1 km?) past where quantum entanglement has been proven, there is no proof or any proof to suggest it should be true. And, I'm sorry, but I have to say. Don't assign my viewpoints to me sir. I will decide what I think based on fact. What I form as opinion, I will state as such. I don't understand how people can read this article with any knowledge of physics and agree with it. None of my professors, mentors, or scientists that I have met would support such statements. The fact that you are doing so proves the disgusting and twisted lengths that some people will go to in order to make established fact comply with their own super-conservative beliefs. It is people like yourselves that are ruining the republican party and make me scared for the future of America.--RobertSJ 23:22, 11 May 2009 (EDT)
- Many still refuse to accept action at a distance (and non-locality), as your own viewpoints demonstrate.--Andy Schlafly 23:16, 11 May 2009 (EDT)
- So even though non-locality and action at a distance have been fully proven in laboratory experiments, you claim "there is no proof or any proof to suggest it should be true" beyond a certain distance. Surely you don't think there is one set of laws for less than an arbitrary distance, and another set of laws for larger than an arbitrary distance. No, the real problem here is that some people, perhaps including yourself, do not and will not accept action at a distance regardless of the proof.--Andy Schlafly 08:35, 12 May 2009 (EDT)
Next point, several "obscure physicists" is not the same as almost the entire community of physicists (which is the actual truth here.) Gravitational redshift perfectly explains the way that signals between earth and GPS satellites are different in time. That is how current GPS positions are calculated.
You mention LIGO at the very end and gravity waves as well. There is no prior mention. The prior mentions should explain what gravity waves are, why they are so weak, why they can probably only be detected from very massive binary systems, and why even when these massive binary systems are found the radiation should be so weak that the immense precision of LIGO and LISA are required.
Just some points on things that are not accurate or need to be clarified in order to not leave the reader with a false interpretation of scientific fact.
- Also edit, I am a physics major attending a well-respected and also conservative school (Vanderbilt). I have conducted research in physics at a national lab (ORNL), and like to keep up on this kind of thing. I am a moderate but conservative leaning voter.--RobertSJ 23:22, 11 May 2009 (EDT)
- I responded in greater detail above, but let me just add that not everything you've learned is true, and not everything your professors state is true either. Hopefully you'll admit at least that.--Andy Schlafly 08:35, 12 May 2009 (EDT)
- Photons have zero rest mass, but they are not at rest. A reference is given for the deflection of light as predicted by relativity theory. So the article seems to be correct about the bending of light. RSchlafly 12:41, 12 May 2009 (EDT)
- I wish that critics of CP would help us write basic physics articles instead of trying to "prove us wrong". Please help me finish the "bending of light" article, in accordance with what we all agree about Newton's discoveries many decades ago. Then we can discuss how to present quantum physics, okay? --Ed Poor Talk 17:04, 19 May 2009 (EDT)
Non-Locality and Quantum Field Theory
There is no action at a distance, nor non-locality, in quantum mechanics nor field theory. None. You're confusing two different subjects.
First, action at a distance: True, in Newton's gravity, there is action at a distance. But this is totally different from anything to be found in QM or field theory, which have no action at a distance. All Hamiltonians in the standard models of field theory (QED, electroweak, QCD) are strictly local Hamiltonians. Forces are exerted by passing virtual bosons back and forth in space, like footballs. Interactions (like electron/photon, then photon/electron) are all 100% local.
The fact that Newton's theory assumed action at a distance (without proof) does not mean that ALL theories require action at a distance. Why should that follow? Why should modern theories be limited by Newton's unproved assumptions? Quantum field theory is immensely more accurate, measured objectively, than Newton's gravity force ever was. QED (with special relativity built in) predicted the anomalous magnetic moment of the electron accurate to one part in a TRILLION. Newton's theory was never even close to that level of accuracy! Newton could never accurately compute the orbit of Mercury or gravitational lensing to one part in a trillion! Or billion. By objective criteria, field theory is more accurate than Newton.
Second, non-locality: non-locality is not the same as action at a distance. Action at a distance requires exertion of a FORCE. Nothing in QM is in fact non-local. The only thing non-local about QM is the Copenhagen interpretation of wavefunction collapse, which is not a part of the equations, but a way of visualizing the effect of observation a QM system.
You have mentioned quantum entanglement as a supposed example of non-locality. Entanglement, and phenomena like quantum teleportation, do not exert FORCES, so they are not actiona at a distance! Further, quantum entanglement can never be used to transmit information faster than the speed of light. Hence, there's no contradiction between QM and SR. Field theory has SR built in. There is no experiment, in quantum teleportation nor EPR paradox, Bell's inequality etc., that can possibly transmit information FTL. Describe one experiment, just one entanglement experiment, that can supposedly transmit info FTL. I dare you. Just one.
So what is this supposed "non-locality" then? The Copenhagen interpretation of QM says that the wavefunction should "collapse" (revert to a single eigenfunction) everywhere simultaneously when an observation is made. If this really happened, it would be a problem for SR, because in SR, simultaneity is relative to the observer. But, two problems. First, this supposed "collapse" can never be observed and can never be used to transmit info FTL. Second, the Copenhagen interpretation is deeply flawed because it never defined what an "observation" was. It is no longer the most popular interpretation; among physicists, the Many Worlds interpretation is more popular now, because it precisely defines what observation means, in terms of quantum decoherence, so MWI connects better to macroscopic thermodynamics.
If you want to (groan) argue the point, you can argue that Copenhagen and Many Worlds are both non-local, but so what? They're visualizations, not equations, and certainly not forces, nor "actions"!! When neither visualization scheme can be used to transmit info FTL, nor exert a force, this is no problem for SR at all!
The only big problem here is that field theory is incompatible with GR, not SR. True. Everybody knows this is the biggest problem in physics. No one knows whether the flaw is in GR, field theory, or both. However, either way, there is no problem between field theory and SR. Field theory has SR built in, and is (objectively measured) the most precise scientific theory in history. If you argue this, I'll swamp you with experimental proofs. Cuddlytakun 15:53, 18 May 2009 (EDT)
- "Cuddlytakun", you've obviously made up your mind that action at a distance and non-locality must not exist. But all evidence is against your view. Would you support spending another billion dollars of taxpayer money looking for gravitons to support your view? I hope not.
- How about this: raise private capital for searching for gravitons to support your philosophy. Then we'll see how many really agree with you, rather than just going along for the ride.--Andy Schlafly 20:10, 18 May 2009 (EDT)
Au contrere mon frere, you made up your mind that action at a distance is the only type force possible. I have nowhere said action at a distance is impossible. I've said Newton never proved, could not prove, it was the ONLY possibility. I suppose it's possible for both to exist. In field theory this would mean a Hamiltonian that is part local and part non-local. Sometimes the idea is kicked around. Mathematically, non-local Hamiltonians are a pain in the ass to compute with, and counterintuitive, but theoretically possible.
Why have you decided that action at a distance is the only possibility? Just because Newton's theory assumed it without proof, this does not mean all forces in nature must likewise be action at a distance. Think about this: suppose you and I are ice-skating. I toss you a football. When I throw the ball, reaction force pushes me backward. When you catch it, the collision pushes you away from me. Basic repulsive force at a distance, composed of local pairwise interactions. All forces in the standard model (electrodynamic, weak nuclear, strong nuclear; that is electroweak and QCD) work that way. The footballs are virtual bosons of spin 1.
"All evidence is against your view"? What evidence? What are you talking about!? "Your view"? Hell of a dismissive thing to say. It's not "my view", it's the view of everybody in physics, including Weinberg and Wilczek. Do you even know the meaning of the quotes you lifted out of Wilczek and Weinberg's speeches!? Seriously, do you have any evidence in mind, any at all, or are you just blowing smoke?
So you drag funding issues into it. As you know, the Europeans paid for the Large Hadron Collider so all the geniuses are moving to Europe. The last smart person to leave America, please turn out the lights.
But don't dismiss field theory as "philosophy". You're playing word games because you can't back up your statements with facts. These are facts: with field theory, you can predict the experimental value of the anomalous magnetic moment of the electron to one part in a trillion. Of the muon, to one part in a billion. You can compute the mass of protons and neutrons and mesons from first principles, a priori! Which is an inherently relativistic computation (m = E/c2, with E from local QCD.) The Z boson's existence and mass were predicted before its discovery via electroweak theory, which is an entirely local Hamiltonian. Newton's gravity could never compute anything to an accuracy of one part in a billion, or compute masses of particles a priori, or predict new particles before they're observed! Why do you call field theory philosophy, but Newton's theory is science? Explain the definition of "philosophy" you're using here. Word games! Cuddlytakun 23:55, 18 May 2009 (EDT)
- Your "word-to-substance ratio" is very high; you are likely a liberal. See point 2 in liberal style.
- I beg you to open your mind and learn here, for your own sake. Look at how you refused to address my simple point. Instead you cling to your perception of what you think others believe.--Andy Schlafly 09:11, 19 May 2009 (EDT)
How can I address your point, when there's no way to know what IS your point?
Is your point "All evidence is against your view"? OK, dish it out. Just list the top 3 evidences showing that action at a distance is the only way possible for particles to interact.
My point is: the horrible paragraph in the Intro about non-locality and field theory, incorrectly implies field theory is defective. It is not. Field theory is the most successful theory in the history of science. Weinberg's statement about field theory not being "robust" cannot be assessed by the reader because "robust" is not defined in this context. Weinberg's speech was written in '79, his criticisms were resolved by later successes of QCD and QED, as Wilczek described. That paragraph should go. You're trashing relativity and field theory too. Why?
Write 3 sentences. Top 3 evidences that action at a distance is the only way for particles to interact.
--Cuddlytakun 16:10, 21 May 2009 (EDT)
- How about ONE evidence, Cuddles? Like the evidence that you refused to go beyond talk and improve the articles. Nothing happened at all by way of action of your part, either in this article, nor in Quantum field theory, which definately needs improvement. Instead of action, all we get is gab from you. Karajou 16:23, 21 May 2009 (EDT)
OK. I have significantly updated the page on Quantum field theory. EdPoor said the page needed writing, and Karajou asked me to make an improvement, so I rewrote it. Now I'm going to fix the last paragraph in the Intro, which trashes field theory. Here I'm going to explain and justify my rewrites, line by line.
"...which [Relativity] assume that time is an intrinsic part of space and assumes absolute locality." I have rewritten as "Unlike Newtonian mechanics, in which space and time intervals are each invariant as seen by all observers, in SR the only invariant quantity is a quadratic combination of space and time intervals (x2 - c t2)."
It does not make sense to say that in relativity "time is part of space", nor is space part of time. The theory is about a space-time continuum, not time as part of space! They're symmetric in the metric, but with different signs.
"The non-locality of quantum mechanics and Newtonian physics contradicts the theories of relativity" I have rewritten as "The (assumed) instantaneous transmission of Newtonian gravitational effects contradicts special relativity." This statement is more accurate.
What does it mean to say "Quantum mechanics is non-local"? Vague. Quantum wavefunctions are non-local, and in the event of quantum entanglement (correlation) the wavefunction is multi-particle. But this is not relevant to relativity because real particles (unlike virtual particles) cannot transmit info faster than light (light cone restriction conserves causality). No entanglement experiment (e.g. teleportation) can transmit info faster than light, in fact teleportation requires classical info transmission SLOWER than light, look it up.
The Copenhagen interpretation of the collapse of the wavefunction upon observation is non-local but it is an interpretation, and likewise, cannot transmit info faster than light.
'Causality breaks down under relativity if information can be transmitted faster than the speed of light. In addition, the uncertainty principle suggests that light photons must sometimes travel faster than the speed of light despite the assumption of relativity; "[t]he only known way to resolve this tension involves introducing the idea of antiparticles."'
I have rewritten as: 'In quantum mechanics, the uncertainty principle suggests that virtual particles can sometimes travel faster than the speed of light which would violate causality, but "[t]he only known way to resolve this tension involves introducing the idea of antiparticles." Consequently, in 1928 Paul Dirac derived the Dirac equation, one of the first quantum mechanical equations compatible with special relativity, by which Dirac predicted the existence of antimatter. Four years later, antimatter (the positron) was discovered by Carl Anderson, as successfully predicted beforehand by relativistic quantum mechanics.'
This statement accurately reflects the facts that, first, some quantum mechanical equations are compatible with SR (e.g. Dirac equation, Klein-Gordon equation), and that Dirac's prediction of antimatter before its discovery was a SUCCESS for relativistic quantum mechanics, not a failure! Which is the point Wilczek was making in the citation from his Nobel speech: success, not failure.
"Quantum field theory is another attempt to partially reconcile relativity with quantum mechanics. But "quantum field theory, which was born just fifty years ago from the marriage of quantum mechanics with relativity, is a beautiful but not very robust child."" I have rewritten as "Quantum field theory, a generalization of quantum mechanics, is fully compatible with special relativity but not with general relativity."
I have deleted the quote from Weinberg because it gives the inaccurate picture that there's something wrong with field theory. There isn't. The Quantum field theory article lists some of its many successes.
Cuddlytakun 16:46, 22 June 2009 (EDT)
The proofs for relativity are both mathematical and physical, yet this article tries to say otherwise. If someone doesn't know them then can I please put them in without them being edited out within minutes?
--Unlikelyconvert 13:14, 20 May 2009 (EDT)
- You're not going to push anything that is false here. Make your very best edit first and let's see how that looks, before you spend a lot of time.--Andy Schlafly 13:20, 20 May 2009 (EDT)
I haven't tried to push anything, I've made a few edits already, corrected a couple of scientific mistakes, and said this. Can you please open your mind for just 10 minutes and look at both sides of this debate? Look at the overwhelming consensus on relativity, and then I will look at any source you give me forwarding your viewpoint. As I've said in another talk page, I am willing to change my views if you can prove them. --Unlikelyconvert 13:27, 20 May 2009 (EDT)
- My mind is open, and I've invited you to make your very best edit first. Or, alternatively, state it here. Keep your word-to-substance ratio low, however. See liberal style.--Andy Schlafly 13:30, 20 May 2009 (EDT)
Looking above, many people have stated the mathematical proofs in their different forms, yet you dismissed most of them almost out of hand. And I am not a liberal in respect to your definition, I am the (in my experience) the more common kind, the kind who will accept evidence. And you don't seem that open minded, as when i offered to put in proofs you started by saying I was trying to spread falsehoods. Proof makes something true, not false.
--Unlikelyconvert 13:34, 20 May 2009 (EDT)
- I'm going to move on to more substantive edits. Your word-to-substance ratio has been very high.--Andy Schlafly 14:20, 20 May 2009 (EDT)
- I'm going to ban uc if he doesn't stop trying to make people change their minds. If he wants to provide information about a novel, unproven or untested theory he's welcome to do that. He can even write about a theory which we conservatives know is false, provided that he doesn't try to present it as valid.
Complex equations of relativity
What do you mean when you write that "Unlike most of physics, the theories of relativity consist of complex mathematical equations...". I believe that most people would consider Maxwell's equations complex...not to mention the equations found in quantum mechanics.
- Your quote is misleadingly incomplete, and Maxwell's equations do not describe an additional dimension.--Andy Schlafly 11:24, 15 October 2009 (EDT)
- Sorry if my abbreviated quotation was misleading. I wrote it that way because I perceived that this article was intending to state that the theories of relativity are more complex than other physical theories. Perhaps I misunderstood the intent. In either case, I agree that the relativity equations are complex, but other physical theories are just as complex.
- Maxwell's equations desribe electric and magnetic fields as a function of three spatial dimensions and time. Although descriptions of relativity may refer to time as the fourth dimension, the equations of relativity use only three spatial dimensions and incorporate time as a fourth MATHEMATICAL dimension (which does not mean that it is another spatial dimension).--RustyR 13:06, 15 October 2009 (EDT)
Quantum Field Theory/Changes to the Intro
The introduction currently contains false information- it asserts that relativity stands apart from the rest of physics, in that it relies on hypotheses and complex mathematics. All of physics relies on hypotheses and mathematics- for instance: Newtonian mechanics relies on the assumptions F=ma, objects at rest remain at rest, objects in motion remain in motion. Quantum mechanics relies on the Von Neumann postulates,etc.
Also, the mathematics of special relativity are really no more complicated then Newtonian mechancis, and less complicated then Maxwell's equations or quantum mechanics.
The introduction also asserts that quantum field theories are not entirely successful (in combining special relativity with quantum mechanics). This is blatantly not true-the standard model is the most successful theory we have, and it is a quantum field theory.
The last change I made was to the rewording of the assumptions of relativity in section 1. The constant speed of light cannot be reworded as nothing can travel faster then light- the latter follows from the former. The first is an assumption of the theory, the second a result of the theory (the difference between an axiom and a statement proven from the axiom).
Also, I think the paragraph about special relativity and Newtonian gravity being in conflict is an excellent opportunity to talk about the need for general relativity, so I would like to add something about that.
On a stylistic note, maybe the references to quantum mechanics should be grouped together in their own section, or their own article? Also, perhaps-we should include an "evidence for" section to contrast with the "evidence against"?--WLink 11:38, 15 October 2009 (EDT)
- You've made a number of false assertions here. Newton expressly rejected relying on hypotheses. His physics is based on observation, in contrast with relativity, where mathematics was developed first and then data was sought to support it.
- Relativity relies on four-dimensional space; other physics does not. It was widely claimed for years that few could understand relativity, and Eddington even has a famous quotation to that effect.
- Quantum Field Theory is incomplete at best and incoherent at worst. Even one of the rare Nobel Prizes for it has an admission of incompleteness in the acceptance speech.
- Relativity is a liberal's fantasy, and Obama even supposedly helped with a paper drawing liberal conclusions from it. Too bad it's all assumption and little more.--Andy Schlafly 13:35, 15 October 2009 (EDT)
Experiment has born relativity out time and time again. Michelson Morley, Ives-Stilwell, Pound-Rebka,Shapiro time delay, etc. The Tevatron has been confirming special relativity millions of times every second for years now.
Now, as to Newton- Newton made a famous statement about relying on hypothesis, that does not mean he didn't do it. I recommend his famous paper on prisms (http://www.newtonproject.sussex.ac.uk/). He advanced a particulate model of light, etc. Newton did make hypothesis, and his physics relied on it. Again, F=ma, the existence of inertial frames, etc. Quantum mechanics rests on highly mathematical postulates (the Von Neumann postulates). At least relativity's postulates are about physics, not mathematics.
Now, when you discuss relativity, you are conflating special and general. General relativity requires a great deal of mathematics, and it is general relativity that Eddington's famous quote was about. Special relativity is much easier. Changing time from an evolution parameter (as in Newton) to a coordinate (relativity) does not complicate things much. Single variable calculus and a good knowledge of algebra is enough mathematics to come to grips with the field. Quantum mechanics and Maxwell's equations require a solid knowledge of vector calc.
Lastly, a quick perusal of the nobel prizes awarded to work on the Standard Model/Field Theories since 1965- 1965,1967,1968,1972,1979,1980,1982,1984,1988,1990,1995,1999,2004,2008. Its not rare at all, a bit better than 1/3 of the prizes. Further, claiming something doesn't make it so- quantum field theories are the most precisely tested theories in all of science. g-2 of the electron is the most precise measurement mankind has made, and it matches the theoretical calculation to 10 significant figures. What more could you ask of in a theory? --WLink 15:45, 15 October 2009 (EDT)
- Point 1: no experiment has confirmed either of the two basic assumptions of special relativity, or many of the claims that are mathematically derived from those assumptions.
- Point 2: you seem to think F=ma is a hypothesis rather than a definition of force. Regardless, your argument does not negate Newton's quote or affect any aspect of this entry.
- Point 3: we do consider special and general relativity to be part of the same overall theory, as most people do.
- Point 4: your reference to "significant figures" (the better term "significant digits") is plainly silly and meaningless. The string of dates for Nobel Prizes counts for even less. When the prize was genuinely given for quantum field theory, the recipient honestly acknowledged how inadequate the progress has been. I don't know of anyone who seriously disputes that.
- Look, we can cut through a ton of subterfuge if you would just address my last point, which you avoided: liberals like Obama (and you?) like relativity for its political ramifications. Suit yourself, but don't pretend it is based on physical observations rather than unproven assumptions.--Andy Schlafly 17:51, 15 October 2009 (EDT)
- : I agree with WLink. It is just not true that the math of relativity was developed before the physics. Relativity does not rely on 4-dimensional space any more than quantum field theory. The first 2 paragraphs of the article (starting with "Unlike") are false in almost every detail.
- The progress in quantum field theory has been huge. Who said it was inadequate? If so, I dispute that, and all those Nobel prizes dispute it.
- What are the politics of relativity? Maybe you should spell that out. RSchlafly 18:08, 15 October 2009 (EDT)
- The politics driving relativity is self-evident: moral relativism, curvature of values, no fundamental frame of reference, no action at a distance, and an implicit denial of the arrow of time. Read the famous Tribe/Obama paper if you want detailed application to specific political issues, such as abortion.
- Name one productive advance made possible by the "huge" progress in quantum field theory. There aren't any.
- General relativity, which is the main component of relativity, certainly was developed before physical observations.--Andy Schlafly 19:43, 15 October 2009 (EDT)
Point 1: Now you are essentially restating the problem of induction- it is a problem with ALL of science, not just relativity. Also, Michelson Morley DOES essentially test the constant speed of light postulate.
Point 2: As I said above, even if we take Newton as a special case, what about quantum mechanics, Electricity and magnetism, etc. All require assumptions! Even if Newton's quote were true, Newtonian science would be the exception, not the rule.
Point 3: Most people consider special and general relativity different, but related theories. They are usually taught in separate courses, and have different domains of usefulness (general relativity being a theory of gravity is used in gravitational problems. Special relativity being a theory of fast moving things is used in particle accelerators).
Point 4- the point about significant digits is not silly- quantum field theory makes the most precise/accurate prediction of any theory of all of science. Further, everyone of those Nobels I listed was given for an aspect of field theory.
As to your last point- reality is what reality is. Whether or not liberals can twist something to fit their ideology is irrelevant.
But, I give up. I wanted to add my expertise as a particle physicist to your educational resource. If you don't want what I have to offer, I have more productive things to do. --WLink 19:12, 15 October 2009 (EDT)
- Point 1: No, the Morley experiment comes nowhere near confirming the postulate of relativity about the speed of light. And it's absurd to tar all of science with the sweeping, unproven assumptions on which relativity depends.
- Point 2: Your answer is unresponsive. Nothing else in physics depends so heavily on broad, far-fetched assumptions as relativity does.
- Point 3: Your answer is disproved by the name "general relativity" itself. It is the general theory, of which special relativity is a special case.
- Point 4: Your claim that something "makes the most precise/accurate prediction of any theory of all of science" is a familiar and silly assertion made by liberals. You haven't explained why that claim should be meaningful, and it isn't. High school-level electromagnetism can make completely precise predictions. If you think there is a striking insight made available by only quantum field theory, then let's hear it. But pretending it is great does not make it so.
- On your last point: you're plainly wrong in claiming that "[w]hether or not liberals can twist something to fit their ideology is irrelevant," because you studied in school what liberals like and haven't even heard with an open mind contrary viewpoints. If you received a good grade for the reciting liberal viewpoints, then it becomes even more difficult for you to reconsider.
- We want open-minded talent here. If you give up, then it is because your mind was made up. I urge you to open your mind more, but that's obviously up to you.--Andy Schlafly 19:43, 15 October 2009 (EDT)
- No, relativity does not rest on assumptions or complex equations any more than any other theory of physics. It is not true that electromagnetism can make accurate predictions without relativity. Maxwell's theory is a relativistic theory. The origin of special relativity is in Maxwell's equations, not in any unconfirmed assumptions. I have pointed to 8 false and unsourced sentences in the article. Your comments make no sense. What do you think the Michelson-Morley experiment was measuring? Do you have some interpretation of it that differs from everyone who has ever written on the subject? RSchlafly 22:34, 15 October 2009 (EDT)
- You seem to be relying on some kind of fundamental distinction between special and general relativity. Special relativity is simply (as its name suggests) a special case of general relativity.
- The Michelson-Morley experiment does not establish the assumption of relativity about the speed of light, or relativity's insistence that action-at-a-distance is impossible. We can edit the Michelson-Morley entry here if you want to get into the details of what it showed, and did not show.
- Basic electrical circuits, like the kind in computers, are predicted perfectly by electromagnetics without any use of relativity.--Andy Schlafly 22:42, 15 October 2009 (EDT)
- Mathematically, special relativity is tangent to general relativity. I am just using common terminology. If you don't believe relativity, that is your business, but it is essential for all of physics in the last 150 years. And yes, it is needed to understand the electromagnetism used in computers. I suggest you find sources for your statements. I repeat, I count 8 false and unsourced sentences just in the first couple of paragraphs. RSchlafly 22:59, 15 October 2009 (EDT)
- The claim that relativity "is essential for all of physics in the last 150 years" is a standard over-the-top assertion of those who were fed it in school and have never reconsidered since. The truth is no one can cite a single achievement of value by the theory. For something supposedly so essential for 150 years, don't you find it odd that you cannot cite anything of value that has come from it???
- I was just pointing out errors in the article, and not trying to start a discussion on "value". RSchlafly 23:38, 15 October 2009 (EDT)
- Special relativity introduced the equivalence of mass and energy, and that explained the extraordinary kinetic energy of the products of radioactive decay and led to harnessing both nuclear power and the nuclear weapons which defeated Japan and maintained peace for sixty years. Linuxgal 23:45, 15 October 2009 (EDT)
- Linuxgal's comment illustrates, perhaps innocently, one (of many) false claims promoted by relativists. In fact, relativity had nothing to do with the Manhattan Project.
- Here's a basic question that relativists should answer: have taxpayers recovered the hundreds of millions of dollars of their money that have been spent in pursuit of relativity claims, such as the futile search for gravitons? (Of course the answer is "no".)--Andy Schlafly 23:50, 15 October 2009 (EDT)
- Sorry to butt in, but I'm wondering how relativity is at all linked to modern electronics. From my (admittedly limited) knowledge, quantum mechanics fundamentally underpins modern electronics (CPU design has to account for quantum tunneling, etc.), but the precepts of relativity are totally irrelevant at the microscopic scale. DouglasA 00:10, 16 October 2009 (EDT)
- No, relativity is not irrelevant. Magnetism is understood as a relativistic effect. The theories that make Maxwell, Dirac, and Feynman famous are all relativistic. RSchlafly 03:34, 16 October 2009 (EDT)
- It's true that relativity has nothing to do with modern electronics, that's actually explained by Quantum Electrodynamics, but Einstein opened that up with his paper on the photon, which was published in 1905 together with his first relativity paper, and people mash it all together (BTW I was the one posting as Linuxgal, I didn't know we had to use real names). Gravitons are not a relativity claim, it is an attempt to make gravity into a gauge field theory like electromagnetism and nuclear forces, which use bosons to mediate interactions between particles (and there's no evidence for it)...general relativity explains gravity as particles following a "geodesic" in the warped geometry of space-time RubyR 09:47, 16 October 2009 (EDT)
- Relativity has produced nothing of value, and this discussion isn't doing any better. The replies above are unresponsive to my points, and historically incorrect. Are you saying that taxpayers should be forced to pay for this unproductive work? Do you donate to it? if your answer is "yes, no" then that speaks volumes.--Andy Schlafly
- RubyR/Linuxgal is incorrect. Quantum electrodynamics has everthing to do with relativity. QED was created to make quantum mechanics relativistic, and it is a fully relativistic theory. That is how we got the Dirac equation of the electron. Without relativity, there is no QED, and no understanding of modern electronics. However, QED has nothing to do with with Einstein's 1905 paper on the photon. Einstein proposed that light is transmitted as a particle, rather than a wave, but QED treats light transmission as a wave.
- Andy, this Talk page is for improving the article. I suggest fixing the errors, and let the reader decide for himself whether relativity is worth taxpayer support. RSchlafly 12:01, 16 October 2009 (EDT)
- I'm all for correcting "falsehoods", but let's start with your own comments. You say, "Without relativity, there is no QED, and no understanding of modern electronics." That's just wrong, historically and logically. The inventors of the transistor at Bell Labs had probably never even taken a course in relativity, let alone used it. Relativity does not come up in the basic QM courses taught in college. Virtually no papers about electronics even mention relativity.--Andy Schlafly 12:52, 16 October 2009 (EDT)
- The transistor inventors used Maxwells equations, a relativisitic theory. Yes, you can learn basic QM (eg, Heisenberg, Schodinger, von Neumann) theory without relativity, but you need relativity for QED (eg, Dirac, Feynman). There is no understanding of quantum fields, except using relativity. RSchlafly 14:24, 16 October 2009 (EDT)
- Maxwell's theory predates relativity by thirty years or more. It is Maxwell that informed Einstein, not the other way round. RubyR 14:38, 16 October 2009 (EDT)
- The transistor inventors used Maxwells equations, a relativisitic theory. Yes, you can learn basic QM (eg, Heisenberg, Schodinger, von Neumann) theory without relativity, but you need relativity for QED (eg, Dirac, Feynman). There is no understanding of quantum fields, except using relativity. RSchlafly 14:24, 16 October 2009 (EDT)
- That's right, Maxwell predated Einstein by 30 years or so. Your point? Maxwell's equations are still relativistic, ie, invariant under the Lorentz group. Maxwell's equations are taught and understood today in terms of relativity. You can view special relativity as just a way of understanding Maxwell's equations. RSchlafly 15:11, 16 October 2009 (EDT)
- A relativist tries to view everything in terms of relativity ... including morality and values and an alleged impossibility of action-at-a-distance like what is described in the Bible. Next thing we'll be hearing relativists claim that Edison's work was relativistic too!
- Ruby is right. Call relativity Maxwellian if you like, but not vice-versa.--Andy Schlafly 15:28, 16 October 2009 (EDT)
- When I make the claim that relativity has nothing to do with electronics, it is to a first order approximation. NASA/JPL engineers fly their space probes all around the solar system with a high degree of accuracy without resorting to Einstein's relativistic corrections to Newton's basic theory. About the only place where relativity must be taken into account in electronics is the collating electromagnets at the CERN collider, where proton streams are accelerated to very close to the velocity of light. Otherwise the "slop" inherent in digital timing (you must wait for a signal to stabilize before accepting it as valid) buries the effects. RubyR 16:35, 16 October 2009 (EDT)
- Magnetism is a relativistic effect. If you are using magnetism, you are using relativity. If you deny relativity, then what is magnetism? RSchlafly 16:48, 16 October 2009 (EDT)
- And what is morality? Look, there's no denying that relativists insist on applying their assumptions to anything and everything. Magnetism doesn't need relativity, and relativity hasn't produced a single thing that is productive.--Andy Schlafly 17:15, 16 October 2009 (EDT)
This discussion has degenerated in Andy arguing points that are not in the article. I suggest fixing these errors:
- Unlike most of physics, the theories of relativity consist of complex mathematical equations relying on several hypotheses. - WRONG.
- These equations assume that it is forever impossible to attain a velocity faster than the speed of light, a hypothesis that can never be fully tested. - No, the equation show increased inertia as the speed of light is approached, something that has been experimentally verified for a century.
- By relying on assumptions about nature rather than observations, ... - No, SR relies essentially on electromagnetic observations.
- Relativity rejects Newton's action at a distance, which is basic to Newtonian gravity and quantum mechanics. - No, only to some interpretations of QM.
- The mathematics of relativity assume no exceptions, yet in the time period immediately following the origin of the universe the relativity equations could not possibly have been valid. - Nonsense. What is the source for this silly statement?
- Relativity has been met with much resistance in the scientific world. - No reputable physicist in the last century has failed to accept relativity.
- To date, a Nobel Prize has never been awarded for relativity. - Prize were given indirectly for relativity in 1902, 1921, 1933, 1993. Plus the QFT prizes already listed: 1965,1967,1968,1972,1979,1980,1982,1984,1988,1990,1995,1999,2004,2008
- Louis Essen, the man credited with determining the speed of light, wrote many fiery papers against it such as The Special Theory of Relativity: A Critical Analysis. - He is a kook.
- Relativity also gravely conflicts with quantum mechanics, and although theories like string theory and quantum field theory have attempted to unify relativity and quantum mechanics, neither has been entirely successful or proven. - No, there is no known conflict. RSchlafly 15:56, 16 October 2009 (EDT)
- That's quite a rant, ranging from calling someone a "kook" to insisting that everyone accepts something. See how your claims contradict each other?
- The bottom line is this: stop wasting taxpayer money on this stuff. If you believe it so much, then donate your own money. But the grand sum of money donated by relativists to something they claim is so great is this: $0. Enough said.--Andy Schlafly 17:15, 16 October 2009 (EDT)
- I did not say anything about money donated by relativists, about morality. Do you want to address something that I did say? RSchlafly 17:49, 16 October 2009 (EDT)
- Your objections are patently absurd. Taking your first objection, of course relativity relies entirely on sweeping assumptions, such as claiming that v can never, ever be faster than c and that there is no difference in frames of reference anywhere in the universe. No other area of physics relies so heavily on such far-fetched and unprovable assumptions.--Andy Schlafly 18:15, 16 October 2009 (EDT)
- That is like complaining that Newtonian physics assumes that energy is conserved. The statement about was observed by Michelson-Morley and others. If you want to call it an assumption, then it was also assumed by Newton in 1687 []. Every other theory of science also has similar assumptions, if you want to call these assumptions. Relativity is no different. RSchlafly 18:38, 16 October 2009 (EDT)
- I looked at your reference and found nothing relevant to this discussion, and you quoted nothing. In sum, relativity has yielded nothing productive, and neither is this discussion. Every minute spent on discussing relativity is a wasted minute, and every dollar spent is a wasted dollar. Relativity is based entirely on sweeping and implausible assumptions unlike any other theory of physics. Suit yourself if you like relativity, but you're wasting your time and please don't waste any more taxpayer dollars on it.--Andy Schlafly 00:01, 17 October 2009 (EDT)
- You complain that relativity is different from Newtonian physics, and then you fail to see the relevance of what Newton said about the principle of relativity. I give up. The CP relativity article is filled with errors. RSchlafly 00:27, 17 October 2009 (EDT)
Some clarifications I hope will be helpful
I signed up for a Conservapedia account after reading this article and talk page, and particularly the back-and-forth between Aschlafly and Rschlafly. I saw what appeared to me to be some points of confusion and miscommunication, and I thought I might be able to help clear them up.
First, on the GPS question, I think I see what Aschlafly is saying about clocks. I think he means that Newtonian dynamics predicts no change in time from one reference frame to another, but rather that the forces on an orbiting satellite may affect a clock on board that satellite, just like bumping a record player can cause it to skip.
This is a very astute observation, particularly given the minuteness of the observed desynchronization. The trouble is, it can't possibly be correct under Newtonian dynamics. The equivalence principle — the most basic Galilean one — says that a freely falling reference frame is indistinguishable from a reference frame which is not accelerating. So there are no forces acting on a clock in an orbiting satellite. (This is an approximation, obviously; tidal forces are at work inside an orbiting satellite. But on that scale, tidal forces are far too minute to have any measurable effect, much less an effect on the scale that's been observed.)
Now, maybe there's some as-yet-unknown force acting on the particular type of clock in a GPS satellite, causing it to desynchronize from ground-based clocks. A magnetic force, maybe, since those clocks are solid-state. We can easily imagine such a force, and define it in a way that matches the observations, just like Newton imagined a "gravitational force" that caused objects to fall in the way he observed. But physicists are (I think understandably) reluctant to do that, since the predictions of general and special relativity combined match the observed effects to the limit of our ability to measure.
It's not accurate at all to say that the desynchronization of GPS clocks proves either theory of relativity. What is accurate is that the two theories of relativity predict that orbiting clocks will differ from ground-based clocks in certain ways (slightly faster by a factor X because they're at a higher altitude, slightly slower by a separate factor Y because they're in motion) and that the observed behavior exactly matches the sum of the two predictions, to the limit of our ability to measure. GPS clocks don't prove relativity, but they also don't contradict it.
It's also more than a bit misleading to say that "relativity has yielded nothing productive," since we wouldn't have PET scans without it for one example. But I'm a theoretician, not an engineer, so I can't contribute too much on that front. I'm also unsure whether you'd consider something like astronomical redshift or gravitational lensing (allowing us to better observe the universe) to be "productive" or not.
I'm generally confused by what you're referring to when you say "sweeping and implausible assumptions." Maybe you're confusing assumptions with predictions. In special and general relativity combined there are only three postulates — things that are assumed to be true by the theory: that the laws of physics are fundamentally the same no matter where you are or how you're moving, that the speed of light in a vacuum is the same to all observers, and that spacetime is everywhere (mathematically) continuous and differentiable.
The third postulate boils down, in layman's terms, to "We assume that mathematics works in the real world." It's admittedly unfounded, but it's also a fundamental assumption of every other theory in physics as well. The second postulate started out as a bit of an assumption, but all experiments conducted to date have produced observations that are consistent with it. And the first postulate is another one of those fundamental assumptions of physics, that the basic laws of physics don't just change arbitrarily from place to place or from observer to observer. Only three assumptions, and none of them are either sweeping or implausible.
Also, I think there's a bit of a misunderstanding (okay, a big, huge, giant misunderstanding) about what E=mc2 means. That's okay, because most people who know what the letters in that equation stand for misunderstand what the equation means. That equation is nothing more than a unit conversion factor. You can convert from feet to inches by multiplying by a constant, twelve. If we define k to be 12, to keep from having to write the number down, then we could say I=kf, or inches equals feet times a constant. The mass-energy equation is just like that, a conversion factor for talking about energy (joules) in mass units (kilograms), or vice versa, just as we can talk about length in either feet or inches by applying a conversion factor. That's all it is. It doesn't say anything about the universe.
If you want to take issue with the mass-energy relation, you should turn your attention to the stress-energy tensor Tμν in the Einstein field equations. That's where the prediction is made that mass and energy are related on a fundamental level. If you want to argue that point, argue it there, not in the unit conversion equation, which doesn't say what you seem to think it says.
Finally (and I'm only stopping here because I don't want to be ridiculously verbose), it's not exactly correct to say that relativity "[claims] that v can never, ever be faster than c." That's sort of true, if you squint, but it's not exactly right. What special relativity predicts — not claims — is that if you start with any object the speed of which is less than the speed of light — say, me, sitting here — and you accelerate that object, then its velocity as measured in any reference frame will never reach the speed of light, no matter how hard you accelerate it nor for how long. That's a more accurate way to describe the prediction. In fact, from a purely abstract mathematical standpoint, the equations of special relativity kind of say the opposite of what you said. Because it's an equally valid mathematical solution to say that objects can exist which move faster than the speed of light, but that when they are negatively accelerated (i.e., decelerated) their speed will never be so slow as the speed of light. These types of masses are called "tachyons."
Of course, there are some serious mathematical problems with tachyons as a solution to the equations of special relativity. It's true that the math works, but it's also true to say that if I have three apples and you take away five I have negative-two apples. A mathematically correct statement, but one that doesn't have meaning in the real world, since you can't physically take away more than I have; "negative-two apples" doesn't have a real-world meaning, and tachyons might also not have a real-world meaning. Special relativity doesn't say they do exist, or that they must exist, merely that may exist without contradicting the theory.
I do apologize for writing at such length, but reading the exchange between Aschlafly and Rschlafly made me deeply sad. You two argued with such vehemence over points of misunderstanding that are really very simple. The coincidence in your names, and the possibility that you might be kin, just made it all the more sad to me. Perhaps it makes me a busybody, but seeing two people in conflict over such a trivial set of misunderstandings made me want to help. I hope you take my comments in that spirit. --KSorenson 13:00, 11 November 2009 (EST)
- More to the point, the article falsely states that relativity assumes you can't exceed c, and thus that relativity is based on untestable assumptions. This is wrong. The speed limit may be a consequence of the theory, but it is not an assumption of the theory. The assumption is that light speed is the same in all reference frames, an assumption that can be and has been tested. Of course it can never be fully tested, but neither can simple motion formulas be tested at all velocities. Thus this criticism of relativity is based on false premises.
- As for the complexity of relativity, this isn't true for special relativity; that much can be derived with just a little bit of linear algebra. And so what if Eddington claimed to be one of the few people who understood it? Is he a source of infallible truth? Are we supposed to fill this encyclopedia with facts, or with stuff people say?
- This encyclopedia is supposed to be guided by conservative principles, including the telling of objective Truth even if the Truth is politically incorrect or offensive to sensitive ears. In this article we are seeing the complete derailing of that fundamental principle. The article barely even describes its own subject and devotes as much space to attacking it with numerous disparaging falsehoods; all because the fact of relativity is offensive to somebody's political sensibilities and/or personal hangups. --NgSmith 13:41, 11 November 2009 (EST)
- There's much verbosity in the above two posts, and I'll gradually try to weed through it. Let me start by saying the obvious: the Lorenzian transformation at the heart of special relativity certainly DOES assume that "v" cannot exceed "c". The equation blows up if that assumption is violated.
- Now that I've addressed one of your points, how about addressing mine: relativity has absurd physical discontinuities, as explained in the entry.--Andy Schlafly
- It's sometimes tricky to say what exactly are the "assumptions" in a theory, but I thnik I agree with NgSmith on this point. One can derive the Lorentz transformations by assuming that the speed of light is the same in all reference frames. Einstein himself wrote a neat short piece "Simple Derivation of the Lorentz Transformation" that does this, even if it's not entirely rigorous. It's available online and quite lives up to its name. Others have done a more careful job of deriving the transformations. You're right that the Lorentz transformations do show we can't go above c, but I think it's more accurate to view this as a consequence of the assumption (c constant in all frames) underlying Lorentz, rather than viewing the Lorentz transformations themselves as the assumption. But I understand this is all up to debate and really comes down to how we want to formalize the theory. --MarkGall 15:40, 11 November 2009 (EST)
- Regarding the complexity of relativity, yes. Relativity is mathematically complex. While it's true that a lot of special relativity can be handled with basic algebra, the geometric interpretation depends on a good understanding of hyperbolic trigonometry, which is reasonably advanced math. General relativity, of course, is based on differential geometry and tensor calculus, which are highly advanced subjects in math. They are mathematically challenging theories, no question.
- I'm not sure that's a good criticism, though. I'm open to the possibility that I'm wrong, of course, but the mere fact that there's a lot of math doesn't seem to be a strong leg to stand on. Math, after all, can be learned by anyone with patience.
- (Just like posts with "much verbosity" can be read and understood by anyone with patience, but that's getting off the subject.)
- On the topic of assumptions, I'm not sure what else to say that I didn't say above. Special relativity does not assume that v cannot equal or exceed c. It assumes that the measured speed of light in a vacuum is the same in all reference frames. It then goes on to predict that under acceleration v cannot reach c. I agree, that alone would be a very difficult prediction to test. Fortunately, special relativity also predicts that proper time in a moving reference frame runs slower than proper time at rest, in proportion to v, and that prediction is not difficult to test. We accelerate particles with known half-lives to high fractions of c and then observe how long it takes them to decay. After enough such tests, the relationship between proper time in the moving frame and proper time at rest can be measured with a high degree of statistical precision. (This is known as the Rossi-Hall experiment, and was first done in 1940.)
- As for the other point about "absurd physical discontinuities" and the example given in the article — and believe me when I tell you I'm trying to say this as respectfully as I can — I'm afraid your math is simply flawed. The example given in the article is that if you take a massive particle, accelerate it to the limit c, and then also reduce its rest mass to the limit zero, you get a different momentum from that of a photon. At the risk of sounding pedantic, of course you do. Rest mass is not a variable in the equations of special relativity; it's not mathematically meaningful to take its value at a limit, because it's a constant. You could just as easily take the value of the gravitational constant G at the limit zero, but you wouldn't get physically meaningful results, because G does not vary. Saying that the equations break when you break the equations is, it seems to me, pretty tautological.--KSorenson 17:18, 11 November 2009 (EST)
- The Lorentz transformation at the heart of special relativity is not a starting assumption; it is a conclusion that is derived from the starting assumptions.
- The article criticizes relativity for using the untestable speed limit as an assumption, which would be unwarranted. Rather, relativity is based on a different assumption, that the speed of light is frame-invariant. That assumption is perfectly justified; it is simply a statement of what experimental data was already telling us. Indeed, relativity was borne out of an attempt to explain that experimental data.
- As for "absurd physical discontinuities," the supposed discontinuity listed in the article is the same for both relativity and Newtonian physics: the limit of mv as m goes to 0 and v goes to c is just 0, while the momentum of light is nonzero. But so what? A photon is not the limit of a shrinking mass, so this limit isn't supposed to equal the momentum of a photon. This is not a "discontinuity" in the laws of physics, simply a misleading mathematical argument. --NgSmith
Comments on Newtonian Mechanics
There are two aspects of Newtonian mechanics that are, I believe, misstated in this article.
One: several times the article claims that Newtonian mechanics predicts deflection of light by massive objects.
Newtonian physics did predict gravitational acceleration of light, back when light was thought to have mass, 200 years ago. But this "corpuscular" theory of light was abandoned long ago due to its false predictions, versus the growing evidence of light as a massless phenomenon. With massless light Newtonian mechanics does not predict any gravitational deflection at all.
It is misleading to represent that old theory, long since discredited, as "Newtonian mechanics," or to represent it as a present-day alternative to relativity. Newtonian mechanics does not model light as corpuscles, and does not claim that light is accelerated by gravity.
Two: the article makes fudge-factor statements like, "it is debatable how much deflection Newtonian mechanics should predict." No, it is not debatable at all: both Newtonian mechanics and relativity have well-defined, concrete laws that you can find in any physics textbook. There is no mystery or lingering uncertainty about what they say, and we know precisely what these laws predict about the path of a mass passing another mass.
It seems like the article is defending an incorrect prediction by arguing that the predicted value is still up for debate. But this is wrong; we know what the predicted value was, and should honestly accept that it does not match observation.--NgSmith
- Thanks for taking the time to find two specific areas for improvement here. This article was first on my list of those to improve — i.e., repair — when I signed up, but I've been working my way up to it because it's just so daunting. You've put the spotlight on a couple specific points, and that really helps.
- I'm in the middle of expanding general theory of relativity and won't finish it until tomorrow. Would you be interested in collaborating with me on this article? I think moving much of the detail of the special and general theories to their respective pages will help clear out some of the junk on this page. --KSorenson 18:43, 13 November 2009 (EST)
- I thought that there were people who predicted light deflection under Newtonian mechanics. Is that not true? Do you have any source for saying that people did not expect light deflection under Newtonian mechanics? RSchlafly 11:48, 15 November 2009 (EST)
- Absolutely. Johann Soldner, 1803, for one. I'm going to put that into the GR page. But probably not quite yet, there's a huge rewrite going on. I'm sure there were people who thought that the deflection under Newton should be zero, but they were just not thinking clearly. Any statement saying the expected deflection was zero should be taken out; not true. BTW, I think the detailed treatment of issues like this belongs in the GR page, and the R page should just link to it. PatrickD 12:01, 15 November 2009 (EST)
- The sequence of events basically goes like this:
- Light is like little cannonballs! (Pretty much everybody from the 11th c. forward.)
- Gravity is a constant force! (In India and Arabia, 9th c. or so, in Europe, Galileo, early 17th c.)
- Gravity varies with the square of the distance! (Newton, late 17th c.)
- There are stars so heavy that light cannonballs from them are dragged back down! (Laplace et al., 18th c.)
- Guys? Light's not cannonballs, it's vibration. So no on your gravity nonsense. (Various, late 17th c. through mid 19th c.)
- Okay, you guys are both right. It's cannonballs that vibrate. Kind of. (Einstein, early 20th c.)
- Oh, and gravity does so pull on it. So nyeh. (Einstein, early 20th c. but slightly later.)
- Basically the question of how light and gravity interact has been bounced back and forth like a ping-pong ball for the past thousand years. Only in the past century has a consistent model of light and gravitation emerged. Some discussion of this exists already here. --KSorenson 12:20, 15 November 2009 (EST)
- RSchlafly, there were indeed people a couple centuries back who predicted light deflection under Newtonian mechanics. But this was only because 200 years ago, light was thought to have mass.
- Newtonian mechanics only predicts the deflection of an object's path if the object has mass. Lose the mass and you lose the deflection. For that reason Newtonian mechanics has not predicted the deflection of light for a very long time. Surprisingly, the article already cites a source, citation no. 32, that says this in so many words.
- It is thus incorrect for the article to state that Newtonian mechanics predicts deflection (or that the deflection of a mass's path is "up for debate.") It seems to me that both of these claims are made in order to argue that relativity isn't necessary, in keeping with the article's apparent negative attitude toward its subject matter.--NgSmith
- That Ref 32 says, "Both Newtonian and Einsteinian gravity predict that the Sun will bend the starlight". It says that a massless particle would not have a Newtonian deflection, but does not say whether anyone thought that at the time. Newtonian gravity would predict a deflection in the limit as the mass tends to zero. So I think that you are contradicting yourself with these comments. RSchlafly 03:16, 17 November 2009 (EST)
- But what does the limit have to do with anything? Universal gravitation predicts a pull on any mass, even as the mass goes to zero. But at zero, there is simply no pull, and the formula says this explicitly: F=GMm/r*r. Everything else follows from this law. It doesn't matter that all masses are deflected as the mass goes to zero: once you hit zero, no mass equals no force equals no acceleration equals no orbit.
- One cannot make a limiting argument here, or rather that argument doesn't imply anything. The laws of physics are not required to give the same answer in the limit. This is what Andy Schlafly has referred to above as a "discontinuity."
- You are correct that the reference is not specific about whether people thought this at the time, but what matters is what people think now. To truthfully say that Newtonian mechanics predicts the deflection of light, that has to be the state of the theory today, and it isn't. We could truthfully write that Newtonian mechanics did predict the acceleration and hence deflection of light centuries ago, but that has long since been abandoned---not the least because if masses accelerated light, we'd see light zipping by at many different speeds.
- Finally, you will observe that while people differed in ages past on whether there was Newtonian deflection, none of those cites show any debate or disagreement over the magnitude of it. The predicted deflection is either zero (today) or 2GM/rcc; there are no varying interpretations of physics that resulted in 1.5GM or 3GM or 4GM or 1.1GM. Yet this seems to be what the article is implying, in defense of the Newtonian prediction being wrong. --NgSmith
- What people think now is that Newtonian theory predict deflection of light. That is what all the sources say, and I don't know why you would say anything else. People now say that light has mass, that Newtonian gravity attracts light, and that light is deflected. RSchlafly 10:59, 17 November 2009 (EST)
- People now say that light has mass? Who says that?
- No, the mass of a photon is zero, and so says every contemporary source I can find. Can we dig up a single textbook from the last 100 years, or in fact any reputable source, that asserts that a photon has mass?
- It is overwhelmingly clear that "what people now think now" is that light is massless, which therefore incurs no deflection under Newtonian gravitation. Indeed, we have long known that the speed of light is constant, and that alone contradicts the idea that gravity can accelerate or attract light; if that was true, then light from each star would be traveling at a different speed when it hit us, depending on the star's distance and mass.
- Granted, people might look at the equations for mass deflection, observe that the deflection is the same regardless of mass, and suspect that deflection may also hold for m=0, i.e. massless light. But while we may suspect that, the equations don't directly predict it. There is no equation in Newtonian mechanics that predicts a gravitational pull on an object of mass 0. --NgSmith
- The rest mass of the photon is zero. The photon is not at rest, and does respond to Newtonian gravity. If you think otherwise, then I suggest that you find some sources. RSchlafly 12:14, 18 November 2009 (EST)
- In Newtonian mechanics, "rest mass" is the only mass there is. Newtonian mechanics does not predict an increase of gravitational mass with velocity. Thus for a photon, the "m" in "F=GMm/rr" is unavoidably zero.
- In relativity, an object's kinetic energy as well as its rest mass can contribute to space-time curvature, i.e. gravitation. But that simply isn't Newtonian mechanics anymore. If you start making relativistic arguments to put a nonzero value in GMm/rr, you may end up predicting deflection of light; but it is still wrong to say that Newtonian mechanics is making this prediction.
- I must stress again that both relativity and Newtonian mechanics have very well-defined laws that are well understood. In Newtonian mechanics, you simply can't have a nonzero gravitational pull on a massless object. The law of universal gravitation is painfully clear on this point.--NgSmith
- Photons are not at rest. Photons do have inertia. You say that the Newtonian mechanics prediction is not correct, but it is a historical fact that Newtonian mechanics did make that prediction. RSchlafly 11:20, 19 November 2009 (EST)
- You are absolutely correct that "Newtonian mechanics did make that prediction." It did, in the past tense, 200 years ago when light was thought to be corpuscular.
- But the article doesn't say that it did, once, predict this; it falsely says that it does, in the present tense, predict the deflection of light. Note that this is not a change in Newtonian mechanics itself, but the assumption of what light is.
- Likewise, scientists did think that light passed through an ether; it would be false to say that they think this now.--NgSmith
- The entry is about physics, not mathematics. The Newtonian "force" equation applies to objects having at least an infinitesimal mass. If light has an infinitesimal mass, then it works fine and there is a deflection. If not, then we would assume the result would be a continuous one, rather than a physical discontinuity. There is no way to demonstrate that light has absolutely no mass, so arguing for a discontinuity here seems particularly pointless.
Relativity is not a "liberal" theory
I was briefly overviewing the article and I found this line:
"Despite censorship of dissent about relativity, evidence contrary to the theory is discussed outside of liberal universities."
As a physics major I must strongly protest to the implication that relativity is a "liberal" theory. Relativity has had many experimental proofs, and is one of the soundest theories in modern physics. There is simply no realistic reason to believe it is not sound. And I do not know where the idea came that the university would squelch opposition to it because it was not liberal. There is no political reason one way or the other for one to view it as right or wrong. The theory stands on it's own merits. (by Jfraatz)
- No idea? Perhaps, just perhaps you should read the ample discussion of these very matters sitting above on this very page. DouglasA 17:14, 23 November 2009 (EST)
- Your sarcasm is noted Douglas, and let me add mine. I've reviewed some of this now and to be quite frank this is a titanic monument of hogwash. It's rather embarrassing that this is on Conservapedia. The discussion above demonstrates that a lot of people here don't know what they are talking about. Several physics people tried to give explanations and show you what was wrong, but you seemed to dismiss there arguments.
Let me point out a few problems here:
First of all non-locality does not contradict relativity. Non-locality does not transmit information, and our latest knowledge of it suggests that it could be related to a sort of "quantum phase velocity" -like a wave in a stadium. It appears because the structure that it is connected to says that when one thing happens another thing must happen because they are both connected to a structure. The objects are not interact on each other directly though.
Secondly, variance in the speed of light does not contradict relativity. Relativity just says you can't go faster than the speed of light in your space-time metric. That does not say however that you can not tamper with vacuum properties of the space-time metric at the quantum level to tinker around with that constant.
Thirdly, there is massive evidence for relativity. The best example would be in particle accelerators. Most subatomic particles decay in a fraction of a second. They are able to keep them alive however for many many seconds to do experiments by accelerating them close to the speed of light and thereby exploiting time dilation. The particles age at a much slower rate from the perspective of the outside reference frame and thus we are able to experiment on them.
Your tone was rather rude before. My major is physics and I've taken a grad level course in relativity, and no offense but I strongly suspect you simply don't know what you are talking about. We'll see though. --Johanan Raatz
- Relativity predicts absurd physical discontinuities and it contradicts logic, the evidence, and the Bible. The biggest promoters of relativity today are more liberal than the Democratic Party, and that's saying a lot. Promoting relativity causes a great deal of harm in how people view the world, and has cost taxpayers hundreds of millions of dollars on fruitless projects like LIGO.
- You've heard none of this before because liberals control universities and don't allow open discussion and debate about their pet theories. Perhaps you think man-made global warming is not a liberal theory either?--Andy Schlafly 19:20, 23 November 2009 (EST)
- All of those statements are completely false. Relativity has no physical discontinuities, logic contradictions, or contradictions from evidence. Relativity promoters are no more liberal than those who promote quantum mechanics, superconductivity, or any other aspect of physics. RSchlafly 10:30, 24 November 2009 (EST)