This year’s Nobel Prizes in Physics have been awarded to Charles Kao, for fiber optics, and Willard Boyle and George Smith, for charge-coupled devices (CCD’s, which have replaced film as the go-to way to take pictures). Very worthy selections, which are being justly celebrated in certain quarters as a triumph of practicality. Can’t argue with that — as Chad says, things like the internet (brought to you in part by fiber-optic cables) and digital cameras (often based on CCD’s) affect everyone’s lives in tangible ways.
But they are also important for lovely impractical uses! When I hear “fiber optics” and “CCD’s” in the same breath, I am immediately going to think of the Sloan Digital Sky Survey (SDSS), which has provided us with the most detailed map we have of our neighborhood of the universe. Almost a million galaxies, and over 100,000 quasars, baby! How impractical is that?
The SDSS is a redshift survey, which means it’s not sufficient to just snap a picture of all those galaxies; you also want to measure their spectra (i.e., break down their light into individual frequencies) to see how much they have been shifted to the red by the cosmological expansion. And you just want the spectra of the galaxies, not the blank parts of the sky in between them. The Sloan technique was to drill giant plates for each patch of sky, with one hole corresponding to the position of every galaxy to be surveyed. (There were a lot of plates.) This image from the Galaxy Zoo blog.
Then you want to bring that light down to the camera. You guessed it — fiber-optic cables. Thanks, Dr. Kao.
The camera in question was possibly the most complex camera ever built — thirty separate CCD’s, combining for 120 megapixels in total, all cooled to -80 degrees Celsius. Thanks, Drs. Boyle and Smith.
And the result is — well, it’s pretty, but it doesn’t materially affect your standard of living. It’s a map of our local neighborhood in the universe. Extremely useful if you’d like to understand something about the evolution of large-scale structure, for example to pin down the properties of dark matter and dark energy.
Also useful for providing a bit of perspective. It’s technological advances like those honored in this year’s Prize that make it possible for we insignificant sacs of organic matter to stretch our senses out into the universe and understand the much bigger picture of which we are a part.
Cool. Nice perspective. Thx.
The filamentary structure of the galaxy distributions in the SDSS map looks fractal.
Also like the distribution of charged particles in a high energy/high density plasma.
Interesting!
RLO
http://www.amherst.edu/~rloldershaw
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Not only are the technology and data impressive, but, the instrument itself is a beautiful, modern sculpture!
Well written. I agree.
WRT #4
I would say that it is sexy cool looking. A piece of artwork, indeed.
Thank you for bringing a grandiose and helpfull perspective to this year’s Nobel in physics.
And behind the SDSS camera (literally in the picture above!) is Jim Gunn, one of the pioneers in bringing CCDs to work for observational astronomers. Long before SDSS, Jim was deputy PI of WFPC-1, which was proposed to use CCDs for the Hubble in 1977, at a time when about all the astronomical images that had ever been obtained with them would have fit on a couple of 9-track tapes. It was a radical leap then, but putting CCDs on the Hubble was profoundly forward looking.
CCDs have completely revolutionized observational astronomy…
Hats off to Boyle & Smith (and Kao, as well for fiber optics), but also to Jim Gunn, and all the others who realized the immense promise of CCDs.
Sean,
Nice perspective on today’s rather lack-luster physics Nobel. BTW, the colloquialism you aimed for is rather `way-to-go’.
I guess I’m a bit disappointed. Sure, its very important technology, but I suspect the three messrs. have won other awards celebrating their technology achievements. A similarly practical physics Nobel from a couple of years back on `giant magneto-resistance’ was important technologically, but hardly extended the frontiers of physics.
Must Hawking, Higgs, Englert, Trout, Kibble, and other Sr.Scientists/Citizens be deprived the crowning award recognizing a lifetime’s work, just because proof positive is not in hand ? Even the recent CKM Nobel leaving out C, was resoundingly criticized, but in the end, there was no righting the wrong. We really need some `sunshine’ to illuminate the clandestine selection process & its inflexible constraints, as it is operated by an oligarchy with absolute power, and total autonomy.
@Jimbo
Practically all results for the last 2.5 decades in observational optical astronomy, including all Hubble work, the discovery of Dark Energy, all of SDSS, detection of extrasolar planets, and on and on has been dependent on CCD technology. Nobels will probably be awarded someday for Dark Energy, and the Crafoord prize (which is at the Nobel level) was awarded to Gunn for the SDSS. The academy is full of astronomers who did their definitive work with CCDs. I don’t understand why one would be dissappointed in celebrating the inventors of CCDs (and fiber optics), to consider their Nobels to be less than lustrous, or to see today as an occasion to examine the selection process. The work celebrated today has transformed both science and society as well, and falls well within historical norms of the prize.
Some of the physicists that you named may yet have their day, but recognizing Smith, Boyle, and Kao in no way is a slight to them.
Is it just me, or did it become fashionable to award prizes to old, really old people? 87 year old Ginzburg in 2003, 87 year old Nambu last year, 85 year old Boyle today. And the average age of recipient this year is 80, it’s probably some kind of record.
And it’s not just intellectual curiosity. It’s risky to keep delaying prizes like that, many worthy people might die before getting the recognition they deserve.
How exactly is the redshift map made? I am talking about which software, how the axes were made round and all those details. For the life of me, I am not able to make the axes go round! How does one make pie plots of redshift surveys?
And I have to say, SDSS is the coolest thing that happened to optical astronomy so far 🙂 I am highly biased!
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Jimbo: “Must Hawking, Higgs, Englert, Trout, Kibble, and other Sr.Scientists/Citizens be deprived the crowning award recognizing a lifetime’s work, just because proof positive is not in hand ?”
Absolutely! That physics is completely overflowing with fashionable speculative theories which have yet to see any firm supporting evidence is sad in itself, if those theories were to deprive scientists who make REAL progress from which all of humanity benefit of their recognition it would simply be pathetic.
Jimbo: ” We really need some `sunshine’ to illuminate the clandestine selection process & its inflexible constraints, as it is operated by an oligarchy with absolute power, and total autonomy.”
No, what you need to do is start your own physics fashion award as Nobel certainly didn’t have speculation in mind when he funded his prize for those who “have conferred the greatest benefit on mankind”.
Arrow,
Well said!
RLO
Lovely piece! My only objection was Sean’s reference to us humans as “insignificant sacs of organic matter” – and I’m a hardcore misanthrope! Our organic matter is the same stuff that makes that image so beautiful. Hard as it is to imagine sometimes, we’re all vibrating with the same quantum mechanical funkiness that the matter in those distant stars and galaxies is. If we could all see and feel ourselves and others to be part of the beauty of physics and cosmology perhaps we’d quit squabbling on our little planet.
Note also that, according to the Caltech alumni newsletter, Jim Gunn is getting the National Medal of Science this year.
I happen to think that these were inspired choices for this year’s Nobels in physics (I wouldn’t have predicted these winners) AND SDSS has produced great science. But compared to the really inventive robotic fiber-coupled spectrographs several of my friends have built ( before SDSS too), the plug plates of SDSS are a real kluge of the brawn and money over brains kind.
(this is not even an implied knock on Jim Gunn, one of the very, very few astronomers both technically and theoretically brilliant. Now, too many observers treat their instruments as just black boxes and have not the slightest interest as to how they actually work.)
@coolstar,
Thank you. You know, I’ve read several times about those plates with holes in them and I still don’t get it. They look horribly impractical, expensive, labour intensive, and a logistics nightmare.
Why do they even need them? If the purpose is to isolate the galaxy’s spectra from the “blank parts of the sky in between them”, then you don’t need a plate, right? Unless the blank sky is producing enough cosmic background signal to mess with the sampling? And even then, it’s a CCD based system for goodness’ sake. You should be able to digitally sample and isolate, and the problem is solved. It’s a problem better solved with software than hardware.
That’s not to take away from the Nobel for the CCD inventors. The CCD has been a boon for digital imaging, all the way from high end one-off instruments, to the cheapest cell phone camera you can think of. The CCD has been a huge win for all concerned.
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@Barbara (16)
Nicely put. I like to tell my friends, “You are a part of the universe that is trying to understand itself.” “You are not outside the universe, looking in at it — you are part of it!”
Yeah, I wondered about the plug plates too. But as I was taking that shot of one, the site manager pointed out that they ran the numbers, and that for the duration of SDSS, it would be cheaper to use the plates (and hire a couple of people to plug and unplug fibers) than build a robot. They have automated setups to handle a lot of logistics (such as which fiber goes where on the detector), so the people need not verify that each fiber goes in a designated hole. As to why the plate – they hold the fibers in place, and the night sky’s diffuse light can be brighter than the targets, so you definitely want to block all the unwanted areas of sky. Some of the fibers deliberately sample blank sky for it subtraction. Even with digital detectors, you can’t defeat Poisson noise, which rises terrifyingly as the object count rate drops below the foreground or background rate.
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The plug plates physically hold the fibers in the correct positions at the focal plane of the telescope. You can’t just have the fiber ends flopping around in open air. The fiber ends are 180 microns in diameter and one wants to hold them in a fixed position through the duration of an exposure (about an hour) to a tolerance of a few microns, as the telescope moves while tracking the sky.
In the case of a fiber-fed spectrograph, the plug plate does not play a role in blocking the sky light similar to the aperture plate of a slit spectrograph. The fibers are lined up at the entrance aperture of the spectrograph, forming their own slit, so to speak. One almost always needs something, either fibers or a slit, to isolate the objects from the surrounding sky. The sky contributes Poisson noise and systematic pattern noise (because there are many atmospheric emission lines, so the noise changes s a function of wavelength). The software has to subtract the sky anyway, because there is sky in front of your objects even with the fiber/slit, but you want to get as little sky as possible. This is a problem where you need to make the hardware as optimum as possible to minimize noise. Good software is necessary too, but astronomers work in a low S/N regime; no software is magic enough to remove noise once it’s in the data. It’s much harder to write software when it has to make up for hardware deficiencies in the instrument.
The plug plates are low tech but they were the most economical solution to SDSS’s problem – remember they are plugging 640 fibers per plate. Robotic fiber positioners are impressive, but they are expensive, take a long time to design and build, and are very heavy. A fiber positioner that big could easily weigh several tons and I don’t know if the SDSS telescope could have carried that weight as-built. Also, fiber positioners take time to reconfigure (unless you go the 2dF route and build two). SDSS has multiple fiber cartridges, so they plug the plates during the day and then just swap between them at night.
sir,
narender sing Kapany who first demonstrated successfully that light can be transmitted through bent glass fibres during his doctoral work at the Imperial College of Science in London in the early fifties, and published the findings in a paper in Nature in 1954.
Since then, Kapany irelessly developed applications of fibre optics for endoscopy during the fifties and later coined the term Fibre Optics in an article in Scientific American in 1960. His body of work provided the basis for the developments of any and all applications in communications.
Charles kao published his findings after kapany. why sweedish accademy didn’t consider kapany?