What is Digg?46 Comments
- desertDenizen, on 10/10/2008, -0/+28Awesome!
Too bad we don't have any more money. :( - MatthewK, on 10/10/2008, -0/+19This sounds exciting! It will make the Hubble telescope look like a Fisher Price toy. The only downer in the article is the year we might have it -- 2020. I'm getting old! They need to accelerate the development of this stuff so I can see more in my lifetime.
- atarijedi, on 10/10/2008, -0/+11Why.... Spin the moon on the craters axis of course!
- Chakat, on 10/10/2008, -0/+10There are lots of observatories in active earthquake zones. A normal extended exposure is a few hours, so a moonquake wouldn't affect things that much.
- ChromaVita, on 10/10/2008, -0/+9Well then I guess we got it ahead of schedule.
- StankInTheBank, on 10/10/2008, -0/+8It's so simple! First you spin ze water, zen, you aim it at ze boobies.
- vaccumpony, on 10/10/2008, -0/+7So what? Is there a rule that Digg can't post stories that get posted to Slashdot?
- Lunarsight, on 10/10/2008, -0/+7Atari - Yeah, that might work.
We would need one of those Titan fellows to do the spinning of the Moon, though.
I know Atlas is pretty busy holding up the earth, but there must be another one we can pay to do that. What is Epimetheus doing these days? - sekhui, on 10/10/2008, -0/+6the best story i've seen on digg in ages. interesting, new, sciency. win.
- Volatile36, on 10/10/2008, -0/+6How will you make the liquid rise up the sides of the crater to form a parabola?
- fquednau, on 10/10/2008, -0/+6Is there a rule I must read slashdot AND digg?
- Causemos, on 10/10/2008, -1/+5Doesn't the moon experience quakes on a fairly regular basis? Not too good if you're trying to get a extended exposure of a region of space and the liquid changes shape even slightly.
- mydingaling, on 10/10/2008, -0/+4Dugg for noodling.
- VanhookJosh, on 10/10/2008, -1/+4Yes, webbles. The liquid would fill up the holes, but think of how long the devastation on the smooth liquid would last. It has to be perfectly smooth. Not only am I sure that they will fix this problem by 2020, but, they will have, by then, solved many of variables like this... Hopefully... (" 'God bless' American tax dollars! ")
Well, we can always hope that China decides to head in the same direction sometime soon, and actually pulls through before then, because unfortunately the way we're headed we won't be seeing any of our vehicles in space anytime soon. :( - vdog, on 10/10/2008, -0/+33. the liquid is spinning. The faster it spins, the deeper the cavity in the middle. This allows it to change the focal length.
You can do an experiment at home. Get a a bowl of water and stir it at different speeds to see what happens. However, if you make a mess in the kitchen, don't blame me. - TheImaginator, on 10/10/2008, -0/+3Excellent - now who has the money and technology ready to go to the moon and make it happen?
- i4ybrid, on 10/10/2008, -0/+3What about all the dust on the moon? There's no atmosphere there and there's a lot of space-dust floating around. There was a big problem with moon dust during space walks. I don't know if this is a maintain-able project.
http://bigblog.com/space_science/moon-dust-particl ... - Trigononamous, on 10/10/2008, -3/+6I've got a better plan! We just fill some of the moon's craters with a reflective liquid, and BAM!! Instant mirrors!
- waywardsoulnf, on 10/10/2008, -0/+3Hmm...quite the awesome. But i'd be faaaaaaar too tempted to stick my finger in it.
- atarijedi, on 10/10/2008, -0/+3If it doesnt explode into a million pieces.... yes.
- ChileanGoD, on 10/10/2008, -0/+2BOMB DIVE!
- Volatile36, on 10/10/2008, -0/+2@Lunarsight
I hear Epimetheus is living in an assisted-care home, since he only had an IQ of 45. - NoozeHound, on 10/10/2008, -1/+3No mention of go-karts either.
- inactive, on 10/10/2008, -0/+2Yes, so they can add some melamine to the liquid and make it seem more protein-rich.
- waywardsoulnf, on 10/10/2008, -1/+3You're aware that none of the above are actually QUESTIONS?
- eboily, on 10/10/2008, -0/+2I did my master thesis with Ermanno a couple of years ago on the liquid mirror telescope - he's quite a nice guy!
Of course you cannot tilt the mirror, it's rotation axis must remain parallel to the gravity. However, you can move the location of the detector to cover an angle off the zenith. Richardson from BC even designed back then a deformable optic system that would allow to cover an interesting fraction of the zenital sky.
The quality of the image can be quite good - comparable to high-quality telescopes. The idea is to damp the vibration coming from the ground and the motor system. In addition, you can cover the surface of mercury with a transparent damping substance (I tested monomolecular layer and carboxy-methil-cellulose on my master degree)
You can also change the focal Length of the telescope by changing the rotation speed. However, this would require either a good mercury depth or an adapting support - both would impose serious constraints and requirements on the overall apparatus and dampening systems. Back then, the mercury container were also parabolic and the thickness of the mercury layer were constant - the focal were then not changeable.
Dust would be a problem - as it was in the lab. We would need to come up with a device to clean the surface (all the dust would float on the mercury since the mercury is very dense) We can think of many ways of doing this, from periodic mercury filtering to protecting the surface with a thin sheet of mylar for example.
One problem we had in the lab that we would not have on the moon would be the microscopic waves the friction of the air were inducing on the surface of the mercury in rotation.
One other consideration on the moon would be that the temperature would probably freeze the mercury. If frozen in rotation with the proper surface quality, we would then have a tilt-able mirror. However, if we want to keep the mercury liquid, we would need to heat it - with a brand new set of challenges.
Anyway, I am quite happy to see Ermanno pushing this idea further and I wish him well! :-) - daeus, on 10/10/2008, -0/+2Whats this go-kart thing?
- Jektal, on 10/10/2008, -0/+2The article doesn't mention it, but their Artist's Conception that's attached shows the telescope being housed in a structure.
- inactive, on 10/10/2008, -0/+2This is a very old old and elegant problem in the calculus of variations. I could see the technique being used to pre-form a mirror before polishing, but spinning the fluid in the telescope seems really dumb and unnecessary. What happens when you want to reorient the mirror (spin vector) at an angle to the gravity vector? The parabolic solution no longer holds. I wonder what the solution is in that case? The Lagrangian is no longer simple and there may be no analytical solution to Euler's Equation.
- P5ycHo, on 10/10/2008, -1/+3RTFA and you would realize that Volatile36 has a point.
- MatthewK, on 10/10/2008, -0/+2But does it blend?
- Lunarsight, on 10/11/2008, -0/+2@Volatile
Yeah, but you figure - how much IQ does it take to spin a moon?
The worse that could happen is he might inadvertently send it hurtling out of orbit, causing a nightmarish apocalyptic scenario on the Earth below.
Aside from that, I see no possible harm from it. - SIRBERUS, on 10/10/2008, -0/+2ITT: People with high school diplomas attempting to weigh-in on the situation and explain why those nasa idiots won't be able to get it to work.
- bgrah449, on 10/10/2008, -0/+2Those NASA scientists are baller
- inactive, on 10/10/2008, -0/+2The mirror shape is parabolic. So moving the secondary mirrors away from the focus will produce no image! The Arecibo Telescope is spherical, so moving the secondary mirror can capture reflections, but they are not focused. A spinning liquid can never hold a spherical shape.
- gingerboy, on 10/10/2008, -0/+1haha love it!!
- inactive, on 10/10/2008, -1/+2Ok, maybe it's me being thick, but I have a few questions:
1.) If it's a liquid design, the n surely it only points in 1 direction?
2.) If it's a mirror lens, then the quality of images would be poor?
3.) It would have fixed focal length?
Maybe that's how life starts. lol. We stick liquid up there, then we die out on earth due to whatever. Human race millions of years later evolves on moon from liquid we put up there. We populate like a virus, then f*** it all up again and find ways to "populate" the earth. Of course we would look and breathe differently and find that the air on earth is not suitable for living as it has a poisonous atmosphere called air. lol - Jektal, on 10/10/2008, -1/+21. RTFA
2. Mirrors are very good for image quality. That's how most nice telescopes work.
3. Hm, good one. I'd assume this relates to #1 - frosted, on 10/10/2008, -0/+1The moon will look just like the Death Star when it is complete!
- Volatile36, on 10/11/2008, -0/+1@Lunarsight
Very true. How long will it take to break him out of Tartarus? - Jektal, on 10/10/2008, -1/+2Very nice big words! Yay!
TFA goes into aiming a bit - the main mirror would remain oriented straight-up, and smaller mirrors above it's surface would move mechanically. - DiggityDugged, on 10/10/2008, -2/+2Sorry, buried for being really old. Saw this on Digg over a year ago.
- webbles, on 10/10/2008, -2/+2this will be great especially because of how many meteorites and other space debris hit the moon every year, and no atmosphere to burn em up.
can't wait.
then again, if one of the pieces of debris hits the lens won't the liquid just fill in the hole? - phybervelocity, on 10/10/2008, -2/+1so..
- jazzman251, on 10/10/2008, -5/+4This was on slashdot yesterday...
- juzsp, on 10/10/2008, -7/+2But can it run Crysis?
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