How do you find the mass of dark matter?

How do you find the mass of dark matter?

Dark matter in spiral galaxies To a fair approximation, assuming Newtonian gravity, the rotational velocity V (r) at radius r is related to the total mass M(r) within radius r by the equation V 2(r) = GM(r)/r, where G is the gravitational constant.

Is there a formula for dark matter?

The informational equivalents of dark matter and the total mass energy of the cosmos are in a ratio 1/4. Dark energy and dark matter are in a ratio 2/ln2. The ratio of dark energy to the total mass energy of the cosmos is ln2. According to the formula (4.5) the ratio Hmax / HM is equal to 83/2 · π2 · ln2.

What percentage of the matter in the universe by mass is stuff we can’t see?

NEW YORK — All the stars, planets and galaxies that can be seen today make up just 4 percent of the universe. The other 96 percent is made of stuff astronomers can’t see, detect or even comprehend.

How is dark matter distributed in galaxies?

Summary: Scientists have shown that the dark matter in galaxies follows a ‘maximum entropy’ distribution, which sheds light on its nature. Dark matter makes up 85\% of the matter of the Universe, but its existence shows up only on astronomical scales. …

How do you calculate the mass of a galaxy?

The elliptical galaxy’s mass = k × (velocity dispersion)2 × (the distance the stars are from the galaxy center)/G, where k is a factor that depends on the shape of the galaxy and the angle the galaxy is from Earth.

When was dark matter discovered?

Originally known as the “missing mass,” dark matter’s existence was first inferred by Swiss American astronomer Fritz Zwicky, who in 1933 discovered 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 …

What is dark matter made of?

These possibilities are known as massive compact halo objects, or “MACHOs”. But the most common view is that dark matter is not baryonic at all, but that it is made up of other, more exotic particles like axions or WIMPS (Weakly Interacting Massive Particles).

What is in dark matter?

Most scientists think that dark matter is composed of non-baryonic matter. The lead candidate, WIMPS (weakly interacting massive particles), have ten to a hundred times the mass of a proton, but their weak interactions with “normal” matter make them difficult to detect.

What percentage of matter is dark matter?

Dark matter seems to outweigh visible matter roughly six to one, making up about 27\% of the universe. Here’s a sobering fact: The matter we know and that makes up all stars and galaxies only accounts for 5\% of the content of the universe! But what is dark matter?

What percentage of the universe is dark matter and dark energy?

It turns out that roughly 68\% of the universe is dark energy. Dark matter makes up about 27\%. The rest – everything on Earth, everything ever observed with all of our instruments, all normal matter – adds up to less than 5\% of the universe.

Where is dark matter distributed?

It is distributed evenly throughout the universe, not only in space but also in time – in other words, its effect is not diluted as the universe expands. The even distribution means that dark energy does not have any local gravitational effects, but rather a global effect on the universe as a whole.

What is the nature of dark matter in galaxies?

Although its nature is unknown, dark matter appears to be such an integral part of galaxies that the presence of dark matter is used to distinguish a small galaxy from a large globular cluster, both of which may have the same number of stars.

Where is most of the mass of a galaxy distributed?

A substantial part of the mass of the galaxy is not concentrated toward the center of the galaxy but must be [160] distributed in some dark, unseen halo surrounding the visible galaxy. The outer regions of galaxies, faint and inconspicuous on a photograph, may actually contain most of the matter.

Is there dark matter in oddball galaxies?

When astronomers using NASA’s Hubble Space Telescope uncovered an oddball galaxy that looks like it doesn’t have much dark matter, some thought the finding was hard to believe and looked for a simpler explanation. Dark matter, after all, is the invisible glue that makes up the bulk of the universe’s contents.

How much of the universe is made up of dark energy?

It turns out that roughly 68\% of the universe is dark energy. Dark matter makes up about 27\%. The rest – everything on Earth, everything ever observed with all of our instruments, all normal matter – adds up to less than 5\% of the universe.