# Where does a photon distort spacetime?

• foolish1
In summary, the conversation discusses the effects of a low energy photon on space-time and whether it would deform the whole region of the packet. It is noted that there is not yet a quantum theory of gravity, but there are classical theories that can be looked into. There are also references provided for further information on pp-wave spacetimes and gravitational waves.

#### foolish1

Lets say I have a very low energy photon moving through space and I want to visualize how space-time is effected by the motion of the photon thru space.

Photons are supposed to be quantized.. If it were possible to build a machine to measure the "gravitational" effect of a single photon would it follow the shape of the wave at each point as it traveled thru space? Would it deform the whole region of the packet? What would it look like if you drew it out?

We don't have a quantum theory of gravity yet. However, if you are willing to discuss classical pulses of light instead of photons then you should look into pp-wave spacetimes.

I would like to clarify that photons do not have a direct gravitational effect on spacetime. Rather, they are affected by the curvature of spacetime caused by massive objects. This is known as the curvature of light or gravitational lensing.

In the scenario described, the low energy photon would follow a straight path through spacetime, but the path itself would be curved due to the presence of massive objects. This is because mass causes spacetime to curve, and the photon follows the curvature of spacetime as it travels through it.

If a machine were built to measure the gravitational effect of a single photon, it would not follow the shape of the wave at each point as it travels through space. Instead, it would measure the curvature of spacetime caused by the photon's interaction with massive objects.

Drawing out this scenario would show a curved path of the photon, with the curvature becoming more pronounced as it approaches a massive object. This is because the gravitational effect of the massive object becomes stronger as the photon gets closer to it.

In summary, while photons themselves do not distort spacetime, they are affected by the curvature of spacetime caused by massive objects. This can be visualized as a curved path of the photon as it travels through space.

## 1. How does a photon distort spacetime?

A photon, being a massless particle, does not have a gravitational field of its own. However, according to Einstein's theory of general relativity, any object with mass or energy can cause spacetime to curve. This means that a photon can distort spacetime by passing through it, just like any other object with mass.

## 2. Does the distortion of spacetime by a photon have any measurable effects?

Yes, the distortion of spacetime by a photon can have measurable effects, such as gravitational lensing. This is when light from a distant object is bent by the distortion of spacetime caused by a massive object, such as a galaxy or a black hole. This effect can be observed through telescopes and has been used to discover new planets and galaxies.

## 3. Can a photon create a black hole by distorting spacetime?

No, a single photon cannot create a black hole. In order for a black hole to form, a large amount of mass or energy must be concentrated in a small enough space. A single photon does not have enough mass or energy to create a black hole.

## 4. How does the distortion of spacetime by a photon relate to the speed of light?

The speed of light is a fundamental constant in the universe, and it is also the maximum speed at which anything can travel. This means that even though a photon can distort spacetime, it will always travel at the speed of light. This is because the distortion of spacetime is a result of the photon's energy and not its speed.

## 5. Can the distortion of spacetime by a photon be reversed?

No, the distortion of spacetime by a photon cannot be reversed. Once a photon has passed through a region of spacetime, it will leave behind a permanent distortion. This is because spacetime is constantly changing and evolving, but the distortion caused by a photon will remain as a part of that evolution.