November 17, 2009
dark matter
We have blogged about dark matter a few years back, and have been tracking it a little as it is interesting if mysterious stuff.
One of the people actually doing the research on which dark matter is based, and so actually well placed to talk about it, is Professor Robert Kirshner from Harvard. Last week I went along to see him speak.
He talked about his research measuring the expansion of the universe via searching for supernovae and measuring their brightness and distance, and how this leads to detecting dark matter and dark energy.
Basically, the expansion of the cosmos should have slowed down due to the effect of gravity. While billions of years ago the expansion of the cosmos was decelerating, the convergence of data is that the expansion of the cosmos is currently accelerating. For this to make sense, there needs to be a lot more matter than we can detect pulling on things.
Hence, cold dark matter, about which little is known, beyond that it is estimated to make up 23% of the universe (as opposed to the 4% of the universe which is “normal” matter, which, according to quantum physics, is frankly in itself pretty peculiar and unknowable stuff*). And dark energy, about which even less is known, but is estimated to be 73% of the universe. The history of the universe can now be seen as a history of the struggle between gravity and dark energy.
There isn’t a hell of a lot to add since so little is known. But it was cool to go through the process of discovery in detail with someone who gets it, rather than reading brief and bizarre articles, and to get a taste of science actually living its myth of exploring the frontiers of knowledge to get us closer to truth**.
Today dark flow appeared on my radar again. Basically, a bunch of galaxies are accelerating away in a particular direction that indicates something really big is attracting them, maybe another universe.
Anyway. Humbling. Stuff is Big. We don’t know much. Be nice. In fact, let’s quote Kurt Vonnegut, who got this particularly right.
“Hello, babies. Welcome to Earth. It’s hot in the summer and cold in the winter. It’s round and wet and crowded. At the outside, babies, you’ve got about a hundred years here. There’s only one rule that I know of, babies—God damn it, you’ve got to be kind.”
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* I would seriously recommend The Dancing Wu Li Masters by Gary Zukav as the best book on physics I have read. There have been a few over the years, so there was a certain amount of scaffolding to build on, but Zukav communicates things clearer and better than anyone else I have encountered.
** If you take exception to that statement, go read The Structure of Scientific Revolutions by Thomas Kuhn.
Filed by billy at 9:49 pm under consciousness,research,the world
1 Comment
” to get a taste of science actually living its myth of exploring the frontiers of knowledge to get us closer to truth. If you take exception to that statement, go read The Structure of Scientific Revolutions by Thomas Kuhn”
The dark matter and dark energy solutions to the flat rotations curves and cosmic acceleration appear to a small number of people as very similar to the ether and epicycles that served to keep the old theory that was not working very well still viable. Dark matter and dark energy are way to obvious to serve as a paradigm shift that can effectively deal with the present “Kuhnian Crisis” that we are presently in.
Beside after years of searching and millions spent scientist have failed to detect dark matter in any way other than gravitationally. Further there are no very believable explanation as to what the dark energy is.
For a paper entitled “Is the warmth of sunlight gravitationally attractive” go here
http://vixra.org/abs/0907.0018 . There you will find 5 table top experiments which show that the weight of test masses will either increase or decrease (by as much as 2-9%) depending on the direction that heat is made to flow through the test masses.
A gravity theory based on the transfer of heat rather than some mysterious yet-to-be-specified property of mass is a plausible way to explain gravitational phenomena that most Scientist will have a hard time embracing as did the Scholastics did with Copernicus’s sensible idea of heliocentric planetary motion.