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0answers
35 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?
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1answer
37 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. ...
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2answers
86 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
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2answers
80 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
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1answer
61 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 ...
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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
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0answers
56 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 ...
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0answers
49 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 ...
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1answer
54 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
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1answer
58 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 ...
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0answers
34 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
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1answer
222 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 ...
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3answers
119 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?
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3answers
91 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
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2answers
72 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?
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2answers
61 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 ...
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2answers
78 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?
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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?
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5answers
117 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 ...
5
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4answers
315 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 ...
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1answer
43 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 ...
2
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0answers
87 views

What is the derivation of $E=mc^2$? [duplicate]

How did Einstein derive his most famous equation: $$E=mc^2$$ Is the above equation a special case of $$E^2=m^2c^4+p^2c^2$$ Its derivation? What is the difference between them?
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1answer
393 views

How quickly does gravity extend from created mass? [duplicate]

I apologize in advance if this is a stupid or off-topic question. Since Energy can be converted into matter according to $E=mc^2$, how fast does it take for the gravity of that new matter to extend ...
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0answers
84 views

What should be the de Broglie's equation?

I have learnt that the equation for de Broglie's wavelength is $$\lambda =h/p$$ where $h$ is Planck's constant, and $p$ is the momentum of the particle. We can derive it from equating Einstein's ...
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2answers
103 views

If rest mass does not change with $v$ then why is infinite energy required to accelerate an object to the speed of light?

I know that as the velocity increases, the mass of the object also increases so it becomes tougher and tougher to move the object which ultimately leads to a requirement of infinite energy to ...
2
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3answers
88 views

What does the $c$ in $eV/c^2$ stand for?

I have been wondering(also searching) for what does the $c$ in eV/$c^2$ stand for? (For example, mass of the electron is $0.511 \, \text{MeV}/c^2$.) I have read that this unit has been derived from ...
0
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0answers
31 views

Beta plus decay…explain one thing [duplicate]

Can anyone please explain how, in beta plus decay, a nucleon can gain mass by changing from a proton to a neutron? Where does it get the extra mass from? Does it convert energy in some way? Does ...
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9answers
735 views

Why does Energy-Momentum have a special case?

I was reading Energy-momentum, and I came across this simplified equation: $$E^2 = (mc^2)^2 + (pc)^2$$ where $m$ is the mass and $p$ is momentum of the object. That said, the equation is pretty ...
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2answers
78 views

How can I understand how $\text{m}^2/\text{s}^2$ is related to $\text{J}/\text{kg}$?

$E=mc^2$ is the famous equation that states the equivalence of mass and energy, with a conversion factor in units of $\text{m}^2/\text{s}^2$. But in my naive mind, the conversion factor of mass and ...
0
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2answers
85 views

Hydrogen Bomb Mass to Energy?

How much mass is converted to energy when a hydrogen bomb explodes? I remember an eighth grade chemistry class where, by going through the nuclear processes, my teacher estimated that roughly 2g of ...
0
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2answers
40 views

Question about electromagnetic Spectrum [closed]

I have question related to electromagnetic Spectrum. If energy of photon is $E=m_e c^2$, to which part of the electromagnetic spectrum does it belong ?
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0answers
40 views

Can mass be totally converted into energy? [duplicate]

Suppose you have 1 kg of lead, can the whole thing be converted into energy so that no mass remains? Or does the conversion stop at the protons/neutrons?
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1answer
70 views

Relativistic Conservation laws [closed]

Conservation of Relativistic mass and thus energy is easily proven by considering an inelastic collision of two bodies while invoking the conservation of momentum. As such the momentum law appears ...
0
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2answers
71 views

Calories Burned While Hiking [closed]

I want to find out how many calories are burned on any particular hike by any particular by using a formula. I figure it's probably a simple physics question, but since I never took physics, I don't ...
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4answers
3k views

Why is there a controversy on whether mass increases with speed?

Some people say that mass increases with speed, some people say that the mass of an object is independent of its speed. I understand how some (though not many) things in physics are a matter of ...
1
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1answer
318 views

What is the cause of the large damage by atomic bomb?

I recently read in the Feynman Lectures that when the nuclei like that of uranium which are at the crucial level of balance between strong nuclear forces and electrical repulsive forces are taped ...
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1answer
73 views

If the mass of an object or system is a measure of its energy content, multiplied by speed of light squared…?

If the mass of an object or system is a measure of its energy content, multiplied by speed of light squared, does it mean that the total potential energy of the rest mass of object or entire system ...
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3answers
92 views

Finding the mass of pure matter [closed]

How would I find the mass of "pure" matter, that is, non-quantized matter, for a given volume?Let's say I have a volume equal to 1 meter squared, and I completely filled it up with matter - that is, ...
0
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1answer
49 views

Conversion of energy to matter or antimatter?

We all know that matter converts into energy, but will energy convert into matter? Does it form antimatter by converting? Illustrate me with example.
2
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0answers
48 views

What does the speed of light have to do with mass and energy? [duplicate]

I've been thinking about Einstein recently, and I came back to the famous equation e=mc^2. Why does this work? It's saying the difference between mass and energy happens to be the speed of light ...
0
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2answers
302 views

How can individual photons have different amounts of energy?

If photon is an elementary particle, how can different photons have different energy, if $E=mc^2$ and all photons have (or don't have) the same mass and the speed of photon is constant shouldn't it ...
-4
votes
1answer
138 views

Massless particles and the speed of light - New? Theories of existence [closed]

"The best understanding we have is that it [light] is a disturbance in the electromagnetic fields of charged bodies." http://einstein.stanford.edu/content/relativity/q212.html This is a link to the ...
1
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3answers
118 views

Do massless particles follow the curved spacetime or not?

I am assuming that zero (rest) mass particles don't interact gravitationally with each other and other particles. Does that mean they experience a "flat" spacetime instead of a curved one? I find it a ...
1
vote
2answers
121 views

Can matter be created from energy? [duplicate]

The small, hot, dense early universe the size of an atom was made up entirely of energy, it wasn't until after the expansion began and the universe cooled down some of that energy began converting ...
1
vote
1answer
60 views

Complete Energy Equation for Non-Zero Masses

The most simplified version of the energy equation (which is also the most known) is $E=mc^2$ However, I understand that this only applies to objects with non-zero mass and zero velocity. I also read ...
2
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3answers
395 views

Problems Understanding Mass Energy Equivalence

So I've had a problem for a long time now understanding energy-mass equivalence, in particular I've had a lot of trouble understanding how something like interatomic potentials can be seen as mass. ...
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6answers
6k views

Why do lasers cut? Is this a case of light acting as matter?

All I found in Google was very broad. From a physics models perspective, why can photons emitted from a laser cut? Does this cut mean that the photons are acting like matter?
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3answers
212 views

$E=mc^2$ resembles kinetic energy formula?

The simplest equation expressing mass–energy equivalence is the famous $E=mc^2$ where $c$ represents the speed of light. Compare this with $E_K = \frac{1}{2}mv^2$. Since $E=mc^2$ can be applied to ...
1
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1answer
43 views

Energy in nuclear decays

After a nuclear decay is it a necessity that the total energy of the products is more than the energy of the original particle before decaying? (NB: by 'energy' I don't intend to include mass-energy ...
0
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5answers
170 views

Why use a hadron collider to search for Higgs Boson

If, according to relativity matter is energy condensed, wouldn't breaking open the endless Matryoshka dolls of matter to find the most fundamental particle which gives mass to matter be fallacious? ...