A very fundamental question about dark matter – what exactly makes it up – is at the center of one of the biggest mysteries of recent years.
This week we're going to talk about dark matter, a type of matter that is invisible and enigmatic but has major implications for the final outcome of the cosmos.
Dutch astronomer Jan Oort proposed the existence of dark matter while investigating stellar motion near the Sun in the 1930s. He thought that since the galaxy was not breaking apart, there must be enough matter in the disk to keep the stars from moving too far from the center of the galaxy. According to Oort's theory, there should be three times as much dark matter as bright matter around the Sun.
Later, when astronomers looked at the bright disks and halos of galaxies and studied their spin curves to get an idea of how some dark matter is dispersed, they found more evidence.
Galaxy cluster surveys provide additional clues to the existence of dark matter. Also in the 1930s, American astronomer Fritz Zwicky discovered that the Coma galaxy cluster, about 300 million light-years from Earth, contains much larger clouds of dark matter. Zwicky discovered that the Doppler shifts of the cluster's individual galaxies require 10 times more mass than what can be seen with the naked eye to keep the galaxies gravitationally bound.
A very fundamental question about dark matter – what exactly makes it up – is at the center of one of the biggest mysteries of recent years. Scientists have put forward a wide variety of hypotheses over the years, and each has its pros and cons when it comes to understanding astronomers' observations. These include large quantities of ordinary neutrinos such as MACHOs (large compact halo objects), exotic particles, axions, large neutrinos, and phototinos, such as brown dwarfs, neutron stars, and black holes.
Given that dark matter accounts for 26% of the universe's total mass energy, whatever it is has a significant impact on the structure and future of the cosmos.
Source: astronomy.com/news – Dave Eicher
Günceleme: 27/03/2023 21:37