Despite what you may have heard elsewhere, science isn’t just reading [Neil deGrasse Tyson]’s Twitter account or an epistemology predicated on the non-existence of god. No, science requires much more work watching Cosmos, as evidenced by [Ast]’s adventures in analyzing data to measure the speed of sound with a microcontroller.
After [Ast] built a time to digital converter – basically an oversized stopwatch with microsecond resolution – he needed a project to show off what his TDC could do. The speed of sound seemed like a reasonable thing to measure, so [Ast] connected a pair of microphones and amplifiers to his gigantic stopwatch. After separating the microphones by a measured distance; [Ast] clapped his hands, recorded the time of flight for the sound between the two microphones, and repeated the test.
When the testing was finished, [Ast] had a set of data that recorded the time it took the sound of a hand clap to travel between each microphone. A simple linear regression (with some unit conversions), showed the speed of sound to be 345 +/- 25 meters per second, a 7% margin of error.
A 7% margin of error isn’t great, so [Ast] decided to bring out Numpy to analyze the data. In the first analysis, each data point was treated with equal weight, meaning an outlier in the data will create huge errors. By calculating the standard deviation of each distance measurement the error is reduced and the speed of sound becomes 331 +/- 14 m/s.
This result was better, but there were still a few extraneous data points. [Ast] chalked these up to echos and room vibrations and after careful consideration, threw these data points out. The final result? 343 +/- 9 meters per second, or an error of 2.6%.
A lot of work for something you can just look up on Wikipedia? Yeah, but that’s not science, is it?
We had a lot of fun with that title. Of course when you’re talking about launching a thousand ping pong balls into space there’s no end to the puns which can be made. But this is actually a fantastic initiative to get people of all ages excited about science and near-space experiments. [John Powell] offers school children the opportunity to send an experiment into space. He’s Kickstarting the next launch, which is scheduled to take place in September. This way each entrant can fly their project for free, then get the results and a certificate back once the weather-balloon-based hardware is recovered.
There is one size restriction for the program. Each experiment must fit inside of a ping pong ball. But you’ll be surprised what can be accomplished. [John] reports that the most simple, yet interesting project is to place a small marshmallow inside the ball. As it rises through the atmosphere it will grow to fill the entire ball, then be freeze-dried by the the extreme temperatures. Some are not so low-tech. There’s an image of a tiny PCB holding a DS1337 and some sensors. It’s an atmospheric data logger that will provide plenty of information to analyze upon its return.
[via Hacked Gadgets]
Batman’s ability to fly is a falsehood. Or at least so says science. We didn’t know science was into disproving super-hero movies (that’s a deep well to drink from) but to each his own. But back in December the Journal of Physics Special Topics took on the subject with their scholarly paper entitled Trajectory of a Falling Batman. The equations presented in the two-page white paper may be above your head, but the concepts are not.
It’s not that Batman can’t fly in the way explained in the film. It’s that he can’t land without great bodily harm. By analyzing the cape in this frame of the film, researchers used Batman’s body height to establish wing span and area. The numbers aren’t good. Top speed will reach about 110 km/h with a sustained velocity of 80 km/h. That’s 80 mph at top speed and just under 50 mph when he comes in for a landing.
Oh Batman, how you’ve let us all down. If you liked this paper, you should dig through the archives. We always wondered if [Bruce Willis] could have actually saved the world from an asteroid.
Whether or not you love Star Trek we’d bet you know what a Tricorder is. The handheld device capable of gathering information about the environment around you, or taking health diagnostics about an injured crew member, seemed like unfathomably advanced technology when first seen on the original television series. But our technology has advance so quickly that you can now build a Tricorder of your own. That’s exactly what [Peter Jansen] has done. He founded the Tricorder project as a way to put a useful scientific instrument in the hands for the curious masses.
In the promo video embedded after the break [Dr. Jansen] gives us a recap of his progress so far. Three versions of the project have already been produced, and a fourth is under way. The first iteration could take atmospheric, spacial, and magnetic readings. This covers things like temperature, humidity, GPS data, light intensity, and distance measurements among others. Housed in a dark grey case it looks much like the original prop.
The second model, which is seen above, implements a swapable sensor board. That’s the part hanging off the top, but the finished model will enclose that part of the case. The hardware on this is fantastic, using an ARM processor running Linux and two 2.8″ OLED touchscreen displays. But both of these models have a price tag that’s just too high for widespread use. He’s been working on two more, the Mark 3 and Mark 4. The most recent is in software development right now with the hopes of mass production when all the details are worked out.
There’s a lot of info to dig through on the project’s site. It’s open source and all the goodies we usually look for are there.
Continue reading “Tricorder project brings the fabled devices into existence”
[Bill Porter] and his friend [Dan Flisek] work together to put on a science-related educational stage show called “Science Brothers”, in which the pair try to convince school children that their field of expertise is the cooler science. While the two are competitive on stage, the main goal of the program is to get kids interested in science, no matter what the specialty.
The pair currently finance the project out of pocket, so they are always looking for ways to make things interesting while also keeping costs in check. With that in mind [Bill] came up with an awesome way to show off the Tesla coil he built a while back. His most recent educational creation is a little something he calls “Tesla Hero”.
Since he already had a solid state Tesla coil hanging around, he dug up a PS2 Guitar Hero controller and got busy getting the two acquainted. The guitar connects to the coil via a fiber optic isolator board, playing one of five notes as he strums along. A series of Arduino-driven LED strips adorn the guitar, flashing various colors while he plays, as you can see in the video below.
It’s quite a cool project, and we’re sure that his audience will be impressed!
Stick around to see a video of Tesla Hero in action, and if you’re interested in learning more about the Science Brothers, be sure to check them out here.
Continue reading “Million volt guitar rocks the house…for science!”
SNES Arcade Cabinet
[Daniel] let us know that he finished up a SNES arcade cabinet he has been working on for awhile. It looks so good, he says that his wife has even agreed to let him keep it in the house!
DIY Overhead projector beamer
[Liquider] sent us some information about a DIY beamer he built using an overhead projector and an old LCD panel. It looks like a great way to get a big-screen wall display set up in no time.
WordClock gets a makeover
[Doug] wrote in to share with us some progress he has made on his WordClock. You might remember our coverage of this creative timepiece a little while back. This time around, he has built a new control board, and is using vinyl stencils for a much cleaner look.
Interactive water fountain
[Gerry Chu] is well known for his water-based imagery and projects. His most recent project is a water fountain that interacts with passers by. There are no real build details as of yet, but we hope to see some soon.
Sixty Symbols explains why glass is transparent
Do you think you know why glass is transparent, but a brick is not? If you looked it up via Google, you are likely mistaken. A professor from the University of Nottingham explains why the Internet is so, so wrong about this, as well as how energy gap determines if photons of light can make it through a piece of glass. [via i09]
[Bogdan’s] latest project is a box that displays web hits for a chosen site. He calls it the Ego Box because depending on how traffic goes it either bloats or crushes your ego. This provides similar functionality as our Troll Sniffing Rat but the biggest difference is that this is a stand-alone Ethernet device. That’s thanks to the ENC28J60 Ethernet controller chip which manages the stack and has been quite popular in DIY electronic projects. In order to monitor your hits [Bogdan] crafted a bit of code to add to the header of your index page. It increments the counter file each time the page is loaded, and the Ego Box simply monitors that file, displaying the traffic on an eight digit 7 segment display.