Rava is an online news portal providing recent news, editorials, opinions and advice on day to day happenings in Pakistan.
“There is a speed in our Universe that is the maximum speed for everything, which has a value: 300,000 kilometers per second,” pointed out the British theoretical physicist Jim al Khalili when we consulted about the possibility that something could travel faster than light .
“Nothing can go faster because that is the speed of the very fabric of space-time,” he replied.
“And it turns out that light travels at that speed, so it is not that light is special in this sense, it is speed itself that is special in our Universe, there may be other universes in which the maximum speed is different.”
But, why is there a speed limit?
“That brings us to the theory of special relativity of Albert Einstein, 1905, which states that the speed of light is what connects time with space,” he said.
And he explained: “Isaac Newton had said that time and space were independent, Einstein said: ‘No, time and space are intimately connected and what unites them is the speed of light in ways that one can see’.
“If you try to travel at a speed closer to the speed of light that is possible, strange things happen.”
Strange things that happen …
To understand those strange things that happen, the cosmologist Andrew Pontzen invited us to travel with him in his Train of Thought .
“Imagine that you are traveling in a train and you throw a ball in the car, you observe it moving and it seems to go at the same speed as always when you throw a ball, which in my case is slow, but you can be better throwing balls” , He says.
“Now suppose someone is standing outside the train, on the platform of a station where your train does not stop, and that person also sees the ball,” he continues.
“That person will see the ball moving at the speed at which the train travels plus the speed with which you threw it , because obviously the two movements are happening at the same time.”
All that sounds very normal. But the problems start when you accelerate the speed of the train.
The closer you get to the speed of light, the ball stops traveling at the speed of the train more at the speed you threw it.
It’s as if something does not allow him to go faster.
“Even if you go a little slower than the speed of light which is more realistic for a tren- and make him follow the ball, it remains true that no longer have the original rate plus a little more: a hard ball pain accelerates as it gets closer to the speed of light, “he adds.
“It’s very strange and everything has to do with the distortion of time-space,” says the cosmologist.
Even stranger …
… is that the closer you are to reaching the speed of light, our train begins to crush.
“From the outside, the train, traveling at that speed, will appear to be crushing and becoming tiny in the direction in which it is moving .”
“At the same time it will seem that the mass is increasing, more and more, that’s another way of answering why you can not go faster than the speed of light: the mass grows and that makes it harder and harder for the train move faster. “
And that is expressed in the extension of an equation that is probably familiar: E = mc²
The complete equation is E² = (mc²) ² + (pc) ² where the ‘p’ represents the linear momentum of the object.
Not so attractive! But the “added” is what describes how the mass will change if there is movement involved.
And even stranger …
… if we talk about what happens with time.
If you could travel at the speed of light, you would experience the entire history of the Universe in an instant .
That’s because if you could travel at the speed of light, all the laws of cause and effect would be broken, and the notion of the past and the future would collapse completely .
In addition, you would need to have infinite mass and energy.
In summary: the universal speed limit is a kind of foundation of Physics.
And how does light achieve it?
Light has no mass, so it is free to travel to that cosmic speed limit.
Is there anything that can travel faster than the speed of light?
As far as we know, no .
Although there was a brief moment in which it was believed that yes .
In 2011, a revolutionary discovery was announced that threatened to nullify everything we know about the speed of light, the Theory of Special Relativity and all modern Physics.
It all started in Italy, home of Opera, acronym (a bit forced) of the Oscillation Project with Emulsion-tRacking Apparatus.
It was a particle physics experiment designed to study the phenomenon of neutrino oscillation.
Unlike light, neutrinos have a tiny amount of mass, so – according to Einstein’s Special Theory of Relativity – they must travel at a speed less than light.
However, that year, Opera gained international attention when it announced the detection of neutrinos traveling at a speed greater than that of light .
“The scientists who carried out these experiments in Italy published the results, the press and everyone was very excited: this was going to revolutionize physics,” Al Khalili recalls.
“It turned out that everything happened because of a loose wire on a digital clock on a computer in the laboratory in Italy.” When someone noticed and connected it well, everything went back to normal and it was found that the neutrinos were traveling at a lower speed than that of light. “
All modern physics questioned due to a loose cable .
However, that was precisely a sample of science functioning as it should be.
“Science is making mistakes and learning from them, it takes extremely strong evidence to overturn a century of physics, but that does not mean it will never happen,” says Al Kalili.
“Since Einstein formulated his theory we have been trying to prove that it is wrong and we have not been able to, but we should never stop trying .”