Science questions not worth a thread I: I'm a moron!

[Loppan Torkel]

Is it possible to hydrate yourself by sitting in a tub full of water?

Yes. I cannot confirm this, but it's been speculated an undertow can be generated if you pass gas underwater.

 

[Meteor Man]

Is it possible to hydrate yourself by sitting in a tub full of water?

No. Skin is actually watertight. The top portion may become waterlogged, but it won't seep in to the arteries.

Yes. I cannot confirm this, but it's been speculated an undertow can be generated if you pass gas underwater.

I concur with this statement, however.

 

[PlutonianEmpire]

Yes. I cannot confirm this, but it's been speculated an undertow can be generated if you pass gas underwater.

What is an undertow and how exactly does that work?

 

[Meteor Man]

What is an undertow and how exactly does that work?

Passing gas underwater spontaneously creates an undertow: a current of subsurface water that moves away from the point of origin. It re-hydrates you through your skin.

Spoiler :

In case you were unaware, I am utterly BSing everything in this comment.

That is what an undertow is, though.
http://en.wikipedia.org/wiki/Undertow_(wave_action)

 

[peter grimes]

I wouldn't underestimate life, though

Fair point.

But then again, we have only found it one place so far...

And the place we did find it required about 2 billion years before anything more than simple mats of organic sludge evolved.

 

[Loppan Torkel]

What is an undertow and how exactly does that work?

What Meteor Man said. Everything.

 

[hobbsyoyo]

may be worth its own thread soon, but nasa hyped up some announcement to-be-made for mars rover curiosity

Scientists working on NASA's six-wheeled rover on Mars have a problem. But it's a good problem.

They have some exciting new results from one of the rover's instruments. On the one hand, they'd like to tell everybody what they found, but on the other, they have to wait because they want to make sure their results are not just some fluke or error in their instrument.

It's a bind scientists frequently find themselves in, because by their nature, scientists like to share their results. At the same time, they're cautious because no one likes to make a big announcement and then have to say "never mind."

The exciting results are coming from an instrument in the rover called SAM. "We're getting data from SAM as we sit here and speak, and the data looks really interesting," John Grotzinger, the principal investigator for the rover mission, says during my visit last week to his office at NASA's Jet Propulsion Laboratory in Pasadena, Calif. That's where data from SAM first arrive on Earth. "The science team is busily chewing away on it as it comes down," says Grotzinger.

SAM is a kind of miniature chemistry lab. Put a sample of Martian soil or rock or even air inside SAM, and it will tell you what the sample is made of.

Grotzinger says they recently put a soil sample in SAM, and the analysis shows something earthshaking. "This data is gonna be one for the history books. It's looking really good," he says.

Source

people have thoughts on what it is?

_____________________
This just in:

NOPE

NASA's Mars rover Curiosity has completed its first soil analysis of the Red Planet with no sign of organic material, the U.S. space agency said on Thursday.

"Rumors and speculation that there are major new findings from the mission at this early stage are incorrect," NASA said in a statement. "At this point, the instruments on the rover have not detected any definitive evidence of Martian organics."

 

[Meteor Man]

Unfortunate.

 

[PlutonianEmpire]

Hah. I knew almost immediately when I first heard about it that it was untrue.

Anyways, question: assuming, for the purposes of this question, that Snowball Earth events may be possible, what's the shortest possible amount of time in which a global glaciation event can occur? Meaning, how short might the transitionary period between a temperate or warm climate and global glaciation possibly be?

 

[hobbsyoyo]

My best guess: on the order of a hundred thousand years, give or take.

Glaciars move quite fast under the right conditions, I would count a snowball Earth as being the right conditions.

 

[Meteor Man]

My best guess: on the order of a hundred thousand years, give or take.

Glaciars move quite fast under the right conditions, I would count a snowball Earth as being the right conditions.

SO you expect a snowball Earth to end as the glaciers run off the mountains? Yeah, don't think so. And I'm pretty sure that the colder the temperature the slower glaciers move.

I expect it to last longer, perhaps a couple million. Well, maybe half a million.

 

[PlutonianEmpire]

I wasn't asking how long the event itself lasts, I was just asking how fast the onset of it is.

 

[emzie]

Depends the cause of the onset. If the sun blinked out of existence, pretty fast

It's a pretty complex question, as hard to model as global warming predictions would be. Harder, really. We have actual data to feed in and to check against models and correct over time. Modelling a snowball earth is done without a known cause and without knowing how extensive the glaciation was. Did the earth freeze over like a shell or did the oceans turn to a slushy mix? The latter allows for ocean currents to still be driven by solar radiation, which, by the way, was a smaller output than today.

My gut wants to say it'd happen quickly. There would be some event which would start a severe cooling trend, and as ice reflected more and more of the sun's radiation into space, the cooling would intensify, creating a feedback mechanism -- a reverse runaway global warming scenario. As to how many years that would be, your guess is as good as mine.

 

[PlutonianEmpire]

Depends the cause of the onset. If the sun blinked out of existence, pretty fast

It's a pretty complex question, as hard to model as global warming predictions would be. Harder, really. We have actual data to feed in and to check against models and correct over time. Modelling a snowball earth is done without a known cause and without knowing how extensive the glaciation was. Did the earth freeze over like a shell or did the oceans turn to a slushy mix? The latter allows for ocean currents to still be driven by solar radiation, which, by the way, was a smaller output than today.

My gut wants to say it'd happen quickly. There would be some event which would start a severe cooling trend, and as ice reflected more and more of the sun's radiation into space, the cooling would intensify, creating a feedback mechanism -- a reverse runaway global warming scenario. As to how many years that would be, your guess is as good as mine.

Ah, ok. I asked because with the two most recent versions of my space program, 1.6.0 and 1.6.1, the user can go 2 billion years into the past and future, and supports a timeline feature (with limited functionality IMO), so I wanted to model not just the most recent event (about 800 Mya), but also a fictitious event that has Earth fully glaciated just 14,000 years from now, and last dozens of millions of years. Dunno how realistic, but entertaining, at least.

 

[Meteor Man]

Ah, ok. I asked because with the two most recent versions of my space program, 1.6.0 and 1.6.1, the user can go 2 billion years into the past and future, and supports a timeline feature (with limited functionality IMO), so I wanted to model not just the most recent event (about 800 Mya), but also a fictitious event that has Earth fully glaciated just 14,000 years from now, and last dozens of millions of years. Dunno how realistic, but entertaining, at least.

Sounds pretty awesome. Is this Celestia? If so, there are tons about it don't know yet.

 

[hobbsyoyo]

SO you expect a snowball Earth to end as the glaciers run off the mountains? Yeah, don't think so. And I'm pretty sure that the colder the temperature the slower glaciers move.

I expect it to last longer, perhaps a couple million. Well, maybe half a million.

I said nothing about when it would end. I was saying that it could happen pretty fast. I was directly answering PE's question, feel free to reread my previous post.

And even if glaciers move slowly in lower temperatures (I am not sure of this), a snowball Earth would start with global temperatures not that much colder than they are today, particularly at the equator.

 

[PlutonianEmpire]

Sounds pretty awesome. Is this Celestia? If so, there are tons about it don't know yet.

Yep.

Here's some documentation:

http://en.wikibooks.org/wiki/Celestia

http://www.celestiamotherlode.net/catalog/documentation.html

https://lepp.cornell.edu/~seb/celestia/

http://shatters.net/celestia/documentation.html

And of course, their forums: http://shatters.net/forum/
(Yes, I have a footprint there too. )

Hope this helps.

 

[peter grimes]

My gut wants to say it'd happen quickly. There would be some event which would start a severe cooling trend, and as ice reflected more and more of the sun's radiation into space, the cooling would intensify, creating a feedback mechanism -- a reverse runaway global warming scenario. As to how many years that would be, your guess is as good as mine.

I also suspect it might be able to happen incredibly fast, geologically speaking. Say, and less than 1000 years.

However, I don't think it could happen anywhere close to that fast today owing to the pattern of ocean distribution. The Pacific, Indian, and Atlantic are well shaped to transfer equatorial heat to the poles. Plus, there's a ton of land within 30 degrees of the equator. If that land were more towards the poles, and situated along latitudes blocking heat transfer, we'd have a potential for much faster snowball.

 

[Cutlass]

Does a geosynchronous orbit have to be an equatorial orbit or close to it? How far off the equator can they get?

 

[emzie]

A geostationary orbit, one where a satellite stays above the same spot all the time, requires being on the equatorial plane. There's no real wander room for that, and such satellites require constant adjustments to not drift out of a geostationary orbit.

A geosynchronous orbit can be any orbit that returns to the same spot every day. It can be inclined all the way to a polar orbit (north pole to south pole to north).