wWhat is faster than the speed of light?

Nothing in our universe. But the universe itself has and is now expanding at faster than light speed.

Things with mass cannot reach, let alone exceed, light speed as there's not enough force in the entire universe to push that mass one iota more to reach v = C, the speed of light. Things without mass, must travel at v = C or lose their identity. So photons, gravitons (if they exist), and gluons, which are all mass-less, travel at light speed; not below, not above, but exactly at light speed.

But then there's space itself. The inflationary big bang hypothesis speculates that between 10^-36 and 10^-34 seconds after the big bang, the newly formed universe expanded some 10^30 to 10^100 fold at faster than the speed of light. There is a compendium of circumstantial evidence in today's universe to support that assertion.

Understand, this is the space metric itself going from ds to dS > ds at greater than light speed. The stuff in space at the time, went along for the ride but not move relative to space itself. So they did not go faster than light speed. An oft used analogy for illustration is the balloon with white dots painted on its surface. The dots are the galaxies and other stuff. As the balloon is inflated, the distance between the dots expands, but the dots do not move relative to the surface. Space just sort of fills in in between them.

According to the so-called Hubble red shift, space is once again expanding. And older space, farther away from us, may be once again expanding at faster than light speed...the jury is still out on that one. Not only is space expanding, it's accelerating in that expansion. This is an observed condition. And it raises the question "What's the force that's making the universe accelerate?" We don't know. So we invented dark energy as the source of the force. We've no clue what dark energy is; only what it does.

Bottom line. Nothing in our universe can go faster than light. But our universe can, has, and is currently going faster than light in some parts of space now in all likelihood.

Since c=3 x 10^8 m/s then a speed of 4 x 10^8 m/s is faster than the speed of light. :)

Faster-than-light (also superluminal or FTL) communications and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a particle (that has rest mass) with subluminal velocity needs infinite energy to accelerate to the speed of light, although special relativity does not forbid the existence of particles that travel faster than light at all times (tachyons).

On the other hand, what some physicists refer to as "apparent" or "effective" FTL[1][2][3][4] depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal or undistorted spacetime. Although according to current theories matter is still required to travel subluminally with respect to the locally distorted spacetime region, apparent FTL is not excluded by general relativity.

Examples of FTL proposals are the Alcubierre drive, and the traversable wormhole, although the physical plausibility of some of these solutions is uncertain.

since the speed of light is absolute, there is nothing faster than light.

Thought?

Any quantum exchange particle, such as virtual photons, has no limit other than infinity.

Nothing physical.

nothing is faster.