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First Cosmological Results From MAP
riptalon writes "The Wilkinson Microwave Anisotropy Probe, a NASA Explorer mission has announced the first results based on a year of observations from the L2 Lagrangian point. MAP carries two
back-to-back microwave telescopes to study variations in the cosmic microwave background, to
much greater accuracy than the COBE satellite. The excruciating details of the results
on the age, geometry and composition of the universe can be found in this paper. Executive summary: 13.7 billion years old, flat, 4.4% baryons, 22% dark matter and 73% dark energy."
Baryons
:)
Dark Energy
Dark Matter
Hope this helps you out a little.
~D:
13.7 billion years old, flat, 4.4% baryons,
95% We don't know.
More information can be found at (including a cosmology tutorial):
w s
http://www.astro.ucla.edu/~wright/cosmolog.htm#Ne
This press release was mentioned in a post in the previous slashdot story yesterday.
Mass media coverage can be found at CNN and the BBC. A list of all the MAP papers can be found here.
You only get 73% of you daily dose of dark matter. That would leave eating bowl after bowl after bowl. Try my new "Extra Dark Total Universe" and get 100% of your Dark Matter in just one bowl!
If religous zealots don't believe in Evolution, then why are they so worried about bird flu?
A baryon is a particle such as a neutron or proton. It's one of the two main classes of ordinary matter particles, the other is the lepton (e.g. an electron or neutrino). Baryons "feel" the strong nuclear force, leptons do not.
Dark matter refers to exotic forms of matter that are "ordinary" from a gravitational point of view, that isn't made up of baryons or leptons. This stuff either interacts weakly with ordinary matter, or doesn't interact at all (other than via gravity).
Dark energy has positive energy but negative pressure, so it causes a gravitational repulsion. Einstein's "cosmological constant" one possible example of dark energy. It can be thought of as a property of space.
4.4% baryons, 22% dark matter and 73% dark energy.
The recipe for coke ?
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
13.7 billion years old, flat, 4.4% baryons, 22% dark matter and 73% dark energy
Except for the age part, that sounds a lot like my ex-girlfriend.
Happy Valentines Day everybody!
Confused by "Dark Energy," "Vacuum Energy," "Dark Matter," and "Exotic Matter?" Here's a great collection of papers. (Mostly from the SNAP project)
[-- Trust the Monkey --]
"MAP, an Explorer mission, cost about $145 million."
If I understand correctly...
Measuring the age of universe, calculating initial proportions of baryonic matter vs. energy, and deriving shape of universe: $145M.
Shuttle flight to install ISS module: $500M.
Shuttle flight to watch ants float in zero-G: 7 deaths, $500M for launch, $2.0B for new shuttle.
Your Congressional District's seat at the trough of Shuttle/ISS pork: "Priceless."
Now that I've bashed, some constructive criticism - cut NASA in half.
One half - NAA - I'll call the National Aeronautics Administration. Its job will be pure Aeronautics. Launch vehicles. Rockets. Engines. From pricy Shuttles to half-decent Shuttle-C heavy-lift modifications, to cheap expendables, to funky crewed vehicles like X-33, VentureStar, or DC-X.
The other half - N(whoops!) let's call it the NSSA - National Space Science Administration - will do science. Build probes. Stick 'em on rockets built by the NAA, or LockMart, Boeing, or Armadillo, and do some frickin' science.
Under such a scenario, we could have avoided the Shuttle/ISS debacle completely; NAA might have had concerns about losing funding once the last Shuttle was built, and probably would have had a significant incentive to keep asking Congress for funding to build newer, better, cheaper-per-pound launch vehicles.
Why? Because they'd be under competitive pressure from every other contractor under the sun building launch vehicles to launch NSSA's space probes. Perhaps NSSA would have come to the same mistake NASA did - and decided that we Really Needed a Space Station - but even if that were the case, the design requirements of ISS would have immediately mandated a heavy lift vehicle, wholly unlike the Shuttle.
In such a scenario, NSSA would have had the choice between building ISS with three FooCorp Big Dumb Booster flights, or 30-40 NAA Shuttle flights.
Unlike the current NASA monolith, in which both halves exist to feed each other, a separate NSSA would have been loathe to spend its hard-begged budgetbucks to use another government department's (i.e. "NAA's") Shuttle, particularly in the face of cheaper alternatives. (And likewise, NAA, seeing that it had no Shuttle customers, would have been forced to spend its hard-begged budgetbucks building the Shuttle's successor, or find itself on the Congressional chopping block.)
In astronomy, "baryons" can also include "leptons", simply because leptons are included in the mass that one measures using a galaxy rotation curve.
"MAP ... to study variations in the cosmic microwave background, to much greater accuracy than the COBE satellite"
And their web page is better too. My satellite can beat up your satellite!
IBM had PL/1, with syntax worse than JOSS,
And everywhere the language went, it was a total loss...
I would interpret this to mean the following:
(no profit recycling please)
1. 4.4 of the energy is stored in atomic nucleuses and some exotic particles.
2. 22% is stored in matter we can't directly observe, but can observe its effects on surrounding objects.
3. 0.6% is electrons and other small mass particles, measurable energy, etc.
Guess: Up to 73% of the original mechanical energy of the big bang is still in the form of mechanical energy (kenetic energy + potential energy).
Guess#2: Or 73% of the original ME of the big bang has been lost to entropy.
Aside Question: Given 2 objects of the same mass and potential energy at rest. Raise one of the objects to a higher potential. Does that not raise its mass relative to the first since the mass is its total energy/c^2? I remember NASA was puzzled by the Voyager probes not making it as far out as they expected them to be by now. Perhaps because they gained mass relative to us? Also, if 2 objects accelarate relative to each other and thier KE increases (relitively), does that not increase the mass, and their for the attraction between the two objects?
Bah, time to RTFA.
Any sufficiently advanced influence is indistinguishable from control.
[darkhumor style=kurtvonnegut]
It turns out some researchers called it God at first but that doesn't look as well in print outside of sacred texts. You know, "God is everywhere, but unevenly distributed and is repulsive, not that anyone would notice or at least they have not. Only we did notice so we're L337 and we're forming our own religion. We hereby declare all other religions apostate and anathema on the strength of our observations."
We pagans know all about Dark Energy. Heck, we're obsessed with it. Only I'm a little surprised that it's not more than 75% of the known universe. I bet a lot of the Cold dark Matter will turn out to be wanna-be Dark Energy too, just tettering on the edge of going over for the last few billion years.
The idea that only 4% of the Universe is "normal" really lines up with the notion many witches and Zen masters subscribe to, where 96% of Everything is utter nonsense. But you can still have loads of fun with the other 4% if you lay your hands on a good spell book. Just don't forget to close your sacred circle, and properly call the gates, and sanctify your athame first. Bless us but you don't want to upset the balance of entropy and cause any of that loitering Cold Dark Matter to get any fancy ideas.
[/darkhumor]
=^..^= all your rodent are belong to us
In Other News:
God, having recently been photographed in the microwave part of the spectrum, has held a press conference. Her spokesangel says "The Almighty resents this intrusion on Her privacy and just wishes some respite from the snapping of paparazzi hounding Her all day and night, never a moment's peace. She will now retire to a private part of the universe for some escape from the tabloids, thank you. But really, She is most upset about those faked pictures of Her wearing a beard. Have you no decency at all?"
God was last seen as a filmy blotch, one millionth of a degree warmer than the next blotch, in the general vicinity of the constellation Sagittarius. She was wearing a floral kimono and sandals from Gucci.
=^..^= all your rodent are belong to us
L2 is nice for several reasons. The instrument on MAP needs to be kept cold. Sitting at L2, the spacecraft can keep the instrument pointing away from the Sun, and still measuring data, without ever needing to worry about interference from the Earth or Moon, and there is this nice big dish (the solar array) shielding the instrumentation from direct sunlight. In addition, NASA has lots of experience with spacecraft at the collinear Lagrange points (L1 and L2), so the orbits and communications are very well understood there. And L2 is far enough away from the Earth-Moon system to avoid complicated orbit perturbations, but close enough for relatively easy communications (that is, the radio doesn't have to be too big).
Hope that helps!
A signature always reveals a man's character - and sometimes even his name. -- Evan Esar
You've got to remember that the terminology astronomers use is a bit...different. This is much like how they call anything heavier than helium a "metal".
But then again, I could be wrong.
nope.
Astronomy/astophysics pays my bills, and I can tell you that 4.4% of baryons from WMAP really means anything that is known in particle physics as quarks, leptons, blah blah blah.
A rule of thumb is that 'baryons' in astronomy/astrophysics is anything that is in the standard model (sans the higgs.)But that's not the whole story.
"baryons" (in the 4.4% of WMAP) is classified as matter that is not "dark". "Non-dark" means it interacts with other stuff and itself beyond just pure gravitation. That includes "radiation", which is stuff that behaves relativistically, and include things like photons, neutrinos,a nd perhaps other relics.
To summarize, there is no difference between "baryons" and "baryonic matter" in astronomy.
I will not call a lepton a baryon, but I will definetely lump leptons in when I say 4.4% of ther universe is made out of baryons. it's just a matter of context, and people in the field will udnerstand that.
Really, astrophysicists are sloppy when it comes to naming stuff. So you have to be careful not to read too much into nomenclature like this, even in the era of "precision cosmology".
Mode (3) smart-aleck mode. Press * to return to main menu.