Airplane on a Conveyor Belt

So here’s the question of the day:

“A plane is standing on a runway that can move (some sort of band conveyor). The plane moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the plane speed and tunes the speed of the conveyor to be exactly the same (but in the opposite direction). Can the plane take off?”

Personally, my first thought was that the plane would not take off because it wouldn’t have enough lift without moving up to speed relative to the ground. But after thinking about what it is that actually causes a plane to lift off, the wind going around the wings, I wasn’t so sure.

The wheels in planes aren’t generally what cause the plane to move forward, it’s the suction of wind through the propeller or engines. Presumably the plane would pull the same amount of wind whether or not it was riding the conveyor belt, therefore, I think it would take off.

While you’re taking a moment to think about this problem, let me tell you that tonight the Mythbuster’s are putting this question to rest once and for all. Will a plane on a conveyor belt take-off? (We’ll see tonight, but I think yes).

Update: here is the clip:


[Mythbusters – Plane on a Conveyor Belt – YouTube]

The Mythbusters official channel has uploaded the full episode:

Amazing Ant Colony

This remarkable video from the documentary Ants! Nature’s Secret Power shows a glimpse into the fascinating world of the ant. The narrator describes the intricate ant nest as an accomplishment equivalent to the building of the great wall of China.

The structure covers 538 square feet and travels 26 feet into the earth. In it’s construction, the colony moved 40 tons of soil. Billions of ant loads of soil were brought to the surface. Each load weighed four times as much as the worker ant, and in human terms, was carried over 1/2 mile to the surface.

I also recommend the TED talk by Deborah Gordon: How do ants know what to do?

Why are evolutionary biologists bringing back extinct deadly viruses

I just finished reading the wonderful New Yorker article Darwin’s Surprise by Michael Specter. This is some of the most interesting reading around (at least in my opinion).

I should have been a biologist.

Nothing provides more convincing evidence for the “theory” of evolution than the viruses contained within our DNA. Until recently, the earliest available information about the history and the course of human diseases, like smallpox and typhus, came from mummies no more than four thousand years old. Evolution cannot be measured in a time span that short. Endogenous retroviruses provide a trail of molecular bread crumbs leading millions of years into the past.

And that trail appears to lead to the very roots of human existence and possibly to a cure for HIV/AIDS.

The Large Hadron Collider

The latest iteration of the world’s biggest physics experiment, the Large Hadron Collider, will be switched on in May 2008 (though the BBC documentary below says November, the time line has been updated).

It’s big, REALLY big, and expensive—costing over 6 billion dollars and crossing between the borders of France and Switzerland at four points. The LHC is being funded and built in collaboration with over two thousand physicists from thirty-four countries, universities and laboratories.

As a side note, CERN has had some impressive byproducts, including the web itself.

The BBC created a great documentary about it called The Six Billion Dollar Experiment, the full running time is 49 minutes, but you can enjoy the BBC’s preview:


[The Six Billion Dollar Experiment – YouTube]

Surrendipity: 2012

Malcolm Gladwell at 2007 New Yorker Conference

Billions and billions of dollars have been spent in the pursuit of new drugs but vanishingly few useful drugs are actually being developed. Dr. Safi Bahcall, the president and C.E.O. of the biotechnology company Synta Pharmaceuticals, and Malcolm Gladwell talk about how mistakes lead to great scientific discoveries and how big drug companies hamper innovation.

Check out their talk, Surrendipity: 2012 from the 2007 New Yorker Conference.

The Truth About Subliminal Influence

Hungry? Eat Popcorn

The interesting thing about the claim of a subliminal influence contained within popular music when played backwards is that the messages are very difficult (if not impossible) to discern unless you’ve been primed to hear them on a conscious level.

I’ve been receiving emails wanting to know how this apparent lack of influence ties in with research that demonstrates subliminal messages can coerce unwary buyers into making purchases they would not otherwise have considered?

A short story is in order, (stop me if you’ve heard this one) Fort Lee, N.J., 1957. Unsuspecting film goers are enjoying “Picnic”, with William Holden and Kim Novak. In the projection room, an important marketing experiment is being staged. Researcher James Vicary has installed a tachistoscope, a machine that can inject subliminal images of tiny fractions of a second—far below that of a person’s conscious threshold. Every five seconds and for a duration of just 1/3000th of a second, Vicary alternated two messages. One read, “Drink Coca-cola” and the other, “Hungry? Eat Popcorn”.

Vicary’s results were spectacular! Coca-cola sales jumped 18.1%; popcorn sales 57.8%. Vicary dubbed this “subliminal advertising”, the practise of manipulating consumers to make purchases they might not normally make.

And if you believe that, I’ve got a pet rock I’d like to sell you.

The great popcorn experiment was a fraud.

Advertisers and regulators doubted Vicary’s story from the beginning, so another researcher, Dr. Henry Link, duplicated Vicary’s experiment and found no evidence that people reacted to the messages. In a 1962 interview, Mr. Vicary admitted the data was all fabricated to gain attention for his business. Some critics have since expressed doubt that he ever conducted the experiments at all.

However, the legend lives on. To this day a great many people still believe Vicary’s claims and will apparently never be convinced otherwise.

As numerous studies over the last few decades have demonstrated, subliminal advertising doesn’t work; in fact, it never worked, and the whole premise was based on a lie from the very beginning.

It is possible to prime the unconscious.

According to a recent experiment, psychologists at Yale were able to alter people’s judgments by simply priming them with either hot or cold coffee.

The study participants, college students, had no idea that their social instincts were being deliberately manipulated. On the way to the laboratory, they had bumped into a laboratory assistant, who was holding textbooks, a clipboard, papers and a cup of hot or iced coffee and asked for a hand with the cup.

That was all it took: The students who held a cup of iced coffee rated a hypothetical person they later read about as being much colder, less social and more selfish than did their fellow students, who had momentarily held a cup of hot java.

As improbable as it may seem, findings like this one have continued to pour forth in psychological research in recent years.

New studies have found that people tidy up more thoroughly when there’s a faint tang of cleaning liquid in the air; they become more competitive if there’s a briefcase in sight, or more cooperative if they glimpse words like “dependable” and “support” all without being aware of the change, or what prompted it.

The article goes on to remind readers that, “studies of products promising subliminal improvement, for things like memory and self-esteem, found no effect”.

If you’re interested in this sort of thing, I recommend reading Malcolm Gladwell’s book, Blink—here’s a very short audio snippet from chapter 2 (650k mp3).

Science vs. Religion in the United States

A recently released Gallup Poll indicates that more Americans accept theory of creationism than the science of evolution.

I have to ask myself, is it because those pesky scientists have been wrong about so many things or because religion has been so particularly good at teaching us about the way the world is?

The data from several recent Gallup studies suggest that Americans’ religious behavior is highly correlated with beliefs about evolution. Those who attend church frequently are much less likely to believe in evolution than are those who seldom or never attend.

I’d be interested if there is also a correlation between those that finish high school and those that trust the science behind the theory of evolution, and again between those that go on to University and if they believe in so called “intelligent design” or evolution.

The data indicate some seeming confusion on the part of Americans on this issue. About a quarter of Americans say they believe both in evolution’s explanation that humans evolved over millions of years and in the creationist explanation that humans were created as is about 10,000 years ago.

Quite frankly, no matter which side of the debate you take, you have to admit the data indicate that about a quarter of Americans are stupid.