RTFA: http://www.youtube.com/watch?v=xHsXcHoJu-A

This is our submission for the Mythbusters video challenge

This post contains the parts list for constructing a DWFTTW vehicle, along with pictures of the finished DWFTTW product. I think the solution is for a few people to build this thing and test it out.

For some background, here’s Boing Boing’s Mark Frauenfelder:

Over a year ago on Boing Boing, I linked to this video from a guy who made a propeller-powered vehicle that he claimed could travel downwind faster than the wind. Some people think it was a hoax, and some don’t.

In Make Vol. 11, Charles Platt made a miniature model of the vehicle and came to the conclusion that there is no such thing as a wind-powered vehicle that can travel faster than the speed of the wind.

Now there’s a new video on YouTube (above) that claims it is possible to sail directly downwind faster than the wind (aka DDFTTW).

It’s obviously not a closed system, and it’s obviously not creating energy out of nothing… but that’s not the question here, either. Assuming the vehicle moves forward, it’s doing this with wind. Honestly, I don’t care how the energy gets transferred into forward motion. If it works, then it is useful. If it doesn’t work, then it just takes a few people to build this kit and it will be proved to be useless.

Well, I haven’t spent any time analyzing this, but it doesn’t seem impossible to me. I’ve been sailing dozens of times, and I’ve flown in a plane a few dozen more times. The short story of my experience is that wind, and air pressure in general, are capable of weird things. This isn’t any reason to conclude anything one way or the other, but I guess I’d like to see this one be proven incorrect before I disbelieve what my eyes are telling me. If I had a few bucks to spend, I’d like to make one of these things.

Here is the parts list, compliments of Spork (the creator of the video above):

- 4.15 Century Tail Gear Set Hawk (Tower LXMJX7)
- 6.95 Century Tail Gearbox Hawk Pro (Tower LXLKD0)
- 2.00 5×13x4 Revolution (2 front prop shaft bearings) (Avid 695-RSZ)
- 3.00 5×11x4 Revolution (2 axle bearings & 1 rear prop-shaft bearing) (Avid MR115-RSZZ)
- 21.00 Prop GWS 15×7.5 Propeller (6 for $21.00) (Tower LXHHZ1)
- 1.75 GWS 3.00″ Wheels (2 for $1.75) (Tower LXHHZ8)
- 7.00 5mm x 40″ Carbon tube for prop shaft and axle (AeroMicro)
- 4.00 4mm x 40″ Carbon tube (40″ for $4.00) (AeroMicro)
- 2 pieces at 2″ used for axle step-down
- 3.20 3mm x 40″ Carbon tube (40″ for $4.00) (AeroMicro)
- 2 pieces at 2″ used for axle step-down
- 9.99 0.08″ Music wire (2 pieces at 2″ used for axle (Tower LXWV01) step down)
@ 9.99 for 15 pieces at 36″ each
- 9.69 1.25″ of 0.063″ Music wire for rear axle (Tower LXWV00)
@ 9.69 for 15 pieces at 36″ each
- 2.00 3/8″ soft aluminum tube (24″) from plumbing dept at OSH
- 2.99 Dubro 2″ Micro Lite wheels; 2 for $2.99 (Tower: LXAZC6)
- 1.00 Nuts and bolts to hold aluminum tube to gearbox
- 1.00 HDPE Bearing block to support rear prop-shaft bearing (Tap Plastics)

Total: $79.72 Plus Tax & shipping (but you’ll have lots of leftovers)

You’ll need:
- super glue
- sand-paper
- 5mm drill bit and some standard sized bits
- exacto knife
- Metric allen wrenches

Suppliers:
www.towerhobbies.com
www.AvidRC.com
www.AeroMicro.com
OSH: Orchard Supply Hardware

The finished version should look something like the following photo gallery. These images are based on the high-quality version of the YouTube video, above.

Representing the skeptics, Charles Platt on Makezine says:

In this forum and in others hosted by Make I have explained repeatedly why a treadmill demonstration does not satisfy my original requirement. The cart should be on a level surface, experiencing a steady tailwind; it should accelerate up to the speed of the wind and should then exceed the speed of the wind. This is what Mr. Goodman claimed to have achieved. For reasons stated in my original article, I believe it is impossible.

There are a few other threads that discuss this topic, too:

James Randi Educational Foundation

Discovery Channel Community

Physics Forum

If you make this kit, please post a comment!

RTFA: http://www.npr.org/templates/story/story.php?story…

Doctors in Spain have implanted a new windpipe into a woman whose airway was badly damaged by tuberculosis. The pioneering operation used a section of windpipe engineered in a laboratory with adult human stem cells, according to Dr. Paolo Macchiarini, of the Hospital Clinic in Barcelona, Spain.

After they were taken from her hip bone, Castillo’s stem cells were sent to a laboratory at the University of Bristol, where doctors placed them in laboratory dishes so that they could grow more … After millions of cells had been produced, scientists injected various chemicals to induce the cells to turn into highly specialized cells.

Especially critical were the cells that line the insides of the airway, says Bristol’s Dr. Martin Birchall. These cells serve a crucial immune system function, fighting off diseases that enter the body through the airways. They’ve been especially difficult to sustain in previous experiments, he says.

As the cells were growing in England, scientists began work on another crucial step — fashioning a kind of scaffolding out of tissue on which the new cells could grow. They started with a trachea — a portion of the windpipe — taken from a 51-year-old man who had recently died. The donor’s trachea was rinsed with antibiotics, and most of the cells were removed with enzymes, a process that took several weeks. What was left was the shell of the trachea, essentially made up of fibrous collagen. Using the shell structure, scientists seeded the outside and inside with the cell cultures. Over a period of four days, they applied nutrients and chemicals to promote the growth of new layers of tissues, which were composed of the same kinds of cells normally found in the trachea. The airway was kept in a special container developed by scientists in Milan, Italy, and rotated continuously to ensure even growth.

In June, Castillo underwent surgery in Barcelona to have a portion of her airway removed — specifically, the left bronchus. Surgeons took the newly created windpipe and trimmed it to the proper size, fitting it into place near the point where the trachea divides to supply both lungs … Castillo recovered quickly from the operation and has not needed anti-rejection drugs. Such drugs are almost always used when tissues are transplanted from one person to another. But because the stem cells coating the new windpipe were derived from Castillo’s own bone marrow, it is thought that her body will not reject the new tissue. Doctors report that she has been well in the months since the operation and “is enjoying a normal life.” Tests show the implant is indistinguishable from the surrounding tissue. Efforts to transplant tracheal tissues have been tried in a handful of cases, with varying degrees of success.

The Spanish case is believed to be one the first to use tissues engineered largely from adult stem cells.

RTFA: http://www.youtube.com/watch?v=gpBZGPAEvUY

Stem cells … praise God for stem cells. Anyone who rejects their use is a minion of Satan. Yes, Satan.

RTFA: http://pan-dan.blogspot.com/2007/08/couple.html

These double-size sheets have a ruler printed on the inside. I can’t believe how excellent this is.

Via http://infosthetics.com/archives/2007/09/ruler_bed_sheets.html

RTFA: http://www.techcrunch.com/2007/09/05/fec-determines-that-blogs-count-as-media/

In two determinations handed down yesterday, the US Federal Election Commission (FEC) found that political blogs and bloggers are media for the purposes of US Electoral Law.

About damn time. I guess.

RTFA: http://nsf.gov/news/news_summ.jsp?cntn_id=109910&org=olpa&from=news

Scientists for the first time have observed elusive oscillations in the suns corona, known as Alfvén waves, that transport energy outward from the surface of the sun.

Alfvén waves are fast-moving perturbations that emanate outward from the sun along the pathways of magnetic fields, transporting electrodynamic energy. Although they had been detected beyond the sun, they had never before been viewed within the corona, the outermost layer of the suns atmosphere.

By tracking the speed and direction of the waves, researchers will be able to infer basic properties of the solar atmosphere, such as the density and direction of magnetic fields. The waves may provide answers to questions that have puzzled physicists for generations, such as why the suns corona is hundreds of times hotter than the surface.

Holy Periodic Fission, Batman!