How comes a photon can travel at the speed of light?

A photon can travel at the speed of light because of wave-particle duality, ie. photons behave like both particles (which require acceleration, and waves (which do not) A photon is an electromagnetic wave. A photon is a form of energy and results from transformations of other forms of energy. When a photon appears it behaves like all Electromagnetic waves. All EMW's travel at the speed of light in a vacuum.

May I suggest that you google 'photon', 'wave-particle duality' and if your feeling brave, 'Planck's Constant' before I have everyone sleeping here.

Hmmmmm a lot of intellegent answers. We have not been able to really judge the exact properties of a photon. The wave and particle theories are based on observation of the behaviour of light. Just bcoz water wets your hands does not mean H2O will have the same properties, but thats what we have as of now.

Well since you have answered your Q, how a photon manages to travel at the speed of light, i will add a few other facts. You knew your answer all along. If light is made up of photons, the speed of photons is the speed of light. Duh !! If the photons travelled at a slower speed, THAT will be the speed of light.

It has been practically proved that almost massless particles can travel at speeds higher than that of light. I think that gonna make you think even more !! he he he.

A photon is a particle of light. It is also electromagnetic radiation and therefore a wave.

It is called the particle-wave duality and this applies to all matter as well. There are some great experiments that show that light behaves as a particle, also that it behaves as a wave.

Einstein postulated that light came in quanta, which is one of the roots of quantum mechanics.* wikipedia reference

So, while physics has a theory that nothing with mass can accelerate to travel at the speed of light, ie it would take infinite energy to get it there, light (photons) are considered massless at rest, and therefore do not have this limitation.

Light is the only thing (we know) that can travel the speed of light. and a photon is a wave/particle/string (whatever) of light.

Think of a spoken sentence travel at the speed of sound where each word, no, each letter is a photon.

Photon sits on a quantum of light and goes whammmmmmbhruuuum

because the "speed of light" has been first defined by the speed ... of light ie photon.

But it's not the only thing that can achieve the speed of light (that we know of). Neutrinos can too.

It took us 50 years between the 1st airplane to take flight (wirght brothers, 1903) and the 1st supersonic flight (in the 50s)... give us a few hundred years to tackle the speed of light, please : it's much more complicated to get close to the speed of light than it is to breach the sound barrier.

And it's difficult because the laws of physics are the way they are (yeah, I know, it's not really an answer, but it's the closest you'll ever get)

Because a photon is light

photn is nothing but a unit of energy

a packet more correct.and it travel with speed of light thats why i also have some questiion that if it is having very small mass or negligible but it would multiply with speed of light and the quantity would be very large and it is momentum if such an photon strike on our head we would have died. no? so its main question why photn donot make any sence when strike on our skin.i mean a battery light.ok

And to further complicate things, some photons... i.e. those emitted from Co60 travel faster than light through water (see cherenkov or cerenkov). I love the blue hue.

There's no reason to say that nothing else can travel at the speed of light - we just haven't been able to achieve it yet.