Why is measuring the speed of light so difficult?

Answer 1

Perhaps you could define what you mean by "so difficult".

Many technologies depend on the speed of light. Using radar to measure distance requires measuring the time it takes a microwave burst to hit a distance and return. The speed of light is used to calculate the distance to the object. The calculation could be run the other way to find the speed of light.

The same could be said of laser distance measuring systems. They are not hard to use. One could have designed the same unit to measure speed of light using a known distance but there is no market for it.
http://en.wikipedia.org/wiki/Radar#Distance_measurement
The global positioning system (gps) works by measuring the time delays of signals from different satellites. These signals travel at the speed of light.

Of course light is fast. Too fast for a stopwatch.

Answer 2

Is the formula E = MC2, difficult to understand?

All I care about is that astronomers can accurately measure the speed of light and have been able to do so since the mid 19th Century, before they understood the theory of relativity (E equals MC squared).

They can tell you how fast the galaxy Andromeda is approaching our galaxy, because of the measurement of the speed of light and the light sensitive equipment designed to measure what has been calculated.

So, if the speed of light has already been calculated, it is not difficult to measure it.

For example, it takes 8 seconds for the sun's light to reach us because we've measured the speed that light takes to reach us from the sun, right?

Well, if the sun were to disappear, would we notice it when the sun is gone instantaneously, or would it take us 8 seconds for the lights to go out?

The answer is it would take 8 seconds for the people on earth to actually notice it, because the speed of light is also connected to the fabric of space/time.

Space/time is how Einstein helped us understand the fourth dimension of space. That gravity, according to Newtonian laws of physics is not the only thing that affects mass.

That light speed is also a calculation that predicts movements and distances in the fabric of space/time, which influences gravity. So, nothing is affected simultaneously, according to Newton's information. It takes as long as light speed to reach the other object in space/time to affect its gravitational force.

So, if the sun were to completely disappear, the earth would not begin to hurl out to space until 8 seconds later.

What's even more fascinating is that light is both a wave and a particle. - Light behaves as both a wave and a particle. - Its as if light is communicating with the out come before it appears when you experiment with waves and particle measurements.

And even more fascinating in quantum physics is that a photon, which is a single element of light, can appear in two places at once. So, if you don't grasp how mind boggling that is... Then, you really haven't grasped how unbelievably awesome this discovery is.

It is telling us that time and distance is an illusion and that matter and energy are really two different forms of the same thing. Now, we are talking quantum physics.

So,when it comes to quantum physics, the fabric of the atom is actually influencing or communicating with another atom billions of miles away in some other part of the Universe and in another time.

In affect, photons are not really here nor there. - They are flashing in and out of existence as a constant vibrating entity! - Just like human thought.

However, this is the only constant that we humans can perceivably measure, which is E = MC2.

Now, boil a pot of hot water, poor into a cup and add tea... Then, ponder this truth for a while.

Answer 3

It is not very difficult. The earlier method was to deduct speed of light by observing the movement of distant planets and use of simple trigonometry. Now accurate speed of light is measured by Piezzo wheels. In this, the light beam is paased through a pair of teethed wheels running at high speed in counter mode and close to each other (similar to geared wheels). The wheels are then gradually accelerated to a high speed. Initially the light beam can pass through the gap between pair of teethed wheels. At a particularly high speed, the light rays will not able to pass through, and the light speed is calculated, which is around 186, 000 miles/second or 300,000 kilometers/second.

Answer 4

because at nearly 300 thousand kilometers per second, it much faster than any of our standard measuring equipment can handle.
There for we have to figure out clever ways to measure it that dont involve stop watches.
The earliest measurements of the speed of light were done by measuring shadows of the earth on the moon, and on the moons of jupiter. Much more accurate measurements have been developed since then.

Answer 5

Since, so far as we know, the speed of light is the only 'constant' in our universe, there is nothing else to measure it against. (Time is not a constant) However, scientists have measured the speed of light, but I don't remember how - you'd have to look it up in a science or physics book.

Answer 6

Measuring the speed of light is not difficult. In fact it is a well known figure: approximately 186,000 miles per second.

Answer 7

The speed of light has been measured many times. Look up the Michelson-Morley experiment of 1887 on Google and see some great websites with videos you can view and interferometry experiments you can do to measure "c".

Answer 8

you cant measure the speed of light because its the fastest thing ever it takes 8 minutes for light to reach the earth but it takes years for a satellite to reach the sun.

Answer 9

because it goes too fast, most measuring devices we have are too slow,