Consolations of the desert

After watching Patricio Guzmán's Nostalgia for the Light, I read a little about the Atacama desert, and came across this picture of penitentes on the Chajnantor plateau.

The is from a  helpful description by the photographer, or the ESO:

The precise details of the mechanism that forms the penitentes are still not completely understood. For many years, people of the Andes believed [them] to be the result of strong winds prevalent in the mountains. However, the strong winds have only a limited role in shaping these icy pinnacles. Nowadays, it is believed that they are the product of a combination of physical phenomena. 

The process begins with sunlight shining on the surface of the snow. Due to the very dry conditions in these desert regions, the ice sublimes rather than melts — it goes from solid to gas without melting and passing through a liquid water phase. Surface depressions in the snow trap reflected light, leading to more sublimation and deeper troughs. Within these troughs, increased temperature and humidity means that melting can occur. This positive feedback accelerates the growth of the characteristic structure of the penitentes.

The name penitentes comes from a culture with a heavy emphasis on guilt and punishment.  This seems out of keeping with a place so remote from humans. It would be nice to have another name and, while I don't believe in angels either except as figments of the human imagination, I'd rather call them angels.  They remind me little of Paul Klee's In Engleshut, where the several overlapping forms suggest a variety of possibilities, not all of them bad (and not, perhaps, as destructive as Walter Benjamin's vision of the Angelus Novus).

Image: ESO/B. Tafreshi

Photon buckets

Caleb Scharf celebrates the go-ahead for the European Extremely Large Telescope:

Equipped with adaptive optics E-ELT should.... be able to routinely study Jupiter down to scales of about 20 kilometers – by comparison the Great Red Spot is at present about 20,000 kilometers across. Mars can be imaged to roughly 5 kilometer resolution (depending of course on the relative separation of Earth). In other words, on a nightly basis we will be able to monitor the worlds in our solar system with a fidelity comparable to fly-by missions of yore. [1]

Images like this (but not this) might become commonplace.

I guess the adaptive optics resemble those at the Keck observatory in Hawaii, where lasers are beamed into the night sky to create artificial stars. The false stars become reference points because astronomers know what the laser should look like in the heavens were there no atmospheric distortion. That, at least, is part of how Steven Johnson describes them in How We Got to Now.

Johnson's reference to Keck is brief as his book explores a range of innovations that make the modern world.  None of those innovations are more important than those that transform the way humans extract energy from their surroundings, and in this regard the book highlights research at the US National Ignition Facility, which seeks "to create an artificial sun on Earth."  In Johnson's analysis this is looks likely to be a, if not the, great hope for meeting the energy challenge. [2]

But could solar technologies such as those being developed by the physicist and astronomer Roger Angel be a significant part of the way forward?   The technologies are, as Lee Billings puts it in this article, essentially clever ways of maximising efficiency in collecting, concentrating, channelling, or diverting the energy radiating from an already existing star. That could, I think, be rather wonderful. [3]


Notes

[1] I reviewed Scharf's book here. He has kindly said that my Book of Barely Imagined Beings contains "some fantastic ideas and insights to the nature of life."

[2] Brian Cox comes to the same conclusion in the last episode of his recent TV series The Human Universe.  A website for Johnson's TV series identifies some solar projects as sources for hope on a small scale.  Thanks to TH for loan of a copy of Johnson's book.

[3] On some environmental impacts of solar concentrators, and other technologies, see Rebecca Solnit.


Image: the site for the future E-ELT looks almost like Mars...if you ignore the blue sky, the snow on the peak and the extensive tracks.