Thanks Red Badger.
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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
All I need is a couple of trillion dollars and a PhD............................
Sheesh!......face palm! This whole time I thought we were talking about anti-matter, not dark matter! I don’t know what’s the matter with me. I would try to shed more light on the matter, but with all the Ebola talk, I’m stuck on fecal matter.
I suppose I’ll have to stop using so much!
Sex?
So they base the assumption of the amount of matter on a hundred year old formula, one that had no way of actually measuring how much mass is in our galaxy, let alone the universe. We are still finding whole galaxies.
There is a photo from the Hubble where they focused on a small ‘empty’ space between visible stars. Found hundreds of new galaxies that were not readily visible. Simply garbage science with zero support from the actual world.
I know where all the dark matter and dark energy went.
If it’s true that time travel is possible, then, it’s also true that, all matter and energy from any particular instance in time, have all gone into the past. The past and the present interact, and the present feels the effect of the matter and energy that have “passed on”.
The most current instance of the “past energy and matter”, can be called the “most recent instance of the past universe”, and that instance will be the most felt in measurements. The instance before, will also have an effect on measurements, but not as great as the most recent. The third instance before the current instance of the universe, will also have an effect on the current universe... and so on... up to the very first instance of the universe. All of those instances comprise the “universes”. All of those universes (or instances of the universe), all interact, and they do exist, and it’s why it might be possible to travel to the past. We won’t be able to travel into the future, since, no instances of the universe have “passed” into future times. We can’t interact with what hasn’t already occurred.
Are you saying that dark matter is where the things that went into the past were?
“Still awaiting explanation of the GRAVITY, and what it is...............”
You obviously haven’t been to one of the “All you can eat” buffets, have you?
They forgot to look in my basement!
The Universe is racist.
Heh heh... and if you have 100 odds and ends on a table, and 99 of them fall off, what do you have left — an odd or an end? [George Carlin]
So, the past exists presently. If we were to go there would time stop in the present? And could we come back to the same time in the present that we left, or would we come back to a point in time that was as far along in time as the amount of time we were gone?
closer to .0065 of warp one.
If “I” traveled into the past, would I take with me the memories of the future that I had already spent time in?
Why? because all the Dark Matter is in prison or hiding?......................
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