Tesla's Dream

If polywell fusion is developed, in what ways will the world change for better or worse? Discuss.

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Mike Holmes
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Tesla's Dream

Post by Mike Holmes »

In another thread, somebody proposed that tractors could be run electrically with "tethers" (maybe I didn't understand the proposition, but it sounds like electric cords to me).

If electric power is cheap enough, however, it might make it economical to start considering moving towards a real "wireless" world:

http://en.wikipedia.org/wiki/Wireless_p ... conduction

This is well understood science, and the only real problem with it is the loss that occurs due to range. Tesla himself made it work with light-bulbs at short range a century ago. And there's even some folks working on finding applications today:

http://en.wikipedia.org/wiki/WiTricity

The main problem is, of course, the loss that occurs. But if you have plentiful enough power... lets say you have a Mr. Fusion polywell in the back yard... I think you'll be able to run your tractor by antenna... remember, it'll be relatively light... won't even need a battery.

Mike

luke
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nonsense

Post by luke »

Just imagine what would happen if someone would cross the beam.

In Tesla's apparatus it would not even be point to point (as a beam) but just radiating energy in space. Transmission efficiency would then scale with one over distance squared. Imagine the power levels needed.
Remember that power levels on the radio receiver side are normally in the nano-watt range. Transmission power must be in the Tera-watt range to be useful.

If you could transmit that kind of power, it would be a weapon of mass destruction, giving a whole new meaning to the word electro-smog.

Tesla's dream was never implemented, there is no conspiracy behind that. The truth is that it is simply a bad idea.

MSimon
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Post by MSimon »

Just for illustration:

A nice strong radio signal which is reasonably detectable by a cheap radio would be 1 millivolt into 50 ohms. 20 nanowatts. A very strong signal would be 100 millivolts. 200 microwatts.

Compare that with the kilowatts needed for transportation or the megawatts needed for plowing.
Engineering is the art of making what you want from what you can get at a profit.

luke
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near field...

Post by luke »

For near field (distance between transmitter and receiver not much greater than the size of the antenna's) it is used, with passive RFID's as the best example. But power levels are rather low (milliwatts).

I would not feel comfortable sitting in the magnetic field of a 100 Watt laptop charger. For instance inductive welding is also done with high frequency magnetic fields.

If cheap electrical energy is available, I would say, let's make hydrogen to transport and store energy for car's etc.

MSimon
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Re: near field...

Post by MSimon »

luke wrote:For near field (distance between transmitter and receiver not much greater than the size of the antenna's) it is used, with passive RFID's as the best example. But power levels are rather low (milliwatts).

I would not feel comfortable sitting in the magnetic field of a 100 Watt laptop charger. For instance inductive welding is also done with high frequency magnetic fields.

If cheap electrical energy is available, I would say, let's make hydrogen to transport and store energy for car's etc.
If you can make hydrogen you can make natural gas. It is a lot less "leaky" than H2. It also requires higher ignition energy making it safer.
Engineering is the art of making what you want from what you can get at a profit.

Helius
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Hydrogen

Post by Helius »

If you can make hydrogen you can make natural gas. It is a lot less "leaky" than H2. It also requires higher ignition energy making it safer.
Yes, If Cheap H2 were available, say from High temperature electrolysis or Nuclear driven Sulphur Iodine process, it would probably be used as a great feedstock for the generation of hydrocarbons and alcohols, being easier to transport, store, and use. It's ironic the main source of Hydrogen is from methane. Methane is great stuff as it is. Burn it, and you end up with 2 moles water for each mole C02.

In the minds eye of the public, the "Hydrogen economy" depends on Hydrogen as the end product, which can't happen easily even if Hydrogen could be generated in great quantity. We'll need to make methane, and longer hydrocarbons to use hydrogen effectively.

djolds1
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Re: Tesla's Dream

Post by djolds1 »

Mike Holmes wrote:The main problem is, of course, the loss that occurs. But if you have plentiful enough power... lets say you have a Mr. Fusion polywell in the back yard... I think you'll be able to run your tractor by antenna... remember, it'll be relatively light... won't even need a battery.
Darwin Award nominee from 10+ years back. Idiot Worker at a Canadian power plant always sits his posterior in front of a microwave transmission tower to stay warm in the freezing Canadian winter. Christmas Eve the Power Company cranks up the transmission power due to peak demand. The next shift comes in on Christmas Day and smells wonderful cooked ham. "Oh how nice, the guy on the overnight shift is so thoughtful..."

Probably apocryphal, but does anyone here want cooked Long Pig?

Duane
Vae Victis

Mike Holmes
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Post by Mike Holmes »

"Radiation dangerous? Pernicious nonsense!" - Repo Man

Yes, with current studies showing that cell phones can cause cancer, as well as electrical wires, the whole idea might well be problematic. Still interesting. We assume that radio waves are non-problematic at the levels at which stations transmit. There might be safe wavelengths.

Tight beam transmission? Might work for some applications.

Mike

kunkmiester
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Post by kunkmiester »

There are plugless chargers out now. Plate with a coil in it is set on your dresser. When you get home, you set your phone on it, and the current in the coil in the plate inducts a current in a coil in the phone. Much closer, more efficient. If you put a similar coil or set of coils underground, and used a similar system, it might work.

Easier would be Cartesian robots on tracks covering long, narrow fields. Easy to run power rails alongside. You might also manage an old fashioned overhead system if you wanted to. As a development of the Cartesian robot, a set of power rails spaced properly for the tractor to drive over and get power from would work too. The Cartesian robot has been a dream of farm engineers for a long time though. The big problem is it can't do absolutely everything, and the initial investment is massive.
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kunkmiester
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Post by kunkmiester »

Hate to resurrect, but I had a thought related to this. There's a small pile of evidence that sitting in an electromagnetic soup like we are(cell phones, wireless, radio, TV, etc.) can be bad for some people's health. If you have enough power to run pretty much everything floating through the air, how would this effect general health?
Evil is evil, no matter how small

Nik
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Don't forget induction hobs...

Post by Nik »

Remember those neat kitchen hobs that work by induction ?

A down-side of transmitted power would be accidental pick-up. Like fragments of foil or gold trimmed plates in your microwave...

Nearest we have today beyond the locale of eg BBC World MW & LW transmitters is that US ELF system which apparently may electrify fence-lines for many miles around...

Don't forget the weird effects of geomagnetic storms...

MSimon
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Re: Don't forget induction hobs...

Post by MSimon »

Nik wrote:Remember those neat kitchen hobs that work by induction ?

A down-side of transmitted power would be accidental pick-up. Like fragments of foil or gold trimmed plates in your microwave...

Nearest we have today beyond the locale of eg BBC World MW & LW transmitters is that US ELF system which apparently may electrify fence-lines for many miles around...

Don't forget the weird effects of geomagnetic storms...
You want an electrified fence? Site it parallel to a HV power line. Insulation wouldn't hurt either.
Engineering is the art of making what you want from what you can get at a profit.

D Tibbets
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Post by D Tibbets »

In my wisdom, I don't see transmtted power being used for heavy work for the above reasons, and probably many others. A portable power source is needed. The little I have learned about hydrogen convinces me that it's use is foolish due to production inefficiencies, and severe storage challanges. Methane or anhydrous ethanol production makes more sense. Bussard liked ethanol made from otherwise nonagrcultural sources with the Polywell providing the process energy, and or (?) direct chemical production of ethanol, again with the polywell providing the power. Ethanol has the major advantage that it fits into our current infrastructure without having to spend 10s of trillions of dollors to convert.
Other options with relatively cheap power delivered to the work site would be quick charging flywheels or super capacitors or battery packs that could be quickly exchanged. Filling the tank with a liquid fuel would remain much easier and probably much cheaper.

Dan Tibbets
To error is human... and I'm very human.

windmill
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Post by windmill »

My understanding is that Tesla's broadcast power idea ws supposed to rely on "longitudinal" wave propogation, and is not not subject to EM inverse square law power limits. This would be great if it actually exists. Somwwhere I read that the technology of automatic door sensors uses some form of L-wave detection, but I wasn't able to verify this claim.

djolds1
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Post by djolds1 »

windmill wrote:My understanding is that Tesla's broadcast power idea ws supposed to rely on "longitudinal" wave propogation, and is not not subject to EM inverse square law power limits. This would be great if it actually exists. Somwwhere I read that the technology of automatic door sensors uses some form of L-wave detection, but I wasn't able to verify this claim.
There was a NASA paper on this... its on the NTRS Server.
Vae Victis

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