# E=mc2 questions?

Discussion in 'The Cesspool' started by theorist-constant12345, Jan 11, 2015.

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1. ### theorist-constant12345BannedBanned

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Hello, can you please clarify my understanding of the Einstein equation E=mc2

This means the total energy in an objects volume?

m*<c*c>

Would the result be in Joules?

Considering a cup, maybe volume is not the correct word .

An objects solidity?

P.s - I have got to ask sorry, how much of this energy from an object is lost to the gravitational constant?

Or by entropy means does it stay at an equilibrium of E=mc2?

Last edited: Jan 11, 2015

3. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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Um...
Evidently not...
(It depends, entirely, what units you use).

Why do you not think "volume" applies to a cup?

Yeah, I wonder if there's a slight clue in the use of the letter "m" (denoting mass). What do you think?

5. ### theorist-constant12345BannedBanned

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Yes I know its mass, mass being the weight ,

So you could say , E=mc2 means the total energy contained within an objects mass?

7. ### theorist-constant12345BannedBanned

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Already my mind is saying that something is very wrong in this equation, mass is made by gravity, without gravity an object is practically weightless,

So how does that work then?

8. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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No it's not.

So, basically, you're saying that you don't understand it.

No it's not.
Weight is due to gravity.

Let me quote Wiki for you (you know, the sort of thing you persistently claim to already know): Mass is not the same thing as weight, even though we commonly calculate an object's mass by measuring its weight. A woman standing on the Moon would weigh less than she would on Earth because of the lower gravity, but she would have the same mass.

9. ### exchemistValued Senior Member

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No, in an object's mass, not its volume.

If you use SI units, think of mechanical work of 1J. 1J is equivalent moving 1 m against a force of 1N (W =Fd). A force of 1N gives a mass of 1kg an acceleration of 1m/sec², (F=ma) so 1N is equivalent to 1 kg m/sec². Hence 1J is equivalent to 1 m x 1kg m/sec² i.e. 1 kg m²/sec². Which are also the units of mc².

Since c ~ 3 x 10⁸ m/sec, c² ~ 10¹⁷m²/sec², so this is the number of Joules of energy you have in a kg of mass. Quite a lot, eh?

Your question about energy being "lost to the gravitational constant" makes no sense to me. The gravitational constant, G, does not come into the calculation, as you can see.

As for the question about entropy I don't follow this at all. Entropy is a thermodynamic concept, to do with the capacity of heat to do work, molecular disorder and related things. E=mc² is not thermodynamics, it is relativity.

10. ### theorist-constant12345BannedBanned

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She would have the same size and form and density, the mass would be different due to gravity, I know how it works. You use weight for mass, so how is weight and mass not the same thing, that sounds insane?

m=100g 100g = weight

weight only exists with gravity, if you had an object in a none gravitational reference frame, the mass=0, according to the calculation 0*<c*c> which will just equal c2 for the result,

So I ask a again what has E=mc2 suppose to mean, because I do not see it having any relevance to E contained in a system ?

11. ### theorist-constant12345BannedBanned

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You say that G does not come into the calculation, that is wrong, the mass is the weight that is made by the gravitational constant?

12. ### theorist-constant12345BannedBanned

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E=mc2 is the energy loss of an object to the attractive force of G?

13. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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Wrong.
And especially so: if, as you claim, her mass was different then she couldn't possibly have the same density.
Mass is not weight.

Wrong.

Not in science.
This may be true in every day usage but ONLY because every day stuff takes such measurements as Earth based for granted.

Wrong.
Mass is not weight.

Yup, and this is the guy who claims - many times - to know science...

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No.

15. ### AlexGLike nailing Jello to a treeValued Senior Member

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I'm sure that within a couple of posts he'll be claiming to be a master of relativity. I wonder if he knows what c^2 means?

16. E=mc^2 was introduced, by Einstein.., within the context of the emission absorption of a photon by an atom. The energy E of the photon contributes to the total mass of the atom on absorbtion and decreases the total mass of the atom on emmission, which might be more clearly stated as m= E/c^2, where E is the energy of the photon and m is the total mass of the atom.

The E=mc^2 form of the equation is just more elegant!

What the equation does not mean is that all mass is energy or that all energy is mass.

17. ### theorist-constant12345BannedBanned

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You keep saying mass is not weight , that does not sound correct from what I have learnt please explain, you are associating mass with size and density when all the calculations use weight.

example - 2*2*2 cube with a mass of 100g on the ground in a static position.

F=ma

m*a

0.1*9.81 = 0.981n

The gravity constant of force imposed on the cube is 0.981n always.

We can say that 0.981n is always equal to 100g in a stationary position.

E=mc2

0.1*c2

So we could say 0.981n*c2=100g force of gravity and energy being lost from the object to G,

18. ### theorist-constant12345BannedBanned

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to the power of and c is the speed of light constant.

19. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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Then, obviously, you were lying when you claimed A) to have learned science and B) to understand what's on Wiki. Start here.
Mass in not weight.
Weight is not mass.

No they don't.
That's why, for example, Einstein used "m" for MASS, and not "w" for weight.

I.e. a MASS of 100 g and a WEIGHT of 0.961 N.

Not on the Moon.
The MASS will be 100 g. The WEIGHT will less.

No.

20. Weight is a localized measurement of the mass associated with an object.., which is dependent on where in a gravitational field you weigh the object. The mass of an object is the same whether it is deep in space and cannot be weighed or sitting on the ground on earth, where it can be weighed... Or on the surface of the Moon where once again it can be weighed but would not weigh the same as on earth. Mass is essentially constant for an object, where weight is not.

21. ### theorist-constant12345BannedBanned

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You are wrong, on the moon an object from earth with m=100g will not have a m=100g on the moon, it weights less because there is less centripetal bounded force of gravity, 100g is a weight when I was in school, mass has nothing to do with size which is what you seem to be saying.

22. ### theorist-constant12345BannedBanned

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You can not have mass without weight, mass is the weight of an object by the imposed force of gravity. The constant that gives the constant mass which is the weight.

23. ### AlexGLike nailing Jello to a treeValued Senior Member

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Once again this is a case of TC being right and the rest of the world is wrong.