... highly rated science videos...

[LukeS]

lyre bird (http://www.youtube.com/watch?v=VjE0Kdfos4Y)

"What bird has the most elaborate, the most complex, the most beautiful song in the world?"

[LukeS]

Please post some of your favourite sci/tech so I can impress my dad.

[Freethinking Ferret]

Here are a couple of science videos I always show the junior high kids when we do a science minicourse (maybe not what you're looking for, but I don't do a lot of youtubing)

http://www.youtube.com/watch?v=m55kgyApYrY - Alkali Metals
http://www.youtube.com/watch?v=f2XQ97XHjVw - Ooblek (a non-newtonian fluid made from corn starch and water) (this one isn't in english)

[PJPSYCO]

http://www.youtube.com/watch?v=m55kgyApYrY - Alkali Metals
The Brainiac video has rubidium and cesium faked. Actual videos of those two can be found here:
http://www.theodoregray.com/PeriodicTable/AlkaliBangs/index.html
also various amounts of sodium being added to water from the same guy:
http://www.theodoregray.com/PeriodicTable/Stories/011.2/index.html

[WCH]

How do we know the Brainiac video is fake? Other than that some guy with a website named similarly to a horror novel said so?

[Freethinking Ferret]

The Brainiac video has rubidium and cesium faked.

Source?

[Acetylhexene]

The Brainiac video has rubidium and cesium faked.

Source?

Would the fact that rubidium and cesium don't actually, physically, act like that on exposure to water count?

[PJPSYCO]

How do we know the Brainiac video is fake? Other than that some guy with a website named similarly to a horror novel said so?
Grey (inventor of the Mathmatica program) is a periodic table nut. It was the great amounts of hydrogen bit that makes it unbelievable. Also the potassium I can say from experience was faked (it tends to extricate itself from the container not immediately explode from under). Also if you read the second Golrace article in my first link Braniac admits it was faked.

Science:
Atomic masses (g/mol): Li:6.941, Na:22.99, K:39.10, Rb:85.47, Cs:132.9
Reaction: 2M + H2O -> H2 + 2MOH (where M = alkali metal)
The thing that 'explodes' is the hydrogen gas.
The amount of hydrogen gas is going down as a function of atomic mass [moles H2 = (1/2)*((mass of metal)/atomic mass of metal))

The lithium produces the hydrogen very slow and never gets the reaction to a temperature that causes the hydrogen to ignite.
Sodium produces the hydrogen faster but produces less per gram (hence the lower fizzing for the same mass), and does actually hit the ignition temperature.
Potassium produces the hydrogen even faster (and tends to jump out of the container because of it). The hydrogen is produces under the metal between it and the water. You'll notice that it ignites earlier as well.
This is important because the next two rubidium and cesium produce less and less hydrogen faster and faster, and hit the ignition temperature faster and faster. To the point where all you get is some flying metal for the both of them with very little explosion because there is not hydrogen built up around the metal (its back at the container).

Though I do understand that reading my explanation may be as cumbersome as reading the linked to one. The linked one very clearly explains why the claim is that the Braniac video is faked.

Flying metal pieces happen sometimes in chemistry as every thermite video on youtube shows:
http://www.youtube.com/results?search_query=thermite&search_type=&aq=-1&oq=

[Freethinking Ferret]

Would the fact that rubidium and cesium don't actually, physically, act like that on exposure to water count?

I've never studied chemistry beyond intro level, so you'll forgive me for not knowing the finer points of how rubidium and cesium react violently with water, and how to tell if it's been faked, without having someone give me at least some explanation. Which is why I wanted a source. No need to condescend.

Science:
Atomic masses (g/mol): Li:6.941, Na:22.99, K:39.10, Rb:85.47, Cs:132.9
Reaction: 2M + H2O -> H2 + 2MOH (where M = alkali metal)
The thing that 'explodes' is the hydrogen gas.
The amount of hydrogen gas is going down as a function of atomic mass [moles H2 = (1/2)*((mass of metal)/atomic mass of metal))

Thanks for your explanation.

[SteveP]

White shirts experiment (http://growabrain.typepad.com/growabrain/2004/11/white_shirts_ex.html)

Ship floating in mid-air (http://www.youtube.com/watch?v=1PJTq2xQiQ0)

Sparks from cans and water (http://www.youtube.com/watch?v=oY1eyLEo8_A)

High voltage motor in 5 minutes (http://sci-toys.com/scitoys/scitoys/electro/electro4.html#franklin)

(I think I got these from IIDB :))

[SteveP]

lyre bird (http://www.youtube.com/watch?v=VjE0Kdfos4Y)

"What bird has the most elaborate, the most complex, the most beautiful song in the world?"

Hehe from the Youtube comments: "That is just amazing!!

How people can not believe in God when they see such a wonderful creation and think it just happened by accident is completely beyond me.

What an amazing and beautiful creature!!" :rolleyes:

[GenesisNemesis]

lyre bird (http://www.youtube.com/watch?v=VjE0Kdfos4Y)

"What bird has the most elaborate, the most complex, the most beautiful song in the world?"

Hehe from the Youtube comments: "That is just amazing!!

How people can not believe in God when they see such a wonderful creation and think it just happened by accident is completely beyond me.

What an amazing and beautiful creature!!" :rolleyes:

In contrast, yesterday I saw a bird defending his/her territory by putting up their tail and sounding an alarm call. It was quite ugly.

[Yggdrasill]

A crow making a tool. (http://www.youtube.com/watch?v=TtmLVP0HvDg)

[LukeS]

thaqnks 4 the contributions I get to watch too ;)

[untermensche]

There is something very eerie about that bird recreating the sounds of chainsaws.

[Yggdrasill]

There is something very eerie about that bird recreating the sounds of chainsaws.The eerie part is how realistic it sounds! :eek:

[Freethinking Ferret]

A crow making a tool. (http://www.youtube.com/watch?v=TtmLVP0HvDg)

Crows are incredible! Speaking of imitations, there is one that hangs around our house that has learned to imitate a cat, and I'm pretty sure another crow has been imitating him lately. I'll chase the crows away from the suet feeders unless I hear one meow... that guy is my buddy, he gets as many peanuts as he likes!

[cpollett]

Here is a cool video:
http://video.google.com/videosearch?q=sphere+inversion&sitesearch=#q=sphere&sitesearch=
on inverting the sphere