So light is the fastest thing. Nothing can go faster than that. It's kind of like the speed limit of the universe.
It's more honest to say that the fastest 'physical' thing in the Universe is light itself (or in fact the entire electromagnetic spectrum). Of course, the Universe has a self-imposed speed limit – the speed of light, which is 299,792.458km/s. Nothing moves faster than this.
What is faster than the speed of light? Nothing! Light is a "universal speed limit" and, according to Einstein's theory of relativity, is the fastest speed in the universe: 300,000 kilometers per second (186,000 miles per second).
Constant Speed
So what does this sentence really mean? Surprisingly, the answer has nothing to do with the actual speed of light, which is 300,000 kilometers per second (186,000 miles per second) through the "vacuum" of empty space.
The fastest speed possible is the speed of light in a vacuum, where its velocity is 670,616,629 mph (1,079,252,848 km/h), equivalent to 10,337,670 cheetahs, 5,082 of the planet Mercury, or 12.5 S4714 stars.
If you turn on a flashlight, the shadow region created by an object reaches a distant wall at the exact same moment that the light reaches the wall, indicating that darkness travels at the speed of light. Public Domain Image, source: Christopher S. Baird.
Because space isn't curved they will never meet or drift away from each other. A flat universe could be infinite: imagine a 2D piece of paper that stretches out forever. But it could also be finite: imagine taking a piece of paper, making a cylinder and joining the ends to make a torus (doughnut) shape.
For centuries, physicists thought there was no limit to how fast an object could travel. But Einstein showed that the universe does, in fact, have a speed limit: the speed of light in a vacuum (that is, empty space). Nothing can travel faster than 300,000 kilometers per second (186,000 miles per second).
In special relativity, the speed of light is the ultimate speed limit to the universe. Nothing can travel faster than it. Every single moving object in the universe is constrained by that fundamental limit.
So will it ever be possible for us to travel at light speed? Based on our current understanding of physics and the limits of the natural world, the answer, sadly, is no.
Light is actually energy made of small particles called photons.
Special relativity states that nothing can go faster than the speed of light. If something were to exceed this limit, it would move backward in time, according to the theory.
According to NASA, time travel is possible, just not in the way you might expect. Albert Einstein's theory of relativity says time and motion are relative to each other, and nothing can go faster than the speed of light, which is 186,000 miles per second. Time travel happens through what's called “time dilation.”
The black hole is one of the most massive black holes scientists have ever spotted. Typically, black holes spin really fast — near the speed of light.
HD 140283 had a higher than predicted oxygen-to-iron ratio and, since oxygen was not abundant in the universe for a few million years, it pointed again to a lower age for the star. As a result of all of this work, Bond and his collaborators estimated HD 140283's age to be 14.46 billion years.
These explosions generate beams of high-energy radiation, called gamma-ray bursts (GRBs), which are considered by astronomers to be the most powerful thing in the universe. What's more, these GRBs could be killing our chances of ever discovering life on other planets.
One such candidate for a truly stable entity is the photon: the quantum of light. All of the electromagnetic radiation that exists in the Universe is made up of photons, and photons, as far as we can tell, have an infinite lifetime.
— Light cannot escape from a black hole, but for the first time ever, researchers have observed light from behind a black hole — a scenario that was predicted by Einstein's theory of General Relativity but never confirmed, until now.
Light waves travel faster than sound waves.
While 1% of anything doesn't sound like much, with light, that's still really fast – close to 7 million miles per hour! At 1% the speed of light, it would take a little over a second to get from Los Angeles to New York. This is more than 10,000 times faster than a commercial jet.
For most space objects, we use light-years to describe their distance. A light-year is the distance light travels in one Earth year. One light-year is about 6 trillion miles (9 trillion km). That is a 6 with 12 zeros behind it!
Intergalactic distances are roughly a hundred-thousandfold (five orders of magnitude) greater than their interstellar counterparts. The technology required to travel between galaxies is far beyond humanity's present capabilities, and currently only the subject of speculation, hypothesis, and science fiction.
Short answer: We don't really know how the universe was created, though most astrophysicists believe it started with the Big Bang. We know that we live in an expanding universe. That means the entire universe is getting bigger with every passing day.
Scientists now consider it unlikely the universe has an end – a region where the galaxies stop or where there would be a barrier of some kind marking the end of space.
Practically, we cannot even imagine thinking of the end of space. It is a void where the multiverses lie. Our universe alone is expanding in every direction and covering billions of kilometres within seconds. There is infinite space where such universes roam and there is actually no end.