The vast majority of mass in our Universe is invisible. And for quite a long time physicists are trying to understand what is this elusive mass. If it consists of particles, it is hoped that the Large hadron Collider will be able to produce a particle of dark matter or the space telescope will see eloquent gamma ray signature of the collision of dark matter particles. Meantime, nothing. This problem makes theoretical physicists to ponder new ideas.
In 2017, the famous theoretical physicist Lisa Randall looked one of the most incredible dark matter. Hypothetical, of course. Instead of considering dark matter as a particle of a certain type, it assumed that dark matter may consist of a whole family of particles, which are dark stars, dark galaxies, dark planets, and maybe a dark life. The chemistry of the dark universe could be as rich and diverse as our own “ordinary chemistry”.
But not so simple.
The problem of dark matter
Our universe is a wonderful, though strange place.
Over the past few decades we have come to the realization that 84.5% of the matter in the Universe cannot be seen. Given its rather awkward nickname of “dark matter”, this substance is in a state in which it does not interact with ordinary matter. Like dark energy, these things are “dark” because we don’t understand them.
If on my Desk now is a piece of dark matter, I’ll never know. A piece of dark matter in General, as such, can not lie on my Desk. He fails across the table and floor, and the crust of the earth, flock to the gravity well at the core of our planet. Or he will evaporate into space inexplicably. Dark matter interacts so weakly with anything that this piece will just fall through ordinary matter like it is not.
On a small scale the gravitational manifestation of dark matter is negligible, but at cosmological distances, presence of dark matter is definitely there — it can be observed indirectly by its gravitational effect on galaxy clusters and its influence on the rotation of galaxies. We know that it exists, just not visible.
And we don’t know what it is. I can only guess.
Ordinary matter — she baryonic matter interacts through the electromagnetic, gravitational, strong and weak forces. These forces transfer energy and give the whole matter structure. Dark matter, on the other hand, is generally regarded as an amorphous cloud of “stuff” that cannot interact through electromagnetic, weak or strong forces. Therefore, it is assumed that dark matter is “non-baryonic”. Non-baryonic matter could reveal their presence only by gravity.
The leading candidate in the search for dark matter is a WIMP weakly interacting massive particle. As the name of vimpa, this hypothetical particle does not interact with normal matter so it is not baryonic.
Established cosmological models predict that dark matter — be it in the form of winow or “axions”, for example — gives our Universe structure and usually simplistically called the “glue” that holds our Universe in General.
Observing the rotation of galaxies, astronomer Vera Rubin noticed that most of the matter in galaxies is not observed. Visible only a small percentage of stars, gas and dust; the rest is hidden in a huge, but invisible halo of dark matter. If our visible galaxy of ordinary matter, just cover on the great wheel of dark matter that extends far beyond what we can see.
In the recently published (2013) Randall and her colleagues were presented a more complex view of dark matter. According to the dark matter halo of our galaxy is not composed of only one type amorphous mass of non-baryonic matter.
“It seems very strange to assume that all dark matter consists of only one type of particles,” writes Randall. “Unbiased scientist should admit that dark matter may not be as diverse as our normal matter”.
Rich “shadow universe”?
Just as our visible universe is controlled by a Standard physics model — well-tested family of particles (including the notorious Higgs boson) and forces, whether in the dark galactic halo function rich and varied model of particles and forces of dark matter?
This study follows the logic, assuming the existence of a rich diversity of unknown physics in the dark sector of the universe — call it the “shadow universe” — which exists parallel to our own and has all the complexities that can offer our visible universe.
Astrophysicists had previously suggested that in our ancient universe may be “dark stars” — stars composed of dark matter — and to this day. If so, says Randall, it may be possible to form and “dark planet.” And if there is a collection of dark matter particles controlled by forces deployed in the dark sector, this may lead to the emergence of complex chemistry? And to life?
However, if the parallel to our universe, there are “dark” or “shadow” life, you can forget about the fact that we will be able to locate the source.
The shadow life will remain in the shadows
It seems tempting to use this hypothesis to explain all the daily riddles or even paranormal statements that can challenge or confirm science. What if “ghosts” or unexplained “lights in the sky” is a trick of the dark creatures living in the wrong side of everything?
Although the TV series or movie kind of logic it is to come, these dark creatures would live in the shadow of the universe, which is totally incompatible with ordinary matter. The particles and forces would have no influence in our universe. You could read these lines, sitting on a stump in a dark forest, and never would know.
But since we live with this shadow universe in the same space-time without extra dimensions or the multiverse theory — it is possible to transmit only one signal.
Gravitational waves were discovered only in 2016, and this is the first detection of ripples in space-time was caused by the collision of black holes. It seems entirely possible that gravitational waves can be recorded in dark sector, but only the most powerful cosmic events in dark sector can be fixed on our end.
In General, we almost certainly never will prove the existence of the lovely creatures of dark matter, but Randall noted an important point. When we think about the source of dark matter, we must move beyond our prejudices; dark sector can be a complex collection of particles and forces of dark matter that are beyond what we could imagine.