Discoveries in the Physics & Astronomy shop | Science, curiosities, and surprises
S’mores! Pretty much everyone likes s’mores, and they’re a great excuse to get outside and be social. And to make a cozy fire on an October evening.
Of course, if you also attempt to do this with physicists, the discussion is bound to turn to fluid turbulence and vortices and all of that…
In case you were wondering: there is a version of this which involves watching the fluid flow with lasers, because of course they have another way to play with lasers…
In our cabinet of meteorites – because everyone has one of those in an odd corner, right? – we have a number of surprisingly-dense space rocks. You can’t really hurt them, considering they’ve already been dropped far harder than any puny human can manage, so occasionally we get to pass them around.
Here we have the Plainview meteorite, from Hale County, Texas. Discovered in 1917, the original find weighed over 400 kg (a lot!), and our little chunk is a mere 184 g. Isn’t it adorable?
For the most part, deciding on constellations is hard. A few really stand out (Orion, Cassiopeia) as do a number of bold asterisms (the Big Dipper in Ursa Major, the Teapot in Sagittarius). The rest of the sky, where there are stars but no super-obvious pattern stands out? Oof.
Picking all 88 sounds like a beastly challenge.
Still… sometimes it seems like someone just starting phoning it in in the end.
Declaring Norma to be a carpenter’s square isn’t helping your case.
In acoustics, there’s a phenomenon known as beats, which is when two similar tones generate an interference pattern that sounds like a pulsing beat. It happens with waves of all kinds, waves being moving energy and all that, but sometimes it’s easier to really get the sensation when you hear it. Graphing out the sinusoids and showing the constructive and destructive interference helps explain it. Hearing that wubwubwubwubwub cements it.
We have what looks, at first glance, like a glockenspiel, with its metal bars all in a row. Tap one with the mallet, and it sounds almost the same as the one next to it. Almost. Tap two at once, and you get the beats.
At one end, it’s 440 Hz. Then 439, 438, 437, 436, and 435 Hz. Not only can you hear the beats, but you can very clearly hear the change in beat frequency as you combine tones in different combinations. It’s very cool.
Also quite unnerving after a while. woobwoobwoobwoobwoob
We have many, many compasses scattered about the department. The vast majority come and go as part of the toy kits for PHYS 212, tiny ones useful for illustrating the effects of magnetic fields. Probably more that than for wilderness orienteering. Note: a physics toy kit, despite its educational and entertainment value, is probably insufficient on its own for wilderness survival. Check with the fine folks at Outdoor Education & Leadership for that.
One of the entertaining compass demos is to array a circle of them around an unshielded wire, and seeing the effect of turning the current on and off. Half a dozen little red arrows snapping to attention never loses its neat-o quality.
There’s also this little gem, tucked away in one of our closets. Inscribed with a nice little dedication, reading “TO BUCKNEL / A FRIEND” on the side. Which, the longer you look at it, seems a little less clear each time.
Maybe you had to be there? Interpret it as you will.
Sometimes, stuff just lingers. It’s unclear how long it’s been sitting on this or any shelf, whether it has any use anymore, how on earth to dispose of it, etc. Of course, those odd objects tend to sport some of the coolest old labels.
So much to enjoy here! Buddy the dog, holding a flag with his name, but also helpfully labeled below as “Buddy,” just in case it wasn’t obvious enough. Directions for using metal polish on non-metallic surfaces, which – to be fair – might not be obvious. (Still mostly amounts to wipe on with a soft cloth, wipe off with a soft cloth.) The prime visual real estate for “Non-Inflammable,” which is an entertaining reminder of the flammable/inflammable quirk of the English language. What a country!
It’s not entirely clear if the yellow color was an original choice or has been caused by many years of aging paper.
At any rate, the steel cap is thoroughly corroded shut, so there’s no telling what remains inside. Whether that corrosion is caused by or despite the contents of the Capital Metal Polish container, we’ll never know.
When you have a regular need to open lots of doors – accessing equipment, supplying labs and classrooms, helping coworkers find their misplaced keys – the powers that be may be kind enough to cut you a master key. Saves time, effort, and several pounds of metal on a keyring. They are, of course, master keys with a limited range. Certain doors are off-limits.
The access door to the elevator-base maintenance? That’s a place we don’t need to be. It’s only important that we don’t stack anything of substance on top. (The roll of plastic seen here could be blown away by a light breeze.) Not that it wouldn’t be neat to have a look inside – after all, who wouldn’t like to check out some new kind of specialized machinery? – but if the elevator’s working, maybe let it be.
That said, it’s hard not to be fascinated by the accompanying light switch:
Sure. Of course. How else would you label it? Dark, forbidden basements should always get the proper horror movie styling.
And then there’s the nubbin of a switch. Makes one wonder. Can’t possibly be from overuse. (Can it?) Implies that someone did that on purpose.
Maybe the answer’s down in the pit.
The Clark, our lovely 19th-century telescope. Much to be written on it another time, but here’s a picture with the dome open on a fine, sunny day.
Just look at that lovely brass set against the black steel tube. Magnificent.
It seems the university has drifted away from this, but if you look around at old equipment, a great deal of it is marked with the date it was acquired and – if it’s old enough – the cost. They’re fascinating glimpses into the past.
Here, an optics bench made by the Central Scientific Co. of Chicago, Illinois. Or, as they’d prefer, Cenco of Chicago, U.S.A. This particular 132cm chunk of cast iron and steel joined the department in late September of 1943, for the low, low price of $40. According to the U.S. Bureau of Labor Statistics’ CPI Inflation Calculator, that’s an excessively specific $681.17 in today’s dollars. (Significant digits!)
Up until now, it’s been in more or less continuous lab use, only recently replaced by brand-new extruded aluminum optics benches. Almost 80 years, and they’re not entirely kaput just yet.
After all, if an apparatus continues to be useful, we’ll keep it around. This one is getting repurposed for future labs, so we’ll see how many more decades it has in it…
When we describe a typical day in the shop, we always hedge and point out that there is no such thing. Walking in to work every morning, you wonder what surprises the shop has in store. At any time, the most unusual requests will walk through the door. Yes, we set priorities. Some needs are more pressing than others. Certain departments (the ones whose budgets support us) get preferential treatment. Some jobs can simply be done in just a few minutes.
We’ll stop all but the most important, time-sensitive work to fix a problem that only takes a few minutes.
Then there are the times when a project is going someplace unexpected. Testing out new ideas. Research outside the usual comfort zone. To be clear: research is always stretching into new, unexplored territory; that’s what makes it so fascinating! But sometimes that territory includes stepping outside the lab.
Physics: not typically set up for regular fieldwork.
Recently it’s become important to brush up on knot-tying. Good, sturdy, easy-to-remember knots for an unusual situation. Testing, tying, repeating. (Making a few mistakes; correcting.) Settling in on the bowline, the alpine butterfly loop and bend, and the trucker’s hitch. Good names. Better knots.
The bowline – rabbit, hole, tree, etc. – is simple to tie, won’t come undone under load, and makes a sturdy loop to fix one end of a rope. A dedicated individual can even tie it with one hand. Let’s all hope it doesn’t come to that.
The alpine butterflies are a pair of near-identical knots for different purposes. The loop creates a sturdy loop in the middle of a length of rope, and can be used to shorten a rope, too. It won’t slip or bind, and no matter how hard you pull it, it’s still a breeze to untie with fingertips. A bend, in knot-tying parlance, connects two lengths of rope, and the alpine butterfly bend is simply a variant on the loop where two ropes of about the same thickness tie together. Repair a damaged rope. Create a longer one. Tie one length into a giant circle. You’ve got options.
Plus, they look neat during the tying process, which wraps the rope about one hand in a butterfly shape before snugging tight. Makes it super-easy to remember, and if you’re learning a series of scouting knots, you know you’re going to end up someplace you can’t check your phone for a last-minute refresher.
Practice, practice, practice.
And then… the trucker’s hitch. It can start with an alpine butterfly loop (so why not?), then loops back about itself to provide a pulley-like mechanical advantage to tighten it down. Just keep pulling the loose rope until you reach the right tension, freeing you from the need to perfectly guess your length. A pair of half-hitches finish it up, distinct from the load pressure, making it a snap to untie when the time comes.
So. Bowline to start at one end. Alpine butterfly for a solid loop, leading into a trucker’s hitch that can tighten down as hard as we can make it. Keep our loads solid and stable in the wind and weather, and they’ll still untie in moments when we’re done.
Can-knot wait to see how this plays out in the field.