THE Second Law

[Lefty]

Got it, thanks. Did a search & found a sweet resizing program from the archives.

[taoistshredder]

hahaha wtf is that?
dude, we need to take you and CJ and lock you in a rubber room...
lmao

Speaking of whom, I haven't seen him in a while, he cool?

[Hippie3]

lefty
that's not going to fly as your avatar,
it crosses the line,
i don't want to see any asshole,
not even a cartoon one.

[vrooota]

All of the sci-fi to reality stuff is great, it encourages me to see the possibilities for the future that people are working on. I don't want to steal any thunder hip....but I thought it would be good to point out just how far the scientists are from making carbon tubes long enough to stretch from the ground to near earth orbit. They are after all carbon NANO-tubes. Even if the only theoretical problems with this space elevator are the size limits of high strength carbon formations, that is an enormous hurdle right now. The max diameter of single carbon tubes is meausured in nano meters, and the length-I believe-don't quote me-tried to find out for sure but didn't turn anything up---is limited by the size of the chamber in which they are formed. Even if they find a way to spin them together like some kind of space age hemp, the financial hurdles are incredible-the stuff is absurdly expensive(from what I saw online anywhere from 50 to 1000 bucks a gram depending on what kind of tubes yur looking for [multiwall, single wall ect.]) and thats just the quality that they sell to colleges or whoever for research, they're only claiming 50-75% nanotubes in their product, the rest is amorphus carbon-graphite essentially. Now I'm no expert so don't get all huffy if I misunderstood something in my own research here, but I think it is important that people don't expect something to be riding space elevators any time soon. It is a feasible concept, but so was star wars; the hurdles are just a little higher than the optimists would like to think.

[Lefty]

Okay Hip, I'll change it

[Hippie3]

It is a feasible concept, but so was star wars; the hurdles are just a little higher than the optimists would like to think.

few hurdles are insurmountable
given the will to accomplish.
technology grows by leaps and bounds,
and nothing would ever get done
if we didn't try.
which requires we assume that
success is possible, even likely.
i think the fact that NASA has picked up
on the concept shows a lot of people think
the engineering problem will be solved.
btw i did say 'molecular' so i thought i'd covered
the smallness issue but nano-tube is good too.

[Hippie3]

Even if they find a way to spin them together like some kind of space age hemp, the financial hurdles are incredible-the stuff is absurdly expensive(from what I saw online anywhere from 50 to 1000 bucks a gram depending on what kind of tubes yur looking for [multiwall, single wall ect.]) and thats just the quality that they sell to colleges or whoever for research, they're only claiming 50-75% nanotubes in their product, the rest is amorphus carbon-graphite essentially

a mere pittance compared to what was spent
on the appolo project or the shuttle fleet.
solve the engineering problem
and money will not be a problem.

[vrooota]

"And you will come to find
That we are all one mind
capable of all imagined and all conceivable"
-Maynard Keenan of Tool
I bet you'd like that song hip- its one of my fav trippin songs

[Hippie3]

i dig some Tool,
unfamiliar with those lyrics tho'.

Originally Posted by Hippie3

umm,
because that was a cartoon ?
the air traffic control nightmare of millions of folks flying around urban areas
is not something i'd relish.

but on the power aspect and orbital space-
entertain for a moment
this possibility.
facts-
1. the earth is moving, spinning on it's axis.
2. the earth generates a magnetic field.
3. a metallic wire moving thru a magnetic field generates an electrical current.

given that,
one could for example
use this space elevator to create a network/mesh of wires in orbit
that would generate essentially 'free' electricity
simply by moving in orbit around the earth.

Many times I've given thought to the whole "wire in space" to generate electricity, and I've never found a feasible means of doing it. Being that I am an electrical engineer in power systems, this problem has always intriuged me. The problems with such an idea are thus:
1) The amount of current you get out of a generator (a generators "rating") is dependent on construction and cooling. Basically, the bigger the diameter (or "thickness") of the wire that make up the coil, OR the more you can coil the wire, the more amps you can get out of it. This is why there are generator capability curves, or "D" curves, so named for the "D" shape of the curve.
2) In space, the is no cooling medium other than infrared radiation, which I do not believe would be sufficient to cool the coil
3) The transmission of power would also be problematic. The frequency would be very low, nearly DC, depending on whether or not we put the coil in orbital rotation opposite the direction the earth spins. But to get 60Hz, the earth would have to rotate 60 revolutions per minute (or the coil would have to spin around the earth that fast). That's pretty damned fast!
4) Transmitting the power to the surface of the planet would be dangerous. It's possible to send the power as microwaves, or some other radio frequency, but the power losses would be huge, no matter how tight you made the radio beam.
5) In order for a current to be induced in the orbital wire, the wire must be relatively stationary compared to the planet. There would be issues of maintaining orbit, with constant corrections to compensate for the orbital decay, especially at the poles. The basic idea of being in orbit is that the ship/satellite/whatever is essentially continuously "falling" around the planet. Since the planet is curved, the "falling" object never reaches the ground. However, truly orbiting objects do see a decay in their orbiting and the have to correct there path with thrusters (compressed gas). The problem with the orbital wire is that, at the poles, the cable would not be in an orbital path. The force vectors from the planet's gravity would cause the wire over the poles to drop like rocks. And of course, the cable can not be placed around the planet's equator since the magnetic field must be orthogonal to the coil.

So, those are just a few of the problems that I've run up against in trying to think out the problem of an orbital power generator.
Our best bet, for the immediate and somewhat distance future is to fully develop nuclear power. Two problems are solved with nukes:
1) abundant energy with zero greenhouse gas or particulate emmissions.
2) if placed along the coasts, an abundant fresh water supply would be had from the nukes using seawater instead of freshwater for the generation. The desalinated water could be bottled or piped inland for use.

The problems faced that have caused nukes to not be built are from the "eco-freaks" who do not understand how nuclear power works and only think of the three things when nukes are mentioned 1)Chernobyl 2) Three Mile Island 3) thermo-nuclear bombs. They do not think "clean abundant power" or "no CO2, NOx, CO, etc. emmissions". And as a result of such thinking, the cost to obtain the permits to build nuclear power plants to cost restrictive. If you run the financial forcasts, the cost to build the plant is so high, you never see a return on the investment.
This way of thinking has got to stop. We do more damage to the land, water, and air by mining coal, drilling for oil, and burning the fossil fuels now than we ever would by going nuclear.

But perhaps until we get rid of most religions, which cause so much hatred between human beings, we will never see the day when we can use nuclear power so readily, without worrying about some religious fanatic stealing the fuel rods and making a bomb....I hope I live long enough to see that day...

Hip-I mis-spoke regarding renewable energy. I misremembered the stats. Correction - if we covered the entire US with solar panels, with today's level of efficiency, only about 20% of US demand would be met. Yes, far far difference from my previous statement. Thanks for questioning me on that.

[omnibot]

Interesting thread. As chance would have it I've been working in a fusion research lab for a little while now. At this point the question is not if, but when. Practical fusion energy is still a long ways off, but we are getting closer and making steady progress. The Department of Energy is pouring money into fusion research. When we succeed, fusion will be in a way the holy grail solution to humanity's energy needs. I'm really not too worried about the end of the fossil fuel era. As soon as fossil fuels are no longer a practical energy source, humans will put more of their energy into researching other energy-getting methods. Once the need is there, the results will quickly follow. Same thing holds for the expansion of the human race. Once our dear planet has reached its human saturation point, I predict that we will quickly put energy into finding ways to continue our expansion. As soon as things begin to get too overcrouded on Earth we will be sending shuttles off to mars. Right now the need isn't there, and we have somewhat stalled in our expansion outwards.

[omnibot]

"In order for a current to be induced in the orbital wire, the wire must be relatively stationary compared to the planet. There would be issues of maintaining orbit, with constant corrections to compensate for the orbital decay, especially at the poles. The basic idea of being in orbit is that the ship/satellite/whatever is essentially continuously "falling" around the planet. Since the planet is curved, the "falling" object never reaches the ground. However, truly orbiting objects do see a decay in their orbiting and the have to correct there path with thrusters (compressed gas)."

What if the coil were orbiting lengthwise? spinning like you spin a ring on your finger. Would that work? Also, what causes orbit decay?

[Hippie3]

so-called 'orbital decay' isn't nearly the problem he portrays,
once the satellite is above the atmosphere of earth.
and i doubt that 'cooling' is much of a problem either,
kinda surprising that an 'engineer' would not think
of any way to make use of extra heat,
such as using it to heat a liquid that could drive a turbine for power
or help keep that orbit right ?
but the scheme i mention isn't my idea,
it's the brainchild of many scientists and engineers far more
knowledgeable than i, and proly you too.

[Hippie3]

The problem with the orbital wire is that, at the poles, the cable would not be in an orbital path. The force vectors from the planet's gravity would cause the wire over the poles to drop like rocks

one can orbit over the poles,
circumpolar orbits are not all that uncommon.
gravity acts just the same
so what are you on about here ?

[Hippie3]

(or the coil would have to spin around the earth that fast).

the coil could spin on it's own axis at many rpm,
assuming it's built strongly enough to hold itself together,
not a real problem.

[omnibot]

"gravity acts just the same
so what are you on about here ?"

the coil would have to be spinning lengthwise or the coil at the axis points won't have any inertia and will tend to dip towards the earth. I think that's what he's saying.

[Hippie3]

if that is indeed his thinking,
then i'm afraid it don't understand.
objects 'orbit' because of the balance
between their velocity/momentum
and the pull of the earth.
the orientation of the satellite with respect to the earth is irrelevant to that
calculation.
of course gravity is slightly higher at the equator
meaning the orbit will be slightly elliptical
but the inertia of the satellite
would not be diminished by any rotation on it's own axis.
so i still don't see the point,
unless he's talking about magnetic lines of force at the pole
but i'm afraid i'm no engineer nor a rocket-scientist
so i'll have to defer to the guys
at nasa who apparently think it could work if only
we could lift the payloads to orbit economically.

[omnibot]

"objects 'orbit' because of the balance
between their velocity/momentum
and the pull of the earth."

exactly, so at the axis points of a spinning ring there is only rotational intertia, no momentum to keep it from falling towards the earth. If the coil is spinning like a bicycle tire around though, there would be no problem.

"the orientation of the satellite with respect to the earth is irrelevant to that
calculation."

on a tangent...
In my mind I have always interpreted this as meaning that there is absolute direction in our universe even though velocity and position are relative. If we wanted to we could set forth a north, south, east, west, up, and down in the universe, and those directions would always hold true. If we once set down directional coordinates, we would be able to refind those coordinates without any reference points, using only calculations of original position, angular velocity, rotational inertia, etc.

[Hippie3]

at the axis points of a spinning ring there is only rotational intertia, no momentum to keep it from falling towards the earth

i don't see that,
an object can move on more than one vector,
the spinning motion does not eliminate
the outward vector provided by the launch vehicle.
a space station shapped like a donut
and oriented so that the hole was parallel to the earth,
making the ring motion bottom out
will not be drawn down to the earth
as the inertia of the lower portion of the ring
is balanced by the inertia of the upper portion,
so centrifugal forces are net zero.

[omnibot]

I think I have been holding a different image of this contraption than you. I've been imagining a coil stretching all the way around the earth, either spinning like a bicycle tire, or spinning about an axis through two points on the coil. If that were the case then the coil at the axis points would not have any orbital motion and would tend to dip towards the earth, no?

Seems you were thinking of a much smaller coil orbiting the earth.

[Hippie3]

indeed i was.
a coil stretching all the way around would be a staggering task
and there's no reason to go to such lengths.
no, i was thinking more like a bundle of wires spinning fast on its own axis as it revolved around the earth.

The problem of the orbiting power coil. Yes, Omni, the coil would have to rotate orthogonally to the magnetic field, it couldn't spin like a ring on the finger. Think of a gyroscope, where the inner metal piece is spinning. Imagine if a globe were afixed to that inner spinning piece. That would represent the Earth. The coil would be the outer ring that runs longitudinally (from north to south) around the globe. That coil would have a current induced in it and the speed of the rotation relative to earth would determine the frequency of current/voltage induced. If the coil spun like the ring on a finger, no current would be induced. The coil has to "cut" through (or across) the magnetic field. The problem of the orbiting coil over the poles is that over the poles, the coil would not have the velocity needed (in a tangential direction to the orbital path) to keep it from falling, whereas the part of the coil at the equator would have the maximum velocity seen on the coil. It is the tangential velocity that allows objects to stay in orbit. When the tangential velocity drops (due to friction or any other opposing force), the object sees a decay in its orbital path. This still works for objects in geosynchronous orbit (i.e. satellites that hold their position over Iran to take photos). Objects in geosynchronous orbit still have the tangential velocity needed to keep them in orbit, even though relative to the earth's surface, they are not moving. This is not contradictory to the coil over the poles because those areas would have no velocity as they would be spinning in place. Think of the system as viewed by a man on the moon. He sees the earth spinning and he sees satellites spinning around the globe. Even the ones in geosynch. orbit have velocity, relative to his position. But when he sees the area of the coils over the poles, he sees that they have no velocity. While parts of the coil that were closest to the equator would be fine, the part over the poles would not be. They would have basically zero tangential velocity and they would therefore tend to fall inward towards the surface of the planet.

Hip - It's easy to say "do something with the heat". But you have to remember that in a thermodynamic system, there must be a source and a sink for the heat for any work to be done. Where is the heat sink in space? The orbiting coil would generate massive amounts of heat, but where can it go? Only infrared radiation can transmit heat in space, but that would not be sufficient to cool the coil (although I admit I have not worked any calculations on that). And you cannot simply say "run a turbine with it" because again, there is no heat sink. A turbine is run with steam that moves from the source (the boiler) to the sink (the condenser). I suppose a condenser of some type could be built in space, but I have not thought of one (yet!).
You did say something that I'll have to give more thought to, that being a smaller coil rotating in one spot (relatively speaking) in earth's orbit. The problem I think (and I'm shooting from the hip (no pun intended!), I'll have to look at the math when I get a chance) that would occur is the area of the field you would be cutting. In other words, since you would be in a small section of the overall magnetic field, I'm not certain that you could get an induced voltage/current on the coil. If you use the right hand rule on two opposite sides of the coil, I think they would cancel each other and result in no voltage/current being induced. But again, I'll have to check the math and induction machine theory on this point.

Omni - I absolutely agree with you regarding fusion and fossil fuels. The day will come when we finally make fusion power a practical and reliable energy source. Have you ever given thought to the impacts that near-free energy will have on every culture and society on the planet? I mean, talk about having more leisure time! With advances in robotics, mankind would be freed from having to perform manual labor tasks. I'm not sure that we as a species are ready for that kind of leisure time. We tend to get in to all manner of trouble when we have nothing to do! "Hey, hold my beer and watch this!" -- famous last words of the Redneck!

References: Physics for Scientists and Engineers, Vol. 1, 3rd ed. by Raymond A. Serway
Electric Machinery Fundamentals, 3rd ed. by Stephen J. Chapman

[Hippie3]

Hip - It's easy to say "do something with the heat". But you have to remember that in a thermodynamic system, there must be a source and a sink for the heat for any work to be done. Where is the heat sink in space? The orbiting coil would generate massive amounts of heat, but where can it go? Only infrared radiation can transmit heat in space, but that would not be sufficient to cool the coil (although I admit I have not worked any calculations on that). And you cannot simply say "run a turbine with it" because again, there is no heat sink. A turbine is run with steam that moves from the source (the boiler) to the sink (the condenser). I suppose a condenser of some type could be built in space, but I have not thought of one (yet!).

well
i'm no rocket scientist
but it seems to me that
one could use that steam
after it's run thru the turbine
as propellant
in effect venting it
and the heat energy it carries
into space.
one might even run it thru
a onboard nuclear reator
so it ionized into plasma
then dump it out a vent
one could fire it in opposition
so to cancel out any inertia
one would then bring more water/whatever as needed

[Hippie3]

a smaller coil rotating in one spot (relatively speaking) in earth's orbit. The problem I think (and I'm shooting from the hip (no pun intended!), I'll have to look at the math when I get a chance) that would occur is the area of the field you would be cutting. In other words, since you would be in a small section of the overall magnetic field, I'm not certain that you could get an induced voltage/current on the coil

the source i last read indicated that a matrix as large as a few/several miles
in diameter might be needed to get useful amounts of current
still that's less daunting than a ring around the planet.

btw
the matrix would not necessarily be in geosynchronous orbit,
it'd cut thru more lines of force if it was in a fast low orbit
wouldn't it ?

[taoistshredder]

Every new post that has come up in here, I've come to read,
but as you can see I haven't posted in a while.
That's because I have this look of Bushian bewilderment
each time I visit, like a deer-in-the-headlights
"I have no idea what's going on" {said in towlie voice}
You guys are hard-core, we should lock ya'll in a room in NASA,
feed you shrooms and see what else you can come up with.

[Hippie3]

The day will come when we finally make fusion power a practical and reliable energy source. Have you ever given thought to the impacts that near-free energy will have on every culture and society on the planet? I mean, talk about having more leisure time! With advances in robotics, mankind would be freed from having to perform manual labor tasks. I'm not sure that we as a species are ready for that kind of leisure time. We tend to get in to all manner of trouble when we have nothing to do! "Hey, hold my beer and watch this!" -- famous last words of the Redneck!

i don't think it'll ever be free,
that's just not how the system works.

[Lefty]

Automation has & will continue to replace an awful lot of rednecks in the labor force. Then they can't support themselves, and further burden "society". Progress at a price as always...

[omnibot]

"i don't think it'll ever be free,
that's just not how the system works."

At first fusion energy would probably be quite expensive. But there would be a hell of a lot of it. Enough to fill anyone and everyone's needs. As technology progressed the price tag would go down.

[Hippie3]

. As technology progressed the price tag would go down.

then why do modern cars cost so much more than old ones ???

Originally Posted by Hippie3

the source i last read indicated that a matrix as large as a few/several miles
in diameter might be needed to get useful amounts o