What is dark matter? There is still no unequivocal answer, but now scientists can say what it is not: a bunch of ancient black holes, as described by Stephen Hawking.
Is a mysterious substance which accounts for 85 percent of the universe's material. While its gravitational force exists throughout the universe, dark matter is invisible and undetectable.
For years, scientists have been trying to learn more about this elusive material that holds the galaxies together. So far, all efforts and tools to find dark matter have come short.
Hawking 's famous theory
Is one of these scientists, comes with the famous theory that dark matter consists of primary black holes.
Soon after the birth of the universe, the Big Bang may generate large amounts of tiny black holes
In areas dense enough for gravitational collapse.
Still, even extremely tiny black holes have a large mass.
To alert science, a black hole with an event horizon of 0.1 mm in diameter will have a mass of more than 67 quintillion metric tons.If many of these tiny black holes exist in the universe, they can account for the large amounts of mass present there.
In addition, if black holes are particularly small zips in space, it will cause the effect known as gravitational lenses, ie a strong gravitational field of black holes will bend the light of the objects that are moving before.
This is a phenomenon that the new research uses to examine Hawking's theory.
Astronomers reject Hawking's dark matter theory
In a new, detailed study
In the journal Nature Astronomy
, An international team used the Hyper Suprime-Cam digital camera on the Subaru telescope in Hawaii to search for ancient black holes in the neighboring Andromeda galaxy.
If these were primary black holes moving between the Earth and a star in the nearby galaxy, the scientists would be able to identify the stars brightening and flickering in a fast "flash" as a gravitational lens effect. The smaller the black hole, the faster the flash will be.
For these primary black holes to produce dark matter, the scientists predicted that it would be necessary to have enough less massive black holes than the Moon to cause approximately 1,000 gravitational lens events. The team was only able to identify a potential event from 190 consecutive images for seven hours.
This single event is an achievement in itself, as noted by a living science
That is perhaps the first ever discovery of a primary black hole.
This is a huge blow to Hawking's theory of dark matter made up of these ancient black holes.
Primary author Masahiro Takada stresses that their research does not completely negate the possibility of dark matter being composed of primary black holes. However, they were much, much smaller than expected.
"Our physicists are very excited that there is still a window," Takeda told Life Science, adding that their data could not rule out the tiny black holes in which flashes are too short to detect. "So we need to think of another method to do it."