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NASA and DoE Team On Dark Energy Research
Roland Piquepaille writes "NASA and the U.S. Department of Energy have teamed up to operate the future Joint Dark Energy Mission. As you probably know, recent astronomical measurements have showed that about 72% of the total energy in the universe is dark energy, even if scientists don't know much about it, but speculate that it is present almost since the beginning of our Universe more than 13 billion years ago. The JDEM 'mission will make precise measurements of the expansion rate of the universe to understand how this rate has changed with time. These measurements will yield vital clues about the nature of dark energy.' The launch of a spacecraft for the JDEM mission is not planned before 2015."
Come on.... "Dark Energy" this should have everyone wearing some form of mask and a black uniform with just a simple white spark on it or something. We complain about not getting kids into science and then when we get something with one of the coolest sounding names around we make it into something dull and boring.
"Dark Energy has been around for 13 billion years but no-one has been able to harness it. Do you have what it takes to join the Legion of Dark Scientists?"
An Eye for an Eye will make the whole world blind - Gandhi
Once they form the Department of Dark Energy they could post job ads reading "Come to the dark side".
Once scientists understand that space and matter is the same thing (something you should be able to test and prove here on earth) they should understand that dark matter is just space.
What they're doing by measuring the anomalies with galaxies, and on the smaller scale by making atoms clash together in large colliders, and looking at the results is basically just measuring an effect, and it's really interesting that they aren't doing it with a clear understanding about what they're measuring or why.
What I mean by that is that they aren't doing this testing/measuring to understand the underlying implications, they're doing it to test current mathematical models, and that's why we've failed to understand so-called dark matter and what it really is.
We're probably at the same point in time with dark matter as when scientists before Isaac Newton were pondering the rotation of planets around the sun. there was extensive research into the behavior of the planets, and mathematical models for them going around the sun (as in measuring an effect), but it took someone like Isaac Newton to show people that there is an underlying force that keeps planets around the sun and the same keeps us rooted to the ground.
When someone finally thinks that space and matter must be the same thing, and starts to test that theory and see where and how the 2 match up, we should finally be able to clear up this dark matter nonsense.
Of course Einstein started this with his e=mc^2 - but no one has really looked at this formula when it comes to space and not matter, he looked solely at matter.
Of course being a couch-scientist (worse than amateur scientist), I might be hugely wrong, but somehow, I don't think I am (surprisingly).
if there's so much dark energy in the universe, then why don't we have any local in our own little solar system or planet? how come dark energy only makes the science of things far away off-kilter, yet all our science locally we can measure to 9 or more decimal places? seems like an awfully big fudge factor, if you ask me.
Actually DOE has always been deeply involved in high energy (particle physics) research. They fund a number of accelerators, including Fermilab. Its not clear that any of that research would lead to usable energy sources either.
You can see the Dark Energy research as the intersection of high energy physics (DOE) and cosmology (NASA).
I was always a skeptic when it came to Dark Matter(I am not an astronomer, so this all technically an uniformed opinion). But now I know that it really is all a load of idle speculation coupled with incomplete investigation, and an excessive dose of hype. It only took a few minutes of googling to come up with this paper.
One of the biggest pieces of evidence for Dark Matter is the Galaxy Rotation Problem. Basically the rotations of Galaxies do not behave as astronomers expect them to do, leading to the hypothesis that there is more matter in them that we cannot see, "Dark Matter". The velocity profiles that Astronomers expect to see are Keplerian. That is, they expect star systems in galaxies to behave like planets in solar systems when it comes to orbit speed and distance from the focus of rotation.
The bottom line is, as shown in the paper, this assumption is totally unjustified. The integrals in the 2D galactic disc case do not work out using Shell Theorem, which cannot be applied. They are instead quite nasty singular integrals, but twenty minutes with MATLAB and the "QUAD" function will be all it takes to see that basic gravitational theory most certainly does not predict that Galaxies should have Keplerian(Solar System-like) rotation curves, and there is no reason whatsoever for astronomers to assume this. It's all basic mathematical physics well withing the reach of many reading this post.
The galactic rotation problem is not evidence for Dark Matter. It is only evidence of the need for more applied mathematics courses in astronomy undergraduate degrees. Of course the Galactic rotation problem is not the only evidence for Dark Matter, but it is a big part. The other big piece of evidence was the Galactic Cluster mass problem. It's been a while since I read the relevant papers, but as I recall, Zwicky played hard and fast with the virial theorem, in particular making assumptions about the stability of Galactic clusters.
Again of course, I am not an astronomer. I am essentially a lay person in these matters, so my posts and opinions (not only in this thread) should be taken with a pinch of salt. Still, I stand by my overall skepticism of Dark Matter theories, and I stand quite firmly on my objections to the interpretation of the Galactic rotation problem. I expect that in the near future, as our ability to analyse and simulate galatic dynamics improves, Dark Matter will finally be debunked.
May the Maths Be with you!
The launch of a spacecraft for the JDEM mission is not planned before 2015.
I have to wonder if this launch has any input from the Department of Redundancy Department.
The lack of specificity in your invitation to a dick-swinging contest is ... illuminating.
You can see the Dark Energy research as the intersection of high energy physics (DOE) and cosmology (NASA).
Except, I don't really see how high energy physics is involved. I mean, it's not as if anybody has proposed a high-energy experiment that could detect it.
Is it true that, presuming one can't grasp it, dark energy doesn't not matter ?
The idea of a luminiferous aether followed naturally from the observation that light acted like a wave, and one of the fundamental things about waves is that they travelled in a medium.
This lead to experiments designed to detect the medium of light (like the famous Michelson-Morley one), to the Lorentz transformations and the Theory of Relativity. The aether conjecture is science at its best: hypothesis, experiment, falsification, paradigm shift. Why it's used as a metaphor for stupidity has always been a mystery to me.
Except, I don't really see how high energy physics is involved. I mean, it's not as if anybody has proposed a high-energy experiment that could detect it.
Ultimately, there must be a particle-physics-based explanation for Dark Energy, whether from string theory or something other theory.
And just because Dark Energy not accessible via "classical" accelerator experiments, this does not mean that it should not be considered experimental particle physics research. In other words, instead of using a ground-based accelerator, the Universe is the "poor man's" accelerator.
Bush even got it into an arms research race with the Protoss!
And if you replace "String Theory" with "Dark Energy Theory" in your statements above, it reads exactly the same. Remember "epicycles?"
In fact, paradigm shift was a useful expression long before it was hijacked by business consultants. I suppose this is the destiny of any phrase that describes, shall we say, a great leap forward -- to be misused and misapplied until people end up forgetting what it once actually meant.
How would you prefer the search for a unification theory to proceed? And why are you so angry? It's not for you to decide how people who are smarter than either of us should spend their time.
Remember "epicycles?"
This is another of those "dumb science" metaphors that are flung around with no regard for history. The heliocentric model of the solar system did nothing to solve the problem of epicycles, and given what was known at the time, would you have come up with ellipses?
If NASA and the DoE start yanking on the Dark Energy in the Universe, they might find that attached to the other end are . . . Dark Energy Creatures.
They might not be amused with the antics of NASA and the DoE.
"Hey, you, Earthling! Is this your Joint Dark Mission Probe, that just broke my window?"
You have been warned.
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
I'm surprised by the low quality of comments so far. Must be the fallout from Turkey Day here in the US... Anyways, Dark Matter and Dark Energy are two very different concepts. Dark Matter is what makes the universe clump together. Galaxies are just the markers or highlights in the densest spots of the Dark Matter distribution, pretty much like foam on the tips of waves. There's plenty of observational evidence besides rotation curves. Simulations of the evolution of the universe these days are pretty much Dark Matter simulations, and they work out surprisingly well coming up with the string/plane and void structure that we observe today. I don't think there's too much left to discuss there concerning the existence of this stuff, even though we do not know at all what it is made of in terms of particle physics constituents (there are plenty of hypotheses of course). Sorry if you missed it... (Seriously, there's a huge job left trying to explain science to the general public. Especially if we want to keep getting funded...)
Dark Energy is a more speculative concept, but the basic fact that galaxies at far enough red shifts seem rarer than even flat cosmic evolution models tell is hard to discuss away. Basically, the universe expands faster than even a completely empty universe would, so you need something else than matter (baryonic = visible, or dark). Adding matter would just make it clump more and slow down the expansion.
Now, the cool thing about all these Dark Energy projects and missions (with JDEM just being the biggest of them) is that no matter what you find in the end, you will learn a great deal about the time evolution of the universe, by looking far back into vast areas of space. Counting supernovae, deducting the lumpy structure of matter (dark & visible) by observing distortions in the distribution and apparent shape of galaxies, all this gives you sort of a time-lapse movie of the large scale evolution of the matter distribution. Just google dark energy, or have a look at the DES white paper (https://www.darkenergysurvey.org/the-project/survey_documents/DES-DETF/DES-DETF_whitepaper_v1.7.7-final.pdf)if you want to learn more about this stuff.
Actually DOE has always been deeply involved in high energy (particle physics) research. They fund a number of accelerators, including Fermilab. Its not clear that any of that research would lead to usable energy sources either.
Good so far.
You can see the Dark Energy research as the intersection of high energy physics (DOE) and cosmology (NASA).
Yes, but don't forget that DOE has its own cosmologists, too. The DOE end of JDEM is being handled by Lawrence Berkeley National Laboratory, which has quite a bit of stuff going on in cosmology, mostly under its physics division.
(I do some work with one of the collaborations based there.)
Village idiot in some extremely smart villages.
scientists don't know much about it, but speculate that it is present almost since the beginning of our Universe
BAD BAD BAD... REALLY?! I could've sworn that [it] WAS present.
And here I was thinking that it has been present.
This is my sig. There are many like it but this one is mine.
g/cm^3
So that is what a ZPM gets it's power from now we need a way to make them and we better do that off world.
If you want to reconstruct the expansion history of the universe, you need to know where various objects were located in the past.
By looking at the redshifted light from a distant star, you can tell by what factor the universe has expanded. (It's equal to the factor by which the wavelength of light is stretched.) By the Hubble distance-redshift relation, you can tell how far away the star is: in an expanding universe, faster moving and more redshifted stars are farther away. That relation only works if the universe's expansion isn't accelerating, though.
You can also tell how far away a star is if you know how bright it is. If it looks really dim compared to its true brightness, then it's far away. This method of measuring distance only works if you know how bright the star really is. There is a special kind of supernova (Type 1A) which always has the same brightness. (Or rather, there is a known relationship between its brightness and the rate at which it fades out after the nova.) If you look at those stars, you can measure their distance just from their apparent luminosity.
The problem is, the two methods don't agree with each other: some supernovae are much dimmer than the redshift Hubble relation implies. That implies that something made them accelerate away, since the Hubble relation assumes no acceleration. By comparing the two measures of distance (redshift-inferred and brightness-inferred), you can work the amount of excess acceleration. This is dark energy.
The JDEM mission is supposed to measure supernova redshift and brightness, and thus measure the strength of dark energy.
See here for more information. This article is on SNAP, the predecessor to JDEM.
This will kill my karma, but I just have to ask: isn't all this "something we can't see that's messing up our physics" putting us off the possibility that our physics models may just be flat out wrong?
I mean, would we have a relativity theory if Einstein had stuck to Newtonian physics and stated that the errors measured were caused bay some misterious force/matter/energy that we couldn't see?
For those wondering why the Department of Energy is building a space telescope rather than focussing on nuclear things, the Department of Energy funds the SLAC Linear Accelerator centre at Stanford and it's people at that centre who have designed SNAP, a spacecraft that happens to fulfill exactly the requirements NASA put forth for JDEM.
The Dark Energy Mission is a wide-field high-resolution space telescope; a hundred million or so pixels of 0.2 arcsecond extent, and a five-foot main mirror. The idea's to survey most of the sky at about four times the resolution possible from Earth (adaptive optics, which are useful for very high-resolution imaging of very narrow fields from Earth, are not useful for these large fields).
There are two mission models: take pictures of galaxy clusters and work out the mass in them implied by the way the gravity of the foreground cluster distorts the light from background galaxies, and take pictures of lots of galaxies looking for supernovae.
It's perhaps not entirely accidental that this large-scale high-resolution survey work will produce very attractive images of the sky for outreach, a task at which the JWST replacement for Hubble, being aimed more at work in the infra-red and on the faintest and most distant objects, is not as superb as Hubble.
Lindsay: Yes. For example, no one was showing up for jury
duty, so we made the experience more exciting by
synergizing it with his comic book collection.
[cut to Moe's tavern. Moe opens an envelope]
Moe: [reading] You have been chosen to join the Justice
Squadron, 8 a.m. Monday at the Municipal Fortress of
Vengeance. Oh, I am *so* there!
given what was known at the time, would you have come up with ellipses?
Probably not. But the elliptical solution had been known for around 1000 years before it became generally accepted, having been discovered by Aryabhata, c. 500CE.
My understanding is that Aryabhata also used epicycles to model planetary movement (and by the way, even if they're not literally there, they can be incredibly accurate, which only adds to my annoyance at the way they get ridiculed). I've heard about the ellipse thing, but never seen any evidence (which, naturally, doesn't mean it's not true!)
I'll wager that this dark energy stuff is actually laziness, and there's heaps more of it than anyone ever imagined.
In other news, astrophysicists have announced that they now know what all that dark matter is: it's stupidity.
I realise you're trolling, but I suggest you read Structure by Khun.
Nick
No, obscurati is already taken. It's defined as "persons claiming to understand Dennis Miller's jokes."
No, you're trolling because the tone of your post seems designed simply to get maximum responses by aggressively attacking a strawman.
In fact I wasn't defending string theory at all, just the phrase paradigm shift. My point about Structure still stands and, troll or not, you'd be better off for reading it.
Nick