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2
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3answers
5k views

Why does an object with higher speed gain more (relativistic) mass? [duplicate]

Today, in my high school physics class, we had an introductory class on electromagnetism. My teacher explained at some point that an object with a very high speed (he said it started to get somewhat ...
2
votes
2answers
191 views

Is there any law that prevents an object with mass to become massless?

I got into a discussion with my physics teacher about the speed of light and I asked What if an object with mass was to lose mass as it gained speed-- would that allow for an object to eventually ...
0
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4answers
355 views

Mass-Energy relation

Einstein mass- energy relation states $E=mc^2$. It means if energy of a paricle increases then mass also increases or vice-versa. My question is that what is the actual meaning of the statement ...
7
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2answers
2k views

What was Albert Einstein's proof for $E=mc^2$?

Most people know the famous equation: $$E=mc^2$$ What were his steps of thinking for this equation that helped us discover so much about our world?
4
votes
0answers
66 views

How fission and fusion create energy? [duplicate]

Possible Duplicate: How to explain $E=mc^2$ mass defect in fission/fusion In order for energy to be released, mass has to be "lost", because mass is a form of energy. In my science class, ...
2
votes
2answers
780 views

Why the energy of a marshmallow is so huge?

In this comment in a blog kudzu computes the energy of a marshmallow with mass $M=25 grams$ by using $E=mc^2$: $E=Mc^2 = 2.247\times 10^{+15} Joules$ I may be wrong but this seems like a huge energy ...
1
vote
2answers
280 views

Does infinite energy imply Infinite mass (and vice versa)?

If some kind of source was able to supply an infinite amount of energy, does that imply that it also must have an infinite mass? Is the contrary also true?
3
votes
2answers
2k views

Einstein's mass-energy relation

Suppose we have 1 kg of wood and 1 kg of uranium and if we need to find out how much energy would each of the substance give, we'd have to use Einstein's mass-energy relation as follows: In the case ...
0
votes
1answer
79 views

Non-conversion of mass & energy?

This article is certainly an interesting alternative perspective, but is it factual or does it contain fallacies? http://www.circlon-theory.com/HTML/EmcFallacies.html Are mass and energy not ...
2
votes
2answers
151 views

How is an ideal mirrored box of photons distinguishable from massive particles?

Suppose you have an ideal mirrored box that contains enough photons as to have a relativistic mass equivalent to the [rest mass + kinetic energy] of an electron. In other words, the two systems have ...
1
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2answers
549 views

Why do photons add mass to a black hole?

Why do photons add mass to a black hole? When photons are taken irreversibly into a black hole does the mass of the BH increase?
10
votes
1answer
3k views

Does the mass of a battery's change when charged/discharged?

... and if so, how much? Is it possible to detect it, or is it beyond any measurement? I'd say there are two possible scenarios (depending on the battery type) and both seem interesting: The battery ...
5
votes
1answer
3k views

How to explain $E=mc^2$ mass defect in fission/fusion

What is the nature of nuclear energy? This is closely related to the correct explanation of mass defect. I did some research of that topic and cannot come to a single comprehensive and consistent ...
11
votes
2answers
2k views

Higgs Boson mass in Electron volts?

Im no physics genius here, I was just interested in the Higgs Boson so I was reading this article : How the Discovery of the Higgs Boson Could Break Physics I came across this Furthermore, ...
2
votes
1answer
225 views

Man on treadmill and energy/mass conservation

Suppose we put a very obese man inside a large air tight isolated room with a treadmill and he runs on the treadmill for 24 hours and at the end of the day he sees his weight has come down (mostly ...
3
votes
4answers
452 views

Does $p=mc$ hold for photons?

Known that $E=hf$, $p=hf/c=h/\lambda$, then if $p=mc$, where $m$ is the (relativistic) mass, then $E=mc^2$ follows directly as an algebraic fact. Is this the case?
7
votes
3answers
227 views

What's the purpose of the arbitary additive constants in Einstein's Inertia of Energy Paper?

In Einstein's paper: Does the Inertia of a Body Depend upon its Energy content? he introduces arbitary additive constants whose purpose I'm confused about. The paper has a frame $(x,y,z)$ where a ...
3
votes
4answers
2k views

Does the mass of an object change as it moves away from the earth?

The mass of a helium nucleus is less than the mass of two isolated protons and two isolated neutrons. When the component hadrons are assembled, this mass is lost as energy ($E=mc^2$). This makes it ...
2
votes
1answer
219 views

Atomic weight in respect to the binding energy?

My book says that the weight of helium (with the nucleon number of 4 and proton of 2) is that of $6,6447*10^{-27}$ kg. Earlier the book stated that if the proton number is left out it means that the ...
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3answers
2k views

Getting from $E^2 - p^2c^2 = m^2c^4$ to $E = \gamma mc^2$ [closed]

What is each mathematical step (in detail) that one would take to get from: $E^2 - p^2c^2 = m^2c^4$ to $E = \gamma mc^2$, where $\gamma$ is the relativistic dilation factor. This is for an ...
4
votes
2answers
632 views

Does the mass of a body absorbing photons increase?

Let's say I have a photon collector in orbit around the sun. It manages to collect photons perfectly efficiently, that is, without radiating off any energy. Then, using Einstein's equation: $$E = m ...
1
vote
2answers
111 views

Is the mass to energy physical process an exact mirror of the energy to mass process?

For my level of understanding the only explanation of mass to energy, ie nuclear weaponry, is limited to a simple summing game where a mass deficit is expressed as energy. For the 'reverse' process, ...
3
votes
3answers
410 views

storing energy (as mass)

When chemical energy is released mass is reduced, if only by a negligible amount. Presumably that's true for all energy. And presumably that works in reverse as well: storing energy involves an ...
1
vote
3answers
748 views

What is the meaning of speed of light $c$ in $E=mc^2$?

$E=mc^2$ is the famous mass-energy equation of Albert Einstein. I know that it tells that mass can be converted to energy and vice versa. I know that $E$ is energy, $m$ is mass of a matter and $c$ is ...
2
votes
1answer
168 views

Can non-free forces change the rest mass?

While reading Hobsen et al.'s "General Relativity: An Introduction for Physicists", I came across a bit confusing derivation. Multiplying the 4-force and 4-velocity, the following derivation can be ...
1
vote
2answers
347 views

Einstein's Mass-Energy Equivalence versus Quantum Kinetic Energy

Using a naive view of Einstein's Energy Mass Equivalence $E=mc^2$ (where m is mass and c is the speed of light), it seems tempting to interpret this as a quantum mechanical version of the inherent ...
1
vote
2answers
212 views

The time component is $\gamma m c$, so shouldn't $E=mc$?

Basically, the book is Brian Cox's Why Does $E=mc^2$?: (And Why Should We Care?). I just finished Chapter 5, where we derived the spacetime momentum vector (energy-momentum four vector, as he ...
6
votes
3answers
10k views

When does 'energy' turn to matter?

I always hear about matter converting to 'energy' - fusion, fission. When does it go the other way around? What conditions lead to it? Are there reproducible experiments on this topic?
5
votes
1answer
794 views

Mass converted to energy in a common fire?

In a common wood fire such as a campfire, is matter converted to energy or is it simply an exothermic chemical reaction and all the mass can be accounted for in the ash and soot?
4
votes
5answers
6k views

What is Energy made of?

We have the famous equation $E = mc^2$, and we also believe that matter is made of particles. Then, What is the energy made of? If the two are interchangeable, there must be some common building ...
3
votes
5answers
5k views

Conversion of mass to energy in chemical/nuclear reactions

Is mass converted into energy in exothermic chemical / nuclear reactions? My (A Level) knowledge of chemistry suggests that this isn't the case. In a simple burning reaction, e.g. $C+O_2\to ...
2
votes
3answers
408 views

Mass in terms of energy

Given the relationships between mass and energy in relativity, and given that particles with mass can be created given energy over the threshold energy, and vice-versa, can we say that mass is simply ...