The "I never knew that" thread

[Craterus]

We blink about 84 million times per year.

General Custer graduated bottom of his class in 1861.

The cigarette lighter was invented before the match.

The most popular car colour in the world is red.

Months that begin on a Sunday always have a Friday 13th.

A can of Spam is opened every four seconds.

[Sartaq]

Duck's quacks don't echo...

That's not true!

A can of Spam is opened every four seconds.

My factoid: If you want to hold your breath for extra long, hyperventilate immediately prior to submerging. It's the buildup of carbon dioxide, not the lack of oxygen that forces you to black out.

I just tried that and it works!

[Don Corleone]

I've never tried this one before, but supposedly, only on the Vernal Equinox, you can balance an egg on end. Don't blame me if it turns out to be BS, I warned you...

Others I DO know about...

-The average voltage of a static discharge (dry air, such as in winter, zapping on a doorknob) is about 4000V, sometimes as high as 6000V. The reason it doesn't cause harm is there is very little stored charge to supply current flow (which is what actually kills you).

-If you want to cool your beer faster, pour salt over the ice in your cooler. It will melt it AND reduce the temperature to about -2C (28F) degrees. In general, 0.3C (32.5F) water cools beer much faster than <0C (<32F) ice, because liquid water has a much lower thermal impedance than solid ice.

-Grey & white hair is caused by a copper defiiciency and (theoretically) is completely reversible.

-Bert & Ernie in Sesame street are named for Bert, the taxi cab driver and Ernie the police officer in "It's a Wonderful Life", Jim Henson's (and my) favorite movie.

-Kennedy's personal's secretary's name last name was Lincoln. Lincoln's personal secretary's last name was.... Kennedy. Kennedy was shot by an assasin in a warehouse who fled to a theater. Lincoln was shot by an assasin in a theater, who fled to a warehouse. Both men had a vice-president named Johnson, and both Johnsons were Southern Democrats.

-In the US Civil War's largest battle (Gettysburg), the North came from the south and the South came from the North.

-Despite all the hooplah about computer security, even today 75% of all computer passwords are: a) the owner's birthdate b) the owner's anniversery date or c) the word 'password'.

-In a room of 20 or more random people, the odds are better than 2 in 3 at least 2 people will have the same birthdate (I've never figured this one out).

-Speaking of statistics... if you toss a fair coin 100 times, and the incredibly unlikely put statistically possible event occurs that you toss 100 straight heads, and you decide to toss that faircoin a 101st time, the odds of it being heads or tails are still 50/50.

-Cats only meow to communicate to humans. It is a behavior that serves no function among cats in the wild, who communicate with scent.

[Sartaq]

I've never tried this one before, but supposedly, only on the Vernal Equinox, you can balance an egg on end. Don't blame me if it turns out to be BS, I warned you...

uh huh...

-Despite all the hooplah about computer security, even today 75% of all computer passwords are: a) the owner's birthdate b) the owner's anniversery date or c) the word 'password'.

-In a room of 20 or more random people, the odds are better than 2 in 3 at least 2 people will have the same birthdate (I've never figured this one out).

I can believe that.

-If you want to cool your beer faster, pour salt over the ice in your cooler. It will melt it AND reduce the temperature to about -2C (28F) degrees. In general, 0.3C (32.5F) water cools beer much faster than <0C (<32F) ice, because liquid water has a much lower thermal impedance than solid ice.

Saw that on Mythbusters, of which I am also a junkie.
Other fun fact from Mythbusters: High speed bullets are less deadly than a slower speed bullet when shooting someone underwater from above water becuase the high speed bullet is shattered on impact with the water surface.

[Sasaki Kojiro]

I've never tried this one before, but supposedly, only on the Vernal Equinox, you can balance an egg on end. Don't blame me if it turns out to be BS, I warned you...

ooh ooh I know this one. You can balance an egg on it's end at any time, but only if you believe you can. If you don't believe you can it affects your control over your fingers slightly and you won't be able to. Nifty.

I tested it out on my sister, told her it was impossible and she couldn't do it, told her it actually and showed her I could do it, and then she was able to.

Duck's quacks don't echo...

http://www.snopes.com/critters/wild/duckecho.htm

-Kennedy's personal's secretary's name last name was Lincoln. Lincoln's personal secretary's last name was.... Kennedy. Kennedy was shot by an assasin in a warehouse who fled to a theater. Lincoln was shot by an assasin in a theater, who fled to a warehouse. Both men had a vice-president named Johnson, and both Johnsons were Southern Democrats.

http://www.snopes.com/history/american/linckenn.htm

[nokhor]

-In a room of 20 or more random people, the odds are better than 2 in 3 at least 2 people will have the same birthdate (I've never figured this one out).

i believe this has to do with people copulating more at specific times of the year [think winter] than at other times.