Testing whether gravity bends light

In summary: If the distance appeared to change, it would support Einstein's theory that light bends when near the sun. This concept can be demonstrated through the use of eclipse observations, where the apparent positions of stars change when their light passes near the sun.
  • #1
Drops of Fire
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The experiment Einstein proposed that supposedly proved successful kind of confuses me. If you can prove a beam of light bends when near the sun, how can we prove that from Earth with a picture because by the time we're able to see it to take a picture, the light has already gone passed the sun and reached Earth and any effect it would've had on it would be gone by then. At that point, all the light would appear to be bent everywhere about the about the same despite whether or not some of it passed the sun to get here, right?
 
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  • #2
The trick is that as the light passes the Sun and bends it leaves the Sun's vicinity along a different line than what it came from. when that light reaches us, we see the object that produced the light in a different position than we would have if the Sun had not bent it's path. By comparing the apparent positions of stars next to the Sun during an eclipse as compared to their normal relative positions, we can tell if they seem to shift position when their light skims the Sun on the way to us.

Here's an image that illustrates this:

http://astrobob.areavoices.com/astrobob/images/1919_light_bending_Jose_Wudka_1.jpg
 
  • #3
In a nutshell, the idea was to observe the (apparent) distance between two stars when the light from each passed close to the sun and when it didn't.
 

1. How does gravity bend light?

Gravity is a force of attraction between two objects with mass. The more massive an object is, the more it bends the space around it. When light passes near a massive object, such as a star, its path is curved due to the bending of space by the object's gravity.

2. Why is testing the bending of light by gravity important?

Testing the bending of light by gravity allows us to confirm one of the predictions of Einstein's theory of general relativity. It also helps us understand the behavior of light in the presence of massive objects and can provide evidence for the existence of black holes.

3. How is the bending of light by gravity measured?

The bending of light by gravity is measured through a phenomenon known as gravitational lensing. This occurs when the light from a distant object is bent and magnified by a massive object, creating multiple images of the same object. By observing and measuring the positions and brightness of these images, scientists can determine the amount of bending that occurred.

4. What experiments have been done to test the bending of light by gravity?

One of the most famous experiments to test the bending of light by gravity was conducted during a solar eclipse in 1919. Astronomers observed the positions of stars near the edge of the sun and found that they appeared slightly shifted, confirming the prediction of general relativity. More recently, space-based telescopes and advanced imaging techniques have also been used to study gravitational lensing.

5. What are the current theories and speculations about the bending of light by gravity?

While Einstein's theory of general relativity has been confirmed by many experiments, some scientists are still exploring alternative theories that could potentially explain the bending of light by gravity in a different way. There are also ongoing studies and speculations about the possibility of using gravitational lensing as a tool for observing and studying distant objects in the universe.

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