Can the position of the North Star tell if the Earth is a sphere?

Yes, if the ground is flat, anyone should be able to see it at the same height angle. But the truth is not at all, people at different latitudes see the North Star at different heights, so the earth must not be flat.

Furthermore, if we measure the distance between two people on Earth and the difference in the altitude of the North Star they see, we can also use geometry to calculate the radius of the Earth.

No. Upstairs, the star trajectory around the North Star is round.

Polaris is approximately a point with no trajectory.

I can't judge.

The judgment that can be made is:

The North Star is on the extension of the Earth's axis of rotation.

Even if the earth is not round, this is what you see when you turn it.

What is the evidence that the Earth is a sphere?

I see the hill of the land from the ship returning home. Prove with a Foucault pendulum. Proven by the phenomenon of lunar eclipses. The altitude of the North Star varies at different latitudes in the Northern Hemisphere. Magellan circumnavigated the globe. The best evidence is satellite**.

If you point a professional camera at the sky where Polaris appears and take a year-long night of non-stop shooting, you can see that Polaris' trajectory is round. The ancients discovered this through precise calculations, patient observation, and homemade instruments.

Downstairs is right. Let me ask here, what if it was filmed in a different region? Can different regions at the same time be judged by the change in the position of the North Star?

Yes, the phenomenon will be different on other planets.

The North Star is only visible at night in various parts of the Northern Hemisphere, but not in the Southern Hemisphere. In addition, when observing the North Star in the Northern Hemisphere, the angle between the observation line of sight and the ground should be exactly equal to the local latitude.

The Southern Hemisphere is definitely not visible, in fact only the middle and high latitudes of the Northern Hemisphere can be seen, but the air pollution is so bad that the stars are not visible!

It depends on where you are looking at it from on the earth. On earth, look at the heavens from south to north. Northern Hemisphere.

The stars are from east to west. It's counterclockwise.

For example, if you stand in Zhejiang, you will turn counterclockwise. Because most of the stars still seem to rise in the east and set in the west. But when observing the starry sky on Earth, it is counterclockwise and clockwise.

It's also relative. It's like if you look at the sun with your head facing south, it moves clockwise throughout the day. If your head is facing north, you will feel that the sun is moving counterclockwise. In the Northern Hemisphere, the starry sky seems to surround the North Star.

Revolve. And in the Southern Hemisphere, the stars seem to revolve around the southern celestial pole.

Located in the constellation Ursa Minor, about 430 light-years from Earth, Polaris is the brightest and most stable star visible in the night sky. Due to Polaris' closest position to due north, people on Earth have relied on its starlight to navigate for thousands of years.

Polaris is a bright star in the north of the earth, very close to the north pole of the earth, almost facing the earth's axis, from the earth, its position is almost unchanged, you can rely on the car to discern the direction. Due to precession, Polaris is not a permanent star, it is now the constellation Ursa Minor, and by 14,000 A.D. it will be Vega.

The position of the North Celestial Pole is relative to us on the road, and the North Star is understood to be a bright star around the North Celestial Pole. Therefore, the North Star gives the impression that it has never moved its position. But as I just said, Polaris is a star around the North Celestial Pole, and the sound of the strings is changed to Polaris is not fixed and does not move to one star, but alternates.

The reason for this is due to the world's nucleus aging, that is, the axis of rotation rotating around the yellow axis (the yellow axis is an illusion axis of perpendicular bisecting the ecliptic plane).

Even if the axis of rotation is changing, then the North Star needs to follow suit. The earth revolves through the sun and rotates at a constant speed, which is closely around an imaginary axis that cannot be seen across the center of the earth, that is, it rotates like a ball pierced by chopsticks, and the two sides of this invisible axis are called the north and south poles. The vast cosmic space encompasses the earth, and the starry sky on the earth is like a ball, and people call this sky inlaid with stars the celestial sphere, which accompanies the rotation of the earth.

The celestial sphere seems to revolve around the earth, so the daily stars seem to rise and set in the west, like daylight. Then one should have a definition, the earth is rotating at a uniform speed, and the celestial sphere of relativity looks like it revolves around the earth, but what about the two sides of the earth? Isn't the extension line of the two poles that deviates from the axis of the heavenly sphere also the axis of the celestial sphere, and how the earth turns another axis seems to be unchanged, so the star that is biased does not seem to move.

In that case, it is impossible to have a star in the sky, which seems to be biased by the axis of rotation, and all the planets in this circular net are qualified to be the North Star, so the North Star does not refer to a single star, but the stars in this circular net take turns to govern. Because the stars are not densely packed on the circular net here, it is very likely that a star will be on duty for many years, or even thousands of years, and with the precession of the earth's axis every year, the polaris that is biased will also be offsetTherefore, it is not easy to be very precise in the air of the axis of rotation, but "basically pointing".

It is impossible to remain motionless, because after all, the earth still revolves around the sun, and the sun still revolves around the center of the Milky Way, but the crux of the problem is not here (because the distance caused by the revolution of the earth is very small and negligible, and the cycle of the sun's revolution is more than 200 million years, and the time is too long to be considered).

I think of course it's movement, because the position of the North Star is different from what is observed throughout the year.

It is impossible to remain motionless, because after all, the Earth still revolves around the Sun, and the Sun revolves around the center of the Milky Way, but the crux of the matter is not here (because the distance change caused by the Earth's revolution is negligible, and the Sun's orbit cycle is more than 200 million years, which is too long to consider).

Therefore, the immediate answer to this question is that the position of the North Star is near the North Celestial Pole, and the North Celestial Pole is an artificially prescribed point.

Because of the rotation of the earth, it can be assumed that the Earth's axis of rotation can be extended indefinitely, and the North Celestial Pole is a fixed point at infinity where the axis of rotation that extends infinitely from the side of the Northern Hemisphere).

Because the position of the North Celestial Pole is fixed relative to humans on the ground, the definition of the North Star is a bright star near the North Celestial Pole. So Polaris feels like it's just not moving.

But as I said earlier, Polaris is a star near the North Celestial Pole, which means that Polaris is not fixed to a star, but is replaced.

The reason is due to the precession of the earth, that is, the axis of rotation is rotating around the yellow axis (the yellow axis is an imaginary axis perpendicular to the ecliptic plane), since the direction of the axis of rotation is changing high, then the North Star will naturally change with it.

The current North Star is called Gou Chenyi, and about 12,000 years from now, the new North Star will be Vega.

Looking forward to your comments and attention!

The North Star is in motion. It's too far away.

Currently, the Earth's axis of rotation passes through the North Star.

Through the North Star.

The direction that can be determined is due north. Polaris is also known as Violet.

Hook Chen. 1. The constellation Ursa Minor, located at the northern end of the Earth's axis, is the star closest to the North Celestial Pole. Polaris is a bright star in the northern core of the sky, almost facing the Earth's axis, and its position is almost unchanged from the northern hemisphere of the Earth, and it can be relied on to discern the direction.

The principle of the North Star pointing north

Because the Earth rotates around the Earth's axis, and Polaris is very close to the northern extension of the Earth's axis, the North Star in the sky at night is almost motionless and is northerly overhead, so it can indicate the north. As the earth revolves around the sun.

The direction of the Earth's axis tilt also changes, but Polaris is much farther away from Earth than it is orbiting.

radius, so the change in the Earth's axis caused by the Earth's revolution is negligible.

Due to the rotation of the Earth, and Polaris is exactly on the axis of rotation of the celestial sphere, it is stationary relative to other stars. But Polaris is not exactly in the positive position of the North Celestial Pole, in fact it rotates at a very slow pace, and it just doesn't seem to change compared to other stars.

The Earth rotates around its axis of rotation, one end of which is defined as the geographic North Pole and the other end as the South Pole. Polaris is located very close to the extension of the Earth's axis of rotation, so no matter how the Earth rotates, Polaris will not rise and set, but will rotate near the North Celestial Pole.

Since ancient times, people have been curious about the sky, and people have been exploring the mysteries of the sky. The most important way for the ancients to observe the sky was to observe the stars in the sky, and they also summed up a lot of useful experiences based on their own life reality, such as relying on the North Star to judge the direction is very practical.

I believe everyone must know the existence of the North Star, no matter where we are, the North Star will always point to the north, which can also help us quickly figure out the direction. If we look closely at the starry sky, we can see that all the stars in the sky are moving slowly, so their corresponding directions are constantly changing, but the North Star is an exception. Polaris is like the center of the sky, and the other stars revolve around it, but it doesn't change itself, so it can show people the way.

As for why this phenomenon occurs, in fact, it is also related to the self-esteem of the earth, we all know that the earth is rotating all the time, so the angle at which we observe the starry sky is constantly changing, because we can't feel the rotation of the earth, so in our opinion, it is the starry sky that is rotating. The reason why the North Bright Pole does not rotate is because it is on the extension of the Earth's axis of rotation, so no matter how the Earth rotates, it seems to us that it is due north of us, so it can also play a role in indicating the direction of the object.

But what many people don't know is that Polaris is not immutable, because Polaris is actually the star on the extension of the Earth's axis of rotation, and the Milky Way.

It's also rotating, so it's going to change people too. The North Star we see now is Hook into One, and Zhuge Liang.

At that time, I saw the Arctic Five, isn't it amazing?