Search results
- Stars, galaxies, dust clouds, exoplanets: all of these emit or reflect or absorb light, creating signals that travel across space for incredible distances to be detected here on Earth. And those signals—that light—tell us the story of the universe.
Light causes gravity while travelling, a clear yes, by Einstein's famous mass-energy equvalence. (Compare this discussion on StackExchange.) The gravitational pull of light is negligible to other mass in large scale.
Jul 5, 2024 · Light is a way for the universe to literally touch you. The least we can do is use that light to learn as much as we can about it.
- The Four Fundamental Forces. Why does Earth stay in orbit around the Sun? How does light travel? What holds atoms and nuclei together? For centuries, scientists have sought to describe the forces that dictate interactions on the largest and smallest scales, from planets to particles.
- Gravitational Force. The most familiar force is gravity. It is responsible for keeping our feet on the ground and holding Earth in its orbit around the Sun.
- Electromagnetic Force. Our television sets are powered by electromagnetism. Light carries this force, which illuminates our houses at night, keeps electrons in orbit around atomic nuclei, and allows chemical compounds to form.
- Strong Nuclear Force. Nuclear forces affect our daily lives, but they work on distances smaller than atoms. The strong nuclear force, or strong force for short, holds together the building blocks of atoms.
- Theory of Light to the 19th Century: During the Scientific Revolution, scientists began moving away from Aristotelian scientific theories that had been seen as accepted canon for centuries.
- Double-Slit Experiment: By the early 19th century, scientists began to break with corpuscular theory. This was due in part to the fact that corpuscular theory failed to adequately explain the diffraction, interference and polarization of light, but was also because of various experiments that seemed to confirm the still-competing view that light behaved as a wave.
- Electromagnetism and Special Relativity: Prior to the 19th and 20th centuries, the speed of light had already been determined. The first recorded measurements were performed by Danish astronomer Ole Rømer, who demonstrated in 1676 using light measurements from Jupiter’s moon Io to show that light travels at a finite speed (rather than instantaneously).
- Einstein and the Photon: In 1905, Einstein also helped to resolve a great deal of confusion surrounding the behavior of electromagnetic radiation when he proposed that electrons are emitted from atoms when they absorb energy from light.
As the light from the universe’s most distant galaxies travels through space, it’s stretched by the expansion of space. By the time the light reaches Earth, that stretching process has transformed short wavelengths of visible and ultraviolet light into the longer wavelengths of infrared light.
Hubble works by gathering light from objects in our universe – some as close as our Moon, and some as distant as galaxy clusters that are billions of light-years away. All that light takes time to reach the telescope, just as it takes time for light to travel from its source to our eyes.
People also ask
How does light travel through space?
Why is light a way for the universe to touch you?
What happens if light travels through space?
Why is light important in space?
Does light cause gravity?
How do light signals tell us the story of the universe?
Feb 18, 2024 · The speed of light in a vacuum is approximately 299,792 kilometers per second or about 186,282 miles per second. This incredible velocity makes light one of the fastest phenomena in the universe. It allows light to traverse immense cosmic distances and reach us from distant stars and galaxies.
