How children learn science

One of the things that any teacher soon realizes is that students come into your class with all manner of theoretical structures in their minds, even if they have never formally studied that topic or even consciously thought about it. People create these structures in order to successfully navigate the world and as long as it works to answer their immediate problems, the fact that it is wildly off from what the scientific community believes is not a hindrance to their adoption.
[Read more…]

Stealing a car that has wireless entry

I have not quite understood what the benefits are of wireless car entry and ignition. You still have to carry the key with you to enable the system to work, so the only advantage seems to be that you do not have to take it out of your pocket, which seems like a very minor benefit. However, I had a female friend who said she really liked it because she uses a handbag and finding and fishing a key out of it is not as simple as with a trouser pocket.
[Read more…]

Brace yourself for renewed UFO mania

The New York Times has an interview with two former US navy pilots who reported seeing a UFO in 2004. It appears that there was a secret multimillion dollar Pentagon program to investigate such sightings and keep a record of them. The program ended in 2012 but monitoring still goes on. The interview article describes in some detail how the two navy pilots pursued the object and its strange behavior, and there is a brief video of the object.
[Read more…]

Using optical illusions as traffic regulators

I love optical illusions and this one in Iceland (that I came across thanks to Richard Kaufman) seems to suggest a pedestrian crossing that is floating on air. But it is not just for fun. Such trompe l’oeil (“fools the eye”) illusions claim to have the benefit of causing drivers, puzzled by what they see ahead of them, to slow down when approaching them, increasing the safety of street crossers.

[Read more…]

Mesmerizing short film about lightning

There is something compelling about lightning, the sight of massive amounts of electrical energy surging through the sky and powering flux capacitors. Via David Pescovitz, I came across this compilation of lightning videos shot at 1,000 frames per second and set to music. The resulting film called Transient was made by Dustin Farrell who spent the summer traveling 20,000 miles within the US to capture all the strikes.
[Read more…]

Cricket match interrupted due to pollution

Cricket is a game that is highly weather sensitive. Matches can be halted by even very light rain or poor light due to overcast skies, and fans are used to this. International games called Test matches between rival national sides last for five days, six hours per day, so there is plenty of time for weather to intervene. But this past week, a Test match between India and Sri Lanka was interrupted several times due to the heavy pollution that has blanketed New Delhi over the past month.
[Read more…]

Fun with mercury

In recent years, mercury has required a bad reputation as a toxic chemical that one should avoid. Back in the day when I was a schoolboy, mercury was the element that was the most fun. We would handle it with bare hands in science classes to measure atmospheric pressure and rejoice when a mercury thermometer broke and we could play with this fascinating liquid metal and its strange properties that would try to form itself into a sphere if possible and would slide over surfaces so easily.
[Read more…]

Circadian rhythms

This year’s Nobel prize for Physiology or Medicine was given to three scientists for their work in understanding the nature of circadian rhythms, the daily pattern of life that we all, animals and plants alike, follow that seems to be governed by the rate of the Earth’s rotation about its axis. This topic has been of interest as far back as the 18th century when astronomer Jean Jacques d’Ortous de Mairan found that the leaves of mimosa plants opened at the time of daybreak and closed at night, even when they were kept in the dark all the time, suggesting that there was an internal biological clock that was not triggered entirely by sunlight.
[Read more…]