10 Interesting Things To Know About Dark Matter
Dark matter is one of the many unknowns of space. This mysterious phenomenon in space cannot be observed through ordinary telescopes. Dark matter emits no light and cannot be seen directly but its gravitational effects can be observed and measured. Unlike normal matter dark matter is thought to be non-baryonic in nature. Dark matter makes up 85% of the matter in the universe and about a quarter of its total energy density. The universe contains 5% ordinary matter and energy, 27% dark matter and 68% dark energy. Here are 10 interesting things that you should know about dark matter.
Interesting Things To Know About Dark Matter
1. Its Effects Can Be Observed:
As dark emits no light and it doesn’t interact much with itself or anything else like observable electromagnetic radiation, we can’t see it, but we can observe and measure its gravitational effects. Galaxies have been observed to spin much faster than expected based on their visible matter, and in clusters, than expected too, scientists can calculate the “missing mass” responsible for this motion. Dark matter’s gravitational pull on the visible matter is what astronomers look for.
2. Gravitational lensing:
Gravitational lensing is what astronomers use to detect dark matter in the universe. The gravity of the dark matter is thought to be responsible for bending light from distant light sources. So, in cases of absence of visible matter, astronomers check for bending of light. Because of dark matter’s strong gravitational force, distant galaxies often appear stretched and oddly shaped.
Although the existence of dark matter still a puzzle, many astronomers and physicists have gathered evidence about its presence. NASA’s Hubble Space Telescope recently provided clues for the existence of dark matter. It sighted more than a million globular clusters of stars moving together in the center of a giant group of galaxies, called the Abell 1689.
But the strongest evidence for the presence of dark matter is provided by gravitational lensing studies of the bullet cluster. In this cluster, the collision of two galaxies was observed. Astonishingly the galaxies merged together without any disaster, or the stars smashing into each other. This means that there was some invisible gravitational field governing the stars of these galaxies which is thought be the dark matter.
4. It’s Responsible For The Structures Of The Universe:
Dark matter is the first type of matter to settle down when the universe expands and the first to form structures under its own gravitational pull. Most experts believe Dark Matter to be omnipresent in the universe and has strongly affected its structure and evolution. Dark matter seeds the filaments along which galaxies later form when visible matter falls into the gravitational potential created by the dark matter. Dark matter is responsible for Planets not flying out of its orbit and wandering around in the universe.
5. Dark Matter Holds The Universe Together:
Dark matter has enough gravitational to hold entire galaxies like a glue. Dark matter is often likened to a giant spider’s web, meshing galaxies in place. According to Fritz Zwicky, a Swiss astronomer, the galaxies needed a lot more mass to hold themselves together, judging by their speed. Which means there was some matter missing to the human eye, that was holding these galaxies together. Dark matter exerts ‘gravitational force’, meaning that it draws other matter towards it. It is true that the universe is expanding nut the universe has its own provision to prevent collisions and disasters.
6. We Know Some Things Dark Matter Can’t Be:
We know more about the things that dark matter can’t be than, it could be. Physicists have lots of ideas what dark matter could be such as the Weakly Interacting Massive Particles. It’s a new kind of elementary particle that has not yet been discovered. Another candidate is Axion. A very light particle that leaves behind some kind of condensate that fills the universe. Though these are just ideas, according to physicists, dark matter can’t be- clouds or normal matter, antimatter and black holes.
7. Underground Dark Matter Labs:
To catch the effects of dark matter and to detect tiny signals scientists have developed Dutch astronomer Jacobus C. Kapteyn buried deep underground, away from the effects of intense background noise. There is SNOLAB in Canada, at a depth of 2 km, and Boulby Underground Laboratory in North Yorkshire, the UK which is located over 1,000 metres below the Earth’s surface. There are many other similar facilities exist across the globe.
8. The First Person To Suggest The Presence Of Dark Matter:
Dutch astronomer Jacobus C. Kapteyn first used the term “Dark Matter” to denote invisible matter in 1922. In 1932, another Dutch astronomer Jan Oort detected the presence of dark matter While studying stellar motions in nearby galaxies. Swiss astronomer Fritz Zwicky is most renowned for pointing out that the mass of all the stars in the Coma cluster of galaxies provided only about 1 percent of the mass needed to keep the galaxies from escaping the cluster’s gravitational pull, supporting the presence of dark matter, in 1933. Although, American astronomer Vera Florence Cooper Rubin is largely associated as the first to uncover the evidence of the existence of dark matter in the 1970s.
According to its velocity, dark matter is classified as cold, warm, or hot. The current models favor a cold Dark Matter scenario, in which structures emerge by the gradual accumulation of particles.
10. It’s Everywhere:
The dark matter halo not only surrounds the whole galaxy but extends beyond its edges. Like our Milky Way galaxy is surrounded by a much bigger halo than the actual galaxy and is spherical in shape.