I suppose I’ll have to stop using so much!< P> Here, Have one on me!.................
Posted on 10/10/2014 1:00:47 PM PDT by Red Badger
New research from the University of Western Australia reveals that the amount of dark matter in the Milky Way is half as much as previously thought.
Australian astronomers used a method developed almost 100 years ago to discover that the weight of dark matter in our own galaxy is 800,000,000,000 (or 8 x 1011) times the mass of the Sun.
They probed the edge of the Milky Way, looking closely, for the first time, at the fringes of the galaxy about 5 million billion kilometers from Earth.
Astrophysicist Dr Prajwal Kafle, from The University of Western Australia node of the International Center for Radio Astronomy Research, said we have known for a while that most of the Universe is hidden.
“Stars, dust, you and me, all the things that we see, only make up about 4 per cent of the entire Universe,” he said.
“About 25 per cent is dark matter and the rest is dark energy.”
Dr Kafle, who is originally from Nepal, was able to measure the mass of the dark matter in the Milky Way by studying the speed of stars throughout the galaxy, including the edges, which had never been studied to this detail before.
He used a robust technique developed by British astronomer James Jeans in 1915 — decades before the discovery of dark matter.
Dr Kafle’s measurement helps to solve a mystery that has been haunting theorists for almost two decades.
“The current idea of galaxy formation and evolution, called the Lambda Cold Dark Matter theory, predicts that there should be a handful of big satellite galaxies around the Milky Way that are visible with the naked eye, but we don’t see that,” Dr Kafle said.
“When you use our measurement of the mass of the dark matter the theory predicts that there should only be three satellite galaxies out there, which is exactly what we see; the Large Magellanic Cloud, the Small Magellanic Cloud and the Sagittarius Dwarf Galaxy.”
University of Sydney astrophysicist Professor Geraint Lewis, who was also involved in the research, said the missing satellite problem had been “a thorn in the cosmological side for almost 15 years.”
“Dr Kafle’s work has shown that it might not be as bad as everyone thought, although there are still problems to overcome,” he said.
The study also presented a holistic model of the Milky Way, which allowed the scientists to measure several interesting things such as the speed required to leave the galaxy.
“Be prepared to hit 550 kilometers per second if you want to escape the gravitational clutches of our galaxy,” Dr Kafle said.
“A rocket launched from Earth needs just 11 kilometers per second to leave its surface, which is already about 300 times faster than the maximum Australian speed limit in a car!”
Publication: Prajwal Raj Kafle, et al., “On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution,” 2014, ApJ, 794, 59; doi:10.1088/0004-637X/794/1/59
PDF Copy of the Study: On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
Image: ESO/L. Calçada
I need only a couple of trillion because I’m very frugal...........................
It doesn’t matter...................
I suppose I’ll have to stop using so much!< P> Here, Have one on me!.................
I’d have to turn up the oxygen flow LOL. At this point in life I’m very grateful for interesting memories.
Does matter need time in order to exist? Many years ago, my young son asked me, “what is a rock”. Being a young father, I could not just say, “I don’t know”. So I told him that a rock is a frozen moment of time.
I had to back up a bit. I was warned at an early age that contemplating this stuff would lead to insanity, so I gotta be careful. Just to review, there are three and only three things: Time, Space and Matter. (Mass and Energy being a subset of Matter.) So, that is that, Time, Space and Matter. Another subset of Matter is “organic matter”. I am organic matter that God gave consciousness and free will. I think, therefore I am. (You may be a figment of my imagination, but that is a discussion for another thread). The way that I have trained myself to look at it is this: there is me, there is what my senses reveal to me, and there is what I make of it. And this can apply to humankind as well. There is us, there is what our studies reveal to us, and there is our cumulative interpretations of those studies. Different cultures over different times have come up with different conclusions. Those conclusions are also available for us to draw upon. Yet, there is still only three. The observer, what is observed, and what the observer makes of those observations. I call these the three “realities”. It also ties in to mind, body and soul. Or heart, head and spirit. The physical, the mental and the spiritual.
As for “dark matter”, this is only something that comes to my awareness via scientists and the use of their current set of measuring instruments. I need to somehow pigeon-hole it. For scientists, unfortunately, I only see that they have two realities - themselves and the findings of their observations. And that is all I have to say about that for now, because my wife just handed me a grocery list.......
Say what?
The Great Attractor is a spot in the universe toward which all galaxies are moving - the question is: why and what?
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