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Dark Matter Measurements
ksp0704 writes: "According to this article at space.com, scientists have finally measured the approximately 90% of the universe we can't see (the dark matter)." I'm sure it will continue to be a topic of debate for years, but two independent measurements agreeing is a good sign.
Why does the big bang have to have a cause? The idea of a chain of events, each causing the next in the sequence, is a bit passé these days. If you ask for a cause for the first event you quickly lead to an infinite regress. What's the problem with there being a first event without cause? I hope you don't think that because most events have causes they all do. That's a bit like thinking that all integers are non-zero because most of them are.
-- SIGFPE
Only further testing will be able to prove that this match is not simply coincidence. They're right, this doesn't "have to be the answer", so let's not jump to conclusions from two friendly tests. (But certainly get excited for the potential! Heh.)
You can have whatever creationist theories you like, but you can't contradict what we *know*.
That's a very humbling thought. Not enough of humanity gets put in their place by the sight of millions of stars anymore. Gives me hope.
Sure.... why is it that no one ever talks about an infinite number of big bangs occuring constantly? Our big bang might just be a fairly small one compared to the one that happened last night a gazillion miles away. Our little "universe" could simply be a little puddle of matter in our little side street of the real infinite universe.
an enormous nuclear explosion called the Big Bang happened 13 billion to 15 billion years ago. From it, the universe appeared in an instant, but as a billion-degree mess of neutrons, protons and electrons.
If ever Big Bang there was, it was not a giant nuclear explosion! Damn at those temperatures there are no nucleus (as they themselves state a few sentences afterwards). It is rather a very FAT release of energy, which later congregated into quarks and antiquarks, neutrinos, etc. definitly not nuclear. And what a hell is "dark matter". They state that "dark matter" congregated and formed gravity pools...
At the time of the original release of light, dark matter had congregated in clumps, which created small fields of gravity that eventually pulled in normal matter as well.
Dark matter does not emit radiation by definition. It thus has to have enough gravitational pull to keep all EM radiation in. That is a freakin big chunk of matter, not small gravity fields! And what do they mean normal and not normal matter... it's all the same stuff, energy. The energy is just "stored" differently.
"The nature of these 'wiggles' is basically saying how the normal matter was responding to that crazy dark matter," explained Fields, "by amplifying the places where the extra density was."
Errhhmmm... that is called matter falling in the black hole to make it larger and thus increase the gravity....
Imperium et libertas
Autocracy and freedom
They look at the galaxies, and estimate how many stars and stuff there is in the galaxy. Any rotating galaxy. And They figure out how fast the galaxy is rotating.
They notice a problem. For any rotating galaxy there is not enough star stuff to hold the galaxy together. The spiral arms should never be there.
The star stuff in the galaxies do not have have enough gravity to hold galaxies together. Galaxcies should not exist at all. Stars should be all flying about because that is how weak the gravity is.
Just how much too weak? The Star stuff has one tenth the gravity needed to do the job. so something has to be doing the other 90%.
That is what the dark matter is. It is a term to label what the other 90% is. The don't know what it is yet. but they are working on it.
"It is a greater offense to steal men's labor, than their clothes"
We have three methods to calculate the mass of the universe. Two are based on electromagnetic interactions. Those two agree. The other is based on observations of gravitational interactions. It gives a result 10X as large for the total amount of matter. Therefore 90% of the universe is made of particles that interact gravitationally but not electromagnetically. The only way to observe them is to observe their gravitational effects. Like, duh. Why is this such a difficult concept to grasp? It's an empirical observation.
Keep in mind that if something only couples gravitationally, it's going to be extremely hard to see. You're prejudiced by your own experience with the world, which is mostly based on electromagnetism- meaning interactions with photons (real and virtual). Get rid of electrodynamics, and most concepts and phenomena you're familiar with- atomic physics, chemistry, biology, optics, materials science, friction, pressure, radiation, viscosity, resistance, reflection, transparency, iridescence, impenetrability- all this stuff goes out the window! Your ass would sink through your chair, right through the ground, until you reached the center of the earth with everything else. Don't underestimate the importance of photon-mediated interactions. Everything else is gravitation, beta decay, and the strong nuclear force. Of those three, only gravitation operates over non-microscopic distances. And it is very weak. There could be up to several tons of dark matter in the room with you right now. You would never know it's there.
Of course, the mass could be ordinary matter that we're just not seeing. Many people like the idea of lots of Jupiter-sized objects. Lots of black holes might also work (although a black hole can feed off either kind of matter).
When scientis finally decide what light is, waves or photons, they will realize that it is neither.