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- SoundJudgment, on 08/01/2008, -0/+13So the SETI@Home project will finally have new raw data to play with?
- mindracer, on 08/01/2008, -0/+12yes but apparently by those remote locations calculating when they receive the waves(?) and stitching all the info together its virtually like the size of earth..
- Joomal, on 08/01/2008, -0/+9Nice to see more international projects like this taking off and being co-ordinated with success.
- hollyminkowski, on 08/01/2008, -0/+8@grantmoore3d
It's not like the size of the Earth in signal sensitivity, but in resolution.
The sensitivity will not be many db above the sensitivity of the best dish (Green Bank at about 82dbi) in the group. By using mathematics to calculate the origin of a signal based on the different times it is detected by each dish in the group and how the dishes are aimed, you can very precisely determine where the signal source is...and roughly how far away it is.
Large dish antennas have a very narrow beamwidth, but at galactic distances that little spot covers a lot of space, and a single dish gives you little data regarding distance.
If you think about how you can determine the distance from you and location of an object using trigonometry you can get a feel for this. You have to make at least 2 measurements of angle to the target to get the base of the triangle for your calculations, and the farther apart these points are the more accurately you can determine the distance and position of the target....using lasers you can get a really good result...this is why surveyors carry so many lasers.
Think of a distant rf signal source out in space sending out a short 'ping', that ping will be detected by the several dish antennas at different times because each will be at a slightly different distance from the source. The timing data from the reception of the ping is fed to the supercomputer which then calculates where the source is in space and roughly how distant it is based on the how the dishes are pointing when they get maximum signal pickup. (trigonometry)
It is a pity that one of the dishes in this network can't be on Mars, at a very great distance...this would drastically increase resolution. - ColorBlind, on 08/01/2008, -0/+6Incredible stuff! It's good to see something not involving war or politics.
- goerg, on 08/01/2008, -0/+6hope this was irony...
- grantmoore3d, on 08/01/2008, -0/+5I don't understand how it's "the size of Planet Earth"... isn't it just several remote locations feeding one database.
- TreeFiddy05, on 08/01/2008, -1/+6"e-VLBI—electronic very long baseline interferometer"
Very long is such a technical term... - mindracer, on 08/01/2008, -5/+953 diggs and 2 comments and its front page? at least its a good story.. :o) dugg
- insanebrain, on 08/01/2008, -0/+4Why ?? can't they rebuild it themselves ?
- andyd273, on 08/01/2008, -0/+3I think it would be cool if they could put a couple satellites in Earths L4 and L5 points... which would be a lot larger base for an e-VLBI...
Or even better, Jupiter's L4 and L5...
Staying earth based is cheaper and easier, true, but it is also limiting. - stealthc, on 08/01/2008, -0/+3It would be a good place to move to if the earth becomes uninhabitable. You can blow a hole clear through it and it will still take 36 episodes before it becomes a problem.
- mnky9800n, on 08/01/2008, -0/+3Actually, radio telescopes are used most often for REAL science. Like in this case.
- Joomal, on 08/01/2008, -0/+3Hehe... but it's been this way in engineering for over 30 years. VL is an acronym that you'll see over and over in electrical engineering.
- reddikilowatt, on 08/01/2008, -0/+3Good, complex explanation of interferometry
http://www.geocities.com/capecanaveral/2309/page3. ... - stealthc, on 08/01/2008, -0/+2Just run a random number generator in the background. It'll accomplish the same thing =P
- Jeremyz0r, on 08/01/2008, -0/+2The only thing I found interesting about this was the amount of data they could move around the world within a second.
- dafragsta, on 08/01/2008, -0/+2Which makes what you said completely moot. All front page stories on digg have 53 diggs and 2 comments at some point.
- reddikilowatt, on 08/01/2008, -0/+1I asked about that while touring the Very Large Array in New Mexico last spring. It turns out that the aperture of the VLA is too narrow to be of much use for SETI, despite what the movie Contact told us.
Since this new telescope is even tighter, I doubt it. - matt510, on 08/01/2008, -0/+1Interferometry is more than just looking at data from different locations. You are actually comparing things like phase and coherence to combine data that makes it look like the data came from one giant telescope. Interferometry has been used in radio astronomy for a long time (take a look at the VLA or the VLBA). It is much more difficult (but not impossible) to do with optical wavelengths because radio wavelengths are much longer (so small errors don't have as much effect).
Here's a decent article from space.com: http://www.space.com/scienceastronomy/astronomy/in ... - matt510, on 08/01/2008, -0/+1Sensitivity and resolution are directly linked. This doesn't have much (if anything) to do with determining location of objects (using parallax on Earth doesn't really help for objects that are far away, even using parallax at opposite locations in our orbit can only help determine distances for relatively close objects). Radio interferometry is used in gaining resolution - this is related to how "clear" an object looks to us, how well we can see it. Think of it this way, at night when a car is far away it looks like it is a single point of light, as it gets closer our resolution increases and we can resolve more detail (the two distinct headlights). In the same way, using radio interferometry we can increase the details seen of distant objects.
- raptor87, on 08/01/2008, -0/+1Not many are on the front page at that point however
- deviouskoopa, on 08/01/2008, -0/+1VLSI - very large scale integration. very long, very large, very technical...
- hollyminkowski, on 08/01/2008, -0/+1Yup, very fine measurements of the arriving waveforms. Having multiple receivers separated by great distance allows more precise measurements.
Like having a supercomputer analyze the patterns of interference from multiple waves on the surface of a pond, generated from different points...whether the waves enforce or diminish one another at various points where they meet.
The measurements are so precise that I do think some rough estimations of distance to a signal source could be made given that the receivers are separated by such great distances...I could be wrong though...I'm not an expert in the field, just an interested amateur :-)
Must be very intricate software to analyze the waveforms from the network of dishes/receivers.
I was trying to get it across that this network did not become equal in sensitivity to a dish the size of earth's diameter...wow, that would be a few db above the VLA :-) BTW they can dynamically change the locations of the dishes at the VLA for interferometry and other reasons by moving them around on a large system of railroad tracks...it's pretty awesome. - drunknmunky1, on 08/01/2008, -0/+1Goldeneye anyone? (It was actually filmed at the one in the picture)
- hollyminkowski, on 08/01/2008, -0/+1Looked at your profile matt. You are an interesting guy, Physics, Astronomy and Theology :-)
You are certainly more qualified than me to lecture on interferometry, you must be very knowledgeable from the study of optical interferometry. I know very little about Astronomy... I do have a small Celestron telescope but I rarely use it any more....I'm more into radio than optical stuff.
I'm just a geeky 20yr old gal with a HS edu and big plans for someday :-)
Right now I am playing with small dish antennas and usb wifi adapters... have made solid connections across several miles with the stuff.
Theology and Physics...that makes me think of the character from the movie "Contact" the divinity school guy hanging around the Aricebo dish who said he was "A man of the cloth...but without the cloth" :-) - macunderdog, on 08/01/2008, -0/+1I've actually been there many times in my life and I always thought that it was working.
Just don't walk to the center if you have a pacemaker! - inactive, on 08/01/2008, -0/+1I wonder if we can spot namek with this telescope.
- hollyminkowski, on 08/01/2008, -1/+1Actually, you might get similar results without the need for expensive dish antennas.
If you had several large flat antennas located at distant points, each of which was relatively rf quiet (like surrounded by mountain ranges). The antennas could simply be large squares of metallic foil, the larger the better, located near the ground and connected to sensitive receivers. This system would give you fair sensitivity and location of the signal source out in space...but not great targeting data for distance. The supercomputer would have more work to do since there would be competing signals at many frequencies and much closer inspection of the waveforms would be needed to weed out interfering signals. If one antenna was located on Mars then good distance data could be calculated since it would create a huge triangle base that was the distance from earth to Mars... the time difference of reception on the 2 planets would allow for very precise distance measurements.
I think I read about an idea something like this somewhere, a long time ago???
Sure would be easier to set up a large flat, foil square on mars rather than a large dish antenna :-) - BatmanStan, on 12/09/2008, -0/+0that is amazing, hopefully they get some world changing results
http://godzillafiguresblog.com - bearcat8543, on 08/01/2008, -1/+1or uranus
- JQP123, on 08/01/2008, -1/+1Wonder how long 'til people start claiming that NASA invented it?
- inactive, on 08/01/2008, -2/+1The last time I checked Puerto Rico was part of the US.
- inactive, on 08/01/2008, -3/+1We broke it we bought it.
- diabolicedict, on 08/01/2008, -3/+0We are not a part of it.
"Made up of radio telescopes in Chile, Germany, Italy, the Netherlands, Puerto Rico, South Africa, and Sweden," - inactive, on 08/01/2008, -9/+0It is too bad that we are wasting money building useless stuff like this when we should be helping Iraq and Afghanistan rebuild.
- cryman159, on 08/01/2008, -13/+0thanx
http://sciences-technologies.blogspot.com/ - supermanred, on 08/01/2008, -16/+1Now we can take pictures of Uranus!
I saw a few... too many moons. - inactive, on 07/31/2008, -20/+2Paris Hilton says she can handle it each one of them...
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