Team finds 'proof' of dark matter

[glenc]

Team finds 'proof' of dark matter

An interesting article is at:
http://news.bbc.co.uk/2/hi/science/nature/5272226.stm

Dark matter - which does not emit or reflect enough light to be "seen" - is thought to make up 25% of the Universe.
By contrast, the ordinary matter we can see is believed to make up no more than about 5% of our Universe.


The other 70% is dark energy.

[g__day]

Pretty interesting stuff, be keen to see it confirmed and more analysis of what are the properties of dark matter, how is it formed and what uses can we make of it.

It's a stepping stone towards verifying dark energy and if we ever crack that one its a key ingrident need to warp spacetime to travel interstellar distances in the blink of an eye though gravitational wormholes.

PS

Personally I'd rather hope someone discover distance is an illusion and one might create a new science or technology that allows one to in effect shift entirely without what we call travel to get past certain universal speed limits that our understanding of reality imposes. Change the rules of reality and we really can boldy go to the stars!

[xelasnave]

G day.. thats not feet on the ground stuff but I compliment your vision of the possibilities.
It seems every second day another "dark matter" candidate is put forward.
They are finding less support for "macro" by virtue of the observations and I dont think the search in the cleaning fliud is finding as many "wimps" as they had hoped (not even in the area of the expected numbers that the experiments should reveal.
I personally think they are barking up the wrong tree in looking for dark matter as "gravity rain" explains it away and although thats only one idea it is an idea that requires no dark matter..it may not be on the money either but it may not be the only idea that can do away with dark matter either.are there alternatives being investigated or will they doggedly stick to the current search...so I say are they looking for something they will not find even though the theory demands it to remain at the front. My observation is simply if dark matter is the major ingredient (supposedly) of our Universe it really should be somewhat easier to determine than the search is showing it to be..if there is so much of it show it to me.. It is difficult to imagine that something that plays such a large part of the machinery of everything simply is so difficult to "show in the flesh"..is that unreasonable, does a laymen have the right to make such a pointed comment? It seems to me that if you want dark matter stop talking and produce the goods... all that has been put forward to date only offers encouragement to keep looking as it seems there is not enough coming thru to say the dark matter issue is a sure thing.
I would love to hear how space time could be bent to form a worm hole I have looked long and hard at as much as I have been able to access re this and again I think it is theory running away withitself ...I mean draw a space time grid on a sheet of paper and experiment how such a thing could occur..I can not see how so it is a matter I reject.. Such a proposition is no better than the prospect of travelling at C x 100,000 as we see in Star Trek and the like...the mind can entertain it but I doubt if it will ever come to pass.
alex

[mickoking]

I reckon it's awsome that the majority of the Universe is made up of stuff we don't know anything about.

[xelasnave]

Just when you think there is some resolution this turns up.
quote from New Scientist

Article Preview
'Ether' returns in a bid to oust dark matter
26 August 2006
Zeeya Merali
Magazine issue 2566
It was declared dead over a century ago, but now "the ether" is being reincarnated to solve a weighty problem
FROM his office window, Glenn Starkman can see the site where Albert Michelson and Edward Morley carried out their famous 1887 experiment that ruled out the presence of an all-pervading "aether" in space, setting the stage for Einstein's special theory of relativity. So it seems ironic that Starkman, who is at Case Western Reserve University in Cleveland, Ohio, is now proposing a theory that would bring ether back into the reckoning. While this would defy Einstein, Starkman's ether would do away with the need for dark matter.

Nineteenth-century physicists believed that just as sound waves move through air, light waves must move through an all-pervading physical substance, which they called luminiferous ("light-bearing") ether. However, the Michelson-Morley experiment failed to find any signs of ether, and 18 years after that, Einstein's special relativity argued that light propagates through a vacuum. The idea of ether was abandoned - but not discarded altogether, ...

Looks like dark matters possition is no more secure than Plutos classification as a planet;)
alex

[robagar]

today's APOD has an fantastic pic: http://antwrp.gsfc.nasa.gov/apod/image/0608/bulletcluster_comp_f2048.jpg

it looks like a nebula at first sight, but the blue is actually the dark matter. You can see clearly how it has continued moving unhindered, while the ordinary matter has formed a shock front. Amazing :D

[iceman]

Great pic! Worth mentioning that it's 500k.

Or link to the data page, which has the description and a cutdown version of the pic:

http://antwrp.gsfc.nasa.gov/apod/ap060824.html

[xelasnave]

What I dont understand is if dark matter plays such an important role in the gravity makeup of "everything" how is it that in the photo the "dark matter" is not subject to the gravity here (I gather that is the point???). It would seem to me that the fact that this stuff is not caught up in a gavity dance it lacks the stuff that can cause a gravitational effect which seems to me to be the main requirement for dark matter.
alex.

[robagar]

Ah yes. sorry. :ashamed:couldn't figure out how to link to the small version. brain the size of a dwarf planet...

[robagar]

no the point is, it's *only* subject to gravity. As I understand it, the ordinary matter shooting out from the collision hits the intergalactic medium and slows down suddenly (hence the shock front). The dark matter doesn't interact with the IGM, and goes sailing on gradually being slowed by gravity alone. End result - the dark matter travels further from the collision.

[xelasnave]

Thanks that makes sence
alex

[Karls48]

Hi G__day
I think that distance is an illusion. Take A4 sheet of paper. Now plot the shortest possible course between diagonally opposite corners. Try as you try you finish with line about 365mm long. Now fold the paper so opposite corners touch. And the distance becomes 0. True, we are manipulating two-dimensional space in three-dimensional environment. But the force required is very small. I would like to know if someone clever calculated the force required to do it in two- dimensions. That would give us idea about energy needed to do it in our three dimensional reality. If we were living in two- dimensional world, existence of third dimension can be mathematically proven. In our reality it can be also mathematically proven that fourth dimension exist. I think that your wish that space travel will be sometime in future posible by shifting to other places in the universe is more feasible then faster then light travel.
Karl

[xelasnave]

I am dubious that such can happen, but the I have no idea of the math that supports these propositions. However when one thinks of the saying "it is a wise man who can imagine a stick without ends" and its application in respect of one grid line of "space time" the difficulties of a bend in space time of the magnitude contemplated in a worm hole situation would seem to decome apparent.
Folding a piece of paper is one thing but to take that (the space time grid line) to space travell it suggests (because the grid line is in effect without ends) that we can only fold a section of the Universe but this would require really a double fold so the "ends" of the grid can continue on their way after our medling... now that I have written this it seems hard to follow I hope my point is not lost.
I guess what I am saying is I would like to see a drawing representing such a concept and what is done with the rest of the grid/ or the ends of the grid lines.
alex

[netwolf]

Dark Matter was much of the subject in the Talk this year at Maquarie Univiersties Astronmy open day on 2nd September. Josh Hawthorne spoke much about an experiment that will occur in 2 years to prove the existance of this energy. Apparenlty its being conducted at the Cycltron in france where they are coliding gold atoms together to study subatomic particles, this apparently allows us to observer there nature which seems to indicate a multidimensional universe. The lecture was a bit over my head so i may have got some of this wrong so forgive me. I think he said something along the lines of that the multidimensions are wraped up inside matter itself. And that by coliding the two attoms one can observe the nature of these multiple dimiensions.
He also indicated that the collision can produce mini black holes, apparenlty black holes are easier to understand if we assume multi dimensions.



Regards

[xelasnave]

The great thing about dark matter is that every one can have an opinion:) , because it is still very mysterious.
Netwolf I like the multi dimentional explanation (which is along the lines I suggested in my "go" at the multi dimention thing put forward in Elegant Universe) finding other dimentions within matter is different to "other parrallel Universes" certainly sounds more realistic than the direction suggested in the Elegant Universe... which makes out a proposition more like one would expect in a Star Trek or Dr Who show, presumably to entertain rather than inform.
alex