Ever wondered how hedges can be shaped into perfect spheres? Via Andrea James, I came across this video of a company that makes trimmers that can create spherical hedges with specific diameters. The rousing Wagner accompaniment is not included.
When roosters crow at the break of dawn, their sound output is quite prodigious, reaching as much as 140dB levels at very close range. If you get that close, you can damage your eardrum in less than a second. But at even moderate distances, levels can reach 100 dB, close to the levels of a chainsaw. So the question arises as to why roosters do not become deaf from their own sound output. Christie Wilcox writes that scientists intrigued by this question have investigated and found the reason.
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It turns out that when the numbers are looked at globally and on a large scale, the condition of people of the world on many different measures has actually improved over the last two centuries. The data is obtained from the site Our World In Data. There is a huge amount of data in easily digestible graphical form at this interactive site.
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How do you know if your computer has been tampered with while it was temporarily out of your sight, say when you left it in a hotel room? The Freedom of the Press Foundation has issued a press release about a new open-source privacy and security app called Haven that a team led by Edward Snowden have developed that will alert you if anyone tries to do so. Haven is currently in its beta phase and they looking for testers to improve it.
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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.
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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.
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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.
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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.
It turns out that if you microwave eggs, they will explode. Here is a video showing it.
