How do you know the earth is moving?

Question

could you conduct an experiment to find out if the earth is moving, obviously you can't just look in a book and know the earth is moving.

thank you

Answer 1

I would say that the sun rising and setting should be enough. Use a time lapse camera to capture the images.

Answer 2

There are two classical 'experiments'.

1) If the Earth were totally immobile, then its surface would provide us with an inertial reference in two dimensions. Meaning: No object would accelerate (or decelerate or change direction) unless you could see a force acting on it.
Of course, this is not true in 3 dimensions because things tend to fall downwards even if you carefully place them in front of your eyes and don't push them downward.

Large air masses should move from high pressure to low pressure centres. However, as they move, they appears to be deflected tot he right (in northern hemisphere) even though no force is acting on them in that direction. The effect is called the Coriolis force and is due to the fact that the Earth's surface is rotating below the air masses' trajectory.

2) When you point a telescope at a fixed star, in general the position of the star (relative to the 'grid' of coordinates) should not change. It is true that stars do have 'proper motion' but that is very small and takes many years to notice.

Yet, over a 6 month period, the telescope has to be pointed differently to keep track of the same star: the angle is not very big but it is measurable. The effect is called stellar aberration: The telescope has to 'lean' forward in the direction of Earth's movement around the sun. The tilt is 20" (= 1/3 of a minute = 1/180 of a degree).

Imagine rain on a windless day. The rain falls straight. However, if you run forward, you will have to tilt the umbrella forward to compensate for your speed (otherwise, your face runs into the rain). This is the same deal: light has a finite speed (even though it is very fast). The Earth is going around the sun so that we have to tilt the telescope forward by a very small amount to catch the light. 6 months later, the Earth is facing the other way, so the telescope has to tilt the other way.

This affects light from all stars. This is not the same as stellar parallax, where the closest stars appear to trace out a loop compared to the much further 'fixed' stars. The size of the loop depends on the size of our orbit and on the distance to the star. Stellar parallax is yet another proof of Earth's movement around the Sun.

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Day, night, seasons, etc. could be explained by having the Earth stand still and the rest of the universe move around. That was the theory used for over 1000 years (until the 16th and 17th century).

The Coriolis effect is difficut to detect without satellite photos of weather system. The aberration of light was difficult to detect before telescope were equipped with very precise mounts. Stellar parallax was difficult to observe before the advent of astro-photography.

Answer 3

Before Copernicus, scientists thought that the Earth was the center of the universe and all celestial bodies (moon, planets, stars) moved around the Earth. In this Earth-centered model, the earth doesn't move.

However we all know that this is wrong thanks to observations made by Copernicus. He found that planets, especially Mars, had "retrograde motions" where planets appeared to suddenly move in the opposite direction for a brief amount of time in the sky. If the Earth were indeed the center of the universe, these motions do not make sense. Ptolemy, in an effort to save the Earth-centered model and support the Catholic church, explained these odd movements by saying planets made "elliptical orbits", which are like corkscrew loops. Modern math has shown that the motion of celestial bodies is not consistent with this model, but is consistent with the helio-centered model .

Answer 4

Observe the contrail of a rocket during launch. What appears to be a curved trajectory is actually straight relative to the launch position. The illusion of a curve is due to the earth's rotation.

A Gyro is stable to a fixed point in space. If you were able to perpetuate it's spin it would rotate 360 degrees in the course of a day.

Answer 5

Day and night. The sun does not move the earth does!

Answer 6

When people make love is a way we know the earth is moving! =<)

Answer 7

We see night and day and the changing seasons. That seems to be a good indicator.

Answer 8

in the morning, put probably a flower pot under the sun and trace its shadow on the sidewalk (using chalk) do it at noon, and in the afternoon too,. goodluck!

Answer 9

You could look up at the sky and watch the sun, moon, or stars roll by.

Have fun. :-)

Answer 10

because it gets dark at night and light in the day. what do you think causes that?