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Speed of Light
Denoted with the symbol "c," the speed of light is 299,792,458 metres per second and is often rounded as 300,000 kilometres per second or 186,000 miles per second.
1,290 Questions
Is the speed of light the same in every medium?
No, depending on the matter, speed of light can vary. It's speed is inversely proportional to the viscosity of the matter. It travels the fastest through Vacuum>>Air>>Liquids>>Solids.
How does the speed of sound waves compare with the speed of light waves?
The speed of sound is at about 344 m/s and the speed of light is at about 3 X 108 m/s. If you would like to test it out, wait for a thunderstorm. The lightning and the thunder start at the same place while the lightning is faster. That will demonstrate the speed difference of light and sound.
Light takes 8 1/2 minutes to reach us from the Sun.
The speed of sound varies with the relative motion of the observer but the speed of light is constant regardless of the relative speed. See Einstein's special theory of relativity.
The speed of light is roughly 882 thousand times the speed of sound.
-- Sound takes about 4.7 seconds to cover 1 mile.
-- Light takes about 0.0000054 second to cover 1 mile.
-- In the time it takes sound to travel one mile, light travels 881,741 miles .
During a thunderstorm, you see the lightning before you hear the thunder,
even though they're caused by the same event.
Another clue to an easy answer: Nothing is faster than the speed of light.
Sound crawls.
Sound speed is about 700 mph. (about 1/5th of a mile per second)
Light speed is about 186,000 mps.
Light goes about 930,000 times quicker.
If someone claps their hands 250 feet away, light can go 8½ times round the world while you wait to hear it.
Speed of light is a lot faster...the speed of light goes 299,792,458 meters per sec and the speed of sound goes 343.2
meters per sec
How many galaxies like your own would it take laid edge to edge to reach the nearest galaxy?
About one. Our galaxy is surrounded by several dwarf galaxies, that are extremely close to us.
About one. Our galaxy is surrounded by several dwarf galaxies, that are extremely close to us.
About one. Our galaxy is surrounded by several dwarf galaxies, that are extremely close to us.
About one. Our galaxy is surrounded by several dwarf galaxies, that are extremely close to us.
If a light source is approaching you at a speed very close to the speed of light, it will appear?
to be blue-shifted and brighter due to the relativistic Doppler effect.
That all depends what color it was when it left the source. Whatever wavelength it had at
the source, if it's approaching you, you'll measure a shorter wavelength (higher frequency)
as it passes you.
But don't forget that regardless of the speed or direction of the source, you'll measure
the light passing you at the 'speed of light' ... no more or less.
Why is the speed of light is faster than the speed of sound?
One reason may be that light doesn't involve actual movement of particles (atoms or molecules in this case). It takes some time to accelerate a particle.
One reason may be that light doesn't involve actual movement of particles (atoms or molecules in this case). It takes some time to accelerate a particle.
One reason may be that light doesn't involve actual movement of particles (atoms or molecules in this case). It takes some time to accelerate a particle.
One reason may be that light doesn't involve actual movement of particles (atoms or molecules in this case). It takes some time to accelerate a particle.
How do you use snell's law to find the speed of light in jello?
Snell's law combines trigonometry and refractive indices to determine different aspects of refraction. The law is as follows:
(n1)(sinX1) = (n2)(sinX2);
where n1 is the refractive index of the first medium, X1 is the angle of incidence (the angle between the incident ray and the normal), n2 is the refractive index of the second medium, and X2 is the angle of refraction (the angle between the refracted ray and the normal).
Setting up an experiment using jello and a laser, one can determine the index of refraction in the jello. Shine the laser at an arbitrary angle and record this angle. Then measure the refractive angle seen in the jello (this is the angle between the ray in the jello and the normal). The index of refraction for air is 1.0003. Now substitute all three values into Snell's law and solve for n2, the refractive index of jello.
An index of refraction is defined as the speed of light in a vacuum divided by the speed of light in a medium. Once n2 is determine, use the following equation:
n2 = c / v.
Substitute n2 and the speed of light in a vacuum (which is approximately 299,792,458 meters per second), and solve for v. The value obtained will be the speed of light in jello.
The nearest star (besides our sun) is 4.24 light-years from earth. This means that light emitted for this star takes 4.24 years to reach earth. Some stars are over millions of light-years away. The closest star is the sun. Beyond that is Proxima Centauri, at 4.24 light-years away. Alpha Centauri is at 4.37 light-years, and beyond that is Barnard's star at 5.97 light-years away.
4.24 light-years = roughly 24,925,000,000,000 miles (rounded to the nearest billion miles) lol
What are light waves used for?
Light waves are used for various applications such as communication (fiber optics), lighting, photography, and medical imaging (X-rays, MRI). They are also crucial in technology like lasers, spectroscopy, and sensors.
What is a sound wave made by an object moving faster than the speed of light?
It is impossible for an object to move faster than the speed of light in a vacuum. According to the theory of relativity, as an object accelerates towards the speed of light, its mass would approach infinity. This would require an infinite amount of energy, making it physically impossible.
How long will it take us to reach the moon in the speed of light?
The Moon averages 386,243km (240,000 miles) away from Earth. In theory that distance could be traveled in 3862 hours (161 days) at 100kph. In practical terms, you'd never get there from Earth. To escape Earth's gravity, a spacecraft needs to travel faster than 11.25 km (7 mi) per second. A speed of 100kph is only a fraction of that (about .027kps), so it wouldn't work. The Apollo Moon missions left the ground and accelerated to about 28000kph, until they entered a "parking orbit" of about 183.465km (114 miles) above the Earth's surface. They then left Earth orbit at about 39000kph. (The spacecraft decelerated on its own, during the trip.)
What is the history of the speed of light?
Before the 17th century, scientists believed that there was no such thing as the "speed of light". They thought that light could travel any distance in no time at all. Later, several attempts were made to measure that speed. 1667 Galileo Galilei: at least 10 times faster than sound
1675 Ole Roemer: 200,000 Km/sec
1728 James Bradley: 301,000 Km/s
1849 Hippolyte Louis Fizeau: 313,300 Km/s S
1862 Leon Foucault 299,796 Km/s
Today: 299792.458 km/s
1667 Galileo Galilei: at least 10 times faster than sound. LIGHTIn 1667, Galileo Galilei is often credited with being the first scientist to try to determine the speed of light. His method was quite simple. He and an assistant each had lamps which could be covered and uncovered at will. Galileo would uncover his lamp, and as soon as his assistant saw the light he would uncover his. By measuring the elapsed time until Galileo saw his assistant's light and knowing how far apart the lamps were, Galileo reasoned he should be able to determine the speed of the light. His conclusion: "If not instantaneous, it is extraordinarily rapid". Most likely he used a water clock, where the amount of water that empties from a container represents the amount of time that has passed. Galileo just deduced that light travels at least ten times faster than sound.-Top-
1675 Ole Roemer: 200,000 Km/secIn 1675, the Danish astronomer Ole Roemer noticed, while observing Jupiter's moons, that the times of the eclipses of the moons of Jupiter seemed to depend on the relative positions of Jupiter and Earth. If Earth was close to Jupiter, the orbits of her moons appeared to speed up. If Earth was far from Jupiter, they seemed to slow down. Reasoning that the moons orbital velocities should not be affected by their separation, he deduced that the apparent difference must be due to the extra time for light to travel when Earth was more distant from Jupiter. Using the commonly accepted value for the diameter of the Earth's orbit, he came to the conclusion that light must have traveled at 200,000 Km/s.-Top- SPEED OF LIGHT
1728 James Bradley: 301,000 Km/s SPEED OF LIGHTIn 1728 James Bradley, an English physicist, estimated the speed of light in vacuum to be around 301,000 km/s. He used stellar aberration to calculate the speed of light. Stellar aberration causes the apparent position of stars to change due to the motion of Earth around the sun.Stellar aberration is approximately the ratio of the speed that the earth orbits the sun to the speed of light. He knew the speed of Earth around the sun and he could also measure this stellar aberration angle. These two facts enabled him to calculate the speed of light in vacuum.
-Top-SPEED OF LIGHT
1849 Hippolyte Louis Fizeau: 313,300 Km/sA French physicist, Fizeau, shone a light between the teeth of a rapidly rotating toothed wheel. A mirror more than 5 miles away reflected the beam back through the same gap between the teeth of the wheel. There were over a hundred teeth in the wheel. The wheel rotated at hundreds of times a second; therefore a fraction of a second was easy to measure.By varying the speed of the wheel, it was possible to determine at what speed the wheel was spinning too fast for the light to pass through the gap between the teeth, to the mirror, and then back through the same gap. He knew how far the light traveled and the time it took. By dividing that distance by the time, he got the speed of light. Fizeau measured the speed of light to be 313,300 Km/s.
-Top- SPEED OF LIGHT
1862 Leon Foucault 299,796 Km/sAnother French physicist, Leon Foucault, used a similar method to Fizeau. He shone a light to a rotating mirror, then it bounced back to a remote fixed mirror and then back to the first rotating mirror. But because the first mirror was rotating, the light from the rotating mirror finally bounced back at an angle slightly different from the angle it initially hit the mirror with. By measuring this angle, it was possible to measure the speed of the light.Foucault continually increased the accuracy of this method over the years. His final measurement in 1862 determined that light traveled at 299,796 Km/s.
Heat waves traveling at the speed of light are called?
Heat waves traveling at the speed of light are called RADIATION! :)
What travels at the speed of light in a vacuum?
All colours of light, as well as all other forms of electromagnetic radiation such as radio,
X-rays, microwaves, heat, gamma rays, television, ultraviolet light, cellular telephone
signals, Bluetooth waves, weather satellite and GPS waves, and the spectrally shifted
light from distant stars and galaxies, all travel through vacuum at precisely the same
speed. The speed is
299,792,458 meters (186,282 miles) per second .What was Albert michelson invention of speed of light?
A. A. Michelson was not interested in measuring the speed of light.
He only measured how it changes if you move toward the light, away
from it, or sideways. (It doesn't.)
E equals mc2 Why is the speed of light squard?
In the equation E=mc^2, the speed of light is squared because it represents a fundamental property of the universe - the speed of light (c) is a constant that is very large (approximately 3 x 10^8 meters per second). Squaring the speed of light helps to relate mass (m) to energy (E) in a way that shows how a small amount of mass can yield a huge amount of energy.
How many miles does light travel in 100 seconds?
The speed of light in a vacuum is 186282.397 miles per second.
The distance something travels in a given time and at constant speed is given by
d = s*t
where d is the distance traveled, s is the speed, and t is the time.
In our case, s = 186282.397 miles per second and t= 100 seconds.
d = (186282.397 miles per second)*(100 seconds) = 18628239.7 miles
So, in 100 seconds, light travels 18628239.7 miles.
Does light travel at 18000 miles per hour from the sun to the earth?
Light travels at 670,616,629 miles per hour from the sun to Earth (or anyplace else in a vacuum). It takes about 8 minutes 12 seconds for the light of the sun to reach Earth.
How much faster is the B-2 stealth bomber than sound?
The B-2's maximum speed is 628 mph while the speed of sound is 768 mph, so ii is subsonic (the B-2 cannot fly faster than sound).
2 (no units)
Slow glass that reduces the speed of light?
Most forms of glass do not change the speed of light. Darker glass lets less light through it Glass at an angle to light may refract ( bend) light or glass may break light up into all the colours the light is made of rainbow / spectrum. The only way anyone has successfully stopped and restarted light is using magnetic beams
What is the speed of light using quartz as your medium?
The speed of light in quartz is approximately 186,282 miles per second, which is slower than the speed of light in a vacuum. The slowing down of light in a medium like quartz is due to its refractive index, which affects the speed at which light travels through the material.
Is light years per century a unit of speed?
While it is truly an unconventional (and not very useful) unit, yes it is. Speed (and velocity) are shown as a ratio of elapsed distance to time. Therefore, since a light-year is a measure of distance and a century is a unit of time, this is a unit of speed (or it could be used to measure velocity).
Newton's work showed that speed of light and sound were constant true or false?
False. Newton's work did not involve the speed of light and sound. The concept of constant speed of light was later formulated by Einstein in his theory of relativity. The speed of sound can vary depending on the medium it travels through.
What is faster a light year or light?
A light year is a measure of distance, not speed.
One light year is simply how far you'd get if you were able to travel at the speed of light for one year.
Space is so big that talking about distances between stars would be difficult if we used miles or kilometers. Even with light years, we quickly get real big numbers. Still more manageable than if we talked about miles though.
