[syhprum (OP)]

E-ELT is a proposed 42m telescope due to be constructed in Brazil (I remember as a boy wondering if the Hale 200" would ever be completed)
An excellent article here lists the technical problems and observing strategy here.

http://www.eso.org/sci/facilities/eelt/science/doc/drm_report.pdf

[imatfaal]

does that Acronym stand for European Excessively Large Telescope? ...Enviably Large, Enormously large, Elephantine Lens...

I must admit I have never understood the physics of why we cannot use a myriad of small mirrors bolted together.  I have three aluminium discs on my desk that are manufactured to an incredibly low error tolerance and yet they are mass produced and fairly cheap (HDD platers - now used as coasters). 

I will read that ESO prgramme with interest - thanks

[CliffordK]

Whew...
A big "summary" for a big telescope.

I suppose I must ask if there is a large benefit of having 100 off-axis mirrors pointed towards a single photo receptor versus having an array of a hundred telescopes each with their own photoreceptors, and able to be focused either together, or independently.

A distributed array wouldn't have to be located at the same site either.

[Soul Surfer]

The advantage of the large single mirror is sensitivity multiple telescopes can offer advantages of resolution although separation distance are limited compared with radio telescopes because of phase stability requirements.

[Bored chemist]

does that Acronym stand for European Excessively Large Telescope? ...Enviably Large, Enormously large, Elephantine Lens...

I must admit I have never understood the physics of why we cannot use a myriad of small mirrors bolted together.  I have three aluminium discs on my desk that are manufactured to an incredibly low error tolerance and yet they are mass produced and fairly cheap (HDD platers - now used as coasters). 

I will read that ESO prgramme with interest - thanks

Imagine bolting lots of them together. The thickness of the composite disk would be the same, but the weight and length would be bigger. It would be too floppy.