In 1676, by studying the motion of Jupiter’s moon Io, Danish astronomer Ole Roemer calculated that light travels at a finite speed. Two years later, based on data collected by Roemer, Dutch mathematician and scientist Christian Huygens became the first person to attempt to determine the actual speed of light, according to American Museum of Natural History in New York City.
Huygens came up with a figure of 131,000 miles per second (211,000 kilometers per second), which is imprecise by today’s standards – we now know that the speed of light in the “vacuum” of empty space is about 186,282 miles per second (299,792 km per second) – But his evaluation showed that light travels at an incredible speed.
to me Albert Einsteinspecial theory Relativitylight travels so fast that, in a vacuum, nothing in the universe is able to move faster.
“We cannot move through the vacuum of space faster than the speed of light,” stressed Jason Casipry, associate professor of aerospace engineering at the University of Alabama’s Propulsion Research Center in Huntsville.
Answer the question, right? Maybe not. When the light not In the void is the rule still in force?
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Claudia de Ram, a theoretical physicist at Imperial College London, told Live Science in an email. She said there are some caveats that must be taken into account.
Light exhibits particle-like and wave-like properties and can therefore be considered a particle (a Photon) and wave. This is known as wave-particle duality.
If we think of light as a wave, de Ram said, there are “multiple reasons” why certain waves travel faster than white (or colorless) light in a medium. One of those reasons, she said, is that “when light travels through a medium – for example, glass or water droplets – different frequencies or colors of light travel at different speeds.”
The most obvious visual example of this occurs in rainbows, which usually have long, faster red wavelengths at the top and shorter, slower violet wavelengths at the bottom, According to the University of Wisconsin-Madison,.
When light travels through a vacuum, the same is not true.
“All light is a type of electromagnetic wave, and they all have the same speed in a vacuum (3 x 10^8 meters per second). That means both radio waves And gamma rays “They have the same speed,” Rhett Allen, a professor of physics at Southeast Louisiana University, told Live Science in an email.
Therefore, according to de Ram, the only thing capable of traveling faster than the speed of light is, somewhat paradoxically, light itself, even though it is not in the vacuum of space. It should be noted that regardless of the medium, light will never exceed its top speed of 186,282 miles per second.
global view
According to Cassiepri, there is one more thing to keep in mind when discussing things that move faster than the speed of light.
“There are parts of the universe that are expanding away from us faster than the speed of light, because Spare time expands.” For example, Recently spotted by the Hubble Space Telescope 12.9-billion-year-old light from a distant star known as Erendel. But as the universe is expanding at every point, Earndale has been moving away from Earth and has been since its formation, so the galaxy is now 28 billion light-years away from Earth.
In this case, space-time expands, but matter in space-time still travels within the limits of the speed of light.
Related: Why is space empty?
So, obviously nothing travels faster than light as we know it, but is there any situation where it might be possible? De Ram said that Einstein’s theory of special relativity, and his later theory of general relativity, is “based on the principle that the concepts of space and time are relativ.” But what does this mean? “If someone [were] Being able to travel faster than light and carry information with them, de Ram said, their concept of time would be twisted compared to ours. “There can be situations where the future can affect our past, and then the whole structure of reality stops thinking.”
This may indicate that it may not be desirable to make humans travel faster than the speed of light. But could that be possible? Will there ever come a time when we will be able to create a craft that can propel materials – and ultimately humans – through space at a speed that exceeds the speed of light? “Theorists have proposed different types of warp bubbles that could enable travel at speeds above the speed of light,” Cassiepre said.
But is De Ram convinced?
“We can imagine being able to communicate at the speed of light with systems outside our solar system,” de Ram said. “But sending actual humans at the speed of light is impossible, because we cannot speed ourselves up that fast.
“Even in a very ideal situation where we imagine we can keep accelerating ourselves at a constant rate – ignoring how we can even come up with technology that can keep accelerating us constantly – we won’t actually reach the speed of light,” she added. “We can get close, but we never get there.”
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This is a point emphasized by Cassiepri. “Disregard relativity, if you want to speed up by 1G [Earth gravity]It would take a year to reach the speed of light. However, you will never really reach that speed because as you start getting close to the speed of light, your mass energy increases, and you get close to infinity.
“One of the few known potential ‘cheat codes’ for this limitation is spacetime expansion and contraction, thus bringing your destination closer to you. There seems to be no fundamental limit to the rate at which spacetime can expand or contract, which means we might be able to get around this speed limit someday “.
Likewise, Allen is confident that faster-than-light travel is highly unlikely, but, like Cassiepri, has pointed out that if humans wanted to explore distant planets, it might not be necessary to reach such speeds.
“The only way we can understand faster-than-light movement is by using some kind wormy In space,” Allen said. This would not actually make us go faster than light, but instead give us a shortcut to another place in space. “
However, Cassiepri is not sure if wormholes would ever be a realistic option.
“It is assumed that wormholes are possible based on a special solution of Einstein’s field equations,” he said. “Essentially, wormholes, if possible, will give you a shortcut from one destination to another. I have no idea if it would be possible to create one, or how we might even do it.”
Originally published on Live Science.
