Why is the speed of light the universal "speed limit"?

It was postulated by Einstein that the speed of light is constant regardless of the speed of the observer or the source. This had been independently and determined earlier by the Michelson Morley experiment. If you accept this postulate, then you have to accept that it's the universal speed limit. Regardless of how fast anything is going , from its point of view light is always pulling away from it at 300,000 km/s

Why would we accept it? Well, apart from the Michelson Morley experiment, it had experimental consequences which have been tested and have checked out. For example, time dilation. And there has been , to date, no observation that has contradicted the postulate.

Again, limited knowledge, but I'll share what I have learned. I wondered this for a long time, until I read a New Scientist article explaining that the speed of light has not always been the same, but has slowed over time. This is true, but can be confusing. At the moment of the (theoretical) big bang, light was the fastest thing, although much faster than today as it had: 1. higher energy to begin with, and 2. traveled much faster than it does now. As the energy was more or less evenly spread throughout the universe right at the moment of the big bang, photons would still move faster than everything else, as photons have no mass. No matter how fast it is traveling of course, nothing else can overtake it, as every other particle has mass, and thereby needs more energy to reach the same speeds - as it gains more energy, it's mass increases. The other thing is the expansion of the universe isn't technically the same as traveling through it. The best way to think of the big bang is not a bomb going off and everything being thrown outwards. Instead, imagine a balloon with dots on the inside of the surface. As it expands everything is is PULLED apart by the balloon itself, galaxies and light. The matter itself was not moving, but the universe's expansion was giving the impression that it was. Using the balloon analogy again, all the dots on the surface are staying fixed in place relative to the surface, but the expansion gives the impression they are moving apart. Sorry I can't explain this too well, but I hope you understand what I mean. So although everything inside the universe is traveling slower than light, the universe itself isn't actually INSIDE itself. The laws of physics simply apply to the inside of the balloon and it's inside surface. As for the expansion - I have no idea what is actually driving this (nor to my knowledge does anyone). All we can say is that expansion appears to be occurring, but not why it started. Much like throwing a ball in a car, it might be the fastest thing in the car, but this is simply relative to the inside, while the car is bombing along much faster. As for the speed of light being the fastest thing - this has been tested experimentally more times than I could count and always shown to be the case. You should really ready A Brief History Of TIme, or The Universe In A Nutshell by S. Hawking as he does a pretty good job of explaining it in simple terms.

Everyone is wrong special relativity only states that objects WITH MASS can never travel faster than the speed of light and that nothing can travel at the exact same speed as light, but can travel faster and slower.

It is the speed limit for objects with mass which is just about everything we know of besides dark energy. Our expansion of the universe is faster than light, because the universe or space is massless it doesnt violate special relativity.

Objects can travel faster than light and some things do today, just very very rare since objects without mass are very very rare.

E=mc>2

To get speed you need energy, but energy is mass. So more energy, more mass meaning you need more energy to accelerate that mass which makes more mass and we go on and on to infinity.

The link below tells it better.

Brian Greene has another explanation, which I quite can't grasp. But everything essentially moves at the same speed. Either rapidly in time and slow through space, or slow in Time and fast through space. When you get closer and closer to e, the speed of light, time becomes slower.

It is the universal speed limit because nothing is faster than it.

Its actually impossible to break. Well you could break it in a sense, but you would be moving in slow motion . Time and speed are all very relative to each other. Watch Into the Universe by Stephen Hawking.

According to the theory of relativity (and quantum mechanics), it would take infinite amounts of energy to move faster than the speed of light.

3*10^8 is speed of light it is maximum speed considrd by various scientists.

No other any thing have such speed.

It's just the fastest thing we know of. The reason it's often referenced as the fastest thing ever is because even taking theoretical physics into account, it is unlikely that anything could go faster.