Can light be slowed down by gravity?

Can light be slowed down by gravity?

Yes, light is affected by gravity, but not in its speed. General Relativity (our best guess as to how the Universe works) gives two effects of gravity on light. It can bend light (which includes effects such as gravitational lensing), and it can change the energy of light. The speed of light is still constant.

Does light interact with itself?

Since light itself does not have electric charge, one photon cannot directly interact with another photon. Instead, they just pass right through each other without being affected. In this process, the energy of the photon is completely transformed into the mass of the two particles.

How can light interact with matter?

As light is transmitted, it may pass straight through matter or it may be refracted or scattered by matter. Absorption of light occurs when light transfers its energy to matter rather than being reflected or transmitted by matter. The temperature of matter increases with the added energy.

Can sound waves travel through empty space?

Sound waves are travelling vibrations of particles in media such as air, water or metal. So it stands to reason that they cannot travel through empty space, where there are no atoms or molecules to vibrate.

Does a sound wave ever end?

Setting matter in motion like this obviously requires energy, which will inevitably become dissipated as the waves pass through the air and more solid materials. Eventually the motion ceases entirely and no more sound can be heard – producing silence.

Why can’t astronauts hear sounds from outside their spacesuits?

Sound does not travel at all in space. The vacuum of outer space has essentially zero air. Because sound is just vibrating air, space has no air to vibrate and therefore no sound. If you are sitting in a space ship and another space ship explodes, you would hear nothing.

Why can we not hear any sound on the moon?

The air here on Earth allows sound waves to move from one point to another (sound can also move through water, steel, earth, etc… it just requires that particles/atoms/molecules are touching one another). Thus there is no sound on the Moon.