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0
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1answer
40 views

Where does mass go when energy is converted in to photons?

If matter and anti-matter annihilate each other they emit a photon with the energy that corresponds to the mass, right? This is the best example I could think of matter/energy being converted directly ...
2
votes
1answer
231 views

Will a hot object have more gravity than a cold object?

Imagine two objects, identical and having the same mass. Now my question is, if you heat one object and do not do anything with the other object, will the hot object possess more gravity (because it ...
2
votes
2answers
45 views

The mass/energy of an $H$-atom and the gravitational force between it and another particle of mass $m$

The gravitational force between an $H$-atom and another particle of mass $m$ will be given by Newton's law: $$F=\frac{GMm}{r^2}$$ The question is, what is $M$ here? I thought the answer would be ...
0
votes
0answers
13 views

How to define the parameter $\beta_{CM}$ of the transformation of pseudorapidity of the referencial LAB to CM

How can I determine $\beta_{CM}$ knowing the energy of the center of mass (CM), and without knowing anything about the particle mass? I have only information about the pseudorapidity in the ...
2
votes
1answer
85 views

Can energy bend space? [duplicate]

I know mass bends the space around it and I also remember matter can be converted into energy and vice versa, so my question is: can energy interact with space in a similar fashion as matter does?
0
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2answers
66 views

Is there any gravitational force between two stationary neutrinos, a billion light years apart?

Gravity is supposed to act over an infinite distance. But if the force is very weak (due to low masses) and the distance is very far, is the force actually 0? Or is the force so low that it is ...
0
votes
4answers
163 views

Mass, energy, and entropy.

I have a seemingly simple question about the relation between these three that for some reason doesn't make sense to me. If entropy is the disorder of a system, then a low entropy state is one of ...
1
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1answer
74 views

Laws of physics in curved space-time

The speed of light is not constant everywhere in a gravitational field. Suppose there is a region of space-time which is curved due to gravity such that the speed of light or any electromagnetic ...
-2
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2answers
78 views

Does matter become energy at the speed of light? [closed]

According to modern physics, we can't push matter to the speed of light. It would slow down (relative to its environment). But theoretically, if matter were to travel the speed of light, would it ...
-3
votes
2answers
51 views

How fast does an object have to be going to turn into energy [closed]

Albert Einstein's equation, $E=mc^2$, says that an object has to be going at the speed of light squared to turn into energy. How fast would this be in miles per hour?
1
vote
1answer
61 views

Is it correct that whenever energy change, mass also change?

Can I simply claim that, according to the mass-energy equation $E=mc^2$, whenever the energy of an physical object (not necessarily a microcosmic one) changes, its mass also change? Okay, I ...
3
votes
3answers
96 views

How is it possible for the wavelength of light to change in a medium?

So my physics class has just finished a long unit on optics while at the same time I've been trying to teach myself relativity. I admit my understanding is probably rudimentary, but I figured all the ...
-6
votes
2answers
134 views

$? = mc^{1.9}$ makes me crazy [closed]

If energy equals mass times the speed of light squared, what is mass times just under the speed of light? It's not energy,,,yet. Michio Kaku said in a physics video that the faster mass goes, the ...
3
votes
2answers
81 views

What would be the photon's effective mass in Newton's Law of Gravitation?

If we equalize the force from the Newton's Law of Gravitation to Force on a photon in a gravitional field (I don't know if there is an equation for it). What would be the photon's effective mass? (I ...
0
votes
1answer
44 views

Why photons are having energy when they are massless? [duplicate]

As per the Einstein equation $E=mc^2$, the energy of the particle is depends on the mass of the particle. Or else in other terms the energy is proportional to the mass. If the photons are having zero ...
2
votes
3answers
444 views

How much energy is needed to create an electron?

I know how to calculate the electrostatic energy of a sphere (it has a well defined radius). But how can I calculate the electrostatic energy of an electron as it is a point particle? By electrostatic ...
5
votes
9answers
439 views

Why does my apple not weigh 500 tons?

Related to this question: What is potential energy truly? $E=mc^2$ - energy equals mass. So, if an object has gravitational potential energy relative to another object, it should have additional mass ...
3
votes
1answer
110 views

What specifically is incorrect about the Dirac Sea interpretation?

So taking the square root of $E^2 = (m_oc^2)^2 + p^2c^2$ yields two solutions. The Dirac Sea treats the negative solution as an infinite space of electrons with negative energy. All the observable ...
3
votes
4answers
398 views

Mass in special relativity?

Is the mass of a object at rest defined by $$E=mc^2$$ where $m$ is the rest mass. I.e. does the rest mass include every thing from thermal to gravitational potential energy and every other possible ...
3
votes
3answers
457 views

Has $E=mc^2$ been experimentally verified for macroscopic objects with potential energy?

In relation to this question: What is potential energy truly?, I'm wondering if $E=mc^2$ has been experimentally verified to hold true for macroscopic objects with increased potential energy? I'm ...
2
votes
3answers
231 views

The mas-energy equivalence for rest mass

It is clear that the kinetic energy can be derived as $(m-m_0)c^2$. However, why do we say that $m_0c^2$ is the rest mass energy? It seems that this mass-energy equivalence for rest mass is just a ...
0
votes
3answers
91 views

Why does relativistic kinetic energy (KE) equal to the total relativistic energy minus the rest mass energy?

OK, I understand why $KE=\gamma mc^2-mc^2$, but why is it also equal to $E-E_0$?
2
votes
2answers
210 views

If photons have no (rest) mass, why would black holes attract light? [duplicate]

I was told that photons have no (rest) mass. However I thought that black holes are called "black" because no light can go escape the gravity force in their vicinity. I somehow think that, if light is ...
1
vote
1answer
60 views

Where does the mass of a nucleon originate in an atom?

The mass of the three quarks in the nucleons make up only about one to two percent of the mass of the nucleons. What makes up the other 98 percent?
-1
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2answers
91 views

Why $E=mc^2$ formula does not include time?

For $E=mc^2$ formula, if an object of mass $m$ kg goes with speed of light (in theory), it transforms energy according to $E=mc^2$ but if there is no time complexity this will not happen. So I think ...
0
votes
1answer
54 views

Relationship between mass and the radius of curvature of space and time

What is the relationship between mass and the radius of curvature of space and time created due to the presence of the mass? please give the mathematical relation if there is any?
0
votes
1answer
116 views

Is there any relationship between the $E=mc^2$ equation and the $a_n=\kappa v^2$ formula for the normal component to acceleration?

To clarify, I know very little about physics and don't pretend to have any insight whatsoever into relativity beyond what has entered the popular imagination; my knowledge is more or less at the level ...
2
votes
4answers
98 views

Mass Defect…cause and origin?

What makes it occur? How do the protons and nucleus know that they have to lose mass to produce energy...? And is the mass of a compressed Spring more than an uncompressed one?? does a body which has ...
0
votes
0answers
39 views

What is the ratio of mass to energy in the universe?

"Stuff" exists either in the shape of mass or energy. Can one estimate the ratio of energy to mass in the universe? What shapes does energy exist in, maybe photons or molecular vibrations? Does mass ...
0
votes
0answers
48 views

Mass of photon, is it possible? [duplicate]

$P=E/C$ In relativistic mechanics a Photon is defined as. $P=hf/C$ Replacing "P" $ mc=hf/C$ $M=h/CT$ What does it mean, did they have mass?
-3
votes
1answer
46 views

Does light or waves have any kind of mass? [duplicate]

Just like the previous question, Even I have been studying Hawking's A Brief History Of Time and even I was thinking of Einstein's General Relativity. But I was unable to accept his view of GRAVITY. ...
1
vote
2answers
164 views

Does spacetime have a “mass” value? or What is “Spacetime” made out of?

When measuring the MASS within the Universe, does "space" or "spacetime" have a value? I only ask, because when speaking of expansion, space is expanding. Could it be possible, to reverse the ...
0
votes
2answers
222 views

Will heating up an object increase its mass? [duplicate]

According to the $E=mc^2$ equation, will an object whose thermal energy (temperature) rises also weigh more? And by the same token, will the mass of an object decrease as its temperature approaches ...
0
votes
1answer
75 views

Can matter be annihilated to form kinetic energy

I don't know much about conversion of energy and all, but I had a simple question: Can the energy released by converting matter into energy be used to set other particles in motion (increase their ...
16
votes
4answers
2k views

Does the mass of an electron change with its “energy state”?

When an electron absorbs a photon, it gets into a higher energy state and goes into the upper orbit/shell. Does (rather should) this absorption of energy also have an impact on its mass (although ...
2
votes
0answers
62 views

$E=mc^2$ what is unique about the speed of light? [duplicate]

What unique property of light, makes it the conversion factor between energy and mass? It has to be more than a coincidence that the speed of light, just happens to be the correct number number to ...
0
votes
0answers
50 views

$E=mc^2$ is incomplete? [duplicate]

So I was going through youtube and I found out these: http://www.youtube.com/watch?v=mkiCPMjpysc http://www.youtube.com/watch?v=NnMIhxWRGNw Can anyone here explain to me (with derivation if ...
2
votes
1answer
99 views

Calculate the mass of a Schwarzchild black hole with Komar integral

In Wald's GR, Komar integral is Eq. (11.2.9): $$M=-\frac{1}{8\pi}\int_S\epsilon_{abcd}\nabla^c\xi^d$$ $S$ can be chosen as a 2-sphere, the boundary of a spacelike hypersurface $\Sigma$ such that the ...
7
votes
1answer
65 views

Why is the energy of particles in accelerators much higher than the energy of the particles they are trying to find?

I have been wondering. In the LHC, or other particle accelerators for that matter, they are colliding particles with energies above TeV. The LHC is going to be 14 TeV or something like that the next ...
0
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0answers
48 views

Definition of mass gap [duplicate]

Why do we say that a system with mass gap has correlation function which decays exponentially and one without a mass gap has a slower power law decay?
5
votes
1answer
241 views

Is it possible for photon to run in circle by its own gravity?

I have heard that gravity came from energy and momentum so photon has gravity too. Then there are theory state that photon has energy tied to frequency. So if a photon has very very high frequency ...
4
votes
3answers
132 views

Meaning of Einstein's equation $E=mc^2$?

Meaning of Einstein's equation $E=mc^2$? How can a 1g mass possess energy equal to 9* 10 ^ 13 J? What does it actually mean?
0
votes
3answers
292 views

Is a photon really massless? [duplicate]

If a photon travels at a speed of light and its massless then it must have no energy but this is not the case as we see in photo electric effect. Also help me to know what are photons made of, how are ...
1
vote
2answers
80 views

Does a Michelson-Morley experiment uphold mass-energy equivalence and special relativity?

If there is an experiment that best supports $E=mc^2$, is it the Michelson-Morley experiment?
1
vote
2answers
65 views

What is energy of light, as we know speed of light?

1.What is total energy of EM waves, as all got same speed? If two em waves has same energy, do they have same mass? If same mass and energy, do they have same frequency or wavelength still ...
-1
votes
2answers
81 views

Why does Einstein's equation of relativity exclude space and time? [closed]

Taking $E={m}{c^2}$, we have mass and energy but no space and time. What is the best way of understanding the ways that space and time are passive and therefore unaccountable as mass and energy?
8
votes
2answers
2k views

Does a cooling mass lose mass as it radiates?

Assume we have a red hot cannonball in space. It starts off with mass M at 1000K. Later it has cooled by radiation to 100K. Has the mass decreased?
3
votes
5answers
134 views

Mass and Energy

Would the mass of burnt firewood be equal to the mass of firewood before burning? Then where does that heat come from? According to Einstein's equation, $E=mc^2$ Shouldn't there be some mass going ...
6
votes
4answers
374 views

Is $E^2=(mc^2)^2+(pc)^2$ correct, or is $E=mc^2$ the correct one?

I have been having trouble distinguishing these two equations and figuring out which one is correct. I have watched a video that says that $E^2=(mc^2)^2+(pc)^2$ is correct, but I do not know why. It ...
1
vote
1answer
48 views

Can we define the effective mass or the moving mass of a photon?

I know that the rest mass of a photon is zero. but the photon can be bent by gravity (which can also be explained by the curvature of space-time due to the effect of mass), this implies that it must ...