Discoveries in the Physics & Astronomy shop | Science, curiosities, and surprises
Our wonderful Clark refracting telescope support column, in all its masonry glory. Structurally isolated from the rest of the building so that footsteps don’t cause wobbles in the telescope’s field of view.
Sometimes, it’s the little things.
For the most part, the light accumulation of dust, pollen, and other stuff on the objective lens of your telescope is a thing you live with and ignore. The damage you can do to the lens and its optical coatings is far more severe than the minor loss of image quality from tiny flecks. Known and accepted trade-off.
Here, however, we have a classic TeleVue Renaissance that’s still in good shape. Aside from the dust and dead spiders, anyway. Exact age is unclear, but we can roughly place it between TeleVue’s founding in 1977 and the construction of the “Halley’s Comet” models in 1985. Serial number 1100, for anyone keeping track at home. Even dust-covered, the optics appear good at a quick glance, and they have a reputation for remaining in good shape for a long time.
There’s a bit of chromatic aberration when you look closely, an issue which has been resolved in their current models. (Optics = hard.) The design type is called a Nagler-Petzval, which uses a pair of lens doublets to correct numerous distortions caused by refraction. Every design has its pros and cons; this one’s quite nice. Our version has – we think – an air-spaced doublet (two lenses utilizing different curvatures) as the objective, and a cemented doublet in the rear.
At least, that how the Halley’s Comet edition was made. The current optics update utilizes two air-spaced doublets – see the diagram for the NP101is – so it’s reassuring to see that the improvements are incremental. Good sign for the one we have.
Okay, the brass could’ve aged better, but it’s got character!
Black on brass looks good.
Even the knurled knobs on the focuser are brass. We don’t want to leave this for display, however. We want to see the stars!
That dust, though.
Yeah, definitely a problem. A cleaning is in order.
Not pictured: the dead spiders removed with air from a bulb blower. Dead spiders do not improve optical quality.
Here, we’re applying a coat of First Contact polymer cleaner, an expensive but effective treatment for safely removing gunk from precision optics. Comes in a wee bottle like it’s nail polish and smell like nail polish remover. Because it’s got acetone and other solvents in it.
Once it dries, that little tab lets us pull away the pink film with all of the dust and debris stuck in it. A good time to wander away from the stink of volatile solvents and get a cup of coffee.
And, well, that’s a substantial improvement.
It’s not perfect. The polymer is very good at removing particulates, but less so at water-soluble stuff. Once we evaluate this with a camera setup, we can see if a follow-up cleaning with deionized water is necessary.
Problem there, of course, is that we run the risk of introducing tiny scratches in the process. Could be worthwhile if the effects are still visible, but we’re still erring on the “do a minimum of harm” side of things.
Will it live up to its potential as an imaging ‘scope? Maybe. There’s a fair chance. If not, we’ll keep it around as a stylish yet usable throwback for visual observation. The best telescope, as they say, is the one you use.
Roof rocket: recoverable.
In 1991, the Astronomy Club had clearly grown tired of plain walls at the Observatory. With a fantastic mural adorning the interior stairwell to access the Clark telescope (subjects of future posts!), the regular hallways must have looked… fine.
Prof. Dave Lien was the faculty member overseeing all of this, and in April the club had decided a scale version of the solar system would look pretty great. Time to check in with the Art folks!
(Also: “Observing, etc.”)
And you know what? It’s way better than white walls! The final design ended up being different from the proposed idea, though the concept is the same. The Sun occupies a place of prominence, and the mural includes both scaled sizes and scaled distances of our solar system, shown side by side.
Not both at once: in that case, it either wouldn’t fit in the building or the planets would be so tiny you couldn’t see them. Both of which really defeat the purpose. (Not that they aren’t fun demonstrations in their own right!)
Five and a half years later, ta-da! After a quarter-century, several building repaintings and a recent renovation, it still looks sharp.
In the early ’90s, we had an Astronomy Club. Reading through old club meeting minutes sometimes turns up little gems, like these:
“Sorry for the late minutes. The secretary had a lot of tests at the end of last week.”
Completely understand. Full respect for those priorities.
“Because of clear skies, the meeting did not last long.”
We’re here for the telescopes, not chit-chat! Again: completely understand!
Do you ever set aside some papers, because you don’t need them right now, but they were maybe interesting for later? And then eventually there’s just a pile or folder or shelf devoted to these, because you’ve inadvertently started a collection? And then, half a century later, someone stumbles across these boxes and wonders, why?
Why do we have boxes of printed press releases from NASA in the early 1970s? Probably the same reason we have old math exams from the 1940s out at the Observatory. (That’s a post for another time!)
Honestly, if we’d been diligent about tidying this stuff, this blog would be way less interesting.
In our attempts to minimize the ever-growing aura of light pollution around the Observatory, we work to form good relationships with our neighbors. And to maintain them.
Back in 1979 – an excellent vintage! – the Keystone Water Company agreed to a switch controlling the light outside their standpipes, just south of the Observatory. For as long as we remain good stewards of the switch, always turning it back on when we’re done observing, they let us adjust the night sky’s brightness just a little bit more each night.
Forty-four years and counting.
Your average TA for an Astronomy night lab is excited about their job. They not only took an Astronomy course, but liked it enough to come back. At night. Irregularly, as the weather permits, sometimes in the cold of a Pennsylvania winter. They’re enthusiastic about their job. We’re enthusiastic about them.
So when you find notes from almost three decades ago with student gripes? Totally understand. We wish every student could bring the same excitement to a night with telescopes and stars.
And, for the record: Saturn absolutely is beautiful through a telescope on a night with no moon. Just phenomenal.
Some years ago, back in 1887, the University received a lovely Clark & Sons refracting telescope, complete with a clock drive to track the stars against the Earth’s rotation. When a shiny new toy scientific apparatus arrives on your doorstep, it’s very important to confirm that it works as intended. Here, in an old notebook, we see the original data on the clock drive’s variance from the ideal sidereal tracking rate.
“Observations for Determining Sidereal Clock’s Rate Nov. 8, 1889”
Then follows a table of stars with known right ascension and declination, then a repeated set of measurements 20 days later. “Rate of Loss per day .268 sec.” Considering the frequency with which proper polar alignment and tracking proves a nuisance more than a century later, that seems pretty good. The clock drive is long gone, of course, so we can only guess at how accurate it was and stayed throughout the decades.
It looks like these entries were by a J. D. Minick, Class of ’88. Best guess is a John David Minick, graduate of Bucknell in 1888, listed as Prof. John D. Minick of Lenoir, N.C. in the Memorials of Bucknell University, 1846 – 1896. Astronomer, apparently. Mathematician? Physicist? At this point, we’re content with the mystery.
Around the same time, Bucknell was also the home of one Jacob Henry Minick, Class of 1891. He’s listed in the link above as from Orrstown, PA, in Franklin County. Any relation?
His name lives on at the university in the form of an endowed scholarship:
“The Jacob H. Minick Fund was established by a bequest from Jacob H. Minick, Class of 1891, the income of which is to be given each year to students who, because of some physical difficulty, are forced to use crutches during all of their college work.”
There’s a story there, no doubt.
As one would imagine, university buildings have tons of books in them. Shelves upon shelves, editions going back well over a century. See above, The American Ephemeris and Nautical Almanac, 1887. Is it useful? Not particularly these days. Does it look cool on the shelf in line with year after year of its subsequent volumes? Of course!
Note the volume near the middle of the image, with the well-worn spine. It’s a duplicate of the book to the right, the 1922 edition, save for one key detail. A bookplate:
Ex Libris Harry Scheidy Everett. Listed in L’Agenda 1925 as Associate Professor of Mathematics and Astronomy and Director of the Observatory, he was already a Bucknell alumnus, having received his Master of Arts on Wednesday, June 18th, 1913, according to the Bucknell Catalogue of 1912-13. (He also played the violoncello.)
Astronomy now lives under the Physics umbrella, rather than Mathematics, although we’re all stacked on top of each other here in Olin Science.
Have a look at that bookplate, and imagine that self-described philomath Dr. Everett was having a grand old time drawing that up. In case you can’t read it, the inscription above the doors reads: “Let none ignorant of Geometry enter here“
Bet he was a unique individual, that Dr. Everett.