The " I always wondered" thread

[CyberGnu]

Why does cold water make a different noise from hot water when you pour it into a mug?

My best guess is that the air that is dissolved in the water makes a sound when it hits the glass and it forms microbubbles. Since warm water dissolves much more air than cold water, you get a different sound.

Only an educated guess, though...

2. Why do run-down batteries sometimes get an extra "kick" of last-minute energy when you turn off the Walkman for a while?


Because of the internal capacitance of the batteries let it sort of "store" up electricity.

Well, that's the point of a bettery, right?

The energy in a battery is stored as chemical energy, which means that a chemical reaction has to occur for the energy to be released. Chemical reactions are often quite slow, though, so when you battery runs out the first time you still have some potential energy stored, but the reacting chemicals aren't in position to react yet.

[Az]

3. Why do guys have nipples?

Because. Not anything in the human body has a reason. It's just the way we were formed during evolution. Sure nipples on guys aren't good for much ( some people might disagree with me here. ), but it's not like they actually are bothering anyone.

[Winston]

Maybe they, along with chest hair, served a function in prehistoric times by attempting to convey to a possible predator the image of a pair of eyes on a man's torso, thereby perhaps marginally increasing the chances of escape for ancient hunters if they were faced with certain enemies/competitors for food. Sort of like we see on wings of today's butterflies and other animals.

Just a thought.

[Az]

ROTFLMAO!!!!

That was great, Winston.

[Winston]

Where's the joke?

[Az]

I just imagine a person just standing there, and the leopard chickening away.

seriously, though, I wonder how would a modern day average height human with a spear fare against a leopard.

[DAVOUT]

Originally posted by DAVOUT
I wonder if the laundring of black money (recycling it into the visible economy) has positive or negative effects on growth.

Any idea on this subject ?

[TheStinger]

Originally posted by Azazel
I just imagine a person just standing there, and the leopard chickening away.

seriously, though, I wonder how would a modern day average height human with a spear fare against a leopard.

against a leopard i'd give the human a slight advantage, aginst a Lion or Tiger I'd have to go with the moggy

[DAVOUT]

Originally posted by Azazel
I just imagine a person just standing there, and the leopard chickening away.

seriously, though, I wonder how would a modern day average height human with a spear fare against a leopard.

We can guess that in the past they hunt dangerous animals in group, and also used traps.

[TheStinger]

No one has answered my Star Trek question.

[Az]

don't confuse the Leopard with the Chitah. The Leopard weighs almost 100 kgs on average. a human could easily wrestle the chitah down, even bare-handed, it weighs around 42 kgs, and is build for speed. A few good punches to the ribs, and heck, it's head is around the size of two fists, so it will make a great coat.

IIRC, Lions weigh around 190 kgm, on average, with males significanlty heavier, and females significantly lighter. a band of 3 human hunters with spears could take on any lion, but it would take small hunting party to take out a pride.

a skilled human with a crossbow and a long knife is fearsome opponent. Only a Tiger could take him out.

[Urban Ranger]

Originally posted by CyberGnu
But CH3- is an amazingly unstable ion, so that won't work...

My understanding is the C-H bond is covalent, so that you can't make a CH₃.

Originally posted by CyberGnu
Don't think you can get H2 that way. This is a standard redox reaction:
4FeO + CH4 -> CO2 + 2H2O + 4Fe

Depending on the electronegativity of carbon and hydrogen, a chemist might be able to coax the reaction to use up more carbon, thus freeing up some hydrogen gas. Of course, this is just a wild guess.

Originally posted by CyberGnu
You could have be thinking of steam reformation, as well:
CH4 + H2O <=> CO + 3H2
an industrial process, possibly catalyzed by iron...

Nah, you overestimated me

[Urban Ranger]

Originally posted by CyberGnu
Well, that's the point of a bettery, right?

The energy in a battery is stored as chemical energy, which means that a chemical reaction has to occur for the energy to be released. Chemical reactions are often quite slow, though, so when you battery runs out the first time you still have some potential energy stored, but the reacting chemicals aren't in position to react yet.

Yes, that's the main point. I was also thinking along the lines of additional electric characteristics of a battery, that it has an internal capacitance. So, in addition to the chemical reaction, it could store up some electricity as well, giving it a bit of an extra kick. Of course, I have no idea how big that would be.

[TheStinger]

I wasn't, Cheetas are a bit whimpy and would leg it anyway. My theory on the leopard was based on the fact that a) the bloke would have a spear and that b) there was a story from about 10 years ago where a south african stangled a leopard to daeth with his bare hands after being attcked in camp.

[Urban Ranger]

Originally posted by Azazel
don't confuse the Leopard with the Chitah. The Leopard weighs almost 100 kgs on average.

A skilled hunter could jam the spear into the ground and let the leopard impale itself.