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China Building World's Biggest Radio Telescope
Zothecula writes "Since its completion in 1963, the Arecibo Observatory in Puerto Rico, with a diameter of 305 m (1,000 ft) and a collecting area of 73,000 square meters (790,000 sq ft), has been the largest single-aperture radio telescope ever constructed. But Arecibo is set to lose its title with construction now underway in Guizhou Province in southern China of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Upon its expected completion in 2016, FAST will be able to see more than three times further into space and survey the skies ten times faster than Arecibo."
than the trend towards arrays of radio telescopes? Is this just for bragging rights or are they interested in really pushing the bounds of what the technology can do?
Given the 5 to 3 ratio in apertures between the two telescopes, I think that it will be able to "peer" (25/9)^0.5 = 5/3 = 1.67 times "further into space," where "peer" means resolve an object at a given signal to noise ratio. Collected light scales with the square of aperture, but signal to noise ratio only improves with the square root of the number of collected photons. In more useful terms, it should be able to resolve the same thing to the same statistical certainty in 3/5 of the time.
"I zero-index my hamsters" - Willtor (147206)
More radio telescopes are generally a good thing. One of the major tensions in the field now is whether one should have large radio telescopes or lots of comparatively smaller ones that coordinate their work. Both methods have different advantages. Lots of smaller telescopes linked has the major advantage that if some of them go down for some reason one can still do good science. However, the larger ones can have lots of neat technologies. As TFA discusses, this telescope (FAST) will be able to deform its mirrors in real time to focus on sources. That will help a lot for work on faint radio sources.
However, I'm not sure that this is the best use of resources. As discussed in TFA, the Square Kilometre array is being built by a variety of countries working together, and it will do a lot of the same stuff. http://en.wikipedia.org/wiki/Square_Kilometre_Array However, the SKA and FAST will be looking at different regions of the sky, and where they do overlap will be looking at different times. So overall this is helpful. Personally, if I were going to be putting this much resources into interesting Earth-based astronomy, I'd probably want to focus more on increasing our neutrino detectors. We're not investing very much in that, and it is a very new, very interesting field of astronomy/astrophysics. Moreover, neutrino astronomy is pretty much the only thing that can give us warning (albeit only a few hours) if a nasty supernova happens in our vicinity. Right now, that doesn't look likely, but it would be nice to have some warning in case our models are off. Moreover, even without a threat issue, since neutrinos can arrive before the light from a supernova (since the neutrino burst occurs before most of what we would call a supernova, and neutrinos travel at very close to the speed of light), they can help us point our optical and X-ray telescopes in the right regions before we the light reaches us, which is really helpful for advancing our understanding of such events.
Overall though, shouldn't be complaining. It is very difficult to get almost any good funding now for astronomy and cosmology research. In that regard, this is a good thing.
yay! more data for the SETI mesh to chew on.
Trying to steal intellectual property from alien lifeforms. Clever, clever bastards.
Don't just game, Dungeoneer
We CANNOT have a Telescope Gap! /with apologies to George C. Scott
Do not look into laser with remaining eye.
Nothing's keeping other countries from making advances of their own, except their own stupidity, short-sightedness, and greed. If you want to do something great, then go do it instead of wasting your money on stupid wars and corporate welfare.
the Arecibo Observatory in Puerto Rico
What the heck is that?
*googles it*
Ohhhh, why didn't you just say "the dish thingy from GoldenEye"?
I always thought that in radio astronomy you can accomplish more by a lot of small radar dishes linked up than with one single huge one? Wasn't there at some point a plan to send a bunch of sats up that would fly in formation to form a friggin' HUGE (read: several thousand miles) array for radioastronomy?
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Why are you trying so desperately to turn any discussion about China into a political one?
Well, why not? Every discussion about the US turns into a long list of complaints about how either a) America sucks and has always sucked, or b) America is giving up its superpower status to the Chinese.
I would care less about the news of a Chinese large-aperture radio telescope if Arecibo weren't constantly held under the axe of NSF funding cuts. We need at least one operating on the planet to track earth-bound asteroids, among other things, and there's no guarantee the U.S. Congress will keep ours operating.
See, you buy stuff at WalMart, and you fund a radio telescope!
Actually they've got so many big projects going that they're waving their scientific instrumentation dick around and building important and useful infrastructure projects at the same time.
I dunno. The politics over SKA, where it would be located, etc, show that people do indeed care. Nobody can put a telescope even the size of the Lovell dish into space, never mind the size of this monster. Single dishes have benefits (such as reduced edge effects) that arrays do not, which is extremely important for some of the science needed. Radio telescopes are still the only systems you can build large interferometers from (you can do small optical interferometers, but that's it). RFI is an increasing problem for radio observatories, due to flagrant abuse of the spectrum by many nations, and it's much easier to shield one site than a hundred. Precision-engineering a single dish of this size will require advances in material science that will have spin-off benefits in other fields.
In short, there's lots of reasons for them to do this and no obvious reason for them to copy SKA or SHA.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Worse, Arecibo is deformed, requiring complex hardware to compensate. There's bound to be some loss of quality when trying to compensate. Also, it's an old telescope now. There have even been plans to shut it down, which would likely go through if presented to Congress today. If China had a rival, even if only of equal size, astronomers needing a single dish rather than an interferometer would have no alternative but to buy telescope time from them.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
well... really damn big variable-geometry parabolic dish + high-output magnetron = enemy satellites go boom. Why need a radio transmitter or fancy expensive satellite-killer missiles when you can just fry the enemy sats from the comfort of groundlevel?