Distance light travels in a given time

In summary, defining the meter in terms of the distance light travels in a given time has several advantages. Firstly, it ensures accuracy as the speed of light in a vacuum is constant and does not change. On the other hand, the length of a metal bar can vary due to factors like thermal expansion. Additionally, using light for measurement purposes, such as in an interferometer, allows for a wider range of applications.
  • #1
sportsnh
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Please Help!

Explain the advantages in having the meter offically defined in terms of the distance light travels in a given time rather than as the length of a specific metal bar

Is it becasue in terms of light is more accurate?
 
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  • #2
Well, I can think of many reasons:
First, the speed of light in a vacuum is everywhere the same. The dimensions of a metal bar can change through thermal extension for example and it it impossible to machine something that is exactly 1.000000000000" or even more acurate.
Second, you can use light to actually meassure a lot of different things like in a interferometer
 
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  • #3
Thank you!
 
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Related to Distance light travels in a given time

What is the distance light travels in a given time?

The distance light travels in a given time depends on the speed of light, which is approximately 299,792,458 meters per second in a vacuum. This means that in one second, light can travel almost 300,000 kilometers.

How is the distance light travels in a given time calculated?

The distance light travels in a given time is calculated by multiplying the speed of light by the time in seconds. For example, if we want to know how far light travels in one minute, we would multiply 299,792,458 meters per second by 60 seconds, which equals 17,987,547,480 meters or approximately 18 million kilometers.

Does light travel at the same speed in different mediums?

No, light travels at different speeds depending on the medium it is passing through. For example, light travels slower in water or glass than it does in a vacuum. This change in speed is what causes refraction, or the bending of light when it passes through different substances.

How is the speed of light measured?

The speed of light is measured using specialized equipment, such as lasers and mirrors, which can accurately measure the time it takes for light to travel a specific distance. This measurement is then used to calculate the speed of light in meters per second.

What is the significance of knowing the distance light travels in a given time?

Knowing the distance light travels in a given time is crucial in many fields of science, such as astronomy, physics, and telecommunications. It helps us understand the vastness of our universe and how light interacts with different objects and substances. It also plays a crucial role in modern technology, as the speed of light is used to transmit information through fiber optic cables and wireless communications.

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