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Monday, July 13, 2009

Hurricanes Versus Bill Gates

Question: What's the difference between Bill Gates and God?
Answer: God doesn't think he's Bill Gates.

Gates' latest area of playing God involves the simple matter of stopping hurricanes:

Recent patent filings have shown Bill Gates and his friends exploring subjects as diverse as electromagnetic engines and beer kegs. Now they're thinking even bigger -- trying to stop hurricanes.

Microsoft's chairman is among the inventors listed on a new batch of patent applications that propose using large fleets of vessels to suppress hurricanes through various methods of mixing warm water from the surface of the ocean with colder water at greater depths. The idea is to decrease the surface temperature, reducing or eliminating the heat-driven condensation that fuels the giant storms.

The filings were made by Searete LLC, an entity tied to Intellectual Ventures, the Bellevue-based patent and invention house run by Nathan Myhrvold, the former Microsoft chief technology officer. Myhrvold and several others are listed along with Gates as inventors.

The idea is actually pretty simple. Large tubes from the surface of the ocean to some depth are attached to floating platforms. Waves slosh over the edge of the platform and the warm surface water from the waves run down the tube to the depths, requiring no external energy source. Build a gazillion of them, stick them in the possible path of a serious hurricane, and presto!, the hurricane is downgraded a couple of notches relative to what it would've been since it no longer has access to that very warm surface water that would fuel it.

Since these could be completely passive devices, it wouldn't cost all that much to build them. The only question is could you actually build and deploy enough of them to make a significant difference.

Oh! And in the long term, there'd be even more heat and energy in the ocean which would mean even more intense and destructive hurricanes. But hey, that's for another generation to worry about.

25 comments:

erp said...

Seems a shame to waste the energy produced by interchanging cold and warm ocean water. Why not hook it all up to generators and produce electricity to recharge the motors of electric cars.

I'll just leave the details of how it would work to you nerds. I only do big picture stuff.

Bret said...

Sure. Once the nice warm water is moved next to the nice cold water it can be used to power a heat engine and convert sea water to hydrogen which can then be taken ashore and used to create electricity.

Piece of cake!

erp said...

See, I knew you could figure it out. No need to thank me. Naming the process after me will be thanks enough.

Susan's Husband said...

Too late to patent that, erp.

erp said...

Darn!

Peter Burnet said...

Never you mind, erp. There's always your brilliant scheme to prevent hurricanes by adding salt to the oceans.

erp said...

Peter, I can't take any credit for that it wasn't my brilliant scheme at all.

Harry Eagar said...

Doesn't work, because -- ta da! -- ain't no free lunch and you have to obey the Second Law, whether you like to or not.

Also, big pipes in the ocean cannot be used passively. They require a great deal of management.

Already been tried at the Natural Energy Laboratory of Hawaii.

Susan's Husband said...

I don't see the violation of the Second Law of Thermodynamics in any of these schemes.

erp said...

SH. I must reveal that I have an honorary degree in thermodynamics bestowed on me in the very early '80s by a Professor of Chemistry whom I helped format a text book entitled, "Laws of Thermodynamics," he was writing using a new fangled contraption called a computer.

It was a Digital mainframe as big as an 18 wheeler which students could access from dumb monitors (can't remember what they were called) in a computer lab and a maddeningly obtuse program called ???? RNO/EDT ??? I can't believe I can't remember what that was called either. It's really awkward trying to go through life without my memory.

Anyway, it was great fun and one of the first text books so written. I had a monitor at home and one of the first modems around campus attaching to my home phone to the main frame. The whole venture was in the nature of an experiment. One that most everybody thought would fail. It didn't. I was prouder of formatting those formulae than I would have had I been a Picasso.

Point of this comment? Don't try to pull any fast ones dropping big words like the second rule of thermodynamics. Some of us kinda sorta remember what it means and could have a breakthrough of clarity at any moment.

Bret said...

I don't see any thermodynamic problems either. Try it in your bathtub. It'll work, though it'll be a little tricky to emulate the temperature gradient. But the part about water sloshing into the platform and running down the tube will work just fine.

Susan's Husband said...

erp, Harry started it!

Harry Eagar said...

It will run down the tube and the tube will fill up and then what?

Partial answer: the water-filled tube will become a habitat for sea creatures, who will clog the tube.

Been there, done that.

erp said...

Gosh Harry, how did you get out?

Hey Skipper said...

Harry:

I don't think so. The wind acts as a pump, continuously pushing waves onto the tube. The resulting head pressure will push water down the tube. With a big enough cross section, sea life on the tube walls won't make any difference.

Of course, there is the problem of holding the darn thing still. I've heard there is a current in the Gulf.

Bret said...

Harry,

What Hey Skipper says.

Hey Skipper,

I don't think they're meant to be permanent. My guess is that their thinking is that the platforms to dissipate energy for hurricanes would be towed into the path of the hurricane or to the hot spots in the gulf and would be left there for only a few days. The prevailing currents would be taken into account for that time period. No significant sea life growth or "clogging" would occur during that time period..

The technology doesn't seem to be the question to me. It's the operational magnitude of building, deploying, collecting, and storing gazillions of such platforms that seems far-fetched to me.

Harry Eagar said...

You cannot push water down into water without a source of energy. Gravity won't do it.

That empty tube would have to be as strong as a submarine's pressure hull to extend down as far as 300 feet or so without collapsing.

If the proposal is to tow dozens or hundreds of empty submarines standing on their heads out to sea, I think it's crazy. Where can I short the stock?

Susan's Husband said...

Why won't gravity do it? Because gravity is too weak to make water flow down a pipe?

The tubes don't need to be very strong, as there's only a negligible pressure gradient anywhere across the structure. There might be some vertical tension depending on the density of the pipe material.

You really ought to try this at home. Get a bucket and cut the bottom off. Then go out in the surf and let the waves go over the top of the bucket while it's in the water. You need merely note that it never fills up then ask yourself "where does all that water go?".

P.S. I am still waiting an explanation of what you meant by "Doesn't work, because [...] you have to obey the Second Law".

Harry Eagar said...

You can look at this 3 ways:

1. It's a boat. When you pour water in a boat it sinks. When you knock a hole in it, it sinks.

2. As a heat pump. It's a reverse OTEC, with the additional complication that its pressures are not equalized. OTEC doesn't work; at Kona the temperature difference between surface and about 2K feet down is only about 20 degrees. To do any useful work, you'd have to move Amazons of water through it.

3. As a perpetual motion machine. This is where the Second Law comes in. You are doing work, pushing water into an incompressible substance (water).

In your bucket, the pressure difference between the open top of the bucket and the open bottom is negligible -- millions if not trillions of times less than the instantaneous pressure flux of the waves.

If you need to get water down any depth, you have to pump it. Gravity is no help. (You can get water down into porous rock by dumping, but if the rock is dense, you have to pump. The air in rock is compressible, but water is not.)

If memory is correct, the mixing zone under a hurricane is about 90 feet, so no matter where the highest thermocline is, you'd have to get your water deeper than 100 feet.

Consider your bucket again. You can pour any amount of water you like into the ocean and it does not sink rapidly to the bottom. It won't sink at all if it's fresh water. The water you pour into the bucket isn't going to the bottom. It's just sitting there, and moving up and down from the wave flux.

Gedanken experiment: replace bucket with a long straw. Very long. Put your thumb over the lower end and submerge all but the top inch of the straw vertically in water. What happens?

Water enters the straw and pushes most of the air out, right?

Now, pour water into the top the straw. Does the water level change?

Susan's Husband said...

None of your three cases match the actual case. The first two I can see where you went wrong, but where you got the third mystifies me, even for you.

"replace bucket with a long straw. Very long. Put your thumb over the lower end and submerge all but the top inch of the straw vertically in water. What happens?

Water enters the straw and pushes most of the air out, right?"

No, the straw remains air filled because there's no entry point for the water. You ought to try real experiments, not gedanken ones, to get a feel for how the world actually works.

"Now, pour water into the top [of] the straw. Does the water level change?"

Depends on how I pour it, but generally the straw will fill up and then overflow. How this resembles the original tube idea escapes me.

Try this physical experiment. Put a straw in water holding the top inch out of the water. Pour water in the top. The water level in the straw doesn't change. Where does the water you poured in go?

Let's go back to this:

"Consider your bucket again. You can pour any amount of water you like into the ocean and it does not sink rapidly to the bottom. It won't sink at all if it's fresh water. The water you pour into the bucket isn't going to the bottom. It's just sitting there, and moving up and down from the wave flux."

Suppose it's a 5 gallon bucket with no bottom floating in the ocean. I pour 5,000 gallons of water in to it, slowly enough so the bucket doesn't overflow. You claim that all 5,000 gallons are still sitting in the bucket, going up and down with the wave flux? Hmmm, if that works I can think of a very cheap way to store liquids. Show me how it's done and I'll split the profits with you.

Bret said...

Susan's Husband,

Thanks for trying to explain simple physics to Harry. I was beginning to think that the laws of physics in my universe were somehow different. Maybe they are different than those in Harry's. That would explain a lot.

Harry Eagar said...

Forgot to ask you to remove your finger.

Susan's Husband said...

Gosh, you will really go to any length to avoid answering a direct question, such as "where does the water go?". Do you already realize how the answer demolishes you case and that's why you won't answer? Or are you just skimming for keywords again? Or you expect us to answer your questions but see no reason to reciprocate? Really, it's kind of bizarre.

OK, so I have the straw in the water, and I take my thumb off (why I had it there in the first place will remain a mystery).

"pour water into the top [of] the straw. Does the water level change?"

The the water level in the straw does not change. I spent the next year pouring water in to the straw and the water level doesn't change. Where does all the water go? Is it still in the straw, or somewhere else? If it's not in the straw, where did it leave the straw? Does it make any difference how long the straw is?

Hey Skipper said...

If you need to get water down any depth, you have to pump it.

Which is what the sun does.

The waves, which exist only because of the sun's heat, continually push water onto the top of an open tube. (Since there is no pressure gradient across the tube, it can be arbitrarily thin, so long as it can support its weight.)

Since there is no bottom, the tube will not support any vertical differential with respect to the surrounding water. Therefore, any wave action will, thanks to the sun, push water out the bottom.

There is one thing this scheme possibly has not taken into account. A sufficient tube area will damp wave action. So if it is big enough to damp a hurricane, it might also be too big.

Harry Eagar said...

I kept puzzling about your comment, Skipper, that the pressure was equalized. I'm kinda slow. It was only, finally, Guy who clued me in -- the tube is meant to be filled with water.

Now I got it.

I thought these guys were crazy enthusiasts, who were selling a perpetual motion machine. It turns out they are con artists.

You aren't going to move much water with a wave-driven pump. Consider a small hurricane 100 miles in diameter moving 6 mph. Each day it will harvest the heat from 15,000 square miles of water.

I don't know how much you'd have to subtract to make a difference, but let's say 1%. You are talking about a lot of very big tubes.

Way too slow.

It's a con. But it might be fun to watch the tugs trying to outrun the storm.