I can get worried about the small things in life. But obsessed by the big things. Like the universe.
How big is the universe? Does it have a beginning and an end? And what is it made of?
Dark matter is the name given to mysterious and invisible particles that we assume must exist because of how it interacts with ‘normal’ matter via gravity.
No one seems to know what dark matter is. It could be ordinary matter, strong man matter – like MACHOs (or Massive Compact Halo Objects). Brown dwarfs (not a very macho-sounding name – is it?) and black holes (far more butch!) are examples of MACHOs.
That’s just one possibility! Dark matter could be something else completely: it could be extraordinary matter, which may or may not, be composed of WIMPs (or Weakly Interacting Massive Particles). Neutrinos are WIMPs and quite possibly photinos and neutralinos (although they do not like being called this).
The best guess is that dark matter is made up of both ordinary and extraordinary matter.
What I find so mind-boggling is that only 10%-30% of the universe is visible. That means that most – well, nearly all – of the universe is hidden behind veils of galaxies and clouds of hot gases; it is invisible, mysterious, perplexing.
This X-ray telescope image shows that dark matter (shown in blue)
makes up most of the mass of this galaxy.
Go out tonight in the dark and gaze upwards to the skies. Enjoy the wonder of the stars and moon. Then take a minute to contemplate the vast universe that we cannot see; that we can only guess is out there.
What miracles does it hold? What song does it sing?
As Carl Sagan once said:
Somewhere, something incredible is waiting to be known.