Tracking The Hamster Marathon

November 2, 2015 by Al Williams 28 Comments

[Michelle Leonhart] has two Roborovski hamsters (which, despite the name, are organic animals and not mechanical). She discovered that they seem to run on the hamster wheel all the time. A little Wikipedia research turned up an interesting factoid: This particular breed of hamster is among the most active and runs the equivalent of four human marathons a night. Of course, we always believe everything we read on Wikipedia, but not [Michelle]. She set out to determine if this was an accurate statement.

She had already added a ball bearing to the critters’ wheel to silence it by cannibalizing an old VCR. What she needed was the equivalent of a hamster pedometer. A Raspberry Pi and a Hall effect sensor did the trick. At least for the raw measurement. But it still left the question: how much distance is a hamster marathon?

[Michelle] went all scientific method on the question. She determined that an average human female’s stride is 2.2 feet which works out to 2400 strides per mile. A marathon is 26.2 miles (based on the distance Pheidippides supposedly ran to inform Athens of victory after the battle of Marathon). This still left the question of the length of a hamster’s stride. Surprisingly, there was no definitive answer, and [Michelle] proposed letting them run through ink and then tracking their footsteps. Luckily, [Zed Shaw] heard about her plan on Twitter and suggested pointing a webcam up through the plastic bottom of the cage along with a scale. That did the trick and [Michelle] measured her hamster’s stride at about 0.166 feet (see right).

Now it was a simple matter of math to determine that a hamster marathon is just under 10,500 steps. Logging the data to SQLite via ThingSpeak for a month led [Michelle] to the conclusion: her hamsters didn’t run 4 marathon’s worth of steps in a night. In fact, they never really got much over 2 marathons.

Does [Michelle] have lazy hamsters, or did she just add to our body of scientific knowledge about rodents? We don’t know. But we couldn’t help but admire her methods and her open source data logging code would probably be useful for some non-hamster activities.

If you are super competitive, you could use [Michelle’s] data to handicap yourself and challenge your pets to a race. But it would probably be cooler to build them their own Starship Trooper-style walkers. Either way, you can check out [Michelle’s] little marathon runners in the video below.

https://vine.co/v/enpFetTQD75

The Eloquence Of The Barcode

November 2, 2015 by Adam Fabio 46 Comments

Beep. You hear it every time you buy a product in a retail store. The checkout person slides your purchase over a scanner embedded in their checkout stand, or shoots it with a handheld scanner. The familiar series of bars and spaces on the label is digitized, decoded to digits, and then used as a query to a database of every product that particular store sells. It happens so often that we take it for granted. Modern barcodes have been around for 41 years now. The first product purchased with a barcode was a 10 pack of Juicy Fruit gum, scanned on June 26, 1974 at Marsh supermarket in Troy, Ohio. The code scanned that day was UPC-A, the same barcode used today on just about every retail product you can buy.

The history of the barcode is not as cut and dry as one would think. More than one group has been credited with inventing the technology. How does one encode data on a machine, store it on a physical media, then read it at some later date? Punch cards and paper tape have been doing that for centuries. The problem was storing that data without cutting holes in the carrier. The overall issue was common enough that efforts were launched in several different industries.

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Stellarator Is Germany’s Devilishly Complex Nuclear Fusion

November 2, 2015 by Elliot Williams 82 Comments

You may not have heard of a Stellarator before, but if all goes well later this month in a small university town in the far northeast of Germany, you will. That’s because the Wendelstein 7-X is finally going to be fired up. If it’s able to hold the heat of a fusion-capable plasma, it could be a huge breakthrough.

So what’s a stellarator? It’s a specific type of nuclear fusion containment geometry that, while devilishly complex to build and maintain, stands a chance at being the first fusion generator to achieve break-even, where the energy extracted from the fusion reaction is greater or equal to the energy used in creating the necessary hot plasma.

There’s an awesome video on the W7-X, and some of the theory behind the reactor just below the break.

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Making The Case For Nuclear Aircraft

November 2, 2015 by Will Sweatman 133 Comments

At any given moment, several of the US Navy’s Nimitz class aircraft carriers are sailing the world’s oceans. Weighing in at 90 thousand tons, these massive vessels need a lot of power to get moving. One would think this power requires a lot of fuel which would limit their range, but this is not the case. Their range is virtually unlimited, and they only need refueling every 25 years. What kind of technology allows for this? The answer is miniaturized nuclear power plants. Nimitz class carriers have two of them, and they are pretty much identical to the much larger power plants that make electricity. If we can make them small enough for ships, can we make them small enough for other things, like airplanes?

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Lithium-Air Might Be The Better Battery

November 2, 2015 by Brandon Dunson 50 Comments

Researchers at Cambridge University demonstrated their latest version of what is being called the Lithium-Air battery. It can be more accurately referred to as a Lithium-Oxygen but Air sounds cooler.

The early estimates look pretty impressive with ~~the energy density being 93% efficient which could be~~ up to 10 times the energy density of Lithium-Ion and claims to be rechargeable up to 2,000 times. Recent improvements toward Lithium-Air batteries include a graphene contact and using lithium hydroxide in place of lithium peroxide which increased both stability and efficiency.

Here’s the rub: Lithium-Air batteries are still years away from being ready for commercial use. There are still problems with the battery’s ability to charge and discharge (kind of a deal breaker if the battery won’t charge or discharge right?) There are still issues with safety, performance, efficiency, and the all too apparent need for pure oxygen.

Do batteries get you all charged up? Check out our coverage of MIT’s solid state battery research, or have a look at the Nissan Leaf and/or Tesla battery packs.

Thanks to [Jimmy] for the tip.

Magnetic Levitation With Arduino

November 2, 2015 by Will Sweatman 7 Comments

Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was able to balance a high density neodymium magnet in midair. He pulled off this tricky project using a set of four coils he got off of Taobao (the Chinese version of eBay), a hall effect sensor, and a handful of current regulation ICs.

The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is straightforward. It appears he uses a potentiometer for a rough regulation of the current going to the coils, doing the fine tuning in the code which can be found here (.RAR direct download).

We’ve seen magnetic levitation here before, and this project adds to the list of successful techniques to accomplish this difficult project.

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Are You Telling Me You Built A Lexus…Out Of Cardboard?

November 1, 2015 by George Graves 32 Comments

So, you want a new Lexus? Well then download yourself a free car, and cut it out on a laser. Add some glue, and bingo, you have yourself a fancy new ride. We’ll, not really.

Sure, this promo video is just a publicity stunt from Toyota (News flash: Your fancy Lexus is actually a Toyota) but we have to hand it to them, it worked. It’s basically 1700 individually shaped, laser cut cardboard cross-sections that are painstakingly stacked and glued together. What we like about this is the technique – that is making a 3D object from 2D.

Using 2D parts to create 3D shapes is nothing new. Most people’s first experience with this technique is with building model airplanes. Instead of cardboard, balsa wood sheets are cut into profiles and connected with stringers to form the shape of a plane. It turns out to be a very efficient way of making 3D structures when you only have 2D materials to work with. And with 3D software now in the hands of the masses, it’s never been a better time to try your hand at building in 3D. For a great example, see this carbon-fiber guitar made using Autodesks free 123D Make software. And don’t limit yourself to parallel layers, you can generate all sorts of shapes including furniture with the free and open source Sketch-Chair software. Which will come in handy, because you’ll most likely need a place to sit while you’re waiting for your new cardboard car to finish printing.

[via CNN]

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