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Unbelievably Large Telescopes On the Moon?
Posted by
CmdrTaco
on Thu Oct 09, 2008 07:46 AM
from the thats-no-moon dept.
from the thats-no-moon dept.
Matt_dk writes "A team of internationally renowned astronomers and opticians may have found a way to make "unbelievably large" telescopes on the Moon.
'It's so simple,' says Ermanno F. Borra, physics professor at the Optics Laboratory of Laval University in Quebec, Canada. 'Isaac Newton knew that any liquid, if put into a shallow container and set spinning, naturally assumes a parabolic shape, the same shape needed by a telescope mirror to bring starlight to a focus. This could be the key to making a giant lunar observatory.'"
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Ob (Score:5, Funny)
Re: (Score:3, Informative)
Re:Ob (Score:5, Funny)
I have a certain amount of... shall we say... practice.... in this area.
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No Way!!! (Score:2, Funny)
I'm Being Followed By A... (Score:4, Funny)
Bitch, V (Score:3, Funny)
vatch me split my letters.
Wow (Score:2, Interesting)
Re:Wow (Score:5, Interesting)
We have. This "news" is literally decades old.
http://www.google.com/search?q=liquid+telescope+moon&sourceid=navclient-ff&ie=UTF-8&rlz=1B3GGGL_enUS264US264 [google.com]
http://inventorspot.com/articles/liquid_lunar_telescope_5345 [inventorspot.com] That one says that it was first suggested in 1991. I bet someone thought of it earlier.
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Re:Wow (Score:5, Informative)
The difference is now they think they may have a liquid they can use - ionic liquids. On earth they use Mercury as the liquid but that is too heavy to lift to space and it will evaporate. Also the costs involved are now demonstrating it is viable for lunar use.
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Re:Wow (Score:5, Funny)
Well, if Obama wins you can kiss this "ionized liquid telescope" idea goodbye. We all know the unionized liquid lobbies have the Dems in their pockets.
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Re: (Score:3, Insightful)
Summary is completely misleading... (Score:5, Insightful)
When I saw the summary I actually HOPED it would be misleading, because it makes it sound like nobody had thought of liquid mirror telescopes before. Now it's possible that they were just copying a similarly misleading article, but no... even has a nice photo of the Large Zenith Telescope to spice things up. Space Fellowship 1 - Slashdot 0.
"It's so simple," (Score:3, Funny)
Re:"It's so simple," (Score:4, Funny)
So you're saying this project is unbelievable?
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New? (Score:4, Informative)
Hmmm...as the article notes, the idea of liquid mirror telescopes isn't new, so it seems a tad odd that this is being trumpeted as a breakthrough.
The ionic liquid coated with silver is cool, though.
Re: (Score:3, Insightful)
I would consider a massive breakthrough building the telescope out of moon dust, or some other material readily available on the moon. That way, we don't have to transport massive amounts of equipment to the dark side of the moon.
Not Dark Side (Score:5, Insightful)
It's FAR SIDE people! Far Side, Far Side, Far Side. Like the cartoon. The Moon is tidally locked to Earth, so there's a Near side and a Far Side. If it were tidally locked to the Sun, then you'd have a light side and a dark side. But it's not, so we don't. There is no dark side of the moon, except for the ever changing half that's facing away from the sun at the moment.
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Re:Not Dark Side (Score:4, Funny)
Oblig. "There is no dark side of the moon. It's all dark."
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Re:Not Dark Side (Score:5, Insightful)
While I generally wouldn't use the term "dark side" myself, you do realize that a lot of terms are just terms because that's what they've traditionally been called right? Just as not everyone who says "Ooh, a falling star!" really believes that it's LITERALLY a falling star, I'd hazard a guess that a lot of people who perfectly well understand that the other side of the moon isn't actually dark, would still call it the "dark side" because it's been called that for so long.
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Re:Not Dark Side (Score:5, Insightful)
but it's at the top, and inside of a crater as suggested in TFA
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Re:Not Dark Side (Score:5, Funny)
It's FAR SIDE people! Far Side, Far Side, Far Side. Like the cartoon.
So... you're saying it's populated by bipedal cows and mad scientists?
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It WILL happen one day (Score:4, Interesting)
Re: (Score:3, Funny)
there is no dark side of the Moon really... as a matter of fact it's all dark
Re:It WILL happen one day (Score:5, Informative)
The so-called "dark side of the moon" does not refer to the lack of sunlight or nighttime conditions. All parts of the moon go through the same kind of night/day cycle that the Earth does, only 29.53x slower.
The phrase refers to radio darkness. The moon spins at the same rate it orbits the Earth, so the same familiar craters are always facing us. Anyone standing amongst those craters is being bombarded by the radio noise chatter of the whole Earth population. Anyone standing on the opposite side of the moon can pick up none of that.
One potential problem with setting up bases on the dark side is how to communicate with them. To maintain the radio silence, you can't just stick a radio-based communication moon-satellite out there. It would be very expensive to maintain a cable or laser hookup for any significant distance along the moon surface. So you're left with small windows of time you can communicate, or you work on a focused laser-based comm link with a moon-satellite. That reminds me... what's the "geosynchronous" radius for moon-satellites?
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Re:It WILL happen one day (Score:5, Interesting)
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Re:It WILL happen one day (Score:5, Informative)
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Re: (Score:3, Interesting)
Don't be ridiculous; the moon is both smaller, less geologically active and less populated that any place on earth.
It would be a simple thing to install a fiberoptic "lunar telegraph" from one side to the other,.
It's not like you have to dig under peoples houses and get easements, after all :)
Re: (Score:3, Interesting)
Re: (Score:3, Insightful)
Um, how will it transmit images back to earth, with the entire moon blocking radio transmissions?
Believable. (Score:2)
The range of unbelievable scale starts at 1000m. This idea could work for a rotating mirror that large, but not on the moon unless you're willing to lay rather a lot of maglev track to support the weight of the outer edges of the mirror, or to take a ludicrous amount of support structure to the moon.
Read TFA, sounds fundamentally flawed. (Score:4, Interesting)
The "liquids" to be used are less dense than water, and being placed on the lunar surface, which is covered in dust several times finer than baking powder.
I'd give it about 3-5 days (depending on the size) before the "revolving liquid mirrors" become revolving lunar mud pies.
Re: (Score:3, Insightful)
couldn't possibly be a lid on it to protect it from lunar dust/solar winds/micrometeorites. No possible way they'd think of that. Absolutely implausible that they'd use a static charge to repel ionized particles either, just fucking inconceivable.
Re:Read TFA, sounds fundamentally flawed. (Score:5, Insightful)
The "liquids" to be used are less dense than water, and being placed on the lunar surface, which is covered in dust several times finer than baking powder.
I'd give it about 3-5 days (depending on the size) before the "revolving liquid mirrors" become revolving lunar mud pies.
How? Is the wind is going to blow the dust onto the mirror??
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Re: (Score:3, Informative)
The solar wind. It "blows" which actually causes a static charge to build up twice a month as the Moon move into and out of the Earth's magnetosphere. This causes the dust to levitate because of electrostatic repulsion.
Re: (Score:3, Insightful)
You might want to read up on how fast that happens.
Ha (Score:5, Funny)
This is total lunacy!
Spin it & freeze it (Score:5, Interesting)
It would mean having to choose the right material (solid at moon temperature, liquid at not too much more, small/no surface crystals on freezing, ionic so that it can be coated with silver, ...). Making something like this on the moon would be much cheaper than taking it up there.
OK: I understand that they might not want to steer if far off vertical to keep things cheap but I would have thought that a little directionality would be a boon.
Re:Spin it & freeze it (Score:4, Insightful)
Smart science type guys do it again. "Hey, we can make 'X' for really cheap on the Moon. The only problem is that we have to get to the Moon to make it really cheap."
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That's no moon (Score:3, Funny)
Or a fully functional battle-station.
It'll never fly. (Score:5, Funny)
Put the telescope 550 AU out (Score:5, Interesting)
...at the sun's gravitational focus. You'd be able to resolve a planet halfway across the galaxy.
First link I pulled from Google (but there are several others): http://www.centauri-dreams.org/?p=176 [centauri-dreams.org]
Oblig. Futurama Reference (Score:3, Funny)
We're whalers on the moon
We carry a harpoon
But there ain't no whales
So we tell tall tales
And sing a whaling tune
Don't make big plans, 'cause you're broke... (Score:5, Informative)
Don't make big plans, 'cause you're broke...
You can't have a trillion dollar bailout of the rich bankers, buy up every dishwasher's quarter-million dollar underwater mortgage, hold a permanent-endless war on the other side of the world, ... and have a giant telescope on the moon. It's not possible, it's science fiction.
All the space exploration projects being talked about and planned for the 2020's may actually happen...in the 2120's or 2220's. Not in ten years from now.
I know that you're all young and starry-eyed, but in the bankrupt USA, reality rules. And reality says that there isn't going to any giant new space program in the 2010's-2020's.
Don't just mod me to -1 for simply telling you the truth. And don't tell me how small the giant new space program is compared to other absurd federal government programs. Those programs are toast also.
My American friends...you are simply broke... you have dreams... but you have no money.
Re:It's so simple (Score:5, Funny)
You just build a big tube. Like a giant internet that goes to the moon.
Parent
Re: (Score:3, Informative)
it wasn't even part of a myth, it was part of a contest between two outside groups trying to start things on fire with mirrors. when they discovered that all teams were technically not fully within the rules they had to revise their mirrors, the one time tried to use plaster in a spinning platform to form parabola but it didn't come out with the correct shape so they had to abandon it. no myth was busted from this.
it was this episode [kwc.org]
Mythbusters wrong! Ohnoes!!one! (Score:3, Informative)
I know this isn't typical slashdottiness, but I actually read the article, and have some knowledge of telescopes in general. But since you won't believe me purely on my supposed knowledge, here's a quote from TFA:
Re: (Score:3, Insightful)
At the risk of sounding adolescent: LOL, BURNED!!
Now, with that out of my system, I must admit that I find it incredibly comical how much some people rely on MythBusters for their info. Don't get me wrong, it's a good show, but seriously, for things like this, they act as if these same two guys can prove or disprove ANYTHING within a day or two of playing around with it.
Fusion research? Why bother? Call the Mythbusters and they'll let us know by next week whether or not it's feasible . . .
Re: (Score:3, Informative)
One hopes they have better things to do. Do you Slashdotters even read articles?
Some people who actually know what they are doing tried it and it [ok4me2.net] did work.
BTW the first working laboratory LMT was built in 1872.
Re:IANAPhysicist, but... (Score:5, Informative)
A lot.
The mass of the moon is ~7*10^22 kg (70 billion trillion kg). The mass of the Saturn V rocket is about 3 million kg. If we sent up a Saturn V rocket for every man, woman, and child on the planet, we wouldn't even be close to an appreciable fraction of a percent of the moon's mass. And even if we were, it is a stable system so there wouldn't be any significant effect.
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Re:IANAPhysicist, but... (Score:5, Informative)
As I understand it, the moon's gravitational pull works against the earth's and the two are in a sort of balance that determines the distance of the moon's orbit, or something.
Yes, but the mass of the object is irrelevant. Very approximately, an orbit is where the outward force due to centrifugal force[*] is equal to the inward force due to gravity; both these terms scale linearly with mass, so if you increase the mass of one, the other increases proportionately and the balance remains.
(This is why the space shuttle and the space station can be in the same orbit a few metres apart, despite being different sizes.)
Also, in general the human race is nowhere near able to do any kind of cosmic engineering, deliberate or otherwise. Even if we bent all our resources to it, we wouldn't even be able to significantly resculpt the surface of our own planet, let alone another one.
[*] To pedants: yes, I know.
(BTW, the moon already is lopsided. The same tides that pull water around on Earth pulls the rock around on the moon. The near side of the moon is significantly larger than the far side. Interesting factoid: the moon is so irregular that setting up a stable orbit around it is really hard [nasa.gov].)
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