- #1
adjacent
Gold Member
- 1,552
- 63
If there are so many galaxies in the universe,Why don't wee see a night sky with full of light(from the galaxies or stars)
adjacent said:If there are so many galaxies in the universe,Why don't wee see a night sky with full of light(from the galaxies or stars)
adjacent said:If there are so many galaxies in the universe,Why don't wee see a night sky with full of light(from the galaxies or stars)
Night sky Martinbnmartinbn said:During the day the number of galaxies doesn't change and we see the sky full of light.
Stars are massive, luminous spheres of plasma held together by their own gravity. They emit light and heat through nuclear fusion reactions. Galaxies are collections of stars, gas, dust, and dark matter held together by gravity. They come in various shapes and sizes, ranging from small dwarf galaxies to massive spiral and elliptical galaxies.
It is estimated that there are around 100 billion stars in our own Milky Way galaxy alone. However, the exact number of stars in the universe is still unknown. It is estimated that there are at least 2 trillion galaxies in the observable universe, each containing billions of stars.
Stars are formed from large clouds of gas and dust called nebulae. These clouds collapse under their own gravity, causing the gas and dust to heat up and form a protostar. As the protostar continues to grow and heat up, it eventually reaches a temperature and density where nuclear fusion reactions can occur, resulting in a fully formed star.
The life cycle of a star depends on its mass. Low mass stars, like our sun, will eventually run out of fuel and become a white dwarf. Higher mass stars will go through various stages, including red giant, supernova, and either become a neutron star or a black hole.
Astronomers use various tools and techniques to study stars and galaxies, including telescopes, satellites, and computer simulations. They can observe different wavelengths of light, such as visible light, infrared, and radio waves, to gather information about the properties and movements of stars and galaxies. They also use mathematical models and theories to better understand the behavior of these celestial objects.