Why can't we exceed the speed of light?

Expert Answers
belarafon eNotes educator| Certified Educator

The important thing to know about faster-than-light travel and communication is that it is theoretically possible given a source of energy that violates current understanding of physics. At the moment, the Laws of Thermodynamics state that energy and matter are finite in the universe; neither can be created or destroyed, only changed in their state. Einstein's famous equation E = mc^2 states that as a particle approaches the speed of light, its mass increases, and therefore it requires more energy to continue acceleration. To approach the speed of light, an object would require an infinite source of energy; infinite mass can only be accelerated by infinite energy. This does not preclude theoretical particles such as tachyons, which are hypothesized to already travel faster-than-light, but all physical matter is prevented from this acceleration by physics. Recently, scientists thought they had successfully accelerated a beam of neutrinos faster than the speed of light, but this measurement was found to be the result of faulty equipment. Until an energy source is found that creates energy instead of transforming it, faster-than-light travel is scientifically impossible.

sylverxi | Student

answer mistake corrections:

mistake :"if u go faster than the speed of light then u will enter into the future, this is not possible."

If you have any speed what so ever, you are traveling in the future relative to an other object with speed 0 relative to you, because of time dilation that occurs(time runs slower for those who are "moving") so it is possible. If you go faser than the speed of light(wich is not posible anyway), logically time is going backwards, so in a sense you would be going into the past.

Reasons why matter could never go faster than the speed of light.

-If any matter even get to reach the speed of light, all the forces that hold the matter together would stop working and therefore any further Force on that matter would not speed it up more but simply rip it apart and turn it into radiation. The reason why this happens is because time STOPS wen you reach the speed of light, therefore everything else will also stops(example gravity, nuclear force, electromagnetic force etc.).

-If you are in a spaceship and would try to reach to the speed of light, you would never reach it or get faster because the reaction that causes the ship to accelerate will start to run slower as as you speed up and as you get very close to the speed of light the reaction will be so slow that the amout of acceleration would be so little that the ship will barley speed up significally any more. Again because of special relativity, as you speed up, Time starts running slower and slower as you speed up. an math example: 1+(1/2)+(1/4)+(1/8) etc.= a little less than 2. Here is the "amout added", represents the acceleration and the "2" the speed of light. here you can see that you can never go faster than the speed of light or even reach it with only an engine, and this is asuming you have enough fuel and technology and no friction(empty space) in space(not such thing as empty space).


agentswift | Student

So, all of that to say, I personally think that anything is possible.  The essential point is that science is very legitimately entering the realm of allowing for some things that exceed the speed of light in our universe.  We are capable of manipulating the speed of light, and, there is a very real possibility that the speed of light has not always been as we perceive it today.  Unfortunately, this is a post-modern world, and I don't usually subscribe to post-modernism, but, as history has proved consistenly to us through the ages, nothing, even in science, is immune to alternate possibilities.  We are capable of accelerating atomic bits and peices through the Large Hadron Collider at 185,999.9999999 miles per second (I think...  my numbers may not be accurate here, but, then too, I am not actually a physicist, just a layman who loves physics.)  We have, in my view, no reason to beleive that in spite of what imperical evidence we have of the absolute reality of our scientific observations today, that they are incapable of changing, transforming, or being different tomorrow.  Absurd as it seems to many, possibly even those reading this now, we have seen it in the past.  So...  again, I'm saying anything is possible.  As it stands, we at least know that there are some instances of "things" in the universe being able to surpass the present constant of the universe.  Science may one day discover how to extend this privilage to things of significant mass.  The thing is, it's not really as big of a deal to consider the time paradoxes invovled with this sort of thing, because, obviosly, they have worked themselves out somehow, someway, at some time already.  Rather, the somewhat more "Newtonian" (if you will) concepts of physics like entropy, mass, gravity and such. 

Anyway... all of this rambling on...  I say, good for you!  Ask these questions!  Find out what limitations the world and science mean to impede your journey of wonder with, then exceed those limitations.  Even if only for a good story, or maybe a real scientific breakthrough, or good conversation, keep asking and who knows, maybe you or those intrigued by you may trailblaze the way into the next era of physics and mind-blowing new discoveries tomorrow that defy what we submit to today.  Good luck!

agentswift | Student

hmmm....  Admitedly, I am much more a metaphysician and philosopher, but, I am an avid lover of science.  Physics, quantum physics, and time in particular.  So...  If I may, knowing I risk being totally destroyed by others with more informed minds and opinions/facts on the matter, I'd like to throw in my two cents.

I would posit a few "devil's advocate" ideas in terms of playing the part of the uninformed.  After all, it is only the posits of the uninfomred mind that lead us to become informed.  (Had Einstein never suggested that time may not be the most constant entity in the universe, we would have had a much more laborious and drawn-out discovery of relativity, if ever.  Or more simply, had Columbus never mistakenly thought himself to discover India when in reality he stumbled upon North America, we would be uninformed of the proper nomenclature of native American's and native Indians.)

I recently checked out a book called "Faster Than The Speed of Light" by Joao Magueijo.  He is, frankly, quite brilliant in my opinion.  He suggests the possiblity that light (the constant, or "c" in E=MC squared) may have traveled faster than 186,000 miles per second at some point in the past.  The implications are incredible.  It has a profound influence on the development of the universe and other cosmological considerations.  I have not finished the book yet, so I'll stop short of speculating on theories I have not studied fully as of yet.  However, I think he has quite a lot of merit to some of his theories.  It is called, VSL. (Varrying Speed of Light theory)  It does not neccasarily stop with the notion of "c" being greater in the past.  It is possible that "c" can be manipulated even now in the scientific world, and the possibility of such happening in it's own "natural" way is not so far-fetched in my way of thinking.  If light itself is capable, albeit by the possible virtue of actually having uniquely different properties than light as we are able to observe it today, of exceeding the constant we all know and love, then via relativity, some manner of warping time, or, more accurately, dilating time to the extent of moving backwards through it, or stopping it all together, would certainly be a reality in the universe. 

This could suggest the possibility of interdimensional activty with possible different universes, (if you beleive in that) that we are incapable of witnessing, at least at present, but see the effects of on a daily basis in that it serves the universe a purpose in keeping the fabric of our "taken for granted" reality sewn together by whatever higher function the mechanics therein may serve.   OR, it could suggest the possiblity of tachyon influence, or presence in the universe as being something real and somehow avoiding the crime of violating the theory of relativty and other conventions of physics that all entities in the universe are supposed to adhere to. 

I, for one, have always been a bit on the absurd side when it comes to considering some of these things.  I obey the rules, for the most part, because they are what they are, and more often than not, they are true and real.  I subscribe to the laws and theories and formulae of modern physics, but I like to play with them on a philosophical level because it entertains my mind and makes for most excellent science fiction.  ( I write science fiction.)