Light Show

As you know, I have a great love for science and cosmology. I seem to have a very technical side that enjoys unraveling mysteries, or at least following the work of those who do so.

But I also love beautiful things, and very often the tools and findings of science are beautiful themselves, even as they reveal the beauty of the universe.

A great example of this beauty is pictured above. The twin Keck telescopes which are perched atop an extinct volcano called Mauna Kea on the big island of Hawaii, at an elevation of 14,000 feet.

The Kecks are masterful designs, true testaments to human creativity. And they are also beautiful. From the graceful domes that protect their delicate instruments to the huge sectioned hexagonal mirrors at their hearts, they just leave me in awe. And can you think of a more beautiful location? They don’t sit there just so astronomers can work in a paradise though, Mauna Kea is a perfect location for a telescope: high elevation to minimize atmospheric distortion, no close mountains to stir up the air, very clear skies, and a thousand miles of temperature-moderating ocean all around to provide stability.

These instruments are designed to “see” in both the optical and near-infrared parts of the spectrum. The 36-section hexagonal aluminosilicate ceramic mirrors are the largest optical/Infrared mirrors in the world.

The two Kecks can work together to form what is called an astronomical interferometer with an effective mirror size of 279 feet, or they can each take observations separately.

The Kecks have one amazing feature that sets them apart from other telescopes and it’s an awesome piece of technology. Because of manufacturing issues and the warping effect of gravity on large heavy objects, segmented mirror designs are needed to produce mirrors larger than about 200 inches (the previous largest telescope, which held that title for many years, was the 200 inch Hale at Mt Palomar). So the Keck uses a set of 36 hexagonal mirrors interlocked to make one big mirror. But these mirrors have to be aligned to each other nearly perfectly. An alignment error of 1 millionth of an inch would be catastrophic to the observation. The Kecks have the most advanced alignment and drive mechanism of any telescope. The mirrors are aligned by a computer that checks their relative heights in hundreds of places twice every second. Minute corrections are made nearly instantly to bring the mirrors into alignment.

That’s all amazing, but there’s more. Because these mirrors can move independently, they can also be used to correct for atmospheric disturbances that hinder the clarity of all ground-based telescopes. The initial design of this system worked like this: the telescope has an optical sensor that locks on to a bright star (which is called the guide star) close to the site in the sky being observed. By measuring the changes in the brightness of the guide star caused by atmospheric disturbances, the system can calculate the corrections required in the mirrors and send that information to the mirror alignment computer which then corrects for them. This is called Adaptive Optics, and as implemented it was an ingenious system but it had a huge limitation: only about 1% of the sky is close enough to a star bright enough to use as the guide star. So the system was re-imagined in a very novel way

The Keck telescopes can now create their own guide stars.

“In the upper part of the Earth's mesosphere (90±10 km altitude), there is a 5-10 km thick layer rich in Sodium atoms, deposited by the ablation of micrometeorites. These atoms can be excited and caused to radiate by spontaneous emission by projecting a pulsed laser tuned to the Sodium D atomic transition (589 nm) in the direction of the science target.”

Laser Guide Star (LR)

So, using powerful lasers, the telescope can excite particles in the extreme upper atmosphere to the point that they radiate light. This light can be used as a substitute guide star for correcting atmospheric disturbances. It’s genius. This new system is called LGS AO (Laser Guide Star Adaptive Optics). You will notice that the guide star laser is a pretty orange-yellow color – that’s the color of a laser tuned to the 589 nm wavelength as needed to cause this effect on Sodium.

LGS AO works so well that the Keck telescopes now routinely produce images that are sharper than the Hubble Space Telescope.

The Kecks have produced some of the greatest discoveries in astronomy during the last decade, including the discoveries of more planets than any other instrument, including the Kepler spacecraft.

All that and of course, I think they really are beautiful to look at.

The Glass Monster

In case you've ever wondered how crazy lenses can get on the ultra high-end, here it is. The "small" lens in this picture is a Canon 800mm beast that would normally stand out in a crowd like Andre The Giant at daycare. It's almost twice the size of the lenses they use at football games.

But seen here dwarfing the 800 is the granddaddy of all SLR lenses, the world's largest autofocus lens, a fire-breathing 1200mm monster that can make out distinct facial features at one mile away and weighs 36 pounds.

The Canon 1200mm lens shown here is no longer in production, but even when it was there were only two of these bad boys made per year, and no more than 20 were ever made. The price tag? A cool $120,000. Used. Even when they were in production the thing was difficult to get, there was an 18 month wait because it took at least a year to "grow" a single-crystal fluorite lens blank that large, and griding it was very slow. And to top it off, the lenses were all made and assembled entirely by hand.

Handholding this lens in actual use is impossible of course, it requires a solid tripod (or two) and it's not for indoor use because the closest distance it can focus is 50 feet away. Notice that the big Canon 1Ds Mark III camera attached to it looks like a child's toy.

So what would a lens like this be used for? Generally it's used in sports photography for scenes that are inaccessible to the photographer, such as horse racing from the far side of the track, and certain Olympic events like ski jumping. I imagine it would be good for surfing photography too.

It's price puts it beyond most amateurs, one source at Canon said most customers had "Agency" in their names. It is known that two are owned by Sports Illustrated, Canon Professional Services owns two, several governments have them, and National Geographic owns one. Oh, and a couple of "wealthy individuals" decided to plunk down their milk money for the bragging rights.

I showed this to Heather and the first thing she said was "No, you can't have one."

Wide And Fast Glass

The enigmatic photographer known alternately as Fergus McCool, Dennis McDowell, Ein Horn, and Vigo Huhnerdrosseler has acquired a most awesome new lens. This newest object of my jealousy is a fast and wide beauty known as the Canon 16-35mm f/2.8L USM. Despite pressure, veiled threats, and offers of candy, I don't think he's going to loan it to me for my reunion this year. Which is a shame, because I would certainly do so for him :)

So, Fergus, during the week of my reunion, look up at that dust-covered lens sitting on top of your fridge and picture the wonderful Rocky Mountain landscapes, majestic clouded skies, and cool-flowing streams that could be passing through it, and think of me.

Bodies Come And Go, But Lenses Are Forever

I'm posting this just in case a rich widow in my vast army of readership wants to get me one of these beauties for a mid-winter gift. :)