What does a field have to do with anything? Anything that would be chasing the particle would also be traveling through that same field.
So if you had a very sensitive scale and put a spin-top on it would weigh x, but if you gave it spin the weight would be x+y where y>(1/∞) ?
What does that mean in a relativistic universe? If you are attached to the particle, then you do not observe a change in size. If you are away from the particle, you can’t measure the size.
I see.
What if say a black whole was pulling on the light? in other words a gravity field.
A particle accelerator applies an electromagnetic field to the particle. No chasing required.
It might cause increased drag that could be noticed…
And that particle isn’t going anywhere near the speed of light, else the field would have no affect on it.
A gravity field can’t affect anything any faster than any other field, “the speed of light” (hypothetically just slightly more than the speed of light).
Photons are special. 
What would ‘drag’ it?
Aren’t we all. 
But wouldn’t the gravity not need to catch up as it would already be in front of the particle (assuming the photon is say moving towards the black whole)?
What i mean is like as air drags on an airplane… um… maybe i’m using the wrong word…friction from the media it is moving through would increase if the size increased… (so there might even be increased heat as well as a increase in resistance to motion that would not be accountable otherwise.)
It wouldn’t matter because all the gravity field does is add to the migration of the particle. But it can only be added to “at the speed of light”. Since the particle (a photon) is already going that fast, nothing gets added that doesn’t also get taken away. From outside the field, the light would appear to be slowing down.
But on the other hand, proceeding into a high gravity field will increase the mass of the object while decreasing the size of it as measured from outside that field. The object becomes increasingly more dense. But the travel speed is not changed from that of light.
And photons are made of the media in which they travel, as are mass particles (which is why the Michelson-Morley experiment didn’t work).
Drag and friction is caused by the interaction of atoms and molecules. You are not going to accelerate anything to relativistic levels if there is a constant impact with other particles which are removing energy from the ‘high’ speed particle. Also note that when a sufficiently high speed impact does takes place, the particle will break down into its components.
As far as why light slows down in a gravity field, Science can’t answer that, but to just say that it does. So let me give you a short RM explanation.
In a gravity field, there are infinitesimal wavelets of electric potential rising and falling very chaotically. Because they are both rising and falling and distributed chaotically, there is no sign of electric overall charge. It is electrically balanced, neutral. But such changes can only occur at or below a certain maximum rate. The closer you get to to epicenter of the mass field, the more points are reaching that maximum and having to wait for brief tic before proceeding. It would be like choppy water waves in a pool that get more choppy the closer you got to the choppy wave source. But in addition, the water waves have a maximum height (for whatever magical reason). Whatever wave tried to surpass that height would just have to wait.
A photon is very similar to that except that it is propagating, not randomly distributing. The photon is trying to change the electric potential up and down as it travels along a straight path. It too has no total electric effect because it raises and lowers the field as it goes.
When the photon enters the gravitational field, it adds to the field changing that is already going on. The closer it gets to the epicenter, the more points it encounters that are already trying to change the field too quickly. When that happens, that tiny bit of the photon gets delayed. And then another and another as the photon keeps trying to propagate in the forward direction. The overall speed of the photon ends up being its original propagation speed minus all of the tiny delays of its bits. In effect, the gravity field causes a “drag” on the propagation of the photon.
That is why light (and everything else) travels slower in a gravity field (according to Rational Metaphysics).
Is it possible that really what happens is that as you get deeper into a gravity field (closer to the source) it causes an increase in inertia. Thus the reason that clocks run slower is not that time is moving slower but because there is an increased resistance to motion?
Those are all kind of the same thing.
Earlier in this thread, I explained how such resonance can stem from material objects, due to the motion of electrons around atoms. As it turns out, harmonic resonance cannot be avoided and is throughout the universe at all times. It is what they currently are calling “cosmic background radiation”, CBR, or “cosmic microwave background”, CMB. The CMB is detected as coming from everywhere. No matter where they aim the satellite, they receive CMB. The CMB is not a "reflection from the Big Bang from the edge of the universe, as preached. The special cavern that I proposed can merely reduce the CMB to a minimum. It cannot get rid of it.