Nothing is important. We’re almost sure it’s there. But we don’t know what it is. But this nothing could control the fate of the universe. And there may even be entire solar systems made of it.
Physicists have been grappling with dark matter — and dark energy — for decades.
It’s where many of our laws of physics disappear in a puff of smoke.
We know gravity. We understand gravity. But there simply isn’t enough stuff in our galaxy — and the known universe — to explain why things are where they are.
Something must be producing 80 percent of the gravity at play. Something we can’t see.
That something is proving to be remarkably elusive.
It’s ‘dark’ because we don’t understand what it is.
Some of the world’s most complex — and expensive — experiments have done little more than offer tantalizing tastes of what could be out there. But even the Large Hadron Collider hasn’t yet isolated any particle that could possibly explain what dark matter is.
There are some mathematical boundaries within which it must fit. But little else is known.
So, it remains a realm of speculation. Of theory. Of mystery.
A group of Russian physicists have recently added another idea to the mix.
They’ve published their argument in the latest edition of the science journal Physical Review Letters.
It could be possible given our current understanding, they argue, for dark matter to clump together.
This has implications.
Dark matter doesn’t work the way our matter does. It doesn’t seem to interact with our matter, either. It’s almost a shadow universe interweaved with our own.
But, buried inside the halos of gas and dust surrounding galaxies could be cold, unseen ‘Bose stars’.
“In our work, we simulated the motion of a quantum gas of light, gravitationally interacting dark matter particles,” says physicist Dmitry Levkov from the Institute for Nuclear Research of the Russian Academy of Sciences.
They did this, they say, because they wanted to understand how a dark matter Bose-Einstein condensate could form.
The idea goes something like this: when temperatures sit just above absolute zero, quantum particles lose the energy to mix and wobble. What’s left behind is a uniform dark ‘slush’.
The individual quantum particles become uniform. And clouds of these dark particles can condense — drawn together by gravity — into superfluids.
“We started from a virialized state with maximal mixing, which is kind of opposite to the Bose-Einstein condensate,” Levkov says.
“After a very long period, 100,000 times longer than the time needed for a particle to cross the simulation volume, the particles spontaneously formed a condensate, which immediately shaped itself into a spherical droplet, a Bose star, under the effect of gravity.”
Dr. Levkov and his colleagues believe that Bose-Einstein condensate may form in the centers of halos of dwarf galaxies in a time span shorter than the lifetime of the universe.
If true, Bose stars could currently exist.
“The next obvious step is to predict the number of the Bose stars in the Universe and calculate their mass in models with light dark matter,” Levkov says.
We know where they must be.
The location of unexplained gravity has been mapped out in fine detail.
We know it likes to cluster around galaxies. So this is the obvious place to start a search.
But for what?
The Russian scientists say Bose stars may be behind the mysterious ‘fast radio bursts’ being detected by radio astronomers. Currently, these have no known source.
But, under the dark star theory, dark matter can interact at an extremely weak level with electromagnetic fields and decay into radiophotons.
“This effect is vanishingly small, but inside the Bose star, it may be resonantly amplified, as in a laser, and could lead to giant radio bursts,” their statement reads.
Among the many postulations about the nature of dark matter is that it may actually be a full family of particles — not just one. And each dark particle could ultimately play a part in a complete shadow ecosystem.
A dark universe, with its own shadowy chemistry as diverse as our own.
“It seems very odd to assume that all of dark matter is composed of only one type of particle,” writes theoretical physicists Lisa Randall. “An unbiased scientist shouldn’t assume that dark matter isn’t as interesting as ordinary matter and necessarily lacks a diversity of matter similar to our own.”
And that leads to an extreme proposition, one that Randall has been toying with.
“An invisible civilization could be living right under your nose,” she says.
And if dark stars can form, she argues, perhaps dark planets can too.
Life is just a logical next step.
But don’t get too excited by the terrifying potential of such shadow beasts, she writes.
“The problem is that cinematographers would have trouble filming this dark life, which is of course invisible to us—and to them. Even if the dark creatures were there (and maybe they have been) we wouldn’t know.
“You have no idea how cute dark matter life could be—and you almost certainly never will,” Randall quips.
But, as with dark matter itself, there is as yet absolutely no proof it is there.
Just an idea.
And chances of finding evidence is slim because dark matter is … dark.
“Dark objects or dark life could be very close—but if the dark stuff’s net mass isn’t very big, we wouldn’t have any way to know,” Randall writes.
“Even with the most current technology, or any technology that we can currently imagine, only some very specialized possibilities might be testable. ‘Shadow life,’ exciting as that would be, won’t necessarily have any visible consequences that we would notice, making it a tantalizing possibility but one immune to observations. In fairness, dark life is a tall order."
This story originally appeared in news.com.au.