The “standard” way to play with Lissajous figures is on an oscilloscope, and the easy way is of course in a web app, but there is also something to be said for a demo that you can hold in your hands. In what follows, we build a simple apparatus that takes a persistence of vision approach to displaying Lissajous figures. Continue reading A simple persistence of vision approach to Lissajous figures→
Nelumbo Nucifera, also known as the Sacred Lotus (amongst other names) is a magnificent oddity of a plant. It roots in the mud of shallow lakes and ponds, growing leaves that float on the surface as lily padslily pads or rise up above the water on hard stalks. The lotus flower itself is the model of a classic and gracefulwater lily flower, where both the flower and resulting seed pod have a characteristic pattern of holes.
The hole patterns continue throughout the plant, showing up in in the stalks and underground stems (rhizomes) of the lotus plant. The rhizomes, usually just referred to as “lotus root” are prepared as vegetable in many types of asian cuisine. Typically you’ll find them served as thin slices through the root (a couple of inches in diameter), showing the distinctive pattern and prepared in many different ways– I’m partial to tempura. (If you haven’t had them, the taste is a bit like a more substantial and nutty version of a water chestnut.)
Another way that you can sometimes find lotus root prepared is as pickled lotus rootlets, which are immature and more tender lotus roots in brine (pictured here). You might find these in a salad or Vietnamese sandwich— they are tasty like their bigger friends.
Appearances aside, the first bizarre thing about the Sacred Lotus is that it’s one of only a handful of known plants that displays “warm-blooded” behaviour: It actively regulates the temperature of its flower to be at a near-constant temperature, even as the ambient temperature varies by a much larger amount. (
The second thing, which I haven’t seen written about anywhere, has led me to ask: how can a lotus root be like a spider?
While staying in Sydney last month, I spent a lot of time at the botanical gardens, and, since it was spring, there were ducklings. I watched one family go from sleeping under the tree to swimming in the pond one morning, and I took a lot of pictures.
What follows after the jump is an annotated photo essay in which one duckling is forced to answer the question, “If your siblings all jumped off a cliff, would you do it, too?” Continue reading The Ducklings go to the Pond→
In this week’s Weekend Projects video podcast, Make Magazine’s Bre Pettis and I show you how to make a Joule Thief. The PDF file that goes with the podcast is here (450 kB PDF file).
So whatsa Joule Thief? It’s a little wisp of a circuit that allows you to drive a blue or white LED from a low voltage. Normally, if you want to light up a blue or white LED you need to provide it with 3 – 3.5 V, like from a 3 V lithium coin cell. But a 1.5 V battery like a AA cell simply will not work. But using the Joule Thief, it works like a charm. Not only does it work with a brand new battery, but it works until the battery is nearly dead– down to 0.3 V. That’s well below the point where your other toys will tell you the battery is dead, so it can steal every last joule of energy from the battery (hence the name). To learn how to make one, watch the video, which is available in a variety of formats.
The original site where we learned about the Joule thief shows you how to make a miniature version of this circuit, such that you can fit it in a tiny flashlight. However, in the video we show you how to make it big, large enough (1) to make with clumsy hands and (2) that you can see what we’re doing.
After the jump, some detailed photos of how the coil is wound in case you need more detail than in the video.
This evening Silicon Valley did a little dance with a 5.6 magnitude earthquake. While there wasn’t much damage here in the land of quake-resistant building codes, it was, as ValleyWag notes, this was “the largest quake to hit the Bay Area since Loma Prieta in October ’89.”
After the house stopped shaking, and then swaying, the first thing we did was to get on the USGS web site and try and find out what we could about the quake. From the main information page, we quickly found the “Did you feel it?” questionnaire for the event, which we filled out. The DYFI program collates the data from responses like ours and uses them to create a map of the earthquake intensity by geographic region, as well as some additional data. The map shown above represents the intensity felt by 60,000 respondents in the first few hours after the quake. It is by far the finest example that I have ever seen of “citizen science” in action– apparently objective data collected over a wide area in a short period of time with (in many cases) good statistics.
Of course, it could be better. Much better. Like other Mac laptops (and many others), my computer contains a “sudden motion sensor” to protect the hard drive in case the computer is dropped. Fundamentally this is just an accelerometer and can be used for any arbitrary purpose besides just waiting for the computer to fall. A program called SeisMac has already been developed that can turn a Mac laptop into a makeshift seismometer. (SeisMac is freeware and based is on open source libraries for the sensor.)
The animals that everyone hears about from Australia are things like koalas, wallabies and platypuses. But the real stars, as far as I’m concerned, are the bats. We saw a few bats in the zoos we went to, including ghost bats and flying foxes. But just walking along in the afternoon in the botanical gardens in Sydney, we looked up and happened to notice that what was hanging from the trees wasn’t leaves or fruit – it was bats. Hundreds of flying foxes. They chattered at each other and flew from one roost to another. While the echidnas were awfully cute bumbling along at the zoo, and the cockatoos were fun to watch at the park, it was the bats in the garden that stole the show.
“Phylm,” pronounced as “film,” is a portmanteau built out of the words “physics” and “film.” It’s also the name given to a new award, The Phylm Prize, aimed at spurring interest in physics and the educational use of new media. Translation: it’s a YouTube contest for physics geeks!
We’ve been invited to sit on the panel of judges for the contest, and so we’ll be looking forward to seeing the submissions. Videos up to two and a half minutes long featuring physics will be judged on clarity, accuracy, and creativity. This year’s winner will receive a check for $100 (US) to be dispersed in June 2007.
You can watch the video announcement at YouTube or (embedded) here:
We are guessing that many of you, our fine readers, already have an interest in physics and/or new media, so get started already! Let’s see your submissions! And don’t let the word “educational” intimidate you– educational propaganda is a highly appropriate diversion for evil mad scientists! (Besides, you could probably use the cash for your world domination scheme.)
Here’s some info from the rules on what kinds of things the clips can contain:
A critique/analysis of the physics presented in a fictional work. For example,
could the bus in Speed have made “the jump,” or how strong would Spider-Man
have to be to throw a car that far?
An analysis of physics as revealed by the examination of a real-world video clip.
For example, what forces does a gymnast experience during his routine?
An explanation/presentation of some physics concept or theory. For example, what is the conservation of energy?
Submissions are due by 12:00 am (GMT) May 1, 2007. We’ll be waiting.
Today on Neatorama and Boing Boing, we saw a great demonstration video of a light aluminum foil boat floating on a layer of exotic heavy gas– sulfur hexafluoride.
You can actually do a version of this trick at home, using stuff that you either already have or can get a the grocery store: You can blow bubbles and float them– apparently in mid air– atop a layer of carbon dioxide; a not-very-exotic heavy gas. You’ll need a big pot, pan or storage bin (made of plastic or metal), some dry ice, and bubbles.
How do you do it? Place your dry ice in the pan and wait a few minutes for a layer of carbon dioxide to form in the bottom of the pan. (We used a 20″ diameter steel wok, which turns out to have a pretty good shape for the job.) Very, very gently, blow some bubbles above the pan and let them fall in. If your carbon dioxide layer is thick enough, the bubbles will bounce off of it, or often even come to rest, sitting in place.
We made a video so that you can get the idea, but you should really just try it yourself because it’s pretty straightforward and the pictures don’t do it justice.
In the mid 1990’s, many things were considered socially acceptable that no longer are. Among these are jokes about Lorena Bobbitt and/or Tonya Harding, anything having to do with Mighty Morphin Power Rangers, and internet humor mailing lists. I am guilty of the latter: From 1994 to 1997 I ran a daily humor mailing list called Quips, Quirks & Quarks, or more commonly QQQ.
The archives of QQQ are on one of my “old” web pages, where you can peruse this vast nearly-organized trove of treasure and trash. The quality of the material varies greatly, and the presentation is an excellent example of web 1.0 (or maybe 0.8 beta) design ethic.
My wife is very immature– Just tell me if this doesn’t sound immature.
She’ll barge right into the bathroom when I’m in the tub and sink all
of my boats!
“Doctor, is it really true that eating carrots improves ones eyesight?”
“Of course. Have you ever seen rabbits wearing glasses?”
