Does a photon accelerate to reach the speed of light?

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Photons do not accelerate to reach the speed of light; they always propagate at 300,000 km/s as soon as they are created, due to their lack of rest mass. The concept of acceleration applies to changes in velocity, which is not relevant for massless particles like photons. While photons do have momentum and can cause recoil when emitted from atoms, they do not require additional energy to maintain their speed once created. The discussion highlights the distinction between classical mechanics and the principles of special relativity, emphasizing that a photon cannot be at rest before accelerating to light speed. Overall, the conversation clarifies that photons inherently travel at the speed of light without the need for acceleration.
woz
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I have been wondering wether a photon has acceleration or not, how does it reach the 300,000 km/s? does a photon even need to accelerate?

I would also appreciate your telling me about rest mass, how does it work, what does it cause, etc.

WoZ
 
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The photon has no rest mass, so it doesn't need to accelerate.
 
An acceleration is a change in velocity. Photons always move at the speed of light, as do all massless particles.
 
There's one thing though. A photon does have momentum, so when an atom emits a photon it has to recoil slightly.
 
Well, what Woz is trying to ask is, how does it start moving in the first place... maybe.

It takes an infintesimal amount of energy to accelerate a luxon, a particle with no rest mass, such as a photon, but not zero. Once it gets accelerated to the exclusively luxonic speed of the speed of light in a vacuum, from that infintesimal amount of energy, it needs no more, it doesn't slow down or speed up, unless of course it goes through a medium.
 
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Mk said:
...it doesn't slow down or speed up, unless of course it goes through a medium.

It may be absorbed or scattered but always propagates at C.
 
The photon is propagating at c as soon as it is created. It is not that there is initially a photon 'at rest' that needs to be accelerated to c.
 
Mk said:
Well, what Woz is trying to ask is, how does it start moving in the first place... maybe.

It takes an infintesimal amount of energy to accelerate a luxon, a particle with no rest mass, such as a photon, but not zero. Once it gets accelerated to the exclusively luxonic speed of the speed of light in a vacuum, from that infintesimal amount of energy, it needs no more, it doesn't slow down or speed up, unless of course it goes through a medium.

When was this "luxon" experimentally discovered or verified? Oh wait... it hasn't?

Then why are you using a hypothetical particle to contradict something that HAS been experimentally verified, and has an unbelievably accurate theory (QED)? That's like using a pseudoscience to disprove a science!

Take note of the statement already mentioned, that if a photon has to accelerate, it means that over some finite time, it IS NOT traveling at c in vacuum! This violates SR! We need to shake a few people up so that they somehow can get free from the classical Newtonian mechanics here...

Zz.
 
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