The following concerns a question in a physics degree exam at the University of Copenhagen.  The story goes like this:

“Describe how to determine the height of a skyscraper with a barometer.”

One student replied: “You tie a long piece of string to the neck of the barometer, then lower the barometer from the roof of the skyscraper to the ground. The length of the string plus the length of the barometer will equal the height of the building.”

This highly original answer so incensed the examiner that the student was failed immediately. The student appealed on the grounds that his answer was indisputably correct, and the university appointed an independent arbiter to decide the case.

The arbiter judged that the answer was indeed correct, but did not display any noticeable knowledge of physics. To resolve the problem it was decided to call the student in and allow him six minutes in which to provide a verbal answer which showed at least a minimal familiarity with the basic principles of physics.

For five minutes the student sat in silence, forehead creased in thought.

The arbiter reminded him that time was running out, to which the student replied that he had several extremely relevant answers, but couldn’t make up his mind which to use. On being advised to hurry up the student replied as follows:

Measuring a building

“Firstly, you could take the barometer up to the roof of the skyscraper, drop it over the edge, and measure the time it takes to reach the ground. The height of the building can then be worked out from the formula H = 0.5g x t squared. But bad luck on the barometer.” “Or if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper’s shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper.” “But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at ground level and then on the roof of the skyscraper. The height is worked out by the difference in the gravitational restoring force T = 2 pi sq root (l/g).”

“…or if the skyscraper has an outside emergency staircase, it would be easier to walk up it and mark off the height of the skyscraper in barometer lengths, then add them up.” “If you merely wanted to be boring and orthodox about it, of course, you could use the barometer to measure the air pressure on the roof of the skyscraper and on the ground, and convert the difference in millibars into feet to give the height of the building.”

“But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor’s door and say to him ‘If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper’.”

Niels Bohr

The student was Niels Bohr, who was known for proposing the model of the atom wherein the electrons were much like the planets in our solar system orbiting around the nucleus. Niels Bohr went on to be the first Dane to win the Nobel prize for Physics and even had an element named after him.

One of his sons also subsequently won a Nobel Prize.

Now disappointingly, this story is not true. It was first printed by Reader’s Digest in 1958 and has been reprinted in various forms (and with different people other than Niels Bohr).  That being said, it still demonstrates one concept quite clearly:

Sometimes the “correct” answer is not always the “right” answer.

If you want to get paid to solve problems you should register as a problem solver on IdeaConnection.

Have you ever outpaced cars and been honked at? Had a car almost wipe you out while making a turn? Do you ever ride your bike so fast that you wish that everyone else could know how close to the speed of light you were? Or sometimes are you riding your bike, cars honking impatiently behind you, wishing that they knew you were actually going more than 10 mph? Or maybe you just want to show off to your buddies that you left in your dust!

Enter… the speed vest!

Brady Clark and Mykle Hansen have invented a wearble speedometer which displays your current speed in large numerals on your back. Made for cyclists, it uses a sensor on your wheel to send a signal to a microcontroller that then turns the numbers on and off on the back of the vest

When asked about the inspiration for the vest, Brady said “[I was] riding my bike down a steep hill one day and “taking the lane” (riding in the middle of the traffic lane) so that no cars could pass me too closely, I thought- Some people must really be pissed at me- I wonder if they knew I was going 25+ mph they’d think the same.”

“we’re trying to learn how it can best be used as an advocacy tool for bicycling. I don’t mean racing- I’m talking about sharing the road safely with motorists. Mykle and I are both lucky to live in cities that have invested in building and retrofitting streets to be more amenable to biking on. Unfortunately even in Portland (#1 bike city in the nation) and Minneapolis (#2) there are missing connections in what would be an ideal network. I’m hoping that by riding the Speed Vest in these areas of deficit that we could lay the groundwork for making these connections before any pen hits paper or paint hits the street.”

Here’s a video demonstrating the speed vest in action:

The speed vest isn’t yet available commercially and only a limited number of speed vests have been made as Brady and Mykle are still trying to decide on whether or not they wish to put more energy into the project as a commercial venture; however they are talking to manufacturers and other companies who are excited about the project, so we might see something in the near future.

Mykle has a fantastic site that describes the speed vest in more detail, including pictures describing how it was made and how it works. Check it out here.

If you’d like to be updated, or if you’re a bicycle advocacy organization and would like to use it for outreach and education, send and email to info (at) speedvest.com.

My first thought was “Why?” … My second thought was “ok, but…How?”

The team, led by Designer Chueh Lee have developed what might be the worlds first camera for the blind. It’s called the “Touch Sight Camera”, and Mr Lee says this:

“Touch Sight is a revolutionary digital camera designed for visually impaired people. Simple features make it easy to use, including a unique feature which records sound for three seconds after pressing the shutter button. The user can then use the sound as reference when reviewing and managing the photos. Touch Sight does not have an LCD but instead has a lightweight, flexible Braille display sheet which displays a 3D image by embossing the surface, allowing the user to touch their photo. The sound file and picture document combine to become a touchable photo that is saved in the device and can be uploaded to share with others–and downloaded to other Touch Sight cameras.”

Incredible. The camera actually works best when the Braille panel is held against the forehead as it also helps stabilize the camera. Chueh mentioned that in instructor who teaches a photography course for the visually impaired found that “the visually impaired have no problems estimating distances, since their sense of hearing is especially sharp. Every rustle of wind in the trees catches their attention and can be used to judge distances.”

“A camera was something prohibited, I never dreamed I’d hold one,” says visually impaired photography student Karina Murninaks. “My parents told me that to take pictures you had to be able to see, that I couldn’t touch the camera. And I always loved hearing the click-click, and at last I can do the click myself. At first it was like a toy, but now I’m really taking photographs.”

The 3 seconds of audio recording help convey distance and also impart the sense of “being there” that a normally-sighted person would feel when looking at the photograph.

This isn’t the first device that helps blind people “see”. There is this device that uses sound, this device that uses touch sense on the forehead and even this device that helps people see with their tongue.

There are no definite plans to bring the device to the market yet, but I sincerely hope that Mr. Lee’s collegues at Samsung decide to put the resources into this evolutionary device. The rest of the design team includes Liqing Zou, Ning Xu, Saiyou Ma, Dan Hu, Fengshun Jiang and Zhenhui Sun.