Why is it impossible to travel at the speed of light or faster?

Question

Why is it impossible to travel at the speed of light or faster?

Answer 1

First a couple of points on other answers.

1. there are no such things as tachyons.

2. the fact that light is a special speed and that everyone gets the same value regardless of how they are moving or the source of the light is moving was an observed phenomena that led Einstein to relativity

Your question though is "why" and this can not be answered. Einstein merely relied on observations and like a good scientist turned that into a theory which has become probably the most verified theory in science since relativisitic calculations are used everyday at every particle accelerator in the world. And Einstein is right on the money.

Now we can "observe" that as you give more and more energy to an electron or proton that it does travel faster and faster. But Newton had it wrong. According to him the energy of a moving particle is (1/2)mv^2 so the more energy you pump into it the faster it goes. And there is no limit. But later experiments showed that this is not the case and that the speed of the particle approaches a limit and that limit is the speed of light.

But back to "why". That is a question that - if you had a truly comprehensive theory of the universe - you could answer. But I think such a theory is beyond anything humans are capable of devising because I think this would involve having access to conditions that exist outside our universe and are therefore inaccessible to us.

Answer 2

This is the answer to your question of "Why"... (it is easy to answer)...

It is an ASSUMPTION from which relativity is then "derived".

It is WRONG to say that the constant speed of light in all reference frames is an observation...it is NOT!  There is no way to measure "one-way" light speed...Einstein ASSUMED that regardless of circumstances, light speed is fixed.  

The other answers you have been given are wrong!

Since relativity has no "fudge factors" and models the physical world so well, scientists have come to believe that c is the "universal speed limit" as set forth by Einstein in his theory of relativity.

As a side note: According to relativity nothing with mass can be accelerated to c from any lower speed.  There may be "tachyons" that already travel faster than light speed.  And just because we have not observed something does not mean that it does not exist...that is just bad logic!

-Fred

Answer 3

lights speed is 299 792 458 m/s and till now no vehicle or robot has been formed that can travel at this speed and humans its impossible even if he/she is worlds best runner because light is a reflection that can travel even more faster than a sound!!!!  

Answer 4

It is impossible to travel at the speed of light because once and object obtains a speed of light which is 186,000 miles/s, the object turns into or is transformed into energy using  Einstein's equation:  E=mcc (cc is read as c squared) where c is the speed of light.

It is impossible to travel with a speed greater than the speed of light because the speed of light is the speed limit in nature.

Answer 5

I guess its not impossible to do so. the matter is that we dont have this technology right now. like before 150 years it was impossible for a man to fly but now its not impossible so may be after a century we may travel at the speed of light

Answer 6

Speed of light is approximately 300,000 km/second. The fastest vehicle in the world is nowhere near that speed.

Answer 7

According to Einstein's theory of relativity, very strange things start to happen when you approach the speed of light.  One of them is that the mass of the object starts to increase.  The closer you get to the speed of light, each additional increase in speed requires more and more increase in the mass.  Of course the energy it takes to go faster increases too because that energy needs to supply the mass, too.  That's where E=mc^2 really comes from.  As you reach the speed of light, ALL the energy goes into increasing mass, and therefore speed does not increase any more.  

The equation is  M  =  m/ sqrt(1- v^2/c^2)

where M is total mass, m is mass at rest, v is velocity, c is speed of light.

Note that even something like a baseball has an increase in mass when thrown, though the increase is VERY small at such speeds.

Electron accelerators get electrons moving at almost the speed of light.  Because they go around corners, their mass is measured by the magnetic field it takes to turn them.  This increase in mass has been measured to be exactly according to the theory of relativity.

Answer 8

first of all it is almost impossible to reach it.

and the theory of einstein said that.

e=mc2 which means that if you are big you need more fuel. but to store more fuel you must be big and so forth. thats why you cannot travel faster than light.

and also its dangerous you will get smaller or worse.

yet the speed of light was broken by two physicists, Gunter Nimtz and Alfons Stahlhofen, in Germany from the University of Koblenz. This seriously questions Einstein's theory that no object or information can move faster than the speed of light in a vacuum. An example of what could happen with this is time travel, but not like you imagine: If you went for a car trip faster than the speed of light, you'd arrive at your destination before you'd even leave, theoretically, of course. As Dr Guenter Nimtz said: "The effect cannot be used to go back in time, only to reduce the time between cause and effect a little bit."