The Square Kilometer Array 131
EyesWideOpen writes "A very ambitious project to build the world's largest radio telescope, named the Square Kilometer Array or SKA, is in its early design stages. As its name suggests the SKA will be one square kilometer in size if it gets built. The SKA consortium (consisting of Cal Tech, Cornell, SETI, the Max Planck Institute and Beijing Astronomical Observatory to name a few) hopes to build the telescope by 2010. "If they succeed the SKA will be so big and precise it will jump the world's current best, the American Very Large Array in New Mexico, by a factor of 100, both in sensitivity and resolution." It's interesting to note that the project is based on technology that will only exist in three, five or seven years -- to account for data rates of tens to hundreds of terabytes per second and storage in the petabytes -- so they're counting on Moore's law to hold true."
SETI (Score:2, Funny)
Moore's Law (Score:2)
Moore's law only talks about cost, not about maximal hardware performance. If Moore's law doesn't hold, the project will only be much more expensive, but still possible.
Re:Moore's Law (Score:1)
Re:Moore's Law (Score:1)
Re:Moore's Law (Score:2)
It is somewhat daring, but I wouldn't call it a gamble. If something doesn't end up scaling in time they'll just have to deal with a bottleneck in the system for a few years. Necessity being the mother that it is, they'll still manage to make the SKA (it's not just a musical genre anymore!) useful. Remember how much grief Hubble got when it first went up?
Re:Moore's Law (Score:4, Informative)
Re:Moore's Law (Score:1)
How many? (Score:1)
Re:How many? (Score:1)
Re:How many? (Score:1)
Re:How many? (Score:1)
So the hard-disk manufacturers will tell you, but it's not actually true.
1Kb = 2^10 bytes = 1024 bytes
1Mb = 2^20 bytes = 1024^2 bytes
1Gb = 2^30 bytes = 1024^3 bytes
1Tb = 2^40 bytes = 1024^4 bytes
Re:How many? (Score:1)
> So the hard-disk manufacturers will tell you,
> but it's not actually true.
>
> 1Kb = 2^10 bytes = 1024 bytes
not the hdd manufacturers, but the SI tells me "kilo" is a factor of 1000. there actually had been a SI proposal once, associating the factor 2^10=1024 with the prefix "kibi" - for "kilo binary". so 1 kibibyte would be 1.024 kilobyte.
Re:How many? (Score:1)
We all know that a kilobyte isn't *really* 1000 bytes.... what is the point of inventing stupid new contrived words to clear up ambiguity that didn't exist in the first place??
Re:How many? (Score:1)
Re:How many? (Score:2, Informative)
Re:How many? (Score:1)
Argh, I was a litle to fast there.. it is of course 1024 TeraBytes, 1048576 GigaBytes or 1073741824 MegaBytes.
ET Phone home! (Score:1)
Re:ET Phone home! (Score:2)
Not everything worth doing can be monetized.
Re: SKA = SUV??? (Score:2, Insightful)
>
> Or is it just a matter or "because we can build
> something bigger, we should"?
Larger telescopes = the ability to see farther.
So a more apt question would be "Should we explore further, just because we can?"
Isn't the answer obvious?
A very small number of people actually explore our planet and universe. Most of the rest of us sit home and watch them do it on the Discovery Channel or National Geographic specials, and are amazed. The rest prefer the Home Shopping Network and say "who cares about the rest of the universe when we have cubic zirconia?"
> Isn't this what led to the Escalade and the Excursion?
Wow, you're actually comparing bigger and better scientific instruments to ever-larger SUVs?
Eventually, larger telescopes will probably allow us to see the edge of the universe.
They will probably allow us to image planets around other stars.
Then continents on those planets.
Who knows what else we will see. Cities?
As we understand them today, the laws of physics confine us to traveling within our own solar system, but we have the ability see much, much farther. Aren't you interested?
Re: SKA = SUV??? (Score:2)
No, the more apt question is how much of our resources should we spend on exploration (meaning science). Of course, I think it should be more than we spend now.
Also very important is, of that amount, how much do we put into big science projects, and which ones... do we put it into big telescopes, massive accelerators, fusion devices, proteonomic surveys, earth observing satellites, or which? Since there isn't an infinite amount to spend, unfortunately choices have to be made. Even more unfortunately, too many these days are made by politicians.
The proper place of politicians in this issue is how much of our finite government resources should be spent on public science projects, not which projects.
Re: SKA = SUV??? (Score:1)
I understand what you mean, but that's a little like saying "This prison cell does not keep me from escaping, my lack of ability to bend inch-thick steel bars does."
By "us" I meant the current crop of Homo Sapiens. Given the current state of the species, we are effectively confined to this solar system.
If you mean "we will not always be confined" I agree, but we must answer several Large Questions first, and big telescopes like the SKA may well help us answer those questions.
Re:ET Phone home! (Score:1)
Re:ET Phone home! (Score:2)
What are you talking about? There are lots of radio images [nasa.gov] around.
Whether it's "audio" or "video" depends only on whether you're using a point detector (like a radio receiver or a photodiode for visual light) or a spread out detector (like a lens or an array of point detectors).
1sq.km (Score:1)
talk shows? (Score:1)
If built. (Score:1, Funny)
--saint
Who is the Creator? (Score:1)
So, they're looking for God then? Which one do you reckon they'll find?
Answer on a postcard please, to the usual address. Cheers.
Re:Who is the Creator? (Score:2)
Re:Who is the Creator? (Score:3, Funny)
Why does she run? (Score:2)
True, assuming you believe that God is omnipotent. The real question is, what are its motives and why does it hide? I naturally mistrust anything with that much power.
Re:Very wrong direction for astronomy. (Score:2)
It's important for a radio telescope to be large (see my other post). Size (at least here
Simon
Re:Very wrong direction for astronomy. (Score:2)
What's the difference between what is referred to as the baseline in a VLBA, and what we're talking about here? If you increase the baseline, you increase the "aperture", right? But that doesn't increase the sensitivty, right? Is the real advantage of a huge array of dishes designed and operated as one telescope (as opposed to an ad hoc assembly) the things that are involved in this story -- i.e., data communication bandwidth and control?
I ask this because I had kind of taken for granted that the real future of radio astronomy was going to be something like an array made out of many dishes in very high orbits...
Re:Very wrong direction for astronomy. (Score:1)
Sensitivity is related to the number of photons you collect, thus with the area of your telescopes. Only increasing the distance between the telescopes (your baseline) does not increase the area thus sensitivity stays the same.
This does not mean that you can increase the baseline without limits. If the number of pixels increases and you still have the same collecting area means that you have to make longer measurements to get the same number of photons per pixel (for a good S/N ratio).
Re:Very wrong direction for astronomy. (Score:2)
The difference between a single dish and a synthetic aperture of two dishes (as far as I understand it anyway) is that increasing the baseline to get the synthetic aperture will increase the resolving power of the telescope, but since you've only doubled your collecting area's size, it won't increase the amount of signal that you get. So yes, higher resolution, much the same sensitivity.
There is also a critical dimension to an interferometer (ie: a synthetic aperture radio telescope) which determines what such a telescope can look at. The angular presentation of the object you're studying must be small in comparison to twice (IIRC) the distance between the two dishes you're using for the interferometer, because you're using the phase difference in the signal arriving at both dishes to infer the resolution you gain. You can't look at objects which extend beyond this limit because the phase starts to overlap. Or so I think, anyway. You might want to ask your ex
One other point is that you can do the same interferometry trick between any two nodes in the array. In fact you can do it to (all nodes)factorial and get as much data as possible. The superposition of all of this would take a fair amount of CPU though...
Simon
Re:Very wrong direction for astronomy. (Score:3, Informative)
Interferometers are very differnt beasts to normal radio telescopes. Single dish scopes look at a single area of the sky, and their sensetivity is proportional to the collecting area (square of diameter). Their angular resolution is proportional to the diamater. When I say the are pointing at a single area of sky, the telescope is actually looking at one point the size of the angular resolution - you may choose to look for a long time, gathering a spectrum (or looking at a pulsar) of that single point, or you may scan the telscope back and forth slowly to generate an image (with resolution equal to the angular resolition of the telescope).
With interferometers, you have a bunch of telescopes. The fundamental unit is no longer a single dish - it is now every combination of 2 dishes. At ATNF narrabri [csiro.au], there are 6 dishes, so there are 15 combinations (5 + 4 + 3 + 2 + 1) (I remember once having to step through each baseline individully, for each frequency for each observation we made, for each.... something else, to mitigate some interference manually, to get the best possible image I could generate for some nifty work I was asked to do) of pairs. The resolution is now a function of the distances between all the pairs.
You generate an image immediately, by getting the fourrier transform of the signals from the pairs, as the earth rotates. To generate the optimal image, with an East West synthesis telescope (such as Narrabri) where the X -resolution is (almost) the same as Y-resolution, you have to let the earth rotate a half turn, ie you sit there imaging for 12 hours. I have gotten away with observing for 4 before, but that was a very specific project. Other telescopes can sometimes do a "snapshot" mode, where you observe for a few minutes or hours, without too much loss of information. But basically, you don't have to scan the telscopes anymore, the centre of the image is where you point the telescopes, and the size of the image can be as big as the resolution would have been if you were using just one telescope.
The resolution you get is effectively from the farthest separated dishes, and the biggest structure you can see is from the resolution of the closest dishes (this all comes from the fact that you have to perform an inverse fourrier transform of the data coming from the pairs, and there are bits missing from the fourrier plane, where there aren't telescope pairs). With a single dish, you can see structures of any size bigger than the resolution. But an interferometer is missing all these bits where telscopes aren't situated, and in particular, has effectibely a hole in the middle of the "telescope" the size of the distance between the closest dishes. So there is an upper limit on the size of structures you can see (as well as a lower limit).
So occasionally, there have been tricks where you combine the high resolution data from interfereters with the low resolution data from a single dish, and you generate a very accurate and imformative image. This was done for generating a map of the Large Magellanic Cloud (no URL handy). But this needs a lot of work and telescope time, both hard to come by.
The sensetivety goes only as the size of the physical collecting area. So 1 square kilometer indeed is much better than the previous 1/30 or so sqaure kilometers we have had in a single setup. Note that, if the telscope is set up in Western Australia, (where I certainly hope it will
I apoligise in advance for confusing you all, but it is kindof a complex topic, and no doubt my head will explode now as well!
Correct location: far side of the moon (Score:3, Interesting)
You wouldn't believe how increasingly difficult it is to do decent Radio Astronomy these days. Heck, the processor in your laptop or desktop is likely radiating right in "L" band (about 1.4 GHz). We thought big hulking monitors were bad until we measured the E/M interference from flat panel displays (it's bad). We're struggling to deal with the onslaught of laptops, 802.11b wireless equipment, PDAs and the like at places like Green Bank. And don't even start to talk about Iridium...
I speak for myself, not my employer.
Re:Correct location: far side of the moon (Score:2)
We got an email on the ATNF system about a month ago from a friend of mine (Daniel Mitchell - no doubt his web page ought to have a bit of info) who researches interference mitigation. He said the people who had been operating at 1.4GHz (or was it 2.8?) had finally turned off their bloody transmitter. Much elation! I've had to work around that bloody frequency before.
With current interferometers (ATNF narrabri [csiro.au] is one) you get rid of some of the interference by default, because hopefully, the signals go to the 2 antennae in the single baseline at the same time, cancelling each other out (I believe this is a gross simplification, I can't remember the full details). Daniel is working on a small peice of equipment at Narrabri for his thesis, where he will be able to get rid of the interference from several land and satellite transmitters completely, by mixing it back with the signals to each of the telescopes. He is researching, along with many others, how best to do this with SKA. One way it to grab a whole bunch of nulls (destructive interference between all the telescopes) and chuck them in the direction of the offending transmitters. Again, I know no details!
Incidentally, somewhere [swin.edu.au], I have a photo from inside the observing room at Narrabri, which is surrounding by a Faraday cage (along with the friggin big correlator computers downstairs), where you can see at the controlling desk 4 or those little LCD beasties. Nice
Re:Very wrong direction for astronomy. (Score:1)
Since radio astronomy on the whole requires larger telescopes than their optical counterparts (radio waves being that much larger than those of visible light) getting an equivalent project in orbit -- or on the far side of the moon -- would be that much more prohibitively expensive to build and lift into orbit.
The only real advantage of placing radio telescopes on the moon would be a relative lack of interference with earthly radio signals.
I don't doubt that space-based astronomy is ultimately the way to go, but don't count out the significant advances ground-based [space.com] telescopes have made in recent years.
8-{)}
Re:Very wrong direction for astronomy. (Score:2, Insightful)
Furthermore, the success of the Hubble space telescope you mention is not all the it's cracked up to be. With modern adaptive optics techniques that compensate for seeing errors, land based telescopes are (in certain areas) superior to Hubble.
Last but not least, research done in the developement of the Dutch Open Telescope has shown that much of the seeing errors are actually caused by temperature difference close to the ground, so by using a dome-less telescope on a special high platform can reduce seeing tremedously, without even having to resort to adaptive optics techniques. All these techniques can be employed for a fraction of the cost of a space based telescope.
Talking about SETI.... (Score:5, Interesting)
Instead of relying on super-powerful transmissions from the aliens, as we do now, we could detect, for the first time, signals at the same strength as our own [ucalgary.ca] and "listen" to most of our own galaxy for them.
This is truly new, and means a SETI "hit" comes into the realm of the probable, IMO. The link is to the "SETI" page on the SKA site. It's down a couple of levels and jargonized, so I don't think I deserve a redundant mod... but you're the boss!
Re:Talking about SETI.... (Score:2)
Interesting comment (Score:2)
- Fraught with uncertainty or doubt; undecided.
- Arousing doubt; doubtful: a dubious distinction.
- Of questionable character: dubious profits.
The search for microbes was dubious, too. Just for instance.If, by your definition, people only attempted "real science" we would never accomplish anything.
Re:Talking about SETI.... (Score:3, Interesting)
I asked one of the SKA people about this very topic at a conference a couple of years ago. I'm not sure if anyone had actually done the math at that point, but they said an earthlike level of RF emission would be detectable at "a couple of dozen" light years. Beyond that it's back to looking for directed beacons again. All the same, it would be interesting to look to interstellar TV from a handfull of nearby solar systems.
Anyone have better information on the SKA's range for earthlike RF detection?
Re:Talking about SETI.... (Score:2)
This is truly new, and means a SETI "hit" comes into the realm of the probable, IMO.
Well, let's not go off the deep end. "Possible", maybe. "Probable", probably not. The evidence suggests that we are totally alone in the galaxy. Fermi's Paradox has pretty much convinced me.
My gut feeling that "life" might be somewhat common, but intelligent, self-aware life is hugely, unbelievably unlikely, if not completely unique in the universe. Self-awareness is just too complex to be common. Of course, it happened here, but that says nothing about how common it is. We could have gone through 1e57 universe cycles (assuming a cyclical universe model) before it happened.
Re:Talking about SETI.... (Score:3, Insightful)
Fermi's paradox doesn't do it for me, although it is a neat way [sai.msu.ru] of looking at the problem.
It's too neat, and that's my problem with it. There are just so many other variables. Like stick no FTL in there. Or no "cryo-sleep". Or not even any way of reliably going, say, past 0.3 C for any kind of duration. And let's face it, interstellar empires of the kind that Fermi was suprised weren't knocking on doors, need one or more of those things to exist. At least "life as we know it" "knocking on doors" type galactic empires. As far as "life not as we know it" goes, I'm not even sure we could detect them if they were living on the Moon. Their goals, communication methods, etc. would surely be truly alien.
I'm not convinced. Maybe everyone goes "Dyson". Or to achieve true technological mastery you must achieve a kind of "spiritual" way of working in large groups that knocks you out of the "galactic resource race", (another prerequisite for Fermi) think of your own reasons, we sure haven't figured any of even the stuff I've listed out yet. Not that these are even close to my favourite explanations. but they serve, I think.
There are other famous "equations" Sagan's or Baugher's [umich.edu], which tends to show nothing more, I guess, than that Clarke's famous axiom [harvard.edu], which he attributes wisely to "Anonymous" is usually pretty spot on.
Re:Talking about SETI.... (Score:2)
I'm not convinced. Maybe everyone goes "Dyson".
The problem with the "maybe everyone" scenerios (maybe everyone destroys themselves, maybe everyone doesn't have an expansion desire, maybe no one likes planets like Earth) is that it only takes one. It only takes one civilization with an expansion desire and relatively low technology (cryo-sleep or just long lived, no FTL, etc) to fill the galaxy in a short (relatively speaking to the age of the universe) amount of time.
I can sympathize with those who just don't want to face the logic of Fermi's Paradox. I would really like it to be not true, but the logic is just inescapable. A million years to fill a galaxy at sublight speeds, give or take. Billions of years of time. If the galaxy was teaming with intelligent life, where the hell are they? Why didn't they take over the earth a long time ago?
Re:Talking about SETI.... (Score:2)
Fermi's paradox still seems to be built on lots of unstated assumptions. I accept the simple logic behind it: one intelligent species can fill up the galaxy on (reasonably) small time scales. What's unstated? That they would want to (ie, same expansion desires as our species - would it be the same for an oceanbound technological species?), that they would be sufficiently interested in our particular planet to colonize it, or at least spend a huge amount of effort to build an indestructible monument in the middle of the Silurian on the off chance that somebody might be around some day to check it out, and that there are no constraints to expansion of which we are currently unaware. I'm sure somebody else can come up with more.
It also assumes, of course, that they are not here. I don't want to open up THAT whole can of worms, but the reality is that all we can do at the moment is make the assumption that they aren't based upon the fact that we can't conclusively demonstrate that they are. All the same, the conclusion that Fermi's paradox says we are alone is predicated upon an assumption which cannot be proved true, to wit the proof of a negative, that they are not or have not been here.
Re:Talking about SETI.... (Score:2)
I'm sure somebody else can come up with more.
Sure, you can come up with as many scenerios on why someone wouldn't do it as you want. But do you doubt that a couple million years from now humans won't have populated the whole galaxy, even at sublight speeds? I don't. So what are the odds that the potential thousand or million (depending on who you ask) intelligent species in the galaxy are ALL non-expansionistic? We're the only one? That seems highly unlikely.
but the reality is that all we can do at the moment is make the assumption that they aren't based upon the fact that we can't conclusively demonstrate that they are.
You can make up all kinds of conspiracy scenerios, but the fact remains that the only statement we can make about other intelligent life is that we have zero evidence of any other intelligent life. That's not just "lack of evidence", that is positive evidence that implies that there is no other life in the galaxy, based on Fermi's paradox. In other words, Fermi's paradox predicts with a reasonable degree of certainty that if our planet shows no signs of having been visited in the past, therefore, we are the only ones in the galaxy.
Re:Talking about SETI.... (Score:4, Insightful)
Sure, you can come up with as many scenerios on why someone wouldn't do it as you want.
I think this is the part that I'm uncomfortable with - the argument seems to rest on the idea that if someone doesn't do it the way we think they should, then they probably don't exist. I accept provisionally that with a "reasonable degree of certainty" we see no evidence that they have ever been here, and thus must assume that either (a) they don't exist, as per the paradox, or (b) something is wrong with the model under which a paradox arises.
You can make up all kinds of conspiracy scenerios
I recognize that my argument treads dangerously close to loony ground. For the record let me state that I'm no UFO nut. All the same, the detritus of tinfoil hats and Von Daniken spoor all around us should not dissuade us from having a look around the territory. We cannot currently say anything conclusive about the frequency of extraterrestrial civilizations even nearby to our own solar system - we don't have the technology. The only thing we can eliminate with certainty is the presence of any nearby high-power directed beacons. Once we have the technology to detect earth-level RF from other solar systems, then we'll be able to say that we are not surrounded by civilizations. Until then, the Fermi Paradox must rest upon the absence of evidence for visitation within our own solar system.
I accept the conclusions of the paradox, but only provisionally. We are still speculating in a sea of unknowns, and I'm uncomfortable with charting out a single string of minimal-assumption hypotheses and then taking the results with anything but a grain of salt.
FWIW, my own personal suspicion is that technological life is incredibly rare, but that simple, bacterial-level life might be common. This is just based upon the one piece of evidence we have - the history of life on Earth. It's only a single data point, but all the same it is an absolute and undeniable example of life evolving in a solar system. Over 4.5 billion years of Earth's history, nearly 3 billion of those were spent as a stable bacterial world. In all that time, only one successfull association of bacteria managed to develop the information capacity of eucaryotic life. That's really bad odds.
Re:I *do* doubt it (Score:1)
Probability of Intelegent Life Existing In the Galaxy = Rate of Star formation in the Galaxy * Precentage of those Stars which are like ours * Precentage of afformentioned with have planets * Precentage of planets which are like Earth * precentage of afformentioned planets which develop life * precent likelyhood life will evolve intelegence * precent likelyhood intelegent life will care enough to communicate * lifespan of the civilization.
Yea... that's long. But the point of the entire exercise is this. No matter how small you make any of the terms (as long as they aren't zero) the lifespan of the civilization should outstrip them all. Back in the 1960s we weren't so sure about that. Most of us were convinced that WWIII was just around the corner and that lifespan of a civilization which can communication was something like 40 years. Today we're thining more on the order of the lifespan of our star. Maybe longer.
Next point: Why are we intellegent? Some would say that mankind is the "super preditor" a race which has evolved for the purpose of killing things with our mighty brain. But think about it. Seriously, how good is say, steak for you? Not very. Our bodies are not desiged to deal with a carnivores diet. We are supposed to eat mostly berries, fruits, grains, etc and meet only rarely. Why is that? Because that's what our diet was when we had to find our food.
So intelegence does not come from being a super-preditor. It comes from social intereaction and a desire to propigate the species. Any type of creature which operates well in groups is a candiate for intelegence. Dolphins... apes.... wait... I see a patern.
Of course, those groups are territorial and they do tend to kill each other over time. But then, so are we, and so do we.
I don't really have an opinion on this. Is there life out there? Probably. There's a nearly infinite number of stars in the universe, surely somewhere there's someone else looking up at the sky thinking "are we alone?" But other galaxies are VERY far away... and the numbers within our own galaxy don't look so good. Who knows... maybe someday we'll see humanities First Contact..... But I won't hold my breath.
Re:Talking about SETI.... (Score:2)
Life expands to fill available resources, and searches for ways to tap new resources. That is the story of evolution.
Re:Talking about SETI.... (Score:2)
To anyone interested in a very good discussion about the Fermi paradox, I recommend Nick Bostrom's essay on it [ndirect.co.uk]. I'm not much of a fan of transhumanism, but I think it's an excellent essay on the details and hidden assumptions involved.
[TMB]
Re:Talking about SETI.... (Score:2)
I recommend Nick Bostrom's essay on it
Interesting article, but it's too top-heavy on nanotechnology for my taste. You don't have to go to the extreme of nanotech to support the Fermi paradox. 1960's level technology is fine.
Personally, I think sci-fi-level nanotech is fantasy on the order of transporters and "infinite reality drive". Sure, we might have self-replicating machines someday (I mean, it's called biology at this point), but "universal assemblers" ain't ever gonna happen, much less in "20 or 30 years" I think the article said.
Any sort of self-replicating von-neumann probe is going to be a very large scale machine, not a very small scale machine.
Re:Talking about SETI.... (Score:2)
infinite reality drive
Yikes! Douglas Adams is rolling in his grave. That should be Infinite Improbability Drive.
Re:Talking about SETI.... (Score:2)
You're a little too optimistic. (Score:1)
Well guess what: there is only one star within four light years of us -- Alpha Centauri.
If the Centaurians aren't sitting around watching their version of Jerry Springer, looks like we're back to only being able to detect directed beacons.
Petabytes!!! (Score:1)
http://slashdot.org/article.pl?sid=02/01/30/033
is waaaayyy obsolete. Where's our Petabyte arrays? Serously though, there are some pretty giant rado telescopes out there. This one had better be worth the extra cash, I mean, you can't even get Astronomy Pictures of the Day with radio telescopes, the pictures ain't pretty enough!
Contact (Score:1)
Re:Contact (Score:1)
The why not a 2sq km is the same as why not 0.5 sq km on the far side of the moon - of course it comes down to money. 1km is ambitious enough for now - we still don't have the tech to economically deal with all that data.
Why bigger is better (Score:5, Informative)
Given that the wavelength of 'visible' light is approximately half a million times shorter than radio wave wavelengths, the collecting area has to be much larger to get the same antennae gain.
An interesting corollary of this is that the naked eye is (very roughly) as powerful (at visible light wavelengths) as Arecibo is (at radio wavelengths). See the The seti league [setileague.org] pages for more info...
Simon.
Re:Why bigger is better (Score:2, Interesting)
I had been to the GMRT in India [tifr.res.in] one of the most powerful radio telescope arrays in the world. It has been designed with over 30 dishes of about 45m in diameter each. The array forms a "Y" shape. As the earth rotates, the telescopes sweep out a gigantic circle of about 25Km in diameter. Using a supercomputer and after hours of observation, they can put together a composite image equivalent to a telescope about 20Km in diameter.
More info about GMRT and cool photos of other radio telescopes are here [cornell.edu].
Re:Why bigger is better (Score:2)
Simon
Re:WAAAH, WAAH!!! NOONE LIKES ME, *SNIFF*! (Score:1)
SETI (Score:1)
if so how can the seti project itself help this other project? other than an advisory role?
Re:SETI (Score:2)
LOFAR (Score:3, Informative)
If this will ever get funded (they recently got some money to make first studies) it will be a telescope the size of half the Netherlands. This is of course not a filled aperture, but a sparse one operating at very low frequencies (10-250 MHz, on both sides of the FM frequencies). It will consist of some hundred small "antenna parks" spread around the country and uses a lot of computer power to generate images. It could be a precursor for SKA.
Re:LOFAR (Score:1)
Also, in addition to the Netherlands LOFAR I believe the US wants one in Texas somewhere, and somebody in Asia does too. Once the technology is proven, they would be very inexpensive to build, since the antennas are not complex items.
Re:LOFAR (Score:1)
Of the hill people?
Small planets not natural radio sources (Score:2)
Interesting designs for the array (Score:1)
One of the proposals for the SKA is to use an array of Luneburg lenses, which are basically big balls of polystyrene like material. The material is a dielectric differentially doped so as to focus the incoming signals. Instead of moving a large dish, you only need to move the receiver to focus on a particular signal.
You can see pictures of a Luneburg lens (which was made in Russia) and an artist's conception of the array at the CSIRO's Australia Telescope National Facility website [csiro.au].
One of the proposed locations for the SKA is in Australia and a number of schools are involved in the SEARFE Project [csiro.au] which hooks up a radio receivers to a computers to produce a database of radio frequency usage ("pollution") across the country.
Resolution (Score:4, Informative)
Fortunately it's only compared to the VLA in regards of resolution. Single radiotelescopes have no chance in hell to get to extreme resolutions. Resolution is all in the diameter, or baseline. Nothing you can do about, it's just basic physics [unlv.edu]. Fortunately you can have big holes in your telescope, or inversely just a few parts of the surface. Excactly the principle of the VLA [nrao.edu] and VLBI in radio frequencies and the VLTI [eso.org] for light. You can even find a simulation applet here [man.ac.uk]
In fact the earth itself is getting too small to get more resolution. Going into space is indeed being looked into, but not in the sense of a satellite like the Hubble orbiting the earth. That would hardly be worth the effort where radio astronomy is concerned. Having a baseline as long as the distance between the earth and the moon, now that would be an improvement. Plus, if it's built on the side that's always turned away from the earth, the telescope will be shielded from all the annoying interference created by all the radiochatter on earth, while it's still possible to look at the same piece of sky as an earth based telescope.
In the visual spectrum, Darwin [esa.int] from ESA looks set to become the next record holder . A first technology demonstration/development flight in the form of SMART-2 [esa.int] is currently under development.
Opening Ceremonies (Score:1)
Built by 2010...? (Score:5, Funny)
ALL THESE WORLDS ARE YOURS--EXCEPT EUROPA.
ATTEMPT NO LANDINGS THERE.
blakespot
Moore's Law and Astronomy (Score:1)
Figures (Score:2)
When the international community is involved in the project, however, a more precise name like "The Square Kilometer Array" is used. Of course, Americans have no idea what a kilometer is, so American magazine Wired refers to it as "this huge radio telescope." Now I can visualize it.
When the U.S. government attempts to top this ten years from now, I'm sure they'll call it "The Very Unprecedented Array in Afghanistan"
Re:Figures (Score:1)
Ever heard of the OverWhelmingly Large Telescope (OWL) [eso.org]?
It's not going to be built by Americans...
Re:Figures (Score:2)
Who Will Run It? (Score:1)
(My two favorite babes...)
(For those who don't recognize the second name, she is the Director of the Miami Planetarium and she also produces musical CD's based on radiotelescope data. She looks like an Italian porn starlet but is really an astrophysicist educated in Milan.)
Re:Who Will Run It? (Score:1)
Ska? (Score:2)
Truly, this is One Step Beyond.
Re:Ska? (Score:1)
Re:Eww the metric system! (Score:1)
If i count in tens, why wouldn't I measure with them
Re:That's pathetic... (Score:2, Informative)