Science Quiz #2: Is E=mc² right or wrong?

a reply to: Arbitrageur

Is the reason c^2 is the necessary value because c is the highest speed any action can take place at, and keep in mind c is a combination of distance and velocity over that distance, so is it saying c is squared because something about dimensions, and/or to account for the degrees of freedom a particle has, or polarized light has, moving forward, as well as in the up and down axis?

So that value, 299,792,458 m / s. A rate of speed, distance and the speed it takes to pass from increment to increment. Times itself. Times the rest mass of an object. Will yield the total energy of the object.

Could it be there maybe are problems with doing this with light, and thinking light has no rest mass, because light is that ultimate light speed. Light speed, is the speed of the light field moving. Mass was defined as, 'not lightspeed', and then created the incremental hierarchy from there. Light is said to be energy, because light is thought to be 'pure movement', in a sense...Of course I dont agree with this, I think light is something, I think the concepts of rest mass must be skewed. (especially maybe with those talks of being able to use only light to make matter).

I guess I must ask what the definition of mass is? Does a static electric field have mass? Does a static electric field exist? You would say, it is a quadrillion photons being passed back and forth at all points of the electron, and there is an energy value associated. But because a photon is not a stable particle (well it is as long as its not interacting with anything) it is not a particle that has mass?

originally posted by: ImaFungi
a reply to: Arbitrageur

Is the reason c^2 is the necessary value because c is the highest speed any action can take place at

The video posted by PhoenixOD doesn't follow the T&C because there's no description, but it is relevant to this thread and it does show how the c² is derived from a relativity example.

Mass was defined as, 'not lightspeed', and then created the incremental hierarchy from there.

This isn't the way mass is defined because we think neutrinos have a small mass and their speed is mostly indistinguishable from that of light though this may be a measurement problem.

I guess I must ask what the definition of mass is? Does a static electric field have mass? Does a static electric field exist? You would say, it is a quadrillion photons being passed back and forth at all points of the electron, and there is an energy value associated. But because a photon is not a stable particle (well it is as long as its not interacting with anything) it is not a particle that has mass?

If you wanted dictionary definitions I suppose you'd look it up. Mass is what causes resistance to movement when you push on it. You can't throw a bowling ball as far as you can throw a baseball because the bowling ball has more mass.

The Particle Data Group publishes the latest efforts to determine masses of particles. Their data shows an upper limit on mass of a photon, but they don't state it's massless because there's probably no way to experimentally distinguish massless from a quantity of mass which is just too small to measure. Here is the link to the booklet, see booklet page 8 (page 10 of the pdf):

Particle Physics Booklet

Aside from that experimentally derived data, theoretical physicists think photons are probably massless. So, photons are an example of where E=mc² equation doesn't work because photons have energy and they don't have rest mass, so when you set m=0 then E becomes 0 and E is not 0 hence why the physicists say it's not the right equation.

The other momentum term they introduce at 2 minutes in the OP video does apply to the photon, because photons do have momentum, and this more accurate equation gives a non-zero value of photon energy.

c²

the speed of light squared ? I understood that nothing exceeds the speed of light

is the process of chain-reaction continuously re-doubled until the reaction happens at quadruple the speed-of-light and goes Boom ?!

a reply to: Arbitrageur

That video didnt explain why c^2.

And in the equation, can we start by knowing energy? Knowing the energy of an electron, and dividing it by c^2 will give us its mass? Can we do that with light, knowing the energy of a particle of light and dividing it by c^2 will give us its mass, Aha! This is where the trouble comes in, because we have different energies associated with photon (this I guess is similar to what in the other thread Kryzma was trying to say about how light and frequency is a time function or something) so using that equation it would result in us receiving different photons having different masses eh? This is why I would argue the concept of mass is contrived, and strictly used against the existence and speed of light, to use as a starting point to build up mass. The literal physical incarnation of the number 0, as mass 0, and then working the way up to the most massive objects, one, .0000000000000000000000000000000000000000000001 at a time.

Also im wondering this. If I have a solar panel on the front of a space ship, and at rest, the light that is emitted in front of me, is absorbed at '10' 'energies'. If my space ship then travels to a velocity much greater then rest, towards the source of light, would the energy absorbed be greater? I guess to be more specific, we can use for example one photon, because otherwise once again it might be a 'time' thing, like 'yes much more energy' but only because you can cram much more energy in, in shorter time. Like how if photons were 'hurdles' for a runner (who was running on a treadmill track, the hurdles moving towards him), a runner who is traveling faster towards the hurdles will 'absorb' more hurdles then a runner running relatively slower.

originally posted by: St Udio
c²

the speed of light squared ? I understood that nothing exceeds the speed of light

First, "nothing" is a pretty broad term, so I wouldn't state it that broadly, for example:

Faster-than-light

If a laser is swept across a distant object, the spot of laser light can easily be made to move across the object at a speed greater than c. Similarly, a shadow projected onto a distant object can be made to move across the object faster than c. In neither case does the light travel from the source to the object faster than c, nor does any information travel faster than light.

Second, when you square something it's no longer the same as what you started out with. Take the floor space of a building which is 10m x 10m, with an area of 100m². Now, let's square the area, so 100m² x 100m² = 10,000 m^4. This 10,000 m^4 is no longer an area measurement, because it doesn't have units of area (which would be m^2, not m^4). Same with the speed of light, when you square it, the units are no longer a speed...it's something else, and it doesn't imply anything travels at the speed of light squared.

is the process of chain-reaction continuously re-doubled until the reaction happens at quadruple the speed-of-light and goes Boom ?!

nothing is happening at quadruple the speed of light, it's just a value in a formula.

originally posted by: ImaFungi
a reply to: Arbitrageur

That video didnt explain why c^2.

It was implied but I guess not fully explained. I'm not going to fully explain it, you'll need to take a course for that, but I can give you a clue.

Take the classical kinetic energy formula, 1/2 mv^2. Now think relativistically, where the velocity can't exceed the speed of light. You've already got a v^2 in the classical kinetic energy formula, and when you make adjustments to the classical formula so that nothing can go faster than light, the v^2 sort of ends up being c^2, though that's not precisely correct but it's one way you can think of it. It's explained slightly further here:

www.scribd.com...

That explanation ends up with the equation shown in the video, and the video takes it from there to show how it ends up as E=mc².

And in the equation, can we start by knowing energy? Knowing the energy of an electron, and dividing it by c^2 will give us its mass? Can we do that with light, knowing the energy of a particle of light and dividing it by c^2 will give us its mass

No you can't do that for precisely the reason why this thread was created, the formula E=mc² is incomplete and can't be used on photons. You need to use the momentum term for that in the more complete equation including the momentum term.

This is why I would argue the concept of mass is contrived, and strictly used against the existence and speed of light, to use as a starting point to build up mass. The literal physical incarnation of the number 0, as mass 0, and then working the way up to the most massive objects, one, .0000000000000000000000000000000000000000000001 at a time.

If you think you've got better ways to measure mass than the particle data group you can try to convince them of your better methods, but I don't think you know how they measure mass so saying their methods are contrived is probably speaking from ignorance, isn't it? Can you explain how they make their mass measurements?

Also im wondering this. If I have a solar panel on the front of a space ship, and at rest, the light that is emitted in front of me, is absorbed at '10' 'energies'. If my space ship then travels to a velocity much greater then rest, towards the source of light, would the energy absorbed be greater?

Yes of course, the photons are blue shifted meaning they have more energy to you compared to the energy observed by someone else at rest. We observe this blue shift coming from the Andromeda Galaxy, and that's how we know it's moving toward us (it's apparently on a collision course with our galaxy).

originally posted by: PhoenixOD

why exactly the cat emitted light ? was it in an exited state ? like energy loaded ?
don't let this cat flash too much or it will dissolve...

I actually never saw a lazy cat doing anything,
just eating and sh... you know what I mean

I actually needed to yell on this stupid cat to chase it away...

maybe this cat has a flash light... who knows

originally posted by: KrzYma
why exactly the cat emitted light ?

They never explained that part, did they? The cat is actually emitting infrared radiation like most warm blooded animals, which of course isn't a "flash" exactly but they are emitting photons. That's how the LAPD tracks the runners when they bail out of the car when their car chase dead-ends, using their infrared body heat to track them. I guess they were trying to "dumb it down" in the video and may have gone a little too far but you can only explain so much in 2 minutes. I don't know why they didn't say something like "a person with a flash camera" instead of "a cat that flashed"?

I actually never saw a lazy cat doing anything,

I agree that's usually the case, but if you can watch this video of a heroic cat actually saving a toddler from a dog attack, you won't be able to say that anymore.

Hero cat saves toddler from dog attack-- Amazing video shows Tara the family cat chasing away aggressive dog

I tried to find the ATS thread where this was posted but couldn't find it. It's pretty unusual; usually the cat is getting chased by the dog, not the other way around.

a reply to: Arbitrageur

Not many people know that E=mc^2 is not the whole deal. But I believe that physicists (and laymen) who are serious in this area will come across Wikipedia's page on it (en.wikipedia.org...) and realize that the equation everyone knows is in fact a simplified version.

Nice thread nevertheless, S&F.

originally posted by: Arbitrageur

originally posted by: KrzYma
why exactly the cat emitted light ?

They never explained that part, did they? The cat is actually emitting infrared radiation like most warm blooded animals, which of course isn't a "flash" exactly but they are emitting photons. That's how the LAPD tracks the runners when they bail out of the car when their car chase dead-ends, using their infrared body heat to track them. I guess they were trying to "dumb it down" in the video and may have gone a little too far but you can only explain so much in 2 minutes. I don't know why they didn't say something like "a person with a flash camera" instead of "a cat that flashed"?

I actually never saw a lazy cat doing anything,

I agree that's usually the case, but if you can watch this video of a heroic cat actually saving a toddler from a dog attack, you won't be able to say that anymore.

Hero cat saves toddler from dog attack-- Amazing video shows Tara the family cat chasing away aggressive dog

I tried to find the ATS thread where this was posted but couldn't find it. It's pretty unusual; usually the cat is getting chased by the dog, not the other way around.

so, the cat has a flash light with it, in form of heat energy, also chemical reactions and other not mass related energy processes in its body.
but what if the cat is dead in cold space ? no heat, no other energy sources, just dead cat. will it still emit anything to support the math of this equation ?!

a reply to: KrzYma
If the cat is dead and emitting nothing, this situation can still be consistent with the equations in the 2 minute video, which is in a sense about conservation of energy. The way conservation of energy works if nothing is being emitted, is all the dead cat's energy is retained by the cat. In this case the energy emitted becomes zero, so the same equations can be applied but the result is not interesting. Applying the math the same way as in the video yields this for E=mc²:

(change in energy of zero) = (change in mass of zero) x c²

originally posted by: Arbitrageur
a reply to: KrzYma
If the cat is dead and emitting nothing, this situation can still be consistent with the equations in the 2 minute video, which is in a sense about conservation of energy. The way conservation of energy works if nothing is being emitted, is all the dead cat's energy is retained by the cat. In this case the energy emitted becomes zero, so the same equations can be applied but the result is not interesting. Applying the math the same way as in the video yields this for E=mc²:

(change in energy of zero) = (change in mass of zero) x c²

not quite, the change in mass is the argument for mc2, no mass change - no argument as proof of mc2

a reply to: KrzYma
Zero is a perfectly valid result for the equation. If you're saying you would also like to verify that the equation holds at other values, that's logical, and that's what the video is about.

originally posted by: Arbitrageur
a reply to: KrzYma
Zero is a perfectly valid result for the equation. If you're saying you would also like to verify that the equation holds at other values, that's logical, and that's what the video is about.

No it is NOT.

about 1:30 it starts with equations and the difference in E is the reason for the argument - mass is energy.
without difference is E all falls apart, kinetic energy = kinetic energy and NO lost in E

BTW: E=mc2 is not coming from Einstein, he adopted this formula

Who discovered that E = mc2? It's not as easy a question as you might think. Scientists ranging from James Clerk Maxwell and Max von Laue to a string of now-obscure early 20th-century physicists have been proposed as the true discovers of the mass–energy equivalence now popularly credited to Einstein's theory of special relativity. These claims have spawned headlines accusing Einstein of plagiarism, but many are spurious or barely supported. Yet two physicists have now shown that Einstein's famous formula does have a complicated and somewhat ambiguous genesis – which has little to do with relativity. One of the more plausible precursors to E = mc2 is attributed to Fritz Hasenöhrl, a physics professor at the University of Vienna. In a 1904 paper Hasenöhrl clearly wrote down the equation E = 3/8mc2. Where did he get it from, and why is the constant of proportionality wrong? Stephen Boughn of Haverford College in Pennsylvania and Tony Rothman of Princeton University examine this question in a paper submitted to the arXiv preprint server. Hasenöhrl's name has a certain notoriety now, as he is commonly invoked by anti-Einstein cranks. His reputation as the man who really discovered E = mc2 owes much to the efforts of the antisemitic and pro-Nazi physics Nobel laureate Philipp Lenard, who sought to separate Einstein's name from the theory of relativity so that it was not seen as a product of "Jewish science".

a reply to: Arbitrageur I wouldn't say that E=MC^2 is right OR wrong. The equation works well enough to get the job done for now. But when you consider how limited our understanding of the universe is, I think it is best to assume that the equation is incomplete.

originally posted by: KrzYma
without difference is E all falls apart, kinetic energy = kinetic energy and NO lost in E

I really have no idea what point you're trying to make here. When the energy transfer falls to zero, it's zero. I wouldn't call that "falling apart".

Take a cold bottle out of the refrigerator, and set it on the countertop at room temperature. Heat will transfer from the countertop and the surroundings into the cold bottle until equilibrium is reached, at which case the heat transfer goes to zero. Whether the heat is transferring (out of equilibrium) or whether the heat has stopped transferring (after equilibrium is reached), no laws of physics are falling apart.

When the energy transfer falls to zero, the system is still following the exact same laws of physics. Basically I read your dead cat analogy as something you wanted to be in equilibrium with its surroundings.

BTW: E=mc2 is not coming from Einstein, he adopted this formula

These claims have spawned headlines accusing Einstein of plagiarism, but many are spurious or barely supported.

Do you see the irony is posting something about claims being "spurious or barely supported" and then not supporting what you post with a source?

a reply to: TheWetCoast
Yes we know it's incomplete. By the time we figure out what the other 95% of the universe is (aside from the 5% baryonic matter), we might have some other energy equations. I suppose this equation might apply to dark matter, though it might not apply to dark energy. It's hard to say until we understand what they are.

a reply to: Arbitrageur

the whole thing about matter being energy falls apart.
right now the whole argumentation is based on the lost of energy, like shown in this video.
but this energy is not matter becoming energy - the argument for mc2, it is "borrowed" energy in form of heat or whatever you may put in as output for the "loss" you need for the whole though experiment to work.
Matter itself do not change into energy !

These claims have spawned headlines accusing Einstein of plagiarism, but many are spurious or barely supported.

and what do you expect after 100 Years of repeating this misunderstanding ?!

first it was discovered by the French physicist/philosopher Poincare, the first man stated the relativity principle, in his equation P=E/C , since P=mv , then at he speed of light mC= E/C, thus E=mc2 .
Derived from Umov Nikolai equation E = kmc2 (1873).

originally posted by: KrzYma
a reply to: Arbitrageur

the whole thing about matter being energy falls apart.
right now the whole argumentation is based on the lost of energy, like shown in this video.

That Was Einstein's resolution to Poincaré's paradox, but there are other examples of matter converting to energy:

What do you think caused these 38 bursts of energy?

Antihydrogen atoms are captured for the first time

To test whether any antihydrogen was actually formed and captured in their trap, the ALPHA team turned off its trapping magnet. The antihydrogen was then free to wander towards the walls, and thus annihilation. The detectors duly observed 38 bursts of energy which the team concluded came from antihydrogen atoms hitting the wall of the trap.

That was in 2010. Electron-positron annihilations have been going on a lot longer and are discussed here:

Antimatter

we need to better understand that tiny part of the laws of physics that differ for matter and antimatter; without such a difference, there would be no way for an imbalance to occur. This distinction is the subject of study in a number of experiments around the world that focus on differences in the decays of particles called B-mesons and their antiparticle partners. These experiments will be done both at electron-positron collider facilities called B factories and at high-energy hadron colliders, because each type of facility offers different capabilities to contribute to the study of this detail of the laws of physics--a detail that is responsible for such an important property of the universe as the fact that there is anything there at all!

So what do you think happens to the electron and positron when they collide at these "electron-positron collider facilities"? Hint:E=mc²

first it was discovered by the French physicist/philosopher Poincare, the first man stated the relativity principle, in his equation P=E/C , since P=mv , then at he speed of light mC= E/C, thus E=mc2 .
Derived from Umov Nikolai equation E = kmc2 (1873).

Umov Nikolai deserves credit for that but he didn't know what "k" was except that it was at least 0.5 and not over 1.

Poincaré himself knew he had a problem with his idea known as "Poincaré's paradox" and if he had solved that himself, he may have got credit for the equation, but he didn't solve it, Einstein did:

Henri Poincaré

It was Albert Einstein's concept of mass–energy equivalence (1905) that a body losing energy as radiation or heat was losing mass of amount m = E/c2 that resolved Poincaré's paradox, without using any compensating mechanism within the ether.

a reply to: Arbitrageur

it is really horrifying how circular your arguments are.
Now you are using the theory as a reason and proof to explain the same theory.

the theory predicts antimatter, true
experiments show some energy "anomalies", true
but this is just an assumption that indicates it is antimatter,
it doesn't have to be, I say

as I read about this experiment
www.economist.com...
I do not see any true evidence of antimatter or matter begin energy, sorry.
the mathematics may say it is, but it's mathematics only

To test whether any antihydrogen was actually formed and captured in their trap, the ALPHA team turned off its trapping magnet. The antihydrogen was then free to wander towards the walls, and thus annihilation. The detectors duly observed 38 bursts of energy which the team concludedcame from antihydrogen atoms hitting the wall of the trap.

I conclude it is not !

I think we should first determinate what matter is before creating other matter forms
Matter can not be created or destroyed, but standard theory creates antimatter all the time.
Why do not create ordinary matter first, instead of antimatter ?

I do not say there are no reverse charged particles, they exist, but the name antimatter is wrong.
negative charged proton or positive charged electron is more correct.
What happens to them, if they really annihilate each other in terms of mass annihilation or just doing a charge reversal I can not tell you now.

originally posted by: KrzYma
I conclude it is not !

You managed to write all that without answering my simple questions:

originally posted by: Arbitrageur
What do you think caused these 38 bursts of energy?

Or this question:

So what do you think happens to the electron and positron when they collide at these "electron-positron collider facilities"?

originally posted by: KrzYma
the name antimatter is wrong

I'm not sure that's true, but even if it is, the term used doesn't really affect the science, does it?