If there is some kind of resistance in space that prevents the speed of light exceeding c, is it theoretically possibly to reduce this resistance to zero - kinda like how superconductors work?
No. The thing that keeps the speed of light exceeding c is the fundamental structure of space and time. It would be substantially more impossible to make light exceed c than it would be to draw a circle with pi exceeding 3.114159....
>fundamental structure of space and time
The speed of light does slow down in mediums like glass and water when it gets refracted.
So just like how in superconductivity it reduces the materials resistance to zero, I was asking whether it is possible to reduce this "space/time" medium resistance to zero.
>the speed of light does slow down in mediums like glass and water when it gets refracted.
No it doesn't, dumbass.
Light traveling through water is like driving your car on a road filled with a shitload of turns. If you drive at 60MPH the entire time, it will take you longer to reach a destination on that road than if you were driving on a completely straight road at 60MPH. But either way, you're still going 60MPH. And even when passing through water, light is still traveling at c, its just bouncing off of a shitload of particles and it's taking longer to get to a destination.
I'm really not sure why I should be explaining this to you, maybe /sci/ isn't the right board for you. Why not try /fit/ or [s4s], something more your speed?
That's not actually true. Technically, what's happening in the material is that the light gains an effective mass. The light isn't bouncing around, it's actually going slower, but the Speed Of Light remains unaffected.
This is actually really common in condensed matter QFT.
Speed of light isn't even slow. It's instantaneous (thanks to time dilation) relative it's inertial reference frame. It's the outside observer that sees it going only 300,000 km/s.
>all the bullshit in this thread
>If there is some kind of resistance in space that prevents the speed of light exceeding c
There's where you're wrong. It's not a resistance, it's an intrinsic quality of the QED vacuum. Vacuum polarization results in the finite non-zero values of electric permittivity and magnetic permeability of "free space" which then sets the value of the velocity of waves that propagate through the electromagnetic field.
In the presence of matter, you can no longer consider the QED vacuum, and the values of the electric and magnetic fields created by charged matter effect the values of the values above. This is a semi-classical interpretation of the slowing of light in a non-vacuum medium.
>The thing that keeps the speed of light exceeding c is the fundamental structure of space and time
True, the Lorentz invariance of the laws of electrodynamics prevent any particle from traveling faster than the velocity of a massless particle no matter the observer. This isn't exactly what OP is asking though.
>So just like how in superconductivity it reduces the materials resistance to zero
That's not what happens in superconductors, but you are excused for not being familiar with BCS Theory or Ginzburg-Landau Theory
In the classical sense, you're not wrong. But you're not completely right either. At most you're unhelpful.
Also stop being a dick.
>Technically, what's happening in the material is that the light gains an effective mass
In BCS theory yes, but to explain ordinary refraction? I'm not too educated on condensed matter theory, but I'm pretty sure it's explained by polaritons (combination of photon and phonons/excitons/plasmons), which have mass. But again, I had to do some google searches to find this so I'm not remotely experienced enough to talk about this.
>they got the group velocity of our pulse to vary
That's not the same thing as the speed of light changing
OP, there are materials where the index of refraction is less than one (which means the phase velocity of light is greater than c), however the group velocity (or what matters if you're sending a signal) is not able to do the same.
So basically the answer to your question is no, unless you want to build a warp drive and send a laser pointer through it.
>This isn't exactly what OP is asking though
Actually, I was talking about the fact that we live in Minkowski space and thus *everything* is Lorentz invariant, and so nothing can ever go faster than c because the concept doesn't even really make sense, and c is what it is because "distance" and "time" are just units for measuring the length of an axis and that happens to be how many meters along a space axis mark out the same length as a second along the time axis.
To change this, you'd either have to change the basic structure of the Minkowski metric (Hence "harder than drawing a circle with pi = 3", since GR at least lets you in theory bend space enough to do that), or change how many meters there are to the second (which would either be arbitrary unit redefinition, or else as fundamentally impossible as making a ruler which was both 1 foot long and 13 inches long.)