We all know our universe has a speed limit: The speed of light. According to Einstein’s Special Theory of Relativity, nothing that has mass can ever travel faster than light in space (299 792 458 m/s or 3×108m/s).
But can you imagine beyond that? Most physicists believe faster-than-light objects cannot exist because they will violet casualty, leading to many paradoxes like the grandfather paradox.
Can these objects really exist? Well, here are the top 6 ways you can break the speed limit barrier (4 ways + 2 misconceptions).
- Big Bang
- Quantum Entanglement
- Laser light and the moon
- A light year long stick
- Negative Mass
From books, documentaries, memes, and articles, we have heard countless times that the universe is expanding.
Although when we were at school, we were told that our universe was expanding, gradually it stopped expanding because of gravity. But the fact is it is not true at all. We now know the universe is not only expanding but also accelerating. We call the unknown force behind this acceleration Dark Energy.
Our Universe was created roughly around 13.8 Billion years ago from a tiny mass right after birth universe started to expand in all directions. So if it started to expand at the maximum Cosmological Speed limit (speed of light), our observable universe would be 13.8 Billion Light Year wide but when we observed the universe closely, we found that it is actually 93 billion light-years in diameter.
What’s the reason?
According to NASA about 5-6 Million years ago a mysterious force started to speed up the universe, a phenomenon that continues today. The mysterious force is none other than Dark Energy.
When we observe distant galaxies through our telescope, we find that most of them are going away from our Milky Way. In fact, some of them are moving faster than the speed of light.
We can imagine that the Galaxies are not moving alone. The space between them is expanding greater than the cosmological speed limit. You can think of it like blowing a balloon. When you start to blow a balloon, it starts to expand, and the space between particles of the rubber increases but from the particle point of view others are moving far away rapidly.
A light year long stick:
Spoiler: Before I continue I want to tell you that it is a misconception.
Here is a fun recall of your childhood. Ever thought that if you have a really long rod, you can move the end of the rod at an extremely high speed by moving the other end with a little speed?
But the reality is you can’t. I know the answer made your childhood idea incorrect but that’s how the universe works. Before I explained you need to understand how pushing works at the microscopical level.
So when you push a rod, you are actually pushing the particles of it. And those particles push others and thus they will reach their information at the end like a wave. And in the end, it would not work.
Laser light and the moon:
Spoiler: this is also a pure misconception but with extra steps.
Here is a Mind task. Think about the exact same experiment as the previous one but instead of a light-year-long rod think about a Laser light in your hand. Now imagine you are flashing it to the moon and dragging it across the surface of the moon within a fraction of a second.
On Moon, An observer will see your laser point will be moving Faster than the speed of Light. So what is the logic behind it?
Actually, no one here moving faster than light speed (not ever the laser light). As you drag a laser beam across a surface, the images from the laser are landing side-by-side and it forms an illusion of going faster. In fact, it does not carry any Information.
Just like Dark Energy, you have heard of this phenomenon before in books, documentaries, memes, and articles. On a tiny scale, physics acts weirdly. According to Quantum Mechanics, we describe a particle as a wave function (this is called Wave-particle duality). Unlike other waves (eg: sound waves, water waves), there is no physical definition of the wave function.
It is pure Mathematical. To get real-world properties like position or momentum, we have to do mathematical operations o this wave function. But weirdly we have no idea if this wave function is real or not.
Now let’s say 2 electron waves meet each other. Their waves interfere with each other and mixed up. Now mathematically speaking we have one wave function that can describe both electrons even if they are far away. Measuring one electron (like spin-up and down) is now correlated with the other one and the effect is instantaneous.
Albert Einstein was very uncomfortable with this idea, If you measure one particle, another can be predicted even if it is billions of light years away. But the fact is the measurement gives you random results so it does not transfer any information.
You might have come across the term tachyons in Science-faction movies or articles. The term ‘tachyon’, comes from the Greek word ‘tachys’, which means fast.
In theory, tachyons have imaginary mass. They are hypothetical because they break several laws of physics such as General relativity. Existing of Tachyons can lead to other paradoxes involving “Time Travel”.
Einstein’s theory suggests that a Tachyons can be identified before it was born. Well STR (Special Theory of Relativity) suggests that nothing that has greater mass than zero can’t go faster than light because it will be led to infinite mass. Only massless particles can travel faster than light(like- photons).
But what if it was always that fast, from the beginning? if it is created in this manner in the big bang that it will be impossible to slow down to the speed of light. Slowing down to light speed will take an infinite amount of energy. As a result, particles will travel at different speeds on either side of the light speed.
This is most probably the coolest way to travel faster than light. As normal matter attracts things toward it, a negative matter repels things from it and expanding the space and time.
The best way to use the Negetive matter is using it in a worm hole. Theoretically wormholes are not stable. It ends as soon as its’ formation. It vanises so fast that light even light can’t travel through it. So physicists suggest to use negative matter to make a stable worm hole.
However, it is not known if negative matter even exists, and whether the wormhole will be stable. To solve the problem we need to under stand Quantum gravity and for that we need to unite quantum and gravity together. The only theory that can do it is string theory but it is so complex that no one has fully understand this.