Why is the speed of light 299792458 meters per second instead of 300 million meters per second?

Although 300 million meters is about the same as 299792458 meters, the speed of light is not only a velocity constant, because it needs to participate in certain calculations under the human theoretical science system, and is also used to specify the international unit of length, and it is not possible to take an approximate value at will.

The value of the speed of light was once a topic of curiosity for scientists, and they proposed some ingenious measurement methods, which measured the speed of light quite accurately, and the value became more and more accurate as the measurement means changed, but it was basically around 299792458 meters per second. In modern times, the speed of light has become a definition due to the advent of the relativistic view of space-time, which is calculated to be (299792500 100) meter seconds.

Many existing scientific theories use the speed of light, and the unification of the standard of length units in daily life also uses the speed of light as the basis for measurement, which has been defined as the distance traveled by light in 1 299792458 seconds since October 21, 1983. The speed of light is no longer just a numerical value, and the more accurate nature is, the more conducive it is to human estimation and measurement, as well as the unity of units.

The value of the speed of light is determined based on human measurements and the development of human theory science, and it is not just a random approximation, although in daily life we can say that the speed of light is close to 299792458 meters, you can say that it is about 299792460 meters, you can also say that it is close to 2998000000 meters, of course, you can also say that the more is equal to 300,000 kilometers per second, which is no problem. However, when participating in the calculation, due to the strong subjectivity of human beings, everyone takes a divisor at will, and the results obtained by the same formula may also be very different, in this case, the speed of light must be a more specific and uniform value, which needs to be specified with the most accurate measurement data.

This is the case now, so the value of the speed of light is still used, and the more accurate the calculation, the more this is the case, but when learning more elementary scientific knowledge, the approximate value is often taken to facilitate the calculation.

Because this is a matter of accuracy, since it can be accurate to 100 million bits, there is no need to round it.

If the accuracy in scientific research is not in the single digits, the resulting calculation errors are likely to lead to disasters, such as the Mars Explorer being disintegrated due to calculation errors.

Because the speed of light is fixed, and it is the ultimate speed in the universe, and it is not allowed to round up, the speed of light is 299792458 meters per second, not 300 million meters per second.

The speed of light is not rounded to 300 million meters per second, which is very fast. According to existing theories, the propagation speed of light in a vacuum is the fastest local velocity in the universe, with a value of 299,792,458 m/s. The speed of light in a vacuum is an artificially defined number followed by zero.

Its value was only really calculated decades ago, and the data obtained by measuring the rollback is only an approximation and is not entirely accurate, because the speed of light is inherently uncertain and cannot be completely accurate. According to Albert Einstein, the world's fastest object will not be faster than the speed of light. But how fast is the light?

That's about 300 million meters per second. Is that the Annihilation of the World real? Numerically, that's about 299,979,2458 meters of seconds, or 300 million meters of seconds.

Readers of IT House may be familiar with a method called"Light years"A unit of length, it means the distance traveled at the speed of light in a year, expressed in numbers as approximately.

And this is an absolutely accurate value, and the decimal point is not rounded; The speed of light in a vacuum is constant, but the value of the speed of light in a vacuum varies with length and units of time. For example, in general calculations, we sometimes take the speed of light as 300,000 kilometers per second, which is more conducive to the calculation process, but the results are incorrect. Since 1983, the definition of a meter is determined by the speed of light, and 1 meter is defined as the reality of light.

However, the speed of light is not only a speed constant, but also used to specify the international unit of length because it needs to participate in some operations in the theoretical scientific system of human beings. For ease of communication, we usually say that the speed of light is 300 million meters or 300,000 kilometers and seconds, which is just a rough approximation and is rounded.

In practical calculations, with this rough approximation, nothing can exceed the speed of light. We now know that the speed of light is about 300,000 kilometers per second. What is this concept?

Remember, the diameter of the Earth is 12,756 kilometers, and the circumference is almost 40,000 kilometers. Einstein's special theory of relativity states that the speed of light is about 300 million meters per second. We all know that the speed of light is 299,792,458 meters per second, but why does it have this value and not other numbers?

Why do we have such a question.

How do you explain this?

Meaningless, and you're obsessive-compulsive.

This is also to blame when Paris ordered the international unit, and there was no technology to measure the speed of light.

By the time scientists were able to measure the speed of light, and wanted to change the 299792458 to an integer to remember, SI units had been used for decades, and it was impossible to redefine the length unit of the meter for an unimportant speed of light???

You think it's easy to redefine units of length? If the 299792458 meter is changed to 3000000000 meters, then the length of the meter will be updated, which means that the new meter will be a few centimeters shorter than the old meter (almost too lazy to calculate), it will not cause trouble for ordinary people, then it will hurt the muscles and bones for the industry, and there are too many examples of losses brought to the factory by the conversion of the imperial system and the metric system.

The result of the new metric system would be as extinct as Esperanto. 299792458 can never become 300000000!

Meters are a human expression, there will be big problems, this number is a definition, it is so long, it is a fixed value, you can call it 1 meter, 300,000 meters is fine. But other values defined by the speed of light are troublesome, such as your ruler, which has to be re-engraved, and all engineering drawings have to be re-marked, which is troublesome.

It doesn't matter what this number is when we are far from reaching it, but we just did it early to make it easier to calculate. It would be nice to know the principle. It's like there are many scientists who say how a star is tens of billions of light-years away from Earth.

I'll go back and refute this. Because these are values that we can't reach no matter how hard we try at the moment. So there's no point in comparing it.

Absolutely, but one problem is that the world has to shrink by 1 meter, and the physical export related to length will be affected. The impact is too great.

For light, the unit of meter is meaningless, you can use meters to measure light seconds, you can also use zhang, feet to measure, light and land oak balance does not care, there is no need to make a whole, even if it is 29999999 meters and seconds, because we want to defend the integrity of science, if you want to die so casually, it will not be scientific.

Who measured such a precise speed.

Come on, you can make one!

I'd like to make it an integer, but historically, the definition of the meter-kilogram-second isn't good enough, and it's not neat enough when it comes to the speed of light. The original definition of meters was that the longitude of the Earth was 40,000 kilometers. One second is a pendulum of one meter, and the period of a pendulum of one second is two seconds.

One kilogram is 4 degrees of water in one cubic decimeter. But it's not the same when it comes to the speed of light. It's a little tricky.

For light, the speed of light is the wavelength multiplied by the frequency Currently, the speed of light waves is considered to be more objective and stable, the frequency is determined by the light source, while the wavelength is subordinate, wavelength = speed of wave.

<> currently consider the wavelength of light (a single wavelength, the length between two adjacent peaks) to be a natural unit, one lightsecond, one light-year, and also a unit of length. This relates to a fundamental question of modern physics: distance (length, displacement), time, speed, who is more stable and who is more trustworthy?

Who decides others and who is decided?

In 1972, scientists based on the basic units of the time"m"with"seconds", the measured speed of light is 299792458 meter seconds. At the time, this was an approximate value. In 1975, the International Conference on Weights and Measures set the exact value of the speed of light at 299792458 meter second, which became the definite value of the speed of light.

On the basis of the accurate value of the speed of light, the 1983 Metrology Congress defined this value as the standard value of the speed of light, and used the value of the speed of light to redefine the meter"Rice primitive"Replaces the standard definition of the metre, specifying that the distance traveled by light in a vacuum in 1 299792458 seconds is 1 metre.

This is also related to the primitiveness of the meter"Rice primitive"The definition is consistent, and it's very close. So no matter how you update or correct your measurement of the speed of light now, it won't affect the number of light, because it's already written as a specified number, but it does affect meters. Taken together, this string of numbers is hard-won and has profound implications for physics and other fields.

This number is the best answer in history.

The speed of light is a physical concept, and human research on light has not yet reached a very transparent level. So this is the speed of light that can be accurately measured at the moment.

The reason why the value of the speed of light cannot be taken as an integer is because there should be a rigorous attitude in the face of science, so it cannot be taken as an integer.

Because if there are zeros and rounds, this speed can be made more accurate, which can be conducive to scientific research and can discover the mysteries of the universe.

299792 km = km 10,000 km;

Answer: The number of decimal places reserved for the cavity ridge sail is about 10,000 kilometers

Therefore, the answer to the Wu hail case is a wild shooting:

Analysis: First of all, rewrite this number into a number with "10,000 and shout" as a unit, keep two decimal places, shout the code accurate to the percentile, and then round the number on the thousandth place 299792 10,000 Zheng Sha; So the answer is: Reviews:

This question mainly examines the rewriting and approximation of integers, and it is important to note that counting units should be used when rewriting and approximating numbers