Science @ NASA: Headlines

Also a fantastic pic of Mimas on that link

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I hope Glom's my pilot. 8)

Your voice would go all squeaky (breathing hydrogen) 8)

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Beautiful view. =D> 8)

I'll bet there is more to the story, however. Look closer at Mimas. The sun is not shining directly on it, and therefore, not on Saturn. We are seeing Saturn near the terminator. I would bet we will see Rayleigh Scattering here better than anywhere. (This needs confirming by someone better at this, however.)

There have been images revealing hints of blue sky, such as.... here [upper right, mainly]

Remember, color is scattered by the 4th power of it's frequency with smaller molecules (upper atmosphere). In wavelength, the shorter blues will scatter almost 9x as much as the longest reds. Violet scatters almost 15x more, but the Sun does not emit enough of it to "catch our eye". :wink: The sun's peak color is blue but not far from green.

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I thought it was helium that would make your voice go squeaky. Awesome pic btw!

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Any low-molecular-weight gas would. Of course, some are healthier to breathe than others...

why douse it do that....

So would argon or methane sweaky your voice?

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***6.8 What causes "helium voice"?

Hydrogen would have a similar effect but as has been pointed out, very dangerous to try

Heavier gasses where the speed of sound would be slower than in normal air should, in theory, deepen the voice though I can't think of any gas it would be even remotely safe to try.

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Hydrogen keeps on getting this bad rap. It's perfectly safe, as long as you don't have any oxygen around...

I know pure hydrogen is pretty safe but presumably you would have to breath it out somewhen, escaping or exhaled hydrogen in a confined room of normal air wouldn't be too clever for someone inexperienced in how to handle the gas. For a student demonstration helium would be much safer but even then it would be advisable to have someone handy who has some medical training.

Slightly different case but we had a guy collapse after using a CO2 fire extinguisher on a small electrical fire in a confined space in our workshop. He was OK after we got him out into fresh air but it gave him a real fright. DIY firefighters be warned!

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haha, i breath in helium whenever i get a helium balloon, always good for a laugh. As for hydrogren, as long as on-ones smoking around you then perfectly safe to try, although its damn harder to get hold of.

Cool 8)

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Xenon!

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Radon?

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Kaptain K wrote:

Yeah - forgot about that, ops: I was more going down the hydrocarbon, chloro/fluoro carbon route.

Mikal555 wrote:

I did think of Radon actually but rejected it as a 'not so safe' gas

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.Aww nuts...[/quote]

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That is correct. 5.9 g/liter
Though it is chemically inert (and thus "safe") I read years ago of a potentially dangerous demonstration. A professor was demonstrating this effect by inhaling helium and then inhaling xenon. He took bigger and bigger hits of xenon to get a longer lasting effect. The problem is that since xenon is so heavy, that it just sat in the bottom of his lungs. He could not exhale strongly enough to expel it, and eventually he got to the point where he was going unconscious because of his decreased lung capacity. Luckily, a couple of the students figured it and and turned him upside down to pour the xenon out of him! I assume they got an A for that. :wink:

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One Earth, One Sky - IYA 2009
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It appears that any atmosphere consisting of a colourless gas would give rise to blue skies because of Rayleigh scattering.
To get other colours in the sky you will need a coloured gas, such as chlorine,
or particulate dust to produce Mies scattering; this acts more like smoke, and produces a white haze (or pink if the dust contains iron oxides as on Mars; other colours are possible).
Mies scattering can produce a smoky blue halo around the sun.

If the atmosphere is very dense Rayleigh scattering apperars to cancel itself out to produce a whitish tone- although greenish colours as seen at sunset have also been suggested.

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New Orion's Arm Site . The Starlark . Against a Diamond Sky (OA Novella Collection) . OA Flickr set

This exact same demo was done once on Letterman. And the subject did exactly that, hanging by his knees from a bar supplied for just that purpose. Took ten to fifteen seconds to drain his lungs...and he was describing what he was doing and why he was doing it the whole time.

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Cool story.

Hmmm...a little BABB humor to keep you awake at 2 a.m.

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