Photons shouldn't exist.?

Question

Mass is energy and energy is mass.
The photon is regarded as an energy packet.
Bearing that in mind. To accelerate an object towards the speed of light you need put energy into it. So adding energy increases its mass. As it becomes more massive more energy is required to accelerate it and so on exponentialy. Therefore the action of accelerating an object to the speed of light would make it infinitly massive and would take an inifintite amount of energy.
The photon travels at the speed of light therefore it should be infinitly massive and have used up all the energy in the universe to get there and so shouldn't exist.
Can anyone resolve this apparent contradiction, or is there something wrong with my argument. Hmmm

Answer 1

Photons do not have any mass*. They are energy waves and part of the Electromagnetic force. Part of your path of reasoning is what led to the development of Wave-particle Theory.

The idea that photons are not accelerated but just 'happen' at the speed of light does not stand up to a test of 'reducto ad absurdum' whether it is a particle with mass or a wave with no mass. Everything is at rest at some point and it requires energy to accelerate it. (ummmm-- until we get deep into quantum physics..., BUT never-mind, that just cornfuseseses the situation).



* The Elegant Universe, Brian Greene, page11, Table 1.2 for just one authority.

Answer 2

yup, something is wrong with your argument - sorry

the equations of Special Relativity, the one that takes care of mass increasing with speed, state that the mass will be the mass at rest, times a factor. So if the mass at rest is zero, the mass at increasingly higher speeds is zero also.

you seem to be confusing mass-energy, and energy. If you take a massive object and accelerate it, close to the speed of light, yes its mass will increase. But the total energy of a moving object, at any time, is the SUM of both its (possibly relativistic) mass energy, and the kinetic energy from the movement. In the case of the photon, the energy from movement can increase (this will lead to an increase in the frequency of the light), but there is zero mass-energy.

there is also another problem in your argument: there are no infinites in physics, and special relativity (and general relativity) most probably break down at some point when you'd get too close to the speed of light. So far, in particle accelerators, people have accelerated electroncs to speeds that are around 99.999999 percent of the speed of light, and special relativity holds. But maybe when you get to 10, or 15, or 20 decimals, the theory breaks down.

you get weird results when you apply equations beyond their domain of validity.

same for black holes. General Relativity says they are mathematical (ie dimensionless) points of infinite density. Which just says that, at very small distances, at very high densities, General Relativity just ceases to hold. Too bad we don't have the theory that would bridge the gap, at least not yet (after about 100 years of working on the problem)

Answer 3

No. Photons do exist and have a mass. The theory that predicts the increase in mass at near the light speed is not valid at high speeds. v = c is a singularity. So the the prediction has to be thrown out. There are also physical reasons to throw out the theory. There is no mechanism built in every mass to convert the added energy in to mass at near the light speed. Therefore the mas less photons derived from this theory should be ignored. There is mass associated with photons and faster than light speed is possible.

Answer 4

It's a common mistake. But Einstein was referring to mass accelerating TO the speed of light. Photons never travel below light speed, and therefore the same rules of mass do not apply to them. The photon is massless.

Another common misconception is that light speed is an absolute. It is the unbreakable brick wall for less than light-speed mass -- BUT -- non-mass particles can actually be made to travel beyond light speed.

Answer 5

Photons is an energy packet and this energy = hv[v=frequency]. h=plank's constant, for a patrticular wavelenth of light frequency is constant. So the energy is constant.
If aparticle moves with a speed of light, mass becomes infinity. This is acc. to relativity. But note that the equation is independent of energy.
acc.to Einstien's mass energy equivalence , the mass can be directly be converted into energy. Thus such a huge mass is converted into such a large energy, which is=hv.
The above said is my opinion. I didn't refer anything. It might be right , I'm not sure.

Answer 6

Sure. Photons don't accelerate. They travel constantly at the speed of light.

Answer 7

You are right that to accelerate a mass to c requires infinite energy. However, photons are massless and always travel at c. They do not accelerate. They carry energy proportional to their frequency.

Answer 8

The photon has no rest mass. See the reference for more of an explanation.

Answer 9

the reason is, is that photons are not actually particles, they are small packets with similar wavelengths each. this means that you would be multiplying itself if you put more energy in.

Answer 10

Something wrong with your argument...
Lots of photons seem to be ignoring your theory..