# science demonstrations/experiments for my office **URL:** \ **Category:** In My Humble Opinion\ **Created:** [October 28, 2019, 3:31pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600 "2019-10-28T15:31:04Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [October 28, 2019, 3:31pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/1 "2019-10-28T15:31:04Z")
I’m populating my office with interesting sciency things. I’ve got prisms and defraction grattings in my window. I’ve built an [analemma](https://en.wikipedia.org/wiki/Analemma) on my wall so I can tell what day it is. I have a ‘drinking bird’ going and I have a small digital microscope with a hay infusion. So I’m looking for other things. I’d tend to avoid things that require a guest to do a lot of activity, plus it should be eye-catching and not messy…so vinegar volcanoes are out. I’ve thought of floating a golf ball in a column 1/2 filled with salt water/fresh water; if I had the equipment I might consider it. any ideas? ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 28, 2019, 3:51pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/2 "2019-10-28T15:51:01Z")
Nitpick – “diffraction gratings”, not “d **ef** raction gratings”. Edmunds used to sell a nifty little book about how to make interesting viewers from prisms – items that showed one picture when you looked in at one angle, one at another. I’d suggest a **radiometer** ( [Radiometer - Wikipedia](https://en.wikipedia.org/wiki/Radiometer) ) , especially if you get direct sun during part of the day. A **gyroscope** and stand (and you can make a nifty inexpensive gyroscope if you buy a Fidget Spinner – I picked up several at $1 apiece recently. Glue a nail to the hub, sticking straight out. If you spin it fast, you can support it, apparently against gravity, from a loop of string around that nail.) Fill a bottle with mineral oil and iron filings, and it’ll make magnetic field patterns if you bring a magnet close. Get some Liquid Crystal thermal paper from Edmund Scientifics or elsewhere – it’ll color from the temperature of your hand. > **[Liquid Crystal Sheets (12x12 inch)](https://www.teachersource.com/product/liquid-crystal-sheets-12x12-inch/chemistry-lc)** > > These laminated sheets of liquid crystal are temperature sensitive. The plastic sheets remain black except for a five-degree temperature range in which they display a series of colors that reflect the actual temperature of the crystal. Using sheets... > **[Temperature Sensitive Liquid Crystal Sheets | Edmund Optics](https://www.edmundoptics.com/f/temperature-sensitive-liquid-crystal-sheets/11878/)** > > Temperature sensitive liquid crystal sheets used in optics and photonics applications are available at Edmund Optics Lots of other possibilities out there. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [October 28, 2019, 4:40pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/3 "2019-10-28T16:40:16Z")
Those gizmos that create a virtual image of a real object using a parabolic mirror are cool. > **[Amazon.com: ComputerGear 3D Mirror Scope Illusion Creator Mirage 3-D Hologram...](https://www.amazon.com/Illusion-Creator-Hologram-Parabolic-Reflector/dp/B001TFV4BE)** > > Amazon.com: ComputerGear 3D Mirror Scope Illusion Creator Mirage 3-D Hologram Maker Parabolic Reflector : Toys & Games Plasma globes can enhance your “mad scientist” image if that’s what you’re going for. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [October 28, 2019, 4:58pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/4 "2019-10-28T16:58:41Z")
I’ve always thought [stirling engines](https://www.amazon.com/stirling-engine/s?k=stirling+engine) where very cool. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [October 28, 2019, 5:02pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/5 "2019-10-28T17:02:13Z")
[Yoshimoto Cubes](https://en.wikipedia.org/wiki/Yoshimoto_Cube). While 1 is fun 2 or more are even funner. Available from [Amazon](https://www.amazon.com/s?k=Yoshimoto+Cube), of course along with similar weird folding 3-D cubical/triangular things. Say it with me: stellated rhombic dodecahedra. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 28, 2019, 5:05pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/6 "2019-10-28T17:05:56Z")
> [@markn\_1](#): > > Those gizmos that create a virtual image of a real object using a parabolic mirror are cool. > [Amazon.com](https://www.amazon.com/Illusion-Creator-Hologram-Parabolic-Reflector/dp/B001TFV4BE) > > Plasma globes can enhance your “mad scientist” image if that’s what you’re going for. A pair of parabolic mirrors, in fact. They’re placed so that the focus of each is at the center of the opposite one (not with the two foci coincident, which is what you’d expect). The original was called the “Mirage” device. It was discovered by accident by a couple of guys playing with war-surplus equipment. I wrote an article about it for _Optics and Photonics News_ a few years back. I agree, this is a nifty item to have on your desk as Gee-Whiz Sciency Thing, although it takes up a bit of space. And it can get scratched up easily. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 28, 2019, 5:30pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/7 "2019-10-28T17:30:34Z")
> [@Sigene](#): > > I’ve built an [analemma](https://en.wikipedia.org/wiki/Analemma) on my wall so I can tell what day it is. Sounds like you have a south-facing window. You could get a small telescope with a solar filter, [like this](https://www.amazon.com/Meade-Day-Night-Telescope-EclipseView/dp/B06ZYHC6S8/ref=sr_1_4?keywords=solar+telescope&qid=1572283513&sr=8-4). It’s enough to see sunspots. (Though we’re pretty close to solar minimum right now, so there isn’t always a sunspot to be seen.) I’ve always liked [Galileo thermometers](https://en.wikipedia.org/wiki/Galileo_thermometer) but I suppose you won’t see much movement in an air-conditioned office. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 28, 2019, 5:39pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/8 "2019-10-28T17:39:23Z")
> [@CalMeacham](#): > > I’d suggest a **radiometer** ( [Radiometer - Wikipedia](https://en.wikipedia.org/wiki/Radiometer) ) , especially if you get direct sun during part of the day. I like those, but it’s so common to see the wrong explanation for how it works. As noted in the wiki article, it doesn’t work by radiation pressure. As I understand: the black side absorbs light/IR and gets warmer, which warms up the surrounding gas molecules, causing them to hit the black side harder. Measuring radiation pressure (photon pressure) takes a much more sensitive instrument. Another idea: two linear polarizing filters mounted at a 90 degree angle, so the pair is opaque. Insert another polarizer or a retarder at a 45-degree angle, and it becomes clear. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [October 28, 2019, 5:44pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/9 "2019-10-28T17:44:45Z")
> [@CalMeacham](#): > > I’d suggest a **radiometer** ( [Radiometer - Wikipedia](https://en.wikipedia.org/wiki/Radiometer) ) , especially if you get direct sun during part of the day. Aha! so _that’s_ what those things are called! A guy who used to sit in an adjacent cube at work had one sitting in the window sill. ---
**Author:** ![SmellMyWort](https://avatars.discourse-cdn.com/v4/letter/s/ea5d25/32.png) [@SmellMyWort](https://boards.straightdope.com/u/SmellMyWort)\ **Post date:** [October 28, 2019, 6:32pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/10 "2019-10-28T18:32:49Z")
For another hands-on gyroscope option, the Dynaflex Powerball is pretty neat: > **[Dynaflex Powerball Lighted Gyro Wrist Exerciser (Amber)](https://www.amazon.com/Dynaflex-Powerball-Wrist-Forearm-Exerciser/dp/B07CKFSJTG)** > > This gyroscope exercise ball made the cover of Time Magazine as one of its top 10 digital devices of the year. The Dyna-Flex Power Ball gyro ball features a balance rotor and removable top cap, which allows insertion of the optional digital speed... Maybe a Lava Lamp? ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [October 28, 2019, 7:00pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/11 "2019-10-28T19:00:57Z")
A [Hoberman sphere](https://en.wikipedia.org/wiki/Hoberman_sphere), perhaps. Surely kaleidoscopes demonstrate something interesting. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [October 28, 2019, 7:12pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/12 "2019-10-28T19:12:26Z")
Build a [Gardner Dragon.](https://www.youtube.com/watch?v=pXvMeupScTs) [Here’s a template.](http://www.cutoutfoldup.com/1101-gaze-following-dragon.php) You can print it out and fold it. Look for illusions by Jerry Andrus – I don’t know what’s out there, but anything with his name on it is amazing. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [October 28, 2019, 7:17pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/13 "2019-10-28T19:17:16Z")
> [@Musicat](#): > > Build a [Gardner Dragon.](https://www.youtube.com/watch?v=pXvMeupScTs) [Here’s a template.](http://www.cutoutfoldup.com/1101-gaze-following-dragon.php) You can print it out and fold it. > > Look for illusions by Jerry Andrus – I don’t know what’s out there, but anything with his name on it is amazing. I kept one of those on the shelf over my desk for years. Still have it now in my box of stuff. **Cal** mentioned a radiometer, always a good one to inspire conversation. There are a variety of ‘floating in air devices’ that are interesting. I have a suspended globe like that somewhere. Just for fun, do the[grape in the microwave](https://geekswipe.net/science/physics/why-does-microwaving-a-grape-produce-plasma/)thing once in a while. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [October 28, 2019, 7:22pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/14 "2019-10-28T19:22:24Z")
> [@scr4](#): > > I like those, but it’s so common to see the wrong explanation for how it works. As noted in the wiki article, it doesn’t work by radiation pressure. As I understand: the black side absorbs light/IR and gets warmer, which warms up the surrounding gas molecules, causing them to hit the black side harder. That’s closer than the radiation pressure explanation but is actually still not correct. Radiation pressure would cause it to spin in the opposite direction than it actually does, so that’s easily refuted. The “hot side causing localized heating which increases pressure” explanation doesn’t quite work because the hot gas would expand in all directions, pushing away some of the molecules which would otherwise impact the vanes. That mostly cancels out the effect of hotter gas imparting more energy to the vanes. The actual explanation is a subtle effect called thermal transpiration, which occurs only along the edges of the vanes. The wiki article explains it. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 29, 2019, 2:50am UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/15 "2019-10-29T02:50:44Z")
> [@markn\_1](#): > > That’s closer than the radiation pressure explanation but is actually still not correct. Thank you for the correction. I should have read the cites in the Wikipedia article. One more suggestion to the OP: the [impossible nail through wood](https://laughingsquid.com/how-to-make-the-impossible-nail-through-wood-trick/). You don’t have to make it yourself, you can just buy one. I’ve seen a room full of rocket scientists get stumped trying to guess how it was made. ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [October 29, 2019, 7:08am UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/16 "2019-10-29T07:08:39Z")
Get a hollow rubber torus, such as an old inner tube. You can cut it so that you wind up with one continuous strip of rubber with a knot in it! > [@](#): > > Obtain a hollow rubber torus […] and cut as shown by the dotted line in Figure 30. The result is a wide endless band tied in a single knot. In this PDF, bottom of book page 75 (PDF page 73): [https://bobson.ludost.net/copycrime/mgardner/gardner04.pdf](https://bobson.ludost.net/copycrime/mgardner/gardner04.pdf) I suggest you start a cut right at the valve so you can cut it out entirely later. Easy to make tetraflexagon! [https://www.youtube.com/watch?v=7H4lDi79YY8](https://www.youtube.com/watch?v=7H4lDi79YY8) Other flexagons can be made, but they’re more complicated. Decades ago, I had a kit called “Kaleidocycles” to make flexahedrons from regular solids, decorated with Escher graphics! Sadly, it’s long out of print. Examples [https://www.youtube.com/watch?v=DGPXm\_5Rc1w](https://www.youtube.com/watch?v=DGPXm_5Rc1w) [https://www.pinterest.com/pin/99219998016009503/](https://www.pinterest.com/pin/99219998016009503/) in French: [Packaging: une lunch box en forme de kaleidocycle - La pigiste blogue](https://blog.la-pigiste.com/2017/04/14/packaging-lunch-box-panier-repas-kaleidocycle-flip-food-flexahedron/) Maybe linking puzzles like this one? [https://www.youtube.com/watch?v=xx8xbQwkEYk](https://www.youtube.com/watch?v=xx8xbQwkEYk) Maybe a puzzle like this? [https://www.youtube.com/watch?v=RkGI9rHIGZk](https://www.youtube.com/watch?v=RkGI9rHIGZk) ---
**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\ **Post date:** [October 29, 2019, 7:22am UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/17 "2019-10-29T07:22:50Z")
Somebody uploaded the “Kaleidocycles” book to [archive.org](http://archive.org)! (This is probably a copyright violation, so I’m not giving the direct link.) MAYBE it includes the plans for the objects, so you could just print them, cut them out and construct them. ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [October 29, 2019, 10:53am UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/18 "2019-10-29T10:53:23Z")
On the life-sciences side, many butterfly caterpillars are quite easy to rear and take up very little space, and are wicked cool to watch especially when forming a chrysalis or “eclosing” (becoming byutiful butterfly). ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [October 29, 2019, 12:24pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/19 "2019-10-29T12:24:39Z")
> [@scr4](#): > > I like those, but it’s so common to see the wrong explanation for how it works. As noted in the wiki article, it doesn’t work by radiation pressure. As I understand: the black side absorbs light/IR and gets warmer, which warms up the surrounding gas molecules, causing them to hit the black side harder. Measuring radiation pressure (photon pressure) takes a much more sensitive instrument. > > Another idea: two linear polarizing filters mounted at a 90 degree angle, so the pair is opaque. Insert another polarizer or a retarder at a 45-degree angle, and it becomes clear. Actually, even the commonly-given “correct” answer to how the radiometer works isn’t really correct. The actual reason the things turns is a rather subtle variation on the “heating up the residual gas molecules” reason. If that were all there was to it, two different effects would cancel each other out. The rotor turns because of edge effects at the edges of the vanes. (see point #4 in the “explanations” section on the Wikipedia page – [Crookes radiometer - Wikipedia](https://en.wikipedia.org/wiki/Crookes_radiometer) ) William Crookes, who designed and built the device, was convinced that it measured radiation pressure (Crookes was a great designer of demonstration apparatus, and his devices are still used today. But he held no academic post and ran his own private laboratory. He investigated new phenomena, but didn’t always understand it. ) His compatriots pointed out the problems with his interpretation of the operation of the radiometer. An interesting guy, who made a big splash. But in his later years he became obsessed with spiritualism and was taken in by some accomplished tricksters in the field. ---
**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\ **Post date:** [October 29, 2019, 12:27pm UTC](https://boards.straightdope.com/t/science-demonstrations-experiments-for-my-office/842600/20 "2019-10-29T12:27:40Z")
Leave a mug of half-drunk sugared coffee on a window ledge for a few weeks. You’ll get a mushroom-like growth (probably poisonous!) This happened in an office I worked in when one chap went on holiday…:smack: