Is the speed of light the fastest possible speed?

10 Answers
Light travels at a speed of 186,262 miles per second, according to physics. Is that speed considered the 'ultimate speed limit' for anything in our 'sphere of existence' (our universe)? What do YOU think?

The speed of light does vary with medium, this is called the refractive index of a medium. In vacuum, the refractive index is defined as 1 and the speed of light is exactly the speed of light in vacuum. In all other materials, the refractive index is greater than 1, meaning that the speed of light in the said medium is slower than the speed of light in vacuum. The refractive index is simply the ratio between the speed of light in vacuum and the speed of light in a medium. If the speed of light would be constant in all media then we would not have phenomenas, such as refraction, and more exotically Cherenkov radiation. Cherenkov radiation is the reason why nuclear reactors give out the faint bluish glow. This glow is caused by particles which travel faster than the speed of light in the medium. When they do this, they will quickly lose kinetic energy through the emission of Cherenkov radiation which has some similarities to the sound barrier and the shock waves associated with objects traveling faster than it.

Currently according to all known physics, we cannot bring an object to travel faster than the speed of light from subluminal velocities. The neutrino experiment which showed neutrinos traveling faster than the speed of light was nothing but an experimental error, where the interfaces between optical fibers joined together was not properly considered. However, the current laws of physics does not prohibit a particle (with or without mass) to be born at superluminal velocities and forever have this velocity. These particles we refer to as tachyons. Of course, no one has ever observed a tachyon and it is unclear how such an observation would be made. There are some absurd consequences, however, in terms of the world a tachyon "experiences" with time going backwards, for example. But nothing really forbids a whole world of tachyons, it is just very unlikely.


The speed of light is constant. It does not vary with a particular medium. However, the speed of sound is different depending on the medium it is traveling through. Sound uses vibrations in nearby molecules to travel. In air, these molecules are spread far apart and so sound takes longer to travel (or it is slow). Yet sound travels much faster through a solid medium because the molecules are packed close together and thus sound doesn't need as much time to travel (it is faster).

Part of the reason the speed of light is regarded as a constant is if you attempt to have something go faster than the speed of light, it will be subjected to time dilation. This is where time becomes out of sync. This is part of a theory with black holes. If an object is close enough within the strength of a black hole's gravity well that object to you will appear like it's still there when in fact the pull of the black hole has moved it faster than light. (It's a complex subject. Spaghetification as some say, is related to this).

If you really want to go faster than light, you need to isolate yourself in such a way that you don't experience time dilation and instead warp space around you. Star Trek anyone?

In Star Trek, this is how they overcame that problem. Starships used warp engines to generate a warp field (you could call it a bubble) around a ship and manipulate space around it. If it wanted to travel froward, it would expand space at the rear while compressing space at the front. Thus giving it faster than light travel, while being isolated from the effects of time dilation.


The speed of light is constant. What may appear as variable speed through different mediums is a quantum mechanical phenomenon involving the interaction of light with the medium itself. This is why it takes years for light to escape the sun but only 8 minutes to reach the Earth. It has nothing to do with the actual speed that photons move at. That cannot be changed and it is the speed "limit" for all positive energy matter or massless particles.

The neutrino experiment was measurement error. Neutrinos have mass so this corroborates the claim because particles with mass can't break the light barrier on paper. We have a right to be skeptical and it paid off. The only thing that can go faster than light is a tachyon or any particle possessing the attributes of a tachyon (negative mass being one).

Another example of faster than light speed is the expansion of the universe. The fabric of space-time doesn't count as any sort of matter. It contains matter. The expansion of the furthest parts of the universe creates new space where none existed and if you were to chase the "front" of the expanding universe, you'd be unable to catch it at any velocity. This is more of a trick than anything though because nothing is actually traveling anywhere. The frame of reference itself is what's changing, thus altering out measurement of velocity.


Neutrinos that were launched in a laboratory in Europe traveled faster than light and it's still a mystery on how they did it, so yes I do believe there is such a thing as faster than light speed. The spookiness at a distance that Einstein mentioned also violates the universal speed limit law. The spookiness at a distance means that when 2 atoms are entangled and separated by vast distances, if you change the polarization of one atom, the other one instantly changes too (no matter how far away they are). There's also been talk about animals or microbes in the ground reacting to radiation from the sun long before that radiation hits. To simply put it, there is not a complete theory of everything yet so we can't say for absolute certainty that the light of speed is the limit in the universe
since there is so much mysteries in the universe like Dark Matter and Dark Energy, even the big bang cannot be fully explained.


Einstein's theory of relativity is based on the postulate that the speed of light is the ultimate "speed limit". There have been reports of faster than light transmission of information but theses have either been ignored or found to be the result of faulty equipment or errors in experimental technique (which does not mean the experimenters were incompetent).

There are also theoretical reformulations of relativity in which there is a "speed limit" higher than the speed of light and some physicists are collecting evidence the speed of light is not the absolute speed limit however all this is currently not accepted by mainstream scientists, for various reasons, including the agreement between experiments and the predictions of relativity theory.

There are also particles known as tachyons which can only travel faster than light and cennot slow down to light speed.


There have been no experiments which found objects or particles which can exceed the speed of light (in a vacuum). There was a recent preliminary result having to to with the measured speed of neutrinos which now has been shown to be in error.

According to Einstein's Relativity, there is a natural limit to speed, which is the speed of light. So, yes, that is the fastest possible speed.of any object, particle, or carrier of information.

There are hypothetical schemes in which it is possible to connect two parts of the Universe via a "worm hole" which would violate this law, but no one has seen or created a worm hole, so that remains in the realm of science fiction.


No, cause it's only like 186,000 miles per second. Light can be slowed down as well. I think it slows down in water too. There is a speed faster than light.

We haven't been able to break that barrier yet. I am not qualified to answer any further on this because I would sound dumber than I have already made myself sound. I wish I was smarter than I am. Thanks for the question.

I heard that if you go faster than the speed of light, cause and effect is reversed. How crazy is that. I hit the target before I shoot the arrow.


The speed of light varies depending on its medium of travel so therefore, how could we determine that the speed of light is the greatest speed we know? Perhaps there are media in which light travels faster than in the vacuum of space.

Like others have mentioned, scientists have managed to observe particles traveling faster than the speed of light. They are not sure how this happened, but it does shed some light on the now fact that the speed of light is not a speed limit!


Objects such as sub atomic particles or matter at the macroscopic level cannot travel at the speed of light. However there is no such limit on space itself and during the Big Bang, it is believed that space expanded faster than the speed of light. So if we can warp space, we can travel to distant stars. To do this however would be extremely difficult if not impossible.


As a an object increases in speed its mass increases...

The more massive an object is the more difficult it is to go faster...

As an object approaches the speed of light its mass approaches infinity....

I don't think anything can go faster than the speed of light (in a vacuum)...