[vanderZwan]

> With this new capability, the 8-metre UT4 reaches the theoretical limit of image sharpness and is no longer limited by atmospheric blur.

Theoretical limit as in diffraction limited? How will this technology "scale" to other frequencies and resolutions? Related to this diffraction limit: is there any overlap in the advances in microscopy and astronomy? For example, do advances in super-resolution microscopy[0] affect advances in optics in astronomy? Could advances in adaptive optics in astronomy somehow translate to microscopy?

(I'm also curious if this technology will make putting telescopes in satellites not worth the cost, but that question was already asked and answered here: https://news.ycombinator.com/item?id=17557482)

[0] https://en.wikipedia.org/wiki/Super-resolution_microscopy

[eisstrom]

Yes, the diffraction limit is meant here. The VLT has four 8 m mirrors, for each of them the angular resolution limit is = wavelength/diameter = 8 * 10^(-8) rad. The practical resolution of the new narrow-field mode is about 4*10^(-7) rad, and it was one order of magnitude larger before.

Adaptive optics is the key invention here. As far as I know, it works better in the near-infrared than in the red part of the optical range, and it gets worse toward the blue part. Due to this, our resolution changes as a function of the wavenlength, since MUSE captures the flux from all wavelengths at the same time.

ESO wants to achieve an even higher resolution at the 40m Extremely Large Telescope (another order of magnitude better): https://www.eso.org/public/teles-instr/elt/

It's funny that your mention super-resolution microscopy because Stefan Hell, one of the Nobel Prize winners for advances in that field, works in the same city as we do. So far, I don't think we have any overlap with what he does.

[vanderZwan]

> The practical resolution of the new narrow-field mode is about 4 * 10^(-7) rad, and it was one order of magnitude larger before.

Amazing! :)

> As far as I know, it works better in the near-infrared than in the red part of the optical range, and it gets worse toward the blue part.

Do you know what is the reason for this? Noise from Rayleigh scattering? EDIT: Already answered here: https://news.ycombinator.com/item?id=17559121

> It's funny that your mention super-resolution microscopy because Stefan Hell, one of the Nobel Prize winners for advances in that field, works in the same city as we do. So far, I don't think we have any overlap with what he does.

Why not arrange a kind of meet-up? :) Surely exchanging ideas would lead to interesting ideas, and in the worst case you can at least by inspired by geeking out over mega- and micro-optics together.

[dekhn]

In my first year of grad school (1995) our microscopy professor showed us an astronomy adaptive optics paper and said "we're going to do that". Years later, they did that.