How to measure the distance between the Earth and the Moon 10

Scientists have been measuring the moon since the Apollo lunar spacecraft took to space. So far, Einstein's theory of gravity and equivalence have been shown to hold true at a precision of 10 to the minus 13th power. But this is still not enough to rule out various theories that try to overturn Einstein's theory of relativity.

At present, the error of measuring the distance between the Earth and the Moon (about 10,000 kilometers) with a laser is only about 17 centimeters. This fall, a new device, funded by NASA and the American Academy of Sciences, will improve the accuracy of this measurement by a factor of 10 to reach a margin of error of just 1 to 2 millimeters. This improvement means that scientists will be able to detect possible flaws in Einstein's theory of gravity on a scale 10 times finer than current levels.

On this scale, it may be enough to find the first evidence that the theory of relativity is flawed.

The new device used by scientists to measure the distance between the Earth and the Moon is called the "Apache Lunar Laser Surveyor" (Appollo, the same name as "Apollo"). In order to achieve the desired accuracy, the timing of laser pulses between the Earth and the Moon must be accurate to the level of a few picoseconds (one picosecond equals one tenbillionth of a second). Since the speed of light is known, the precise distance between the two points can be obtained by measuring the time it takes for a laser pulse to travel between the Earth and the Moon (between the Apache Lunar Laser and the reflective array placed on the surface of the Moon, to be precise).

Physicists have expressed their eagerness for the upcoming solar system version of the "Leaning Tower of Pisa" experiment. For years, scientists have struggled with the incongruity between general relativity and quantum mechanics. One of these two theories is to describe the macrocosm and the other is to describe the microcosm.

They are all extremely outstanding in their respective fields and have proven to be successful time and time again, but there are major differences between them, as if they are describing the universe in different languages and in fundamentally different ways.

Now some scientists hope that by revealing a flaw in the basis of relativity, it may lead to some kind of new "theory of everything", and finally combine the theory of quantum mechanics and gravity into a coherent theoretical system.

The Moon is only 10,000 kilometers away from the Earth when it is closest to the Earth, and the Moon can reach 10,000 kilometers when it is farthest from the Earth. What we are familiar with is the average distance, about 385,000 kilometers. The distance between the Earth and the Moon can be said to be quite large compared to the size of the Earth and the Moon itself.

Therefore, measuring the distance between the Earth and the Moon is actually a very difficult thing to do. Aside from theoretical calculations, how do we know the distance between the Earth and the Moon? If a measurement method is used, what are the specific methods?

Today, let's talk about that.

The astronomical community is a very common problem in the astronomical community, and there are various methods of ranging and ranging.

For example: triangulation, spectroscopy, laser ranging. You must know that measuring the distance between the earth and the moon is not something that only us modern people can do, but the ancients can do. So I'll first introduce the measurement methods of the ancients.

There was an ancient Greek astronomer named Eva Valley, who invented many sophisticated observation instruments. To measure the Earth-Moon distance, he assumed that sunlight was parallel light. Then observations were made in Turkey and Alexandria by total solar eclipse observation in two different places, Turkey and Alexandria.

What was seen in Turkey was a total solar eclipse, and when you arrived in Alexandria, a solar eclipse was observed, in which the moon obscured four-fifths of the sun's area. This makes it possible to calculate the time difference of the moon. Time difference refers to two different observation points far away from the target, observing the difference in the direction of this target, and the two observation points and the target form an angle, the difference angle.

If there is a time difference, a similar triangle can be made, and the distance between the Earth and the Moon can be calculated to be 370,000 kilometers using plane geometry, which can be said to be relatively close to the value we have measured now.

If we measure distances in our daily lives, there will generally be rulers. But can we find such a long ruler in **? Even with such a long ruler, we can't measure it with this ruler.

Is there nothing that can replace a ruler and a rangefinder tool that we hold in our hands? The answer is with lasers. Obviously, a laser can be used to go back and forth, and then the distance between the Earth and the Moon can be obtained by time * speed of light = distance.

But this also requires a mirror or receiving device on the moon. In fact, scientists do. Here's how it works.

At that time, when the United States and the Soviet Union were vying for supremacy, an arms race was held, in which space technology was competed. Both sides are competing to see who will land on the moon first. Later, Armstrong's "Apollo 11" landed on the moon, which was the first manned lunar landing technology for mankind.

It can be judged by the time it takes for light to arrive, multiplied by the speed of light.

The distance between the Earth and the Moon is measured by satellites launched into the universe by humans, and it is only at the end that the difference between the two is determined.

The distance between the Earth and the Moon is measured with a laser, and this is also a new technology developed in the sixties of this century.

The average distance between the Earth and the Moon is 384,400 kilometers.

If a person were to move kilometers per second at the speed of light, it would only take about a second or so to get from the Earth to the Moon. After research, the Moon is leaving the Earth at a distance of four centimeters per year. The distance between the Moon and the Earth's perigee is 10,000 kilometers; The farthest apogee distance from Earth is 10,000 kilometers.

Moon distance is an astronomical unit of length that is generally used to measure the distance between celestial bodies in space.

The lunar distance refers to the average distance between the Moon and the Earth as about 60 re), and the angle of intersection between the orbital plane of the Moon around the Earth and the equatorial plane of the Earth is 5. It is a unit of length in astronomy. The average distance from the Earth to the Moon is about 10 times the circumference of the Earth's equator.

The diameter of the Moon is 3476 km, which is about 3 11 of the diameter of the Earth. The surface area of the Moon is about 1 14 of the Earth's surface area, which is slightly smaller than the area of Asia. The volume of the Moon is only 1 49 of the volume of the Earth. The mass of the Moon is approximately equal to 1 of the mass of the Earth.

The earliest ancient people to measure the distance between the moon and the moon were through visual observation, and the first person to measure the distance between the moon and the earth was Ibargu, who was born around 180 BC in Asia Minor, which is now Turkey.

In fact, in modern times, it is not difficult to measure the distance from the earth to the moon, and there are many waysOne method is to emit electromagnetic waves to the moon, the second is the trigonometric parallax method, and another method is to measure the distance between the moon and the earth, which is to use the phenomenon of solar eclipses. Although it is not 100% accurate, the basic deviation is not large.

The principle of the method of measuring the distance between the earth and the moon with electromagnetic waves is as follows: first, electromagnetic waves are emitted from the earth to the moon, and then the electromagnetic waves reflected from the moon are received from them, and we know that the speed of electromagnetic waves is also the speed of light. This value is known to us, so we can easily calculate the distance from the Earth to the Moon. <>

The method of measuring the distance between the earth and the moon with trigonometric parallax is actually to connect three points to form a triangle, and we can choose the moon, the center of the earth, and a certain point on the earth to construct this triangle, because we know that the radius of the earth has been measured by modern science and technology. We construct an alpha angle ratio between the moon, the center of the earth, and a certain point of the earth. Then we can calculate the actual distance from the Earth to the Moon by solving the trigonometric function, but in order to get a more accurate value, we can select a few more points on the Earth to measure the distance between the Earth and the Moon, and then take the average to get a more accurate distance from the Moon to the Earth.

Another method is to use the solar eclipse phenomenon to measure the distance between the earth and the moon, when the eclipse occurs, the moon is just in the middle of the earth and the sun, and a straight line will be formed between the sun, the earth and the moon, at this time we can use some theories about the shadow of the object to calculate the distance between the moon and the earth, so that the distance between the moon and the earth can be calculated.

Nowadays, the world's scientific and technological level is already very developed, and some things that we didn't dare to imagine and understand before can be realized with today's technology. That's all for today's article, if you have any ideas, you can comment below and communicate together. <>

Of course, it is measured by the speed of light, calculated by the time it takes to arrive at the speed of light. Of course, it was very accurate. So we have to believe in science.

The exact distance is measured by corner reflectors, which have been brought by the American Apollo, the Soviet Lunar Series Lunar Rover, and Chang'e 3. The principle is the same as the red corner reflector on the back of the bicycle, which reflects the light parallel to each other. This is done by shining a laser light on these reflectors and then receiving a return light, measuring the time multiplied by the speed of light divided by two.

The measured distance is certainly not 100% accurate, but only an approximate distance.

The distance from the Earth to the Moon is measured using trigonometry, which measures the distance from the Moon to the Earth at the spring and autumn equinoxes, respectively. Then, with the radius of the public orbit as the baseline, this method is studied by scientists and is infinitely close to the correct one.

The distance between the Earth and the Moon is measured by sending a laser. Of course, it's accurate, because the products made by scientists are still very useful.

One of the methods I know is the principle of aperture imaging, which uses the knowledge of physics and mathematics to know the diameter of the moon, the diameter of the image, the distance between the aperture and the light screen, and the distance between the aperture and the light screen.

This distance is measured using a laser ranging device, and the measured data is quite accurate, and the deviation is not particularly large.

The current method is to use the emitted laser to carry out electronic ranging, and the effect is very significant and fast. I think it's very accurate.

1. Laser ranging is now used. After the Apollo moon landing, a total reflecting prism was installed on the moon, and ground-based observatories used lasers to measure the round-trip time (equivalent) and calculate the distance between the two.

2. The method of ultrasonic waves can also be used to send ultrasonic waves from the earth to the moon, and the ultrasonic waves will rebound and return to the earth after reaching the moon.

Let the distance between the moon and the earth be s, the speed of the ultrasonic wave is v, and the round-trip time is t, because the ultrasonic wave has traveled a round trip, so the distance traveled by the ultrasonic wave is 2s, so 2s=vt, so we get s=vt 2

Measuring the distance between the Earth and the Moon with a laser is a new technology developed in the sixties of this century. Its principle is: through the telescope, a pulse laser beam is emitted to the moon from the ground observation station (station), and then the laser echo reflected back from the surface of the moon is received, and the timer on the ground records the time of the laser round trip, from which astronomers can calculate the distance between the earth and the moon.

For more than two decades, the technology has been evolving. In order to improve the accuracy of ranging, the astronauts first placed five backward reflector devices on the moon, and the observation equipment on the ground was constantly improved. At present, the ranging accuracy has reached the level where the error does not exceed eight centimeters.

- A new U.S. optical probe at the White Sands spaceport can measure the distance of the Moon from Earth more than 10 times more accurately than previous measurement equipment. The test will launch a laser from Earth onto a specular reflector mounted on the surface of the Moon, and the distance between the Moon and the Earth can be calculated by recording the time of the emitted and reflected lasers. It is understood that in this experiment, scientists can make the calculation of time accurate to one trillionth of a second.

In addition to this, scientists carefully consider the effects of the atmosphere and the Earth's motion on the reflection distance of the laser. It is said that the error of this measurement will be in the range of two millimeters.

The basic idea of calculating the distance of a celestial body according to the law of gravitation is: according to the motion of the planet (or satellite), the centripetal force of the planet (or satellite) is calculated, and the f direction = f gravitational force. According to this series of equations.

For example, if the mass of the Earth is known, the period of the Moon's orbit around the Earth is 30 days, find the distance from the Moon to the Earth's center of the sphere.

The centripetal force of the Moon orbiting the Earth, i.e., the gravitational force between the Moon and the Earth, is:

f direction = f lead = gm m month r 2 = m month (2 t) 2*r

r3=mgt 2 4 2=

r=4×10^8m,2,

The Earth-Moon distances are as follows:

The distance between the earth and the moon is 384,000 kilometers, when humans first landed on the moon, it took 75 hours and 50 minutes to fly from the earth to the moon, and Chang'e-1 flew for 13 days and 18 hours, because the rocket did not go straight to the moon, but had to fly around the earth first, adjust the orbit parameters, and then fly to the moon.

The distance between the Moon and the Earth's perigee is 10,000 kilometers, and the distance from the Earth's apogee is 10,000 kilometers. The moon is the closest planet to the earth, usually the moon is about 400,000 kilometers away from the earth, because the moon around the earth is an elliptical orbit with an axis as the mainstay, therefore, the moon is farthest from the earth than the nearest 50,000 kilometers more than the nearest silver banquet.

Earth-Moon distance: On July 30, 1969, the Earth's California to the lunar surface lunar longitude:; Lunar Latitude:

The distance of this place is: meters. Thanks to laser technology and mirrors on the surface of the moon, the accuracy of human measurement of the distance from the Earth to the Moon has suddenly increased to 15 centimeters.

On August 30, 1969, after a lapse of one month, humans measured it again and got the value: meters. As a result, mankind discovered that the sharp orbit of the moon around the earth is not an exact circle, but an ellipse sometimes close to the earth and sometimes far from the earth.

On December 30, 1969, the Earth's distance from the Moon: meters. After many and continuous measurements, the same data commonly used in today's textbooks has been obtained: the average distance from the Earth to the Moon is about 10,000 kilometers.