Stories tagged echo

Researchers at the University of South Florida recently found that the fungicide chlorothalonil, in the same family as DDT, killed almost 90% of the frogs exposed to it. They tested several species of frogs, and all had the same reaction. They are now testing the chemical's mortality rate for other organisms, including bees.

Nov
03
2006

All week, the comic strip "Non Sequitur" has been running gags about whether or not a duck's quack echoes. The joke is that once someone asks you the question, you can't stop thinking about it until you know the answer. It's Friday, and I've resisted the temptation to look it up until now, but I've caved!

I can't think of a single scientific reason why a duck's quack WOULDN'T echo, but I had to look it up anyway. The good news? I'm hardly the first person to do it. When I googled "Does a duck's quack echo?" I got 105,000 hits, including links to some real research.

Here are some of the best sources of info:

BBC news: "Sound science is quackers"

Salford University: "The duck's quack echo myth" (This is an awesome page.)

The Straight Dope: "Is it true a duck's quack won't echo?"

Science Made Simple: Does a duck's quack echo?"

About.com (Urban Legends and Folklore): "A duck's quack doesn't echo"

MadSci Network: "Why won't the quack of a duck echo?"

SPOILER: Yes, a duck's quack, like any other sound, echoes. But the WAY a duck quacks, with the long "AAAAAACK" sound at the end of the call, tends to mask echoes, making them hard to hear.

Aug
09
2006

Q: Why do people blink?

A: People blink because the eye needs to be kept clean and moist. Every time you blink your eyelid coats the eye with fluids that keep your eyes moist and that flush away gunk. Blinking also helps prevent gunk from entering your eyes in the first place – lowering the lids and eyelashes forms a barrier that is hard for gunk to penetrate. Interestingly, you bink less when you are concentrating on something (like driving or surfing the internet).

Q: How tall can a willow tree be when they are full grown?

A: That depends on what species of willow tree you are referring to – there are lots. The White Willow can reach heights up to 100 feet, while the Artic Willow grows to less than a foot in height!

Space shuttle bathroom: A typical space shuttle bathroom.  Image courtesy NASA.
Space shuttle bathroom: A typical space shuttle bathroom. Image courtesy NASA.
Q: How do astronauts go to the bathroom in space?

A: Typically, there are toilets similar in function to toilets on Earth, but they use air suction instead of water to make the waste go where they want it to, since there is no gravity. Solid wastes are compressed and stored on-board, and then removed after returning to Earth. Waste water is vented to space, although future systems may be able to recycle it. The NASA web site has a short video on the subject.

Q: Why doesn’t a duck quack echo?

A: This is an urban legend – duck quacks do echo. This site proves it.