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Biggest Detector To Look For Gravitational Waves
Hugh Pickens sends in coverage in the Telegraph of a joint NASA-ESA experimental mission, to launch around 2020. It involves three spacecraft orbiting the Sun, separated by 3 million miles, each with a payload of two lasers and a 4.6-cm cube of gold-platinum alloy. The point of it all is to look for gravitational waves. The mission is called LISA, a reasonably non-strained acronym for Laser Interferometer Space Antenna. The Telegraph makes a point of LISA being the largest experiment ever constructed (in terms of its dimensions). Neither that newspaper nor the project page at NASA mentions how much the experiment will cost, but it's almost certainly an order of magnitude or more above the $66 million estimated for a gravitational wave detector the size of the galaxy, which we discussed last fall.
I read that as a 4.6m cube of gold/platinum alloy and was thinking that was just the sort of thing Lex Luthor would want to steal.
Now come on, it'd make a great show ...
"Cats like plain crisps"
Shooting all our remaining gold into space so they can shine lasers at it. Typical.
This detector would be 3,000,000 miles across when measured from one man-made component to another. The article linked to as a 'galaxy sized detector' is actually about a proposal to observe pulsars looking for the effect of gravitational waves.
When observing pulsars, I assume it is not possible to be 100% of what one is seeing, considering that pulsar observations continue to accumulate and scientists have not had the chance to see a pulsar close-up.
In comparison, using man-made scientific instruments, which are much more under the control of the investigating scientists, to perform the measurement is more trustworthy than observing pulsars. In this regard, the huge scale of the equipment (3 Million Miles) is very significant -- the instruments will be able to make a fine measurement across this distance -- and comparing it with the size of the galaxy is not really a valid comparison.
On the other hand, the snark-value of the comparison was high, and providing the link without these details only raised the snark-tasticness.
From memory, LISA is usually listed as being in the $1.5- $2 billion dollar range, which puts in the same category as Hubble or the forthcoming James Webb telescope.
Worth every penny, too, in my opinion.
What happens if they don't find anything?
Do gravitational waves radiate energy? Have we seen instances, such as during a supernova, where there was missing energy which could be explained by them?
http://www.masturbateforpeace.com/
I believe the slashdot summary and TFA are misleading, because they make it sound like LISA will definitely be built. According to the WP article, LISA is competing against two other space-based science projects for funding, and the decision won't be made until 2013.
Personally, I would love to see LISA fly. Gravitational waves were first predicted in about 1914. Most aspects of general relativity have been tested pretty thoroughly at this point, but almost a century later we still have no direct confirmation that gravitational waves exist (although there is very strong indirect evidence). And if they can be detected, then it opens up an entirely new way of doing astronomy: not with electromagnetic waves, but with gravitational ones.
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Damn, I thought one could just write papers to prove something. Now we have to spend millions.
I bet gravity "waves" don't exist.
As I recall, the last LISA was [also] a grossly overpriced failure.
Won't the Ferengi attack the satellites to steal the gold-pressed latinum?
by TheSpoom (715771) Uncaring Linux user here. I have nothing to add to this but please continue. *munches popcorn*
Just point it in the general direction of their local Jenny Craig, or wherever Kirstie Alley happens to be.
Just to let you all know, LISA and the Pulsar observations are not observing the same things. Sure they are fighting to detect the first gravitational waves but they are looking at different regimes. Its like comparing the GBT radio telescope to Hubble, they are fundamentally different even if they are looking for the same type of objects. http://www.physik.hu-berlin.de/qom/research/freqref/lisa explains what frequencies LISA will be sensitive to. The Pulsar array is most sensitive to 10^-4 where as LISA is higher frequencies. LIGO is even higher in frequency. You learn about different objects and new phenomena by studying ALL frequencies available to you. Many astronomy projects are expensive as hell but they develop new technologies that benefit our daily lives. Who knows what laser interferometry in space will generate for the public funding the project.
I never understood how it is that people expect that the shape of gravitational influence between things in the universe could somehow be different than the mass/energy distribution of the actual objects.
If there are black holes quickly orbiting each other then anyone at a constant distance from the center of the orbiting black holes will see their gravity change as the black holes get closer and farther away from them... No mystery..big whoop.. nothing worth going out of your way to research. When you throw in realitivity objects moving realitive to each other see a mass and therefore gravitational difference based on the lorentz factor... again well understood... no mystery...
My second statement because I love basking in my own ignorance.. why do we need massive distant objects to show that gravity waves exist again? Doesn't gravity follow a sqaure law.. and these objects are how far? If we can use gravitometers to map oceans or determine the density of rocks a few feet under the ground why can't we just as easily detect gravity waves from nearby local objects here on earth under our direct control?
Maybe I just don't believe in gravitational waves because for godsake I'm too stupid to understand what the hell they are even supposed to be.
Shootin' all our remaining gold inta space so they can done shine them laseeebeams at it. Dagnammit!
FTFY.
Wouldn't a lump of lead work as well and be cheaper?
Years ago I rented a tiny travel trailer that was quite old. The rent deal was fabulous and the guy that owned the park was a good fellow. At any rate I seem to have created my own gravity wave. I bedded a young woman and in the act of passion all four legs of the bed shot right through the floor. I never missed a stroke.
The fellow that owned the park came to make the repair the next day while the girl was still there. After he put in a new floor in the bedroom I entered and he congratulated me for the strength and success of my passions.
The moral being that if we musty have gravity waves we should get some good fun out of it!
There are noe gravitional waves. There are no black holes. There are no dark matter. There are no dark energy. There are no big bang.
We need fresh, new ideas which actually make an attempt to explain what we observe.
Star Trek - miseducating nerds for over forty years!
... each with a payload of two lasers and a 4.6-cm cube of gold-platinum alloy ...
... which they intend to use as a duodynetic field core. 5 or 6 pounds should be sufficient.
We know the Holy Grail is to have a Grand Unified Theory of the four forces. To date, three have been combined with gravity being the lone holdout.
Is there a reason why gravity can't be a force unto itself but rather, the result of the other three forces? By that I mean, since the Strong and Weak forces hold things together, is there some reason they can't be creating gravity with their forces weakening the further out you go, similar to how radio waves get weaker as they propagate outwards.
Even though this experiment is an attempt to detect gravitational waves, since we haven't found any to date, could the above be a different explanation for why we haven't found any (yet)?
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
They won't find one. Why? Because gravity is a feature of mass in space - not a force or an energy. There are no gravitons and there are no gravity waves.
Will we ever find out if 64 really is the answer? Is our universe base 8?