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Unbelievably Large Telescopes On the Moon?
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.'"
Actually, it just seems large because the moon looks so small. My guess is you're holding the telescope the wrong way round.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
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.
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
http://inventorspot.com/articles/liquid_lunar_telescope_5345 That one says that it was first suggested in 1991. I bet someone thought of it earlier.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
The article implied that they have been thinking about this for years.
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.
If this were really happening, what would you think?
You just build a big tube. Like a giant internet that goes to the moon.
Maybe not
This is total lunacy!
Knowledge is power. Knowledge shared is power lost.
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.
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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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??
we don't have to transport massive amounts of equipment to the dark side of the moon.
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.
When our name is on the back of your car, we're behind you all the way!
Stick at relay satellite at the Earth-Moon L4 or L5. That means the telescope couldn't be exactly opposite Earth, but if there's still a lot of room where it's shielded from Earth but still in view of L4 or L5.
Dude, the grandparent was making a reference to a Pink Floyd album. *sigh* Kids these days... http://en.wikipedia.org/wiki/The_Dark_Side_of_the_Moon
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.
Look, I don't care who you work for sonny, you are not flying with more than 100ml of liquid in your luggage, so hand it over. Bloody astronauts think they are so superior.
Home fucking is killing prostitution.
...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
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.)
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.
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.