Wikipedia:Reference desk/Archives/Science/2020 May 21

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May 21

Is e= MC square really useless equation?

I don't see any uses of it online. Please acknowledge me. Ram nareshji (talk) 17:17, 21 May 2020 (UTC)

It depends what you want to use it for. Generally, the people who use such equations do not receive primary instruction in the theory or application of this type of equation from online sources; rather, one undertakes a formal university-level study program culminating in a Bachelor of Science degree in physics, chemistry, or materials engineering, or a related discipline; then, one pursues advanced specialization in a related scientific specialty; and one may readily find applications of this type of mathematical expression in areas that pertain to electronics, nuclear energy, optics, material science, and many other diverse areas of the applied and theoretical sciences.

Indeed, we might actually and truthfully say that you are online because the very productive people who normally use this equation decided to take a momentary break from their real job, and they created the Internet as you know it, during their down-time.

Nimur (talk) 17:21, 21 May 2020 (UTC)

the bulk of the work, and the most essential part, was done by the the Arpanet pioneers. Lots of clever men and women, like the guy at CERN who did it, were available to come up with the CERN guys idea, in the months or year after he did it, if for some reason he hadn't been there to think of it first. But it took a lot of vision and doggedness by the Arpanet pioneers to get it ready.144.35.45.155 (talk) 21:46, 21 May 2020 (UTC)

Do we use it in rocket launches along with Newton thirds law? Ram nareshji (talk) 17:48, 21 May 2020 (UTC)

(edit conflict)

The mass–energy equivalence equation E=mc² was intended by Einstein as an explanation for a general reader by analogy, decades after he expressed M = μ + E₀/c². The equation has since found many other uses. 107.15.157.44 (talk) 17:52, 21 May 2020 (UTC)

If it just for analogy, then why this tiny equation is sensation ? Ram nareshji (talk) 18:14, 21 May 2020 (UTC)

Are you aware of the nuclear bomb? ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:27, 21 May 2020 (UTC)

E=mc² fits nicely on T-shirts, mugs, etc., and makes ordinary folks look smart. 107.15.157.44 (talk) 18:30, 21 May 2020 (UTC)

It is sensational partly because it is a "tiny equation". 107.15.157.44 (talk) 20:19, 21 May 2020 (UTC)

Its a description of the fact that a small amount of mass is equivalent to a large amount of energy. If you can find a way to covert mass to energy, you can produce quite a lot of it. If there were no equivalence of mass and energy, nuclear weapons wouldn't work, but you don't have to type in the equation to get the bomb to go boom. --Khajidha (talk) 20:24, 21 May 2020 (UTC)

Concretely using this equation the difference of mass between two hydrogen nuclei and one helium nucleus tells you how much energy would be freed in the conversion. Same the mass difference between an uran nucleus and the products of its splitting (fission). Another every day use is to calculate how much the mass of an object increases as you accelerate it. So if you are designing or managing a particle accelerator you have to consider that as your charged particles accelerate you must feed more current in the deflection magnets than you would expect from the increase in velocity alone. 2003:F5:6F08:8200:AD1F:2C43:13C8:746E (talk) 21:55, 22 May 2020 (UTC) Marco PB

User:Khajidha If it is practically working equation, why it didn't brought nobel prize to Einstein? Ram nareshji (talk) 04:00, 22 May 2020 (UTC)

You'd have to ask the Nobel Prize committee. The thing is, what he did get it for, the photoelectric effect, was a huge deal in providing supporting evidence for quantum mechanics and particle/wave duality being an actual thing. It was tremendous. E=mc² is tremendous in its own right, but it didn't lead to a revolution that practically rewrote all of physics, the way the photoelectric effect did. --OuroborosCobra (talk) 04:06, 22 May 2020 (UTC)

It says that the inertia of a system is equal to the total energy content of a system in its rest frame and c^2 can be omitted because that's just an artifact of measuring inertia and energy in different units. Count Iblis (talk) 05:36, 22 May 2020 (UTC)

In 1922, when Einstein received the Nobel Prize, major predictions of his theoretical explanation of the photoelectric effect had been rigorously tested and confirmed to a high precision. At the time, a precise experimental test of the mass–energy equivalence was not yet possible.  --Lambiam 12:29, 23 May 2020 (UTC)