# Work Begins on the World's Largest Telescope

**URL:** <https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [June 30, 2005, 9:51pm UTC](https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594 "2005-06-30T21:51:22Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\
**Post date:** [June 30, 2005, 9:51pm UTC](https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594/1 "2005-06-30T21:51:22Z")

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[Let’s see 'em try to do this at Lenscrafters!](http://www.newscientistspace.com/article.ns?id=dn7608)

> [@](#):
>
> Expert mirror makers are gearing up to cast the first component of what is planned be the world’s largest telescope. When completed, its seven 8.4-metre mirrors will more than quadruple the power of today’s best observatories.
> 
> Like other multiple-dish instruments, such as the four 8-metre dishes of the Very Large Telescope in Chile, the planned Giant Magellan Telescope will take advantage of its expansive surface area to boost its sensitivity to light.
> 
> But unlike the VLT, the GMT will arrange its multiple mirrors into a single "super dish” - with one mirror at the centre and the other six curved around it like petals. Such “off-axis” mirrors have never been made as large as this.
> 
> The design makes the telescope’s vision keener than it would be if all seven mirrors remained separate. It will have 10 times the resolving power of the Hubble Space Telescope.

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**Author:** ![MaxTheVool](https://avatars.discourse-cdn.com/v4/letter/m/9fc29f/32.png) [@MaxTheVool](https://boards.straightdope.com/u/MaxTheVool)\
**Post date:** [June 30, 2005, 10:45pm UTC](https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594/2 "2005-06-30T22:45:45Z")

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The precision with which mirrors that big have to be built is truly hilarious. They have to account for all sorts of things, like droop-due-to-gravity, etc. It wouldn’t surprise me if they were sensitive enough that the bloody coriolis effect kicked in 🙂

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**Author:** ![Rhubarb](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@Rhubarb](https://boards.straightdope.com/u/Rhubarb)\
**Post date:** [July 1, 2005, 3:07am UTC](https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594/3 "2005-07-01T03:07:13Z")

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> [@MaxTheVool](#):
>
> The precision with which mirrors that big have to be built is truly hilarious. They have to account for all sorts of things, like droop-due-to-gravity, etc. It wouldn’t surprise me if they were sensitive enough that the bloody coriolis effect kicked in 🙂

No problem. Just put it at the South Pole. Air’s thinner there anyway.

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**Author:** ![slortar](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@slortar](https://boards.straightdope.com/u/slortar)\
**Post date:** [July 1, 2005, 1:10pm UTC](https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594/4 "2005-07-01T13:10:34Z")

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Yeah, but how big of an ant could you fry with it?

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**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\
**Post date:** [July 1, 2005, 2:02pm UTC](https://boards.straightdope.com/t/work-begins-on-the-worlds-largest-telescope/310594/5 "2005-07-01T14:02:31Z")

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I recently heard about a plan by SETI to use old-style TV satellite dishes (the big ones they used to have) to make a large radio telescope array. IIRC it is going to be either a mile square or a km square.