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→Examples of how meaningless E=mc² is: descriptions for the layman
::::::No, it doesn't. It causes your energy to increase by a number of foot-pounds equal to '''one pound''' times the speed of light squared. I've explained this to you already and it isn't difficult. --[[User:SamCoulter|SamCoulter]] 16:23, 1 April 2012 (EDT)
::::::No, it doesn't. It causes your energy to increase by a number of foot-pounds equal to '''one pound''' times the speed of light squared. I've explained this to you already and it isn't difficult. --[[User:SamCoulter|SamCoulter]] 16:23, 1 April 2012 (EDT)
:::::::The equation is essentially just a conversion ratio, its not difficult to understand that units of energy (Whether it is Joules, pound-foot, or erg) look essentially like a velocity squared times a mass (in SI units - kg m^2/s^2) this is not relativity or theory dependent, its the definition of Energy. The Special Relativistic analysis that results in the basic equation just determines that the conversion ratio is precisely that universal constant '''c''' in whatever units are convenient. There is no blindingly obvious or intuitive reason why this SHOULD be the case (conceivably the conversion ratio could have any number of complicated dimensionless constants in front), but basic mathematical logic allows us to derive this simple relationship from the postulates of Special Relativity. That being said, its a rather useless equation on everyday scales. In reality, after consuming a pound of cake your body begins to break down the chemical bonds in the sugars/fats/proteins to extract usable energy, about 1500 food calories worth of it. If you had a precise enough scale and could somehow keep a human in a hermetically sealed bag that prevents the escape of any moisture/gas etc. you would be able to measure that after consuming and digesting the cake your bodyweight would not be +1 lb, but about 70 pg (picograms - 10^-12 grams) less, so if you weighed 150.0lb and ate a pound of cake (total of 151lb), after digestion you would actually weigh 70pg less than 151lb. It is important to note that this "mass" isn't "lost" it is merely the "weight" of the energy stored in the chemical bonds, in other words in a pound of cake there is (1lb - 70pg) of stuff and 70pg worth of "chemical energy" with a conversion ratio of c^2. If you had some magic machine that could convert mass to energy at 100% efficiency the detonation of a body sized bomb would release 20 times more energy than the largest nuclear weapon detonated by man kind, however due to the nature of nuclear transitions/processes such a 100% conversion rate is not possibe . On the scale of nuclear bonds (order of MeV) this difference becomes conceivably measurable, but even so, in the detonation of a hiroshima sized nuclear weapon, the loss of mass due to the nuclear fission is approximately 500mg, the rest of the nuclear material is dispersed as fallout, considering that there was ~60kg of nuclear material in the weapon, this corresponds to an energy "efficiency" ~1%, which is typical of fission devices. In a 100MT nuclear bomb this is conceivably larger at nearly 5kg, and the fusion type weapon that can achieve this high yields has considerably higher mass-energy conversion efficiency at around ~20% [[User:DenisTR|DenisTR]] 16:53, 5 April 2012 (EDT)
:::::::The equation is essentially just a conversion ratio, its not difficult to understand that units of energy (Whether it is Joules, pound-foot, or erg) look essentially like a velocity squared times a mass (in SI units - kg m^2/s^2) this is not relativity or theory dependent, its the definition of Energy. The Special Relativistic analysis that results in the basic equation just determines that the conversion ratio is precisely that universal constant '''c''' in whatever units are convenient. There is no blindingly obvious or intuitive reason why this SHOULD be the case (conceivably the conversion ratio could have any number of complicated dimensionless constants in front), but basic mathematical logic allows us to derive this simple relationship from the postulates of Special Relativity. That being said, its a rather useless equation on everyday scales. In reality, after consuming a pound of cake your body begins to break down the chemical bonds in the sugars/fats/proteins to extract usable energy, about 1500 food calories worth of it. If you had a precise enough scale and could somehow keep a human in a hermetically sealed bag that prevents the escape of any moisture/gas etc. you would be able to measure that after consuming and digesting the cake your bodyweight would not be +1 lb, but about 70 pg (picograms - 10^-12 grams) less, so if you weighed 150.0lb and ate a pound of cake (total of 151lb), after digestion you would actually weigh 70pg less than 151lb. It is important to note that this "mass" isn't "lost" it is merely the "weight" of the energy stored in the chemical bonds, in other words in a pound of cake there is (1lb - 70pg) of stuff and 70pg worth of "chemical energy" with a conversion ratio of c^2. If you had some magic machine that could convert mass to energy at 100% efficiency the detonation of a body sized bomb would release 20 times more energy than the largest nuclear weapon detonated by man kind, however due to the nature of nuclear transitions/processes such a 100% conversion rate is not possibe . On the scale of nuclear bonds (order of MeV) this difference becomes conceivably measurable, but even so, in the detonation of a hiroshima sized nuclear weapon, the loss of mass due to the nuclear fission is approximately 500mg, the rest of the nuclear material is dispersed as fallout, considering that there was ~60kg of nuclear material in the weapon, this corresponds to an energy "efficiency" ~1%, which is typical of fission devices. In a 100MT nuclear bomb this is conceivably larger at nearly 5kg, and the fusion type weapon that can achieve this high yields has considerably higher mass-energy conversion efficiency at around ~20% [[User:DenisTR|DenisTR]] 16:53, 5 April 2012 (EDT)
:::::::: Another way of thinking about is this. Consider your typical AA batery, it is not a difficult stretch of the mind to understand that this battery stores electrical energy, approximately 2Ampere-hours at 1.5v which is approximately 5000J worth of STORED electical energy. Now, CONSUMING this battery does not cause your kinetic energy to increase by 5000J the same way that consuming a pound of cake does not cause your kinetic energy to increase by 1lb*c^2, you are still limited by your ability to convert between different energy sources. So A RC car would be able to use that battery to move around for several hours, YOU on the other hand will most likely just pass the battery through your body and the basic chemicals that are storing this electric energy will come out unaltered. The same way that a pound of cake can sustain you for a day, but try stuffing it into the battery compartment of your RC car and it won't move an inch. "Mass-energy" works much the same way, sure consuming a pound of cake increases your "rest energy" or by an enormous amount, but in reality there is no way to convert mass directly to energy so its much the same as swallowing a battery or stuffing cake into the RC car. [[User:DenisTR|DenisTR]] 17:05, 5 April 2012 (EDT)
:At any rate, eating a pound of cake, is not nuclear physics, it is chemistry, where your cells digest and utilize the sugars within. Protiens are also converted into sugar.[[User:JonM|JonM]] 18:28, 1 April 2012 (EDT)
:At any rate, eating a pound of cake, is not nuclear physics, it is chemistry, where your cells digest and utilize the sugars within. Protiens are also converted into sugar.[[User:JonM|JonM]] 18:28, 1 April 2012 (EDT)