299,792,458 meters The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 feet) per second. That’s about 186,282 miles per second — a universal constant known in equations as ‘c,’ or light speed.

## How long is 1 second in light speed?

The light-second is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in one second, and is equal to exactly 299,792,458 metres (983,571,056 ft).

## How far can a light travel in a minute?

186,000 miles * 60 seconds = 11,160,000 miles/minute So light can travel 18,000,000 kilometers in one minute! Let’s see how many light minutes Earth is from the Sun.

#### How far does light travel in 3 second?

if you travelled three light seconds, 552,000 miles , at the speed of light, would it take you three seconds or zero seconds Since its not possible to travel at the speed of light the question is not meaningful.

### How fast does light travel in 30 seconds?

Explanation: — Light travels approximately 299792458 m/s or 17987547. 48 km/min. To find out how far light travels in 30 seconds, #C= 17987547. 48/2# #color(white)(C)= 8993773. 74km#.

## What’s the speed of dark?

How fast is the speed of darkness? — Strictly speaking, dark is simply the absence of light, and thus has no speed at all, according to noted astrophysicist Neil deGrasse Tyson.

### How fast is light per mile?

Light from a stationary source travels at 300,000 km/sec ( 186,000 miles/sec ).

### How many Earth years is a Lightyear?

An image of distant galaxies captured by the NASA/ESA Hubble Space Telescope. Credit: ESA/Hubble & NASA, RELICS; Acknowledgment: D. Coe et al. 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!.

#### Does time stop at the speed of light?

«I heard that Einstein’s Relativity said it is possible to stop time. Is that true and, if it is, how do you do it and what do you experience when time stops?» The simple answer is, «Yes, it is possible to stop time. All you need to do is travel at light speed.

» The practice is, admittedly, a bit more difficult. Addressing this issue requires a more thorough exposition on Special Relativity, the first of Einstein’s two Relativity Theories. (Special — 1905; General — 1916).

Special Relativity pertains specifically to light. The fundamental tenet is that light speed is constant in all inertial reference frames, hence the denotation of «c» in reference to light. To phrase this tenet in a more friendly manner, it means that a light beam’s speed remains unchanged even if the observer moves relative to it.

This consistency is wholly foreign to us macroscopic world dwellers, because an automobile’s speed appears to increase if one is moving toward it and seems to decrease if one moves away from it. Light’s behavior is different.

We know that an object, or a light beam’s, speed measures the distance traversed over time. How can we reconcile this relationship with the fact that a light beam’s measured speed remains constant for all observers, moving or stationary? Time dilation affects this reconciliation.

- Time dilates on moving vessels: the greater the speed, the greater the time dilation;
- Only when such velocities* approach light speed do such effects become significant;
- If, and this one of those extreme IF’s, a vessel could attain light speed, time aboard the vessel would cease altogether;

Any person on that vessel would experience nothing at all. Though Spock and Kirk are able to trade barbs and witticisms at warp, in the real world, they would experience no time at all. Let’s say, to play with this fantasy world a bit, that a vessel moves at light speed from now (2014) to 2214.

For us, two hundreds years would elapse. No time would pass at all on the vessel. What would be two centuries on Earth would be instantaneous on the ship. Extremely strange, but, theoretically true. Now, we ruin the moment when some pragmatism: accelerating a ship to such a velocity is not possible, at least not with our technology.

The problem is that a vessel’s mass also increases with increasing speed. A vessel at light speed would have infinite mass! Special Relativity indicates that a vessel’s mass increases, length contracts with increasing velocity. Time dilation is not the only effect.

- The fastest human made vessels, the Helios Probes I and II, established heliocentric orbits that were closer to the Sun than Mercury;
- Consequently, they attained speeds of more than 170,000 mph;
- Here, we extend as much credit to the Sun as to the engineers, for these impressive speeds;

However, even the Helios probes moved at less than 1/3600th light speed: not particularly impressive by Starfleet standards. Will we ever construct starships capable of light speed? (In so doing, we could send people to remote locations without worrying about them aging to dust or getting on each others’ nerves.

) We can’t today, but who knows what humans will eventually accomplish? We certainly hope so. *Using the terms ‘speed’ and ‘velocity’ interchangeably is not precisely an excommunication offense, but should be avoided.

Speed is a scalar quantity: 100 mph or 90 kilometers per second are both speeds: values without direction. Whereas 100 mph east of the police barracks is a measure of velocity, as it includes a direction. We use them synonymously out of sheer laziness..

## Is time Travelling possible?

In Summary: — Yes, time travel is indeed a real thing. But it’s not quite what you’ve probably seen in the movies. Under certain conditions, it is possible to experience time passing at a different rate than 1 second per second. And there are important reasons why we need to understand this real-world form of time travel..

## What distance is 1 light-year closest to?

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A light-year is a measure of astronomical distance: Light travels through a vacuum at precisely 983,571,056 feet (299,792,458 meters) per second, making a light-year approximately 6 trillion miles (9. 7 trillion kilometers). (Image credit: ikonacolor via Getty Images) A light-year is a measurement of distance and not time (as the name might imply). A light-year is the distance a beam of light travels in a single Earth year, which equates to approximately 6 trillion miles (9.

- 7 trillion kilometers);
- On the scale of the universe , measuring distances in miles or kilometers is cumbersome given the exceedingly large numbers being discussed;
- It is much simpler for astronomers to measure the distances of stars from us in the time it takes for light to travel that expanse;

For example, the nearest star to our sun , Proxima Centauri , is 4. 2 light-years away, meaning the light we see from the star takes a little over four years to reach us.

## How far can light travel in 5 seconds?

Explanation: — to get answer multiply this value with 5. =1498962290 meters..

## Is light speed possible?

Gianni Woods/NASA The idea of travelling at the speed of light is an attractive one for sci-fi writers. The speed of light is an incredible 299,792,458 meters per second. At that speed, you could circle Earth more than seven times in one second, and humans would finally be able to explore outside our solar system. In 1947 humans first surpassed the (much slower) speed of sound , paving the way for the commercial Concorde jet and other supersonic aircraft.

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. According to Albert Einstein ‘s theory of special relativity , summarized by the famous equation E = mc 2 , the speed of light ( c ) is something like a cosmic speed limit that cannot be surpassed.

So, light-speed travel and faster-than-light travel are physical impossibilities, especially for anything with mass , such as spacecraft and humans. Even for very tiny things, like subatomic particles, the amount of energy ( E ) needed to near the speed of light poses a significant challenge to the feasibility of almost light-speed space travel.

#### How did Einstein know the speed of light was constant?

Besides Michelson and Morley experimental results, Einstein also considered the theoretical aspects. It can be derived from Maxwell’s equations that the speed at which electromagnetic waves travel is: $c=\left(\epsilon_ \mu_ \right)^ $. Since light is an electromagnetic wave, that means that the speed of light is equal to the speed of the electromagnetic waves.

$\epsilon_ $ and $\mu_ $ are properties of the vacuum and are constants, so $c$ will also be a constant. Thus from Maxwell’s theory of electromagnetism alone we can already see that the speed of light in vacuum should be constant.

On the other hand, Galilean invariance tells us that the laws of motion have the same form in all inertial frames. There is no special inertial frame (as far as Newton’s laws are concerned). Another key element here is Galilean transformation , which was the tool used for transforming from one inertial frame to another. It can be easily seen that considering the first two elements to be valid:

- Maxwell’s theory of electromagnetism — speed of light is constant
- Galilean invariance — the laws of motion have the same form in all inertial frames

means that we can no longer apply the Galilean transformation, because otherwise we will get a contradiction. Thus at least one of these three «key elements» must be wrong.

- Maxwell’s theory of electromagnetism — speed of light is constant
- Galilean invariance — the laws of motion have the same form in all inertial frames
- Galilean transformation

It turned out that the last one (Galilean transformation) was wrong. Einstein considered the first two correct and built the special theory of relativity. The correct transformation from one inertial frame to another, in the assumption of the validity of the Maxwell’s theory and Galilean invariance, turns out to be Lorentz transformation.

It is nice to check that the Lorentz transformation does indeed reduce to the Galilean transformation in the $v\ll c$ limit. That’s why, in a sense, Galilean transformation is not wrong, but rather incomplete or a particular case.

We can say that Galilean transformation needed to be generalized, and this was acomplished by introducing the invariance of the speed of light and maintaining the Galilean invariance.

## Is there anything faster than the speed of light?

—> Warp drive: could positive-energy solitons move a spacecraft faster than the speed of light? (Courtesy: iStock/VikaSuh) Albert Einstein’s special theory of relativity famously dictates that no known object can travel faster than the speed of light in vacuum, which is 299,792 km/s. This speed limit makes it unlikely that humans will ever be able to send spacecraft to explore beyond our local area of the Milky Way. However, new research by Erik Lentz at the University of Göttingen suggests a way beyond this limit. The catch is that his scheme requires vast amounts of energy and it may not be able to propel a spacecraft.

Lentz proposes that conventional energy sources could be capable of arranging the structure of space–time in the form of a soliton – a robust singular wave. This soliton would act like a «warp bubble'», contracting space in front of it and expanding space behind.

Unlike objects within space–time, space–time itself can bend, expand or warp at any speed. Therefore, a spacecraft contained in a hyperfast bubble could arrive at its destination faster than light would in normal space without breaking any physical laws, even Einstein’s cosmic speed limit.

#### How fast is gravity?

In the wake of recent news that astronomers finally detected the space-warping boom of colliding neutron stars , measuring the merging of black holes might seem kind of old hat. You might have moved on, but researchers are still picking through the data gathered from those previous ground-breaking thunderclaps.

Now two teams of physicists used figures from the variety of gravitational waves to narrow estimates on just how fast we think gravity moves, and while their results aren’t shocking, they are strangely comforting.

A few centuries ago, Isaac Newton assumed gravity’s tug was instantaneous; a claim later Albert Einstein refuted by reasoning the force travelled at the speed of light. Going by Einstein’s reckoning, space isn’t just an empty stage for matter to move on, but is a major actor itself.

- Mass pulls on the very fabric of space, curving time and distance in such a way that objects accelerate towards one another;
- Just as the speed of a massless particle of light in a vacuum is restricted by the Universe’s upper speed limit, the massless distortions of spacetime would also be energy zipping along at top speed;

Or, to be more precise, gravity moves at 299,792,458 metres per second , a rate we can just call c. Of course you’d be a fool to bet against Mr. General Relativity himself, but good science demands that even geniuses need to be checked against reality. And in spite of being intimate with Earth’s strong grip, the force of gravity is kind of hard to measure.

«Until the advent of gravitational wave astronomy, we had no way to directly measure the speed of gravity,» Neil Cornish, a physicist from Montana State University, told Phys. org. The numbers are pretty insane.

As objects dozens of times more massive than our Sun orbit one another thousands of light years away, they lose energy by making space ripple. In that final moment before finally colliding, that effort equals something like 10 times the amount of energy pouring from every star in the Universe.

- Mind blown? By the time it reaches us, each wave is ten thousand times smaller than a proton, and passes in just one fifth of a second;
- We rely on a network of 4 kilometre (2;
- 5 mile) long light beams arranged at right angles to spot those signature distortions;

It might all sound simple in practice, but the technology behind the detectors – worthy of a Nobel Prize – is about as cutting edge as it gets. The growing pool of data collected by these detectors is opening the way for scientists everywhere to dig for evidence on everything from hidden dimensions to the basic properties of space.

- «The speed of gravity, like the speed of light, is one of the fundamental constants in the Universe,» says Cornish;
- By comparing the exact timing of the gravitational waves as they hit different observatories across the globe, researchers can get a good idea of the wave’s overall speed;

Cornish’s team of researchers combined the timings of the first three detections to narrow down the speed of the waves to between 55 and 142 percent of c. If enough detectors stay in top working order, this method could be used to calculate the figure to within just 1 percent of c by measuring just another five gravitational waves.

- Before you start marking off the days on your calendar, another team made up of a small army of physicists used the burst of gamma rays captured from last month’s neutron star collision to come up with their own estimate;

Their method was a little more precise. Ok, a whole lot more precise. They found the difference between the lightning flash of the gamma ray burst and the thunderclap of the gravitational wave was extremely close — within -3 x 10^-15 and 7 x 10^-16 of c.

Close enough to call it a tie, really. To be fair, the previous team couldn’t have predicted the neutron star collision, so hats off to them for going old school. Having multiple methods come to similar conclusions also gives us confidence we’re on the right track, and that’s pretty damn cool.

This research was published here and here ..

### How many second is a light speed?

speed of light , speed at which light waves propagate through different materials. In particular, the value for the speed of light in a vacuum is now defined as exactly 299,792,458 metres per second. relativistic velocity combination If you race at a beam of light, why doesn’t the light approach you faster than the speed of light? If you run away, why doesn’t the light approach you slower than the speed of light? This video is an episode in Brian Greene’s Daily Equation series.

- © World Science Festival ( A Britannica Publishing Partner ) See all videos for this article The speed of light is considered a fundamental constant of nature;
- Its significance is far broader than its role in describing a property of electromagnetic waves;

It serves as the single limiting velocity in the universe, being an upper bound to the propagation speed of signals and to the speeds of all material particles. In the famous relativity equation, E = m c 2 , the speed of light ( c ) serves as a constant of proportionality, linking the formerly disparate concepts of mass ( m ) and energy ( E ). Britannica Quiz All About Physics Quiz Who was the first scientist to conduct a controlled nuclear chain reaction experiment? What is the unit of measure for cycles per second? Test your physics acumen with this quiz. The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Adam Augustyn ..

## How far can light travel in 5 seconds?

Explanation: — to get answer multiply this value with 5. =1498962290 meters..

## What distance is 1 light year closest to?

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- Science & Astronomy

A light-year is a measure of astronomical distance: Light travels through a vacuum at precisely 983,571,056 feet (299,792,458 meters) per second, making a light-year approximately 6 trillion miles (9. 7 trillion kilometers). (Image credit: ikonacolor via Getty Images) A light-year is a measurement of distance and not time (as the name might imply). A light-year is the distance a beam of light travels in a single Earth year, which equates to approximately 6 trillion miles (9.

7 trillion kilometers). On the scale of the universe , measuring distances in miles or kilometers is cumbersome given the exceedingly large numbers being discussed. It is much simpler for astronomers to measure the distances of stars from us in the time it takes for light to travel that expanse.

For example, the nearest star to our sun , Proxima Centauri , is 4. 2 light-years away, meaning the light we see from the star takes a little over four years to reach us.

## How many times can light travel around the Earth in 1 second?

The speed of light is 186,282 miles per second. The circumference of the Earth is 24,901 miles. Therefore if you traveled at the speed of light, you could travel around the Earth roughly 7. 48 times in one second.