Posted tagged ‘telescopes’

June 4, 2012

Can’t say how much I chortled in glee at this report (by old friend Dennis Overbye).

It seems that one of our deep spook agencies, the National Reconnaissance Office (AKA the other NRO) somehow managed to accumulate not one, but a matched pair of Hubble-class space telescopes.  These now belong to NASA.

What’s coolest is that these instruments were optimized for a particular task — reading the label on my undershorts — but it turns out that the design choices made to enhance the two ‘scopes capacities as ground surveillance tools are also nicely tailored for two of the key observational goals of the next space observatories.  The instruments are much shorter than the Hubble, which gives them a wider field of view.  That wide angle capacity — useful indeed if you’re sitting a few hundred miles up and trying to pick out details at Parchin or Houla — turns out to be just fine for some serious astronomy and cosmology:

The two telescopes have a 94-inch-diameter primary mirror, just like Hubble, but are shorter in focal length, giving them a wider field of view: “Stubby Hubbles,” in the words of Matt Mountain, director of the Space Telescope Science Institute, adding, “They were clearly designed to look down.”

Dr. Grunsfeld said his first reaction was that the telescopes would be a distraction. “We were getting something very expensive to handle and store,” he said.

Earlier this spring he asked a small group of astronomers if one of the telescopes could be used to study dark energy.

The answer, he said, was: “Don’t change a thing. It’s perfect.”

Even bigger advantages come, astronomers say, from the fact that the telescope’s diameter, 94 inches, is twice as big as that contemplated for Wfirst, giving it four times the light-gathering power, from which a whole host of savings cascade. Instead of requiring an expensive launch to a solar orbit, the telescope can operate in geosynchronous Earth orbit, complete its survey of the sky four times faster, and download data to the Earth faster.

Equipped with a coronagraph to look for exoplanets — another of Wfirst’s goals — the spooky Hubble could see planets down to the size of Jupiter around other stars.

Caveats: the instruments themselves account for only a relatively small fraction of the cost of actually launching and running an observatory in space.  And Dennis has his snark meter set (subtly) on eleven when he writes that “responsible adults in Congress, the Office of Management and Budget and the Academy of Sciences have yet to sign one.”  But still, given the years of starvation predicted for the space science side of NASA, this is the first news in a while that gives me the sense that we’re in with a chance.

I’ll admit, it’s been hard for me to see much good in the news lately.  But this story reminds me that it ain’t all bad; far from it.  We can build unbelievably cool stuff — not bad for a bipedal ape (or a thinking radish).  And sometimes, it seems, a tool built to study the darkness of the human condition can in fact turn around, and capture the light that pierces the expanse through which we journey on our pale blue dot.

Image:  Gerard Dou, Astronomer by Candlelight, c. 1665

A Little Post-Lunch Star P*r*o*n (Entirely SFW)

June 8, 2011

Have a look at this latest bit of cosmic eye candy to cross my desk:

What with all the wretchedness that comes from too deep an immersion in the craptastic nature of our politics these days, it is sometimes necessary (for me) just to stop, look up, and enjoy the view.

This is an image of the star-forming region Messier 17, alias the Omega Nebula or the Swan Nebula.  It is the first released pic from data taken by the European Southern Observatory’s new survey telescope, the VST.  It’s not large, as modern telescopes go — 2.6 meters in diameter, or roughly half the diameter of the venerable Palomar 200 inch Hale Telescope.  But it’s been designed as an instrument to make surveys of significant portions of the sky with very high resolution and optical/image quality.  The ‘scope boasts active optics, and delivers its photons to what sounds like the coolest instamatic ever made…with initial results as you see above.

Just in Case You Were Wondering…

June 11, 2008

…When a lab created black hole might next form and end life as we know it….

(Joke, folks, in case you weren’t sure.)

…Follow this countdown to the activation of the Large Hadron Collider. (h/t Peter Steinberg via Planet Musings.)

Given that by pretty much any standard I can think the LHC of is the most complex machine ever built, this seems like a milestone worth noting.

One thing that does strike me in this last month before lift-off (or perhaps better, dive-in ) is the seeming reversal of roles in the fact of how often, and how frequently breakthrough science turns on top-flight engineering.

That is: a ton of science turns on instrumentation. A leap in the power of key instruments produces not just better data, but qualitatively new information. Think of how much of modern astronomy — and really, modern cosmology – turns on the twin transformations in the size of the light buckets of modern telescopes, and the enormous increase in the resolution and throughput of spectrographs. Everything from exoplanets to the fundamental questions raised by the observation of dark energy emerges directly from the engineering advances that produced the observational astronomy renaiscance of the last two decades. (Many of which, to be sure, were led by scientist-engineers, among whom Jerry Nelson may be taken as the type specimen).

High energy physics is in the same boat, perhaps more so: when and as observation of the universe fails to supply sufficient data (see above) only large machines focused on very small spatial interactions can do the job. It’s a cliche to call accelerators as the telescopes of the microcosmos, but the analogy ain’t bad. It is precise in this way: each significant increase in the power of the two types of instruments yields new science. The making of the tool precedes the discoveries that we then, rightly, celebrate

Which is my point: engineers take their lumps for, in the phrase I remember from a now-mislaid Seth Lloyd interview, trading in science so well established that even engineers can understand it. See xkcd‘s take for the succinct version of the basic trope:*

Well, for the last ten years or so, it has been the engineers ascendancy. In a few weeks and over years to come, physicists will again dominate the life and meaning of the LHC. Consider this a tip of the hat to the extraordinary creative skill that will permit the glamorous side of high energy physics to strut the catwalk once more

*There is also J. Robert Oppenheimer’s “compliment” to the chemist George Kistiakowsky, whose leadership of the implosion group was essential to the completion of the Manhattan Project’s plutonium bomb. In an interview late in his life conducted by Carl Sagan, ultimately edited and broadcast on NOVA, Kistiakowsky said that Oppenheimer told him that as a chemist, he was a very good third rate physicist.

Friday (Isaac) Newton blogging: February 8. Mark the day …

February 8, 2008

…because if modern science has a birthday, this could be it. (Think of February 8 as the analogue to Christmas: a useful and not-provably-wrong conventional solution to when something significant in human history got its start.)

What happened on February 8?

On that date in 1672, Henry Oldenburg, secretary to the Royal Society, arranged to have a letter read at the Society’s regular meeting. That letter was from the still young, relatively recently installed Lucasian Professor of Mathematics at Cambridge, Isaac Newton.

The Society had reason to pay attention to Newton, for all that this was the first significant piece of his writing that had come its way. He had sent the society a working telescope of a radical new design in 1670 — and that invention propelled him from more or less complete obscurity to the first rank of those who communicated with the Society.

A critical feature of this new reflecting design was the elimination of chromatic aberration — a distortion produced by the fact that the lens used in a Galilean telescope has different refractive indices for different wavelengths of light.

This encounter with color and light prepared the way for what was to come. Newton would become famous for his reluctance to publish — and especially for his aversion to criticism.  It took him almost two years to summon up the courage or the ambition to submit the paper that would lay out the underlying theoretical and experimental work that produced the telescope as a by-product. But at last, on February 6, 1672, he mailed his letter to Oldenburg. Two days later, the news became one of the founding documents of the public record of modern science.

That letter begins with one of the most impressive deadpans in the history of science: “Sir, To perform my late promise to you I shall without futher ceremony acquaint yo, that in the beginning of the Year 1666 (at which Time I applyed my self to the grinding of Optick glases of other figures than Spherical,) I procured me a Triangular glass-Prisme, to try therewith the celebrated Phenomena of Colours.”

(The entire paper can be found in The Correspondence of Isaac Newton, Volume I, Cambridge University Press, pp 92-107. “Of Colors” — Newton’s write-ups on the work as he did it in 1665-1666 can be found online here. Check it out — the transcript comes with copies of Newton’s sketches, including the cringe-worthy illustration of his experiment deforming his own eyeball with a bodkin.)

Newton’s letter to Oldenburg was incredibly rich in new science, but in fact, as Newton’s best recent biographer, Richard Westfall described, there was a long and in many ways very productive history of optical investigation that preceded it. So why was this one document so special?

Because of the experimentum crucis — Newton’s crucial, irrefutable experiment, in which he used two prisms to demonstrate that “Light consists of Rays differently refrangible.

And even more, as Westfall argues, because of the design of that experiment, and the way Newton used his mathematical tools to drive the interpretation of his observations. As Westfall wrote, “In shattering the conception of color as a scale of gradation between opposing qualities, Newton made possible their mathematical treatment.” This was more than mere technique:

“Newton now identified colors with given rays possessing other objective, measurable qualities. Degrees of refrangibility could be arranged on a single absolute scale, whereas a scale stretching from white to black necessarily lacked an absolute reference. The subjective sensation of color became little more than a convenient symbol to signify the measurable entity.”

(Richard S. Westfall, “The Development of Newton’s Theory of Color,” ISIS 1962, Vol. 53, Part 3 173, p 158.)

The 1672 letter was not Newton’s last word on the subject, and in the immediate context of the day, it embroiled him in precisely the kind of wrangle he loathed, a battle over the accuracy of some of its details with Robert Hooke.

But it was what some have called the first true scientific paper. That kind of top ten listing is always something of a mug’s game, but this much is true:

With hsi letter to the Royal Society, Newton laid down what would be required to do meaningful science from that point forward, from the way he designed his  experiment, to the way he used mathematics in the interpretation of data, to the manner in which both results and interpretation would now need to be reported to the community.

Put that another way: I’ve talked elsewhere in this blog about science as a set of habits of mind. Here Newton provides a synoptic view of how those habits work in action:  the systematization of observation; the skepticism needed to put your initial results to the test; the interplay, back and forth,  between evidence and theory.

It’s a quibble to argue if this was the first paper we can imagine John Maddox ever accepting. It’s a fact that this one letter from a proud and fearful man working alone in the stagnant backwater of Cambridge showed his world that there was a new way to comprehend the world.

Now all we need is a name for the day. Happy Prismas anyone?

Update: A bunch of minor edits to correct typos and remove some nasty word repetitions and the kind of sentence structures you get when writing something at the tail end of the Friday of the first week of term.

Images: Newton’s Reflecting Telescope (replica). Photograph by Andrew Dunn c. 5 November 2004, licensed under Creative Commons Attribution ShareAlike 2.0.

William Blake, “Ancient of Days,” 1794. Location: the British Museum, London. Source: Wikimedia Commons.