Where F=MA or force equals mass time acceleration for a photon F =0 because F=zero mass x A
which is zero.
Now we do know that the photon has a definite rate of acceleration . Problem is that for a photon it is most likely based on non existent metrics. A photon has no way to position itself in space until it impacts something of material substance. The value of A for a photon is probably actually negative. that is because a photon carries no energy and no mass but does carry code that can jolt an electron from it's atomic position by removing energy from its underlying momentum. Giving a photon thus a negative value for A acceleration then makes perfect sense. The math however is not worth very much. The periodic table and the elector magnetic spectrum charts do identify the approximate level of energy removal from momentum with in the range. electro microscopic images suggest a more hit or miss probability scenario . we are dealing with many photons and many affected electrons in many atoms and not anything totally absolute. defining a photon as having only acceleration for its coded message makes perfect sense because we already use the spectrum to send our own coded message including recorded music and voice, pictures and text. photons serve the same purpose in nature that we humans have harnessed them to use for our own purposes.
We use radio and tv / satellite broadcasting , wifi sending a stream of photon radiation as pure code and we are not concerned as much as sending mass or energy when we do it. The code is sent and usually amplified at a remote location where the signal is collected and then it is interpreted from code . Nature uses photons in almost exactly the same manner only to apparently send energy when it is really just acting on remote material interfaces to remove existing energy from outer most electrons until you rev up your photons to xrays and gamma. Where F is zero you still have observed acceleration . it can take photons 8 minutes to travel to mars and another 8 minutes to get a message back. easy to time and retest.....acceleration is there then but not force.