rowing through mercury - one for the curious physicists

[dylanwinter]

a few what ifs about rowing through various liquids


http://what-if.xkcd.com/50/

 

[Dipper]

It's lucky the sea and lakes contain water or we wouldn't have any boating forums. I suppose the lounge might survive though.

 

[BlueChip]

I seem to remember being told as a boy that lighthouse lenses floated in a tank of mercury?

 

[alahol2]

I reckon a normally shaped sailing boat floating on mercury could be very unstable, top heavy.

 

[AntarcticPilot]

That is a very weird web-page!

However, molten lava does exist at the Earth's surface - it ought to be possible to go boating on a nice fluid flow of basaltic lava. Density (I guess) around 3 or 4 - a catamaran might work better for stability (it would be the answer for stability problems in mercury, too). Hawaii strikes me as the obvious location! Or a carbonatite lava in Africa, perhaps. No good on acidic lavas - they're not fluid enough. But basaltic lavas and carbonatites are nice and runny.

Now, Titan has some interesting lakes - liquid ethane and methane (http://en.wikipedia.org/wiki/Lakes_of_Titan). A former colleague had to think (seriously!) about the possibility of instruments that would operate in a lander that happened to hit a lake on Titan. I think some of his ideas were incorporated in the Surface Science3 Package of the Huygens lander.

 

[prv]

That is a very weird web-page!

Randall's been doing them for about a year. New one every Tuesday, answering reader questions about taking science (usually physics) to odd extremes. The basic idea is to take an absurd premise or two, and then deduce logically from there.

Pete

 

[nigelmercier]

I seem to remember being told as a boy that lighthouse lenses floated in a tank of mercury?

They did indeed, an excellent bearing surface.

Mythbusters did a test to see if swimming through custard was easier than water, I think it was inconclusive.

 

[Lakesailor]

Depends if it's thin or lumpy.

 

[penfold]

The Beeb paid for a swimming pool filled with custard; no-one swam in it, they just ran across the top! Non-newtonian fluids are cool.

 

[macd]

Depends if it's thin or lumpy.

...or shark-infested

 

[nigelmercier]

Non-newtonian fluids are cool.

http://www.youtube.com/watch?v=S5SGiwS5L6I

 

[Burnham Bob]

when younger my daughter asked me 'if all the puffer fish in the world blew themselves up at the same time, would the ocean level rise?'

maybe they can answer that

 

[prv]

when younger my daughter asked me 'if all the puffer fish in the world blew themselves up at the same time, would the ocean level rise?'

maybe they can answer that

Well, you can but ask. Send your questions to whatif@xkcd.com . He does get an enormous number of questions, though, so the odds of yours being chosen are slim.

Especially since the answer is not very interesting. They use the water to inflate themselves, so the total volume of fish and water doesn't change.

Although I'm sure Randall could draw some interesting pictures of puffer fish.

Pete

 

[oldbilbo]

a few what ifs about rowing through various liquids http://what-if.xkcd.com/50/

Hmmm. In a previous incarnation, I found myself working with 20L Dewar flasks of liquid nitrogen, pouring 1/2L slugs of it every few minutes into the top of a first-generation RTIR imaging device, while bucking about in the back of an RAF Puma helo, in the dark of a sleeting Jan/February night, 'somewhere over South Armagh'.

The box of tricks I was serving was at eye-height, and the stuff I spilled ran hissing and spitting all over the aircraft floor.

No-one mentioned this at the time....

A Dartmouth engineering page on liquid nitrogen safety includes the following phrases:

"violent reactions with organic materials"
"it will explode"
"displace oxygen in the room"
"severe clothing fire"
"suffocation without warning"

- From Dylan Winter's reference above

 

[Gymnopedie]

How about rowing through glass - a (super cooled) liquid? Come to think of it if you had a glass bottom boat (vide holiday trips to view submarine features) you wouldn't need an anchor since as soon as you stop the boat's bottom will have the same viscosity as the glass you are rowing through and the two will effectively fuse and render you motionless.
Any body know of any opportunities for creative Sci-Fi writers?