If you point a laser pointer at the moon, will there be a red dot?

Truth originates from reality and is nothing more than an abstract generalization of reality. Throw the pinball out, if there is an end, such as encountering a hard object, such as a tile, then it will come back to you; If you come across a soft object, such as a pool, it will definitely not reach your hand; If it encounters a lot of friction on the way when it is thrown out, and the energy consumption is so great that it is not able to go back and forth, then it will not be able to come back. If there is no end, then it will not come back.

The same goes for lasers, which shoot a continuous "pinball" (called photons by physicists), some of which go directly to your eye, so you see the laser line, but some of them hit the wall and then reach your eye, so you see a red dot. So how do you explain why the red dot doesn't appear when you point a laser pointer at the moon? Is it because there is no end?

No, the moon is an end. Is it because the moon is soft? This one is possible.

In fact, physicists believe that the main reason is that the road is too far away, the friction on the road is too large, that is, the ability is not enough, so they are gone. Of course, don't think that all lasers can't go back and forth to the moon, because lasers are still divided into high and low grades, laser pointers have low levels and low capabilities, while laser machines for space exploration have high levels and strong capabilities, and they can go back and forth.

There will be no red dot when the laser pointer is pointed at the moon, because the laser has no energy after such a long distance, so there will be no red dot on the moon.

Definitely not, because the laser is a straight line. Even if it is refracted to the moon, there will be no red spots. Light is emitted when it encounters air and does not gather in one place.

Definitely not, this is because the earth is far away from the moon, and the light radiation of the laser pointer cannot reach the moon at all, and it is blocked by other materials in the middle. The red dot is also not visible.

The light intensity of the laser pointer is too weak, on the other hand, the distance is too far, so the laser shot from the laser pointer spreads very well after a long distance, and basically the photons that can hit the moon in the end are very small.

There will be no red dot in this, and the transmission distance of the laser pointer is only a few kilometers, which cannot irradiate the moon.

First, the laser beam emitted by the laser pointer is not powerful enough, and it may be blocked and consumed in the atmosphere. Second, the laser beam emitted by the laser pointer will diverge and become a huge spot of light, and the reflected light is extremely weak.

In fact, someone has long tried to point a super-large laser pointer at the moon.

As early as 1962, both the United States and the Soviet Union began using lasers to measure Earth-Moon distances. And on July 21, 1969, the U.S. Apollo 11 put the first laser reflector array on the designated location on the moon. Relying on this 46-centimeter-square reflector, we finally made an accurate measurement of the distance between the Earth and the Moon.

There will be no red dots. To see the red dot of a laser on the moon, the laser needs to be large enough to see the red dot on Earth.

There will be no red dot when the laser pointer points at the moon, and the moon is so far away from us, and the laser pointer can't point that far.

No, the light of the laser pointer is too weak, and it diverges very much after long-distance propagation, so no, you can use a laser to measure the distance of the moon, but you need a special machine.

Probably not, because the range of the laser pointer is limited, it may not be seen from a few hundred meters away, and the moon is still specially selected from us, and there is no way to receive it at this distance.

No. Because the Moon is far away from us, when the light of the laser pointer reaches the Moon, its light has already been dispersed, and there is no oxygen in space, and the light travels very slowly, so the Moon cannot receive red dots.

If you shine a laser pointer on the moon, will there be a red dot on the moon?

To put it simply, the light intensity is too weak on the laser pointer. On the other hand, the distance between the moon and the earth is too far, so that the laser shot from the laser pointer spreads very well over a long distance, and basically the photons that can hit the moon in the end are very small.

In fact, not to mention that you use a laser pointer to do this experiment, even if you use a laser device with sufficient strength to shoot a beam of high-energy laser, the number of photons on a small area of the moon can be pitifully small, let alone reflect back to the earth from the moon, even a large-aperture telescope can accept not many photons. So why do lasers scatter? The reason is that our atmosphere has a lot of water vapor and dust, and these impurities will scatter light in the process of propagation.

Herein lies the problem, since we cannot change the state of the atmosphere itself, we have to find a way to do it ourselves, which includes several aspects: for example, the intensity of the laser, the aperture of the telescope used to receive the reflected photons. Another important thing is to make the photons on the surface of the moon return successfully, so it is impossible to directly reflect the surface of the moon without doing something, because it is basically impossible, so there must be a device to let the photons hit on the moon return along the same path.

The principle of this device is very simple, just like the mirror on the back of the bicycle, at night there are lights shining on it, the light will return along the same road, so that others know that there is a person riding a bicycle in front of them and will not crash into it, the same principle, launch a mirror like this to the surface of the moon, but the size should be larger.

Because we are too far away from the moon, we can't see it.

Because the Moon is too far away from the Earth to exceed the range of the laser pointer.

The distance is a bit far, and it also takes time for light to propagate

The moon is so far away from the earth, you can't see the bright spots.

The moon is so big, even if there are bright spots, you can't see it.

Because the moon comes out at night, the light is dark.

It's too far away to be seen if it's closer.

Because the moon is too far away to find an end.

It must be because of the distance.

It's so far away, how can you see it, it's impossible.