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A question here, behaviour of water on Mars
spdf
post May 24 2007, 12:38 AM
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A question here

There are signs that in the past there was liquid water on Mars. So lets assume thats true.
Since the gravity on Mars is much lower than on Earth, so how does water (waves) behave on Mars compared to Earth?
Someone did say, that waves would have been much higher but also much slower. Is this true? Does anyone have an animation where you can see a waive on Earth in comparsion to a wave on Mars?

Thanks
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silylene
post May 24 2008, 03:21 AM
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QUOTE (spdf @ May 24 2007, 12:38 AM) *
A question here

There are signs that in the past there was liquid water on Mars. So lets assume thats true.
Since the gravity on Mars is much lower than on Earth, so how does water (waves) behave on Mars compared to Earth?
Someone did say, that waves would have been much higher but also much slower. Is this true? Does anyone have an animation where you can see a waive on Earth in comparsion to a wave on Mars?

Thanks


Many chemists use a piece of equipment called a 'rotary evoporator', more commonly called a 'rotovap', to quickly evaporate solvents out of a round bottom flask to leave behind a concentrated liquor or salts. In a rotovap, the flask containing the liquid is rotated at an adjustable speed (which can be a quite fast rpm) + an adjustable vacuum is applied to suck off the solvent + an adjustable optional heating is applied to the flask exterior via a heating bath, which can be heated up to 100C.I n this setup, you can also induce sloshing of the liquid by jarring the equipment. Sometimes it is useful to cause sloshing to prevent 'bumping' which is rapid nucleation and boil-over from a super-saturated condition.

So basically you can watch the behavior of evaporating liquid at various g-forces (centrifugal spinning) of 1 or higher, at various vacuum forces (1 atm to near zero), with applied external heating or not.

If you do this using a rotovap, and induce sloshing, then you can see the behavior of waves as a function of vacuum or as a function of gravity (g=1 or greater). So I tried with water.
It seems that slosh-induced waves settle down the same speed regardless of applied vacuum. (i.e. vacuum has no obvious effect on wave height).
It seems that slosh-induced waves are smaller and settle down faster as the centrifugal force increases. (i.e. increasing gravity greater than earth's gives smaller waves).

From this I would infer on Mars that wave heights would be higher due to a lower surface gravity, and the reduced atmosperic pressure would not be a significant effect on waves.
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rlorenz
post May 24 2008, 01:27 PM
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QUOTE (silylene @ May 23 2008, 11:21 PM) *
If you do this using a rotovap, and induce sloshing, then you can see the behavior of waves as a function of vacuum or as a function of gravity (g=1 or greater). So I tried with water.
It seems that slosh-induced waves settle down the same speed regardless of applied vacuum. (i.e. vacuum has no obvious effect on wave height).
It seems that slosh-induced waves are smaller and settle down faster as the centrifugal force increases. (i.e. increasing gravity greater than earth's gives smaller waves).

From this I would infer on Mars that wave heights would be higher due to a lower surface gravity, and the reduced atmosperic pressure would not be a significant effect on waves.


More of this kind of experiment needs to be done!

Some related wind-tunnel experiments I did are at
http://www.lpl.arizona.edu/~rlorenz/marswit.pdf

Note that while atmospheric pressure doesnt affect waves directly, it appears to strongly influence
how effectively momentum is coupled from wind into the liquid.
I wonder if the sloshing in this rotovap thingy relates to the centrifugal force due to the mechanical
configuration. I'd imagine that these waves are small enough that they are capillary waves (controlled
by surface tension) rather than gravity waves...
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Posts in this topic
- spdf   A question here   May 24 2007, 12:38 AM
- - tuvas   This is just a guess, but I would guess waves woul...   May 24 2007, 08:19 PM
- - ugordan   I believe the higher-and-slower waves is the corre...   May 24 2007, 08:44 PM
- - nprev   Another major variable would have been atmospheric...   May 24 2007, 11:17 PM
- - dvandorn   Actually, liquid water on Mars would behave consis...   May 25 2007, 07:50 AM
- - AndyG   ...and add bigger drops. Surface tension will play...   May 25 2007, 08:31 AM
- - nprev   Great story, oDoug! Yeah, I should have bee...   May 25 2007, 11:50 AM
- - Juramike   While there would be no really big tides on a Mart...   May 25 2007, 03:41 PM
- - helvick   On earth the average atmospheric pressure of ~101k...   May 25 2007, 04:52 PM
|- - marsbug   I have a question I've not been able to resolv...   Nov 15 2007, 06:14 PM
|- - dburt   QUOTE (marsbug @ Nov 15 2007, 11:14 AM) I...   Nov 15 2007, 11:30 PM
|- - Gsnorgathon   Not to rain (metastably or otherwise) on anyone...   Nov 16 2007, 12:41 AM
|- - Juramike   QUOTE (Gsnorgathon @ Nov 15 2007, 08:41 P...   Nov 16 2007, 08:57 PM
|- - nprev   QUOTE (Juramike @ Nov 16 2007, 12:57 PM) ...   Nov 17 2007, 03:49 PM
|- - Juramike   QUOTE (nprev @ Nov 17 2007, 10:49 AM) .....   Nov 17 2007, 05:02 PM
|- - ElkGroveDan   QUOTE (Juramike @ Nov 17 2007, 09:02 AM) ...   Nov 17 2007, 05:38 PM
- - Greg Hullender   Here's a couple of useful comments from a NASA...   Nov 15 2007, 06:41 PM
- - djellison   And of course, the fact that water can exist, at s...   Nov 15 2007, 07:12 PM
|- - rlorenz   QUOTE (djellison @ Nov 15 2007, 02:12 PM)...   Nov 16 2007, 01:47 AM
|- - ngunn   QUOTE (rlorenz @ Nov 16 2007, 01:47 AM) I...   Nov 16 2007, 01:03 PM
- - Juramike   Both theory and experiment agree that cold brine s...   Nov 15 2007, 10:41 PM
- - nprev   Mike or HDP Don, how different are the curves for ...   Nov 16 2007, 01:06 AM
|- - dburt   QUOTE (nprev @ Nov 15 2007, 06:06 PM) Mik...   Nov 16 2007, 08:27 PM
|- - nprev   QUOTE (dburt @ Nov 16 2007, 12:27 PM) Ver...   Nov 17 2007, 01:17 AM
|- - dburt   QUOTE (nprev @ Nov 16 2007, 06:17 PM) Tha...   Nov 17 2007, 01:40 AM
- - ngunn   Thanks for that Hecht link. Definitely some counte...   Nov 16 2007, 08:51 PM
- - nprev   They don't call ya Herr Doktor Professor for n...   Nov 17 2007, 01:50 AM
|- - dburt   QUOTE (nprev @ Nov 16 2007, 06:50 PM) The...   Nov 17 2007, 03:03 AM
- - marsbug   Thank you very much one and all, I can look foward...   Nov 17 2007, 05:25 PM
- - nprev   Rats...knew I shoulda gone to EGD's alma mater...   Nov 18 2007, 12:15 AM
- - Juramike   Space.com article says that the crust of Mars is c...   May 15 2008, 07:03 PM
|- - dburt   QUOTE (Juramike @ May 15 2008, 12:03 PM) ...   May 17 2008, 01:14 AM
||- - dvandorn   QUOTE (dburt @ May 16 2008, 08:14 PM) ......   May 17 2008, 07:06 AM
||- - Juramike   QUOTE (dburt @ May 16 2008, 08:14 PM) Hop...   May 17 2008, 12:53 PM
||- - dburt   QUOTE (Juramike @ May 17 2008, 05:53 AM) ...   May 19 2008, 02:58 AM
||- - SickNick   QUOTE (Juramike @ May 17 2008, 10:53 PM) ...   Jun 8 2008, 02:38 PM
|- - Juramike   QUOTE (Juramike @ May 15 2008, 02:03 PM) ...   May 18 2008, 06:35 PM
- - dvandorn   As a general comment to the "discovery" ...   May 17 2008, 07:17 AM
- - silylene   QUOTE (spdf @ May 24 2007, 12:38 AM) A qu...   May 24 2008, 03:21 AM
|- - rlorenz   QUOTE (silylene @ May 23 2008, 11:21 PM) ...   May 24 2008, 01:27 PM
|- - Juramike   QUOTE (rlorenz @ May 24 2008, 09:27 AM) M...   May 24 2008, 03:05 PM
|- - silylene   I agree that the problem with resonance waves make...   May 25 2008, 02:05 AM
- - Juramike   A rotovap simulation experiment! That...is......   May 24 2008, 04:28 AM


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