If we know the exact speed of light then it’s clearly not infinite. If that’s the cause, what is preventing us from sending something faster then the speed of light( ignoring our current technology limitations).
In: Physics
There are a multitude of reasons. The first, and most basic to realize why it’s fundamental is that the bonds of atoms are actually made of photons. Oscillating electric and magnetic fields are what light is made of, and that’s what binds atoms together. Therefore, even if you got an object to the speed of light, then it would instantly rip apart into fundamental particles, because it would be going faster than the thing that holds it together.
You can’t ask this question and then say (ignoring our current technological limitations). Because the only reason we can’t do it is that we don’t have the technology.
Light isn’t the fast thing possible…well it’s not the only thing electromagnetic radiation and gravitional waves can also travel at the speed of light
* Normally, how fast something is going depends on who is asking.
If you are sitting in a bus, you aren’t moving. But if the bus is moving, someone standing on the side of the road will see you moving at a particular speed. Someone driving by in a car will see you moving at a different speed. Someone walking down the aisle in the bus will see you moving at another speed. Provided things are not accelerating (so changing speed or direction) there is no “preferred” viewpoint. Each is just as valid as any other, so speeds are all *relative.*
* But it turns out there is a special speed that is the same for everyone (locally);
So if something is travelling at this speed according to one person, it is travelling at this speed *according to everyone*. So something moving past you at this speed is also moving at that speed according to the person on the side of the road, or in the car, or walking in the bus, no matter how fast any of them are going compared to you. Conventionally, this speed is called “*c*”, and is about ten million miles per minute (fun fact; *c* is an example of convergent labelling – it came from several different areas of physics, where it stood for something different, but where it turned out they were all related).
For example, if you were sitting on the bus, and your bus was travelling at 1/2*c* (which would be very fast for a bus), something travelling at *c* faster than you, would still be travelling *c* faster than someone stood on the side of the road (not 1.5 *c*, as we would expect).
* This means something cannot get to that speed, or if at that speed, cannot change speed.
If this speed is the same for everyone, you can *never* accelerate up to it. Imagine trying to catch up to something travelling at this speed; you start speeding up and get to 1/2 *c*. But because *c* is the same for everyone, that thing is still travelling *c* faster than you. So you speed up some more. Except it is still going *c* faster than you. And so on. No matter how much you speed up, it is always going faster than you (effectively, space and time warp a bit around you so this works).
If someone is travelling at this speed already, everything kind of gets messed up. Due to how space and time are warped, *no time can pass for that person*, so there is literally no time for them to speed up or slow down.
* “Light” travels at this speed (sometimes – as with everything, physics is more complicated) because it has no mass.
Mass is the stuff that slows us down (the more mass, the more work it takes to speed us up). Light doesn’t have any mass to slow it down, so it will go as fast as it can – and the fastest it can go is this speed, *c*.
The speed of “things” is greatly determined by their mass, photons are (arguably) zero-mass and therefore are unbound
So…it has nothing to do with technological limitations. But before we get there, it’s not just the speed of light. The speed of any massless particle (including photons) in vacuum is a universal constant. It just is how our universe behaves. The physics that explains the relationship basically links space and time was demonstrated by Einstein, and it basically shows that photons (and other particles moving at “c” ) do not have time. Imagine a movement in a 4 dimensional spacetime – three spatial and one dimension of time. If you move slow, you cover a little bit of distance in a lot of time (that’s what “slow” means after all). If you move fast, you cover a lot of distance in very little time. The faster you move, the more distance you cover > and less time. If you move really really fast, you cover very little time….until you hit zero time. Once you hit zero time, you are moving at maximum speed (since time only flows one way, there’s no negative time we have observed). So if there’s a limit on time you can cover (in this case 0), there’s a limit on distance you can cover. That speed turns out to be ~300km/s and is known as “the speed of light”.
It has nothing to do with technology.
Relativity isn’t exactly a ELI5 sort of subject, but I’ll take a stab at it. The speed of light, c, is the speed of light through space, but is the speed of all things through spacetime. Everything travels at c. This is the only possible speed. The catch is that the speed of any object has two velocity components: its speed through space, and its speed through time. Photons travel at the speed of light through space, so from the perspective of a photon, it doesn’t experience time. The entire journey of a photon is instantaneous from its perspective. Conversely, an object which travels at c exclusively through time would not move through space at all. We’re pretty close to that, though we do move slowly through space, so our speed through time slows down ever so slightly the faster we travel.
Photons can travel at c through space because they have no mass, and hence there is no energy required to accelerate them. Conversely, any massive object requires energy to accelerate it to move faster through space, and the amount of energy required increases the closer that velocity through space gets to c, the only possible speed of objects through spacetime. As such, no matter how much kinetic energy you add to any moving object, the best you can do is to approach c asymptotically. To actually get there would require an infinite amount of energy input, which is of course impossible.
A smart guy named Einstein showed us that is you push something faster, which we already knew took energy, that energy gets added to the mass of the thing being pushed. He also showed that the more you push, the more and more mass is added, and it turns out by a formula that relation has a limit just before the speed of light — you can never push something all the way there, just closer and closer.
Light (or photons) have no mass, so they jump right to that speed, where (again) nothing else can catch them, ever.
Some good answers already so I’ll just add… The term you want to dive into is “the speed of causality” it’s the same as the speed of light but more accurately describes the limit on how quickly information can move through the universe
We technically don’t know the speed of light (the one-way speed of light, that is). Derek from Veritasium explains it well here: https://youtu.be/pTn6Ewhb27k
It’s been a month since I’ve seen that video, so I don’t know if it’ll directly answer your question, but I thought it was interesting.
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