Talk:Cockcroft and Walton Experiment
- 1 A few questions for Aschlafly regarding this experiment
- 2 This experiment by John Cockcroft and Ernest Walton is claimed by some physicists as demonstrating that E=mc2.
- 3 But in fact the overall energy expended to attain this transmutation is greater than the energy produced by it
- 4 The claims of mass-energy equivalence have not been replicated with more advanced modern technology.
- 5 Abuse of a quotation
A few questions for Aschlafly regarding this experiment
I'd appreciate an answer by Aschlafly (and him alone) to the following questions:
1. Do you accept that the mass of the Lithium-kernel (7Li), of alpha-particles (4He) and of protons (1H) can be measured fairly accurately, as these are charged particles?
2. Do you accept the measurements for the mass of the particles as used by Cockcroft¹ and Walton, i.e.
particle mass 1H 1.0072 amu 4He 4.0011 amu 7Li 7.0130 amu
If not, which values do you think to be right?
3. Do you agree that before the reaction the mass of the particles involved was 8.0202 amu?
4. Do you agree that after the reaction the mass of the particles involved is 8.00220 amu?
5. Do you agree that there is a mass decrease of 0.0180 amu?
6. Before the experiment, the Li was at rest and the proton had a kinetic energy of less than 1MeV. Do you accept these values?
7. After the experiment, a pair of alpha-particles was observed, both having an kinetic energy of 8.6MeV. Do you think that this value is correct?
8. Can you tell me where the mass went? Can you tell me where the energy came from?
9. If your answer to question 8. is no in both accounts, than my answer is that there is a theory which explains the conversion of mass to energy, even if you don't like it!
As this theory works for this experiment, and for all the other fissions and fusions, it isn't liberal claptrap, but a meaningful theory. And you can't blame physicists for using it! Of course, you can blame journalist to abuse the formula - but this isn't the result of liberal physics, but of bad reporting, as an abuse of the dictum 1+1=2 doesn't reflect badly on number-theorists, but only on the person misattributing it.
AugustO 01:01, 23 January 2013 (EST)
This experiment by John Cockcroft and Ernest Walton is claimed by some physicists as demonstrating that E=mc2.
This should read is claimed by virtually all physicists: I added a fact-tag to the some until at least a few (2-3) physicists are found who think that it doesn't demonstrate the equation! I don't know any who hold such a belief... --AugustO 19:28, 23 January 2013 (EST)
- Instead, a hand-waving claim was made that an excess in kinetic energy of the resultant helium nuclei, which is greater than the energy of the original nuclei, must be attributable to a loss in mass. See (and answer!) # A few questions for Aschlafly regarding this experiment! There is no hand-waving, the loss of mass is observed!
- But in fact the overall energy expended to attain this transmutation is greater than the energy produced by it. Yes, as most accelerated protons just go through the target - it isn't in the nature of physical experiments to be energy efficient!
That isn't a very promising start! --AugustO 00:56, 24 January 2013 (EST)
But in fact the overall energy expended to attain this transmutation is greater than the energy produced by it
Andrew Schlafly, I hope you know that this means only that the experiment is not very effective, and not that it failed to show that in a single actual transmutation a comparatively great amount of energy (17.6 MeV) is released... --AugustO 15:30, 6 February 2013 (EST)
The claims of mass-energy equivalence have not been replicated with more advanced modern technology.
Cockcroft and Walton build one of the first particle accelerators in history, thus they were the first to observe artificial nuclear disintegration. Every accelerator since then has performed similar experiments, generally with the best technology available, so the statement that "claims of mass-energy equivalence have not been replicated with more advanced modern technology"" is patently absurd. --AugustO 10:06, 7 January 2015 (EST)
- How do you know Andy wasn't referring to just this particular experiment? Or, on the other hand, to the notion that no experiment has yet proved the equivalence? VargasMilan 18:53, 7 January 2015 (EST)
Because he didn't say "have not been replicated by re-running the Cockcroft-Walton experiment." He said "have not been replicated."
To all who want to take the position that the Cockcroft-Walton experiment wasn't correct, or didn't validate E=mc², I would point out that the Large Hadron Collider (LHC) is generally considered to be modern equipment, and it validates the equation every nanosecond that it runs. Also, every periodic table chart hanging in high-school physics and chemistry classrooms illustrates the principle.
Relativity denial at Conservapedia is not for amateurs. The debate has been going on for several years, and very few people (Andy, AugustO, Wschacht, and myself are probably the only ones left) know their way around the issue enough to debate it sensibly. If you jump into this debate not knowing what you are doing, you just run the risk of coming across as a sycophant, which is probably not what you want. The people named above (and several others who are long gone) have been discussing this issue for years, in great detail and with great precision.
If you believe you are qualified to jump into the discussion, please establish your credentials by:
- going to the Essay:Rebuttal_to_Counterexamples_to_Relativity page and write up a refutation of every point made there. You can put it right below, on this page.
- going to this section of the Community Portal and answering the three questions that I posed there (precession, time dilation, and mass change, that is, E=mc²).
I believe the questions are very precisely drawn, and I want the same precision in the answers. SamHB 20:18, 7 January 2015 (EST)
- Sam, you have hurt my feelings. You characterized the conversation I entered into as so enormous and far-reaching that I could never be a part of it without passing a demanding and rigorous extrance exam, naturally, to be determined by you. No neutral observer would regard resistance to this type of sweeping and contemptuous effrontery (if I take your "Relativity denial" epithet to carry the typical liberal connotations of "denial") as sycophantic towards anyone. Your inconsistencies between profession and reality indicate to me a desire to entrap your conversational partners rather than a desire to join them in pursuing the truth. I will adjust my expectations accordingly. VargasMilan 21:22, 7 January 2015 (EST)
- SamHB did not intend any personal offense in his remarks. It is just that when talking about highly complex areas such as this, people can talk past each other or start quibbling over definitions. The technical journals are filled with articles that are carefully written with many equations to describe these concepts. There are also many good physics textbooks. There is a lot of reliable material outside of CP to demonstrate E=mc2. I must say that most of the argument on the opposing side comes from CP itself or is derived from it. I suggest that we leave the friendly jousting to those already in the fray, and read a good physics textbook if you want more detail. Wschact 23:48, 7 January 2015 (EST)
Ah, my "withering patrician disdain" friend! I'm going to assume, from that discussion of a few months ago (you actually had me perplexed before you told me where it came from), and from your florid writing above, that your feelings are not genuinely hurt, and that some good-natured back-and-forth is OK with you. There is no need to "adjust your expectations" of me—what you see is what you get.
Now, to get to the point, I certainly didn't mean to imply that you need to be an expert on relativity to participate in the discussion, only that you needed to be knowledgeable about the relativity debate as it is carried on at Conservapedia. Very little scientific expertise is required.
But you need to know, and this is where I think people come up short, that Andy's views on relativity are so unusual that he is probably the only person on the planet who truly embraces them. Whenever someone appears to side with Andy, I assume that he is a vandal or a sycophant, because I find it extremely improbable that another person would hold those views. In the latter case, the person is presumably trying to curry favor, most likely to get some kind of promotion. You already have block powers, and the next step, administrator, is essentially never given out. So, I'm sorry, but coming down on the "E=mc² is liberal claptrap" side is a big red flag issue for me.
So, no, I'm not going to require a "demanding and rigorous extrance exam, naturally, to be determined by [me]". I believe you are fully qualified to discuss relativity. (You certainly have the vocabulary for it :-) So ignore the perceived entrance exam, and go straight to the two bullet points I listed above. And accept my apology for suggesting that some special expertise is needed. SamHB 00:46, 8 January 2015 (EST)
Abuse of a quotation
"As Stuewer (1993) has suggested, Cockcroft and Walton use mass-energy equivalence to confirm their hypothesis about what happens when 7Li is bombarded by protons. Hence, it does not seem we ought to regard this experiment as a confirmation of E=mc². However, if we take some of the other evidence that Cockcroft and Walton provide concerning the identification of the products in reaction p + 7Li → α + α as sufficient to establish that the products are indeed α-particles, then we can interpret this experiment as a confirmation of mass-energy equivalence, which is how this experiment is often reported in the physics literature."
Omitting the sentence starting with "however" - which shows that the assumption made in the sentence "it does not seen we ought..." is indeed not entirely correct - misleads the reader! --AugustO (talk) 03:36, 16 July 2018 (EDT)