Why cant we travel at the speed of light?

Question

Einstein said so...but why..just why...
if we manage to stuff enough energy into a spacecraft,(it's next to impossible, but it just might;MIGHT be possible)we would be able to go at the speed of light...

Answer 1

You could go at the speed of light, just not faster, because we don't have anything faster than that to propel the ship.

Answer 2

The way the numbers work out - the ones that experiment support - as an object looks to approach the speed of the light, the more energy it needs to accelerate. To get to the speed of light, you'd need more energy than the universe has. To get even close requires a part of that big number. It's just the kind of universe we have. It's a natural speed limit

Answer 3

Observers can't ride on a gamma ray beam. That would violate the second postulate of Relativity: that light rays (or gamma rays) travel at c as measured locally by *any* observer. So you're not allowed to ask Relativity what happens when you are riding a beam. If you could do that, then the theory would be completely wrong and we would have no basis at all to answer the question.

Answer 4

Einstein's Special Theory of Relativity is the key to understanding this particular question. Any reference on the subject (and I'm sure there are loads of them written for a wide range of students) will have some discussion on this. Briefly, to make an object accelerate from rest to any speed, we must expend some energy (by using a rocket engine, say).
For low speeds (much less than the speed of light --- 186,000 miles per second; all all humans have traveled only at very slow speeds compared to that of light), an increase in the energy expended results in a reasonable increase in the speed of the object. However, as the SR theory says, when the object is traveling at very large speeds (= a considerable fraction of the speed of light), then an additional expenditure of energy will not result in as large an increase in speed as it would have at lower speeds.
In other words, we have to expend quite a bit of energy to increase the speed by only a little bit, if the rocket ship is already traveling fast. If the rocket ship is traveling at 95% of the speed of light, a trememdous amount of energy will be necessary to make it travel at 96% the speed of light. In trying to make it travel at the speed of light, we would need to expend an infinite amount of energy --- in other words, we can't make it travel at the speed of light.

Now, every space ship, or other plane, etc., has traveled at a speed very small compared to light, so you might be wondering how we know the Special Relativity Theory is correct (why should we believe it without evidence?).

Although, we have never made any large object (like a space ship) travel at a considerable fraction of light speed, experimental particle physicists are constantly making electrons and the like travel at speeds like 99% of the speed of light in particle accelerators.
These accelerators only work properly because they are constructed obeying the laws of Special Relativity. To make the electrons accelerate, when they are already at 90% of the speed of light, does indeed take quite a bit more energy than would a comparable speed change when they are only moving at 10% of the speed of light. Special Relativity theory appears correct, in detail, even under the extreme speed conditions of a particle accelerator.

Answer 5

thats the problem. it aint possible.
scientists carried out that experiment in the dawn of the previous century. they stuffed enough energy in an electron which they hoped will speed it up to around 2c, through the simple equation 1/2mv^2 equals energy. but to their amazement, the electron always kept its speed less than that of the mighty photon, no matter how much they stuff. they noticed that change in velocity for lesser velocities is very much as expected. but as you go faster and faster, the rate of change of veocity is getting far less than expected. when they hoped that the electron will go at a speed of 1.96c, it was having speed just 0.98c. this phenomenon was almost going in the cold case files, when einstein came to the rescue. and you know after that.

Answer 6

there is a very simple answer to this question:

Because we just dont dont know how yet!
im sure einstein made his theory based on his knowledge of the universe as he knew it.
but as we know the universe encompasses far more than einstein or any of us could possibly ever hope to fathom
therefore any argument that says that any one thing is impossible is not relevant as this argument would then assume that the individual knows absolutely everything and can prove without a shadow of a doubt that they are correct,

besides whose to say that the laws of physics even apply in different parts of the universe.

the fact is we just simply do not know enough yet

so all you have to do is decide whether you are going to sit with the growing bunch of people who just say "nope it can never be done" or are you going to figure out a solution to the problem?

Kevin

Answer 7

yes why not. you may move as fast as the light unless and until you have the devices to move in such a large speed thats 3*10^8m/sec. but the problem is that we dont have those devices. one more fact is that when u go on increasing your speed ur mass increases and if u go at the speed of light ur mass will go to infinity. as this is not possible so u cant travel in that speed now, then or near future.

Answer 8

Mass is relative and increases with speed and tends to infinity at the speed of light. Thus to accelerate an object with intrinsic mass past the speed of light would require infinite force.
There is also the physiological problem at speeds higher than quite low percentages of the speed of light; the increase in the inter-molecular gravitational pull (due to increased mass) of all the molecules in our bodies would alter our biological workings and kill us in short order. E.G. our blood would become denser and we'd die of a heart attack.

Would time start to run backward if we exceed the speed of light. So would we have to be late to be on time for the super-optic bus?

Answer 9

It is not possible to travel at the speed of light because, do you know that the mass of light is Zero and it has no density.So if we are able to make our mass Zero then we might travel at the speed of light.

Answer 10

in order to travel at the speed of light we would need an infinite source of energy and we do not have that right now(or ever will) and travelling at the speed of light is impossible!

Answer 11

It is not possible, because of this.
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Theory of the Disintegration of an Object at speed of light.
By
minootoo.


At the speed of light all of the mass converts to energy.

This means that some day, if we ever achieve this (make an object travel at the speed of light), it can be achieved by object’s expense only.

The object will disintegrate and give out light only.
Q.E.D.



The theory has bases in the Lorenz-Fritzerald Contraction Phenomenon.

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Lorenz-Fritzerald( Or is it Lawrence-Fritzerald Spell?) Contraction Phenomenon:

Lorenz -Fritzrald experiment is the forerunner, we need to learn from it and project the results, to what might happen at the speed of light.
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Lorenze-Fritzerald took a measured slim rod, and subjected it to very high speed, rod was measured while in motion and it was found to noticeably shrink as it was put thru various increasing speeds.