Can you exceed the speed of light

For instance, if wormholes exist, you could use one to take a shortcut from earth to the North Star. Compared to a bit of light that traveled from earth to the North Star and did not go through the wormhole, you would have been traveling faster. In other words, you would have reached the North Star first. This is allowed because you never locally exceeded the speed of light.

If a different beam of light was sent from earth to the North Star and did go through the worm hole with you, there is no way you could outrun it. As another example, there are some distant stars in the universe that are moving away from each other at a speed faster than light. So, if mass can't travel at the speed of light, how come light can?

Light is made up of photons, which are massless particles and therefore they don't require energy to move. Time dilation. Time slows down as you approach the speed of light and when you reach it, time stops. For a photon, there is no time, everything happens instantaneously. Trying to make a photon go faster than the speed of light is like bringing your car to a stop and trying to go slower.

Time dilation affects us all the time in everyday life, but its effects are so small we can't see it. Light comes in The light that passes through the prism appears to bend, as it travels at a slower speed than the light traveling through air did earlier. When it re-emerged from the prism, it refracts once again, returning to its original speed. However, particles suffer a different fate. If a high-energy particle that was originally passing through a vacuum suddenly finds itself traveling through a medium, its behavior will be different than that of light.

Rather than bending instantly, as light appears to, its trajectory changes can only proceed in a gradual fashion. When particles first enter a medium, they continue moving with roughly the same properties, including the same speed, as before they entered.

These scattering events are tremendously important in particle physics experiments, as the products of these collisions enable us to reconstruct whatever it is that occurred back at the collision point. Here, a proton beam is shot at a deuterium target in the LUNA experiment. The rate of nuclear fusion Fixed-target experiments have many applications in particle physics. But the most interesting fact is this: particles that move slower than light in a vacuum, but faster than light in the medium that they enter, are actually breaking the speed of light.

This is the one and only real, physical way that particles can exceed the speed of light. And when they do, something fascinating occurs: a special type of radiation — Cherenkov radiation — gets emitted. Cherenkov was studying radioactive samples that had been prepared, and some of them were being stored in water. The radioactive preparations seemed to emit a faint, bluish-hued light, and even though Cherenkov was studying luminescence — where gamma-rays would excite these solutions, which would then emit visible light when they de-excited — he was quickly able to conclude that this light had a preferred direction.

It wasn't a fluorescent phenomenon, but something else entirely. Today, that same blue glow can be seen in the water tanks surrounding nuclear reactors: Cherenkov radiation. Reactor nuclear experimental RA-6 Republica Argentina 6 , en marcha, showing the characteristic As these particle travel faster than light does in this medium, they emit radiation to shed energy and momentum, which they'll continue to do until they drop below the speed of light.

When you have a very fast particle traveling through a medium, that particle will generally be charged, and the medium itself is made up of positive atomic nuclei and negative electrons charges. The charged particle, as it travels through this medium, has a chance of colliding with one of the particles in there, but since atoms are mostly empty space, the odds of a collision are relatively low over short distances.

Instead, the particle has an effect on the medium that it travels through: it causes the particles in the medium to polarize — where like charges repel and opposite charges attract — in response to the charged particle that's passing through.

But if c is not in fact the fastest possible speed in the universe, and things can go faster, this may have to be adjusted in special situations. Perhaps the special speed of neutrinos deserves to win the title of ultimate speed limit instead. The Standard Model is the name of the reigning theory of particle physics, which describes all the known subatomic particles that make up our universe. But if the speed of light rule, and the theory of relativity are rewritten, this model too may need adjusting.

String theory is the cutting-edge idea that all fundamental particles are actually tiny vibrating loops of string. This assumption turns out to have broad-ranging implications, including the possibility that our universe has more dimensions than the known three dimensions of space and one of time.

String theory is incredibly difficult to test, and there is no proof that it's correct. But if the neutrino measurements are correct, some physicists say string theory may offer the best bet of explaining them. Perhaps, some physicists have suggested, the neutrinos are not traveling along the straight line we thought they were, but instead were hopping into one of the extra dimensions predicted by string theory, and taking a shortcut to their destination.

If they traveled a shorter distance in the measured time, then their actual speed may not have been faster than light. Perhaps the new discovery doesn't mean that just anything can travel faster than light, but merely neutrinos. If that's the case, then there's definitely something special that scientists didn't know about these particles.

Neutrinos are already understood to be oddballs. They are neutral, nearly massless particles that hardly ever interact with ordinary matter.