Trains and planes both have very efficient engines, and expend almost all their thrust overcoming air resistance. Trains also lose a little in rolling resistance and some to turbulence because they are close to the ground. Planes move faster, and must waste some thrust on lift, but travel through less dense air. Trains have denser air at slower speeds, and can pull more people behind one front cross-section (in other words they are longer). Cars are way less efficient in all respects, but move much more slowly.
Even disregarding the details of the California regime there are factors that make electricity an
area where standard market forces don't work well:
1. at the end user level it is a natural monopoly. Few houses or even factories have more than one incoming power cable, so whoever owns that or the equipment upstream has to be regulated in some way.
2. electricity is (almost) impossible to store on this scale, so the supply and demand have to balance second by second.
3. new capacity takes a very long time to plan and build (even disregarding regulatory issues)
4. The costs to the user of a supply interruption
are huge.
I'm really astonished at New Scientist giving this one house room.
From the article, it appears simply to be a high-tech version of the trick where you can propel yourself forward in a boat, or on some kind of wheeled cart, by moving slowly in one direction and then quickly in the other. The slow movement is not sufficient to overcome static friction, and nothing moves, while the rapid "jolt" does overcome friction and the boat or cart moves.
In other words, the whole effect depends on friction, and would not work in space. This is one of the oldest and commonest kinds of erroneous or fake perpetual motion or reactionless propulsion systems.
Actually I thought it was interesting how slow the P4 was EVEN WITH these optimizations. On most of the scores it only narrowly beat the 1GHz Athlon, so would probably have narrowly lost to the 1.2GHz version.
It really does appear that we're going to have to wait for Northwood and the new socket, and/or see whether Intel can ramp up the clock speed faster than AMD can before the P4 will offer much.
Costs to land something are far lower than costs to launch it. If you want to land lumps of asteroidal iron, nickel or gold, you just sculpt it into a vaguely aerodynamic shape, attach some small steering rockets and a simple electronics package and point it into the atmosphere aimed at your favourite desert. Atmospheric braking would get it down to a few times the speed of sound, at which speed it should stay mostly in one piece as it comes in, and then you just drive out to the middle of the crater and start carving.
Offshore stations do have an impact on the shoreline "behind" them. You would not want to put too many of them off one stretch of environmentally sensitive coastline. Still, there's lots of coastline, much of it already developed.
It's rewritable, although it might be like flash RAM, where you have to zero it in quite large chunks. To erase an area, you warm it with a laser until the surface flows, and surface tension flattens out all the little scratches which mark the bits.
As far as I know, you can do this as often as you like.
It isn't as slow as it sounds, because the areas involved, and the amounts and distances flowing are so tiny.
I don't see why it should be especially over-sensitive. The pins would be suspended over a rotating disk, just as a magnetic head is now, and held at constant (small) altitude by a feedback loop and a piezo. The feedback loop is also the sensor. I imagine the feedback loop would be running at hundreds of KHz or even a few MHz, so most external shocks would be so slow that the signal processing software wouldn't even see them.
Basically, the heads are so small and working so fast, that external movement will no more disrupt them than a gently rocking ship disrupts your eye-tracking when you read a book.
The control and sensing electronics would be susceptible to interference just as a current magnetic devices are, but shielding is easy.
Writing is also safe enough. Think of using a pen on shipboard (not in a gale).
Actually I suspect it will be fine. At any visible scale, there will be just one head, flying over the disk in the normal way. At a microscopic scale, the head has a comb with 1024 tiny tines. Each tine is constantly adjusted to remain at a fixed height over the disk, by an individual feedback loop, and a piezo-electric actuator (a crystal that stretches or shrinks under electrical control). There are NO moving parts in the usual sense, just a few that stretch or bend. By reading off the activity in the feedback loop, and a fair bit of signal processing, the exact shape of the underlying surface can be read. In laboratory AFMs this is to literally atomic precision. I imagine the AFM disk would sacrifice a little of this for robustness.
Writing is accomplished by pushing the tine down a little further and scratching the (plastic) surface. Re-writing by heating a small area slightly with a laser so that it softens and surface tension flattens it.
Actually this has been proposed, at least by SF writers, and more for Jupiter's moons (or for Mars) than for Titan, but the idea is the same.
A body without (much) internal heat anywhere in the Solar System is heated by solar radiation, which is mainly visible light. In equilibrium it re-radiates that energy mainly as infrared (the colder it is, the longer the wavelength). If you can surround it with something that is transparent to visible light, but opaque, or reflective, to infrared, then it can;t radiate the heat away and gets hotter. CO2 has such properties to a modest extent. Various rather exotic gasses much more so. It has been computed that adding 1 part per million of some of these gasses to Mars's atmosphere would warm the equator of Mars to the temperatures of the arctic on Earth.
Titan would be a much bigger problem, and it might be more efficient to use some more direct heating method, but the greenhouse effect has its part to play.
The nature of gamma rays is rather well understood -- they are simply electromagnetic waves of very short wavelength.
The nature of gamma ray bursters is much less well understood. Assuming that they are as far away as we think, and that they are emmitting their enegergy more or less in all directions, not beaming it at us, then they are VERY energetic! Each GRB during its burst is brighter than the whole of a normal galaxy
This battery technology has high power/weight and mediocre energy/weight. To me that sounds ideal for applications where you have a steady low-power energy source and want short bursts of much higher power from time to time. Where is this, we ask:
1. Small planetary exploration robots: charge slowly off the solar cells, then use a burst of power to move/dig/analyze/transmit, then go back to sleep and recharge.
2. Similar story for remote sensing -- run the sensors and slowly charge the battery of a small solar cell, then use a burst of power to run the radio transmitter and report
Your options for storing hydrogen are basically four:
1. as a gas under high pressure. This requires a rather sttong, and so heavy tank, and the pressure translates into quite a lot of energy when its released, so there is potential for the tank to explode, or rocket out of the wreck of the car. Also, if all the hydrogen vented suddenly, mixed with some air and then got a spark, you could have a fairly serious flash-over.
2. as a liquid at very low temperatures (possibly combined with moderate pressure). Now your tank needs to be a vacuum flask and your car will slowly vent hydrogen when it's not being driven. If the hydrogen spills it will freeze anything it hits (you for instance) and boil off very rapidly (very low specific heat) leading to an explosion hazard nearly as bad as 1.
3. adsorbed onto a surface,usually under moderate pressure. Metals dusts are one of the best choices of surface, but there might be others. This is attractive if the hydrogen/metal weight ratio can be controlled, and if a reasonably large proportion of the gas can be recovered without too big a variation in the pressure.
4. In chemical combination with something. You can, I think, make methane (and water) from carbon dioxide, hydrogen and possibly some energy. Burning the methane (in a fuel cell or a flame) yields carbon dioxide and water. The net effect is hydrogen + oxygen -> water, with the carbon being recycled. In this model, your power station makes methane (and oxygen) from water, atmospheric CO2 and energy, and your car burns the methane with atmospheric oxygen. If this could be made efficient enough it's quite nice. Similar cycles could probably be concocted using methanol as the "hydrogen carrier".
To me 1 & 2 are really not attractive for cars, although enough engineering might make them workable. 3 & 4 are much more appealing if they can be made efficient.
I imagine a big part of it was not the computer technology, which is indeed, not really cutting edge any more, but the cryptanalytic methodology, which is much slower to change. Computers now can search 10^9 cases per second (say) now insteaqd of 10^3 then, but the analysis of operation procedure, message formats, procedural errors, etc. that gets you down to this many cases probably dates much less quickly.
A few years ago there was a landmark action. The first files relating to UK covert foreign intelligence work (spying) EVER were declassified. They turned out to relate almost exclusively to the Napoleonic wars. I believe they are considering declassifying some Crimean and Boer war material sometime this century.
This is rubbish. It may not work economically, but optically, the following setup works:
At the top, a large (say 10m x 6m elliptical) optically flat mirror, mounted steerably. This reflects light from the chosen area of the sky, so that it comes straight down the barrel of the LMT.
Next a small flat secondary mirror, say 1m x 50cm elliptical, suspended above the LMT, on its axis, just below the focal point, tilted permanently at 45degree. The back of this mirror, and it's mount need to be very black. This mirror moves the focal point of the LMT (where you want to put your cameras, etc.) off to one side, out of the way.
Optically this works, and you replace the problem of steering a parabolic glass mirror, with the problem of steering a rather large optical flat. The latter problem is certainly easier (ie cheaper) but I'm not sure how much cheaper.
The details of even the proposed pathfinder mission (I can't find any details for the main mission) are fairly mind-blowing. The pathfinder is effictively an X-ray telescope with a 450km (300 mile) focal length. This is two spacecraft flown in formation at this distance with their relative positions and angles controlled and sensed to hideous precision.
Of course pointing the telescope at a new target takes a while.
I think this could work, but it has to be done sensibly. In the UK we have specialist family courts, and various kinds of specialist commercial courts. The judges are still judges, meeting theusual criteria for the job, but, since they work in the specialized courts, they build up a general background knowledge in their area.
A tech court judge would not be expected to know everything about every topic they would be called upon to judge, but they would be in a better starting position to understand when one or other side tried to explain the technical background of their argument. The tech courts might also have special rules or procedures, for example allowing the court to appoint neutral expert assessors, or allowing more streamlined procedures for complex technical submissions. They would also be an expert on the most relevant areas of the law
Could be worth trying, but needs to be done sensibly.
Basically you have two ingredients (muonic tritium and a deuterium nucleus) and you need to bring them together very carefully with exactly the right sized bump. If you do then, with luck, they go bang, producing an enegetic alpha particle, an energetic neutron and an energetic muon. You would then need to
a) recover the energy from the alpha particle
b) use the neutron to breed more tritium (lithium blanket
c) catch the muon and reuse it (quite a lot of times)
Probably the way to do this is in quite high vacuum, so that you can have cold beams of uT and D atoms coming in and reacting, largely unaffected by the energetic reaction products flying outwards to be caught somewhere. The hardest part of this would be stripping the muons off the alpha particles, separating them, cooling them and recycling them quickly enough and with enough efficiency, but it might be possible.
Use the slashdot system, but don't tell people whether they have moderator status or not. Just let everyone moderate and ignore the actions of those who don't currently have the status.
One cannot prove that the universe was not created yesterday out of nothing, with all our memories and all its other internal records made consistent. On the other hand, such a theory has very little predictive power, since the next thing you look at might be the one thing that is not consistent. One cannot prove that the behaviour of gravity will not change tomorrow to cause the Earth to crash into the Sun.
Scientists always have to choose among the theories that fit the available evidence. Then they seek more evidence to test their choices. Experience leads to some "meta-theories" about which choices seem to work out better:
* simplicity -- once you have the right language (usually mathematics) then theories that derive lots of behaviours from a few simple rules seem to do well
* predictive value -- theories that don't let you make predictions about experiments not yet performed are not much use.
* mediocrity -- theories that have our location, our species or our epoch in the history of the universe as somehow special do not seem to do well
* aesthetics -- a bit of a two-edged sword, but brilliant and experienced scientists often seem to develop an effective intuition for which theories are "beautiful enough" to be true.
Anyway, returning to the question of evolution. All reasonably simple theories consistent with the biology that we observe seem to have
+ Mendelian inheritance, with minor modifications + Malthusian pressure resulting in not all juvenile creatures actually breeding + mutations
A consequence of this is the sort of evolution by natural selection that can be seen going on over short timescales in (for instance) butterflies adjusting their camouflage to smoke polution, or cod breeding at younger ages under fishing pressure.
The next question is what happens if this process goes on over geological timescales (assuming for the moment the basic theories about the age of the Earth and the basic geological processes acting). Here, you will find more divergence among theorists about details, but most surviving theories do have species emerging, diverging and dying out, matching the fossil record. Recent theories suggest this may be less gradual and more jerky than earlier theories, with processes like the isolation of small populations on islands playing a larger role.
Finally, you can ask whether processes like these have been taking place in past, and if so, how the existing range of species fit in, which brings me back to where I came in: you cannot disprove creation yesterday, or one second ago. On the other hand, teh available records, mainly fossils, but also ice cores and other things, are really quite consistent with the broad thrust of evolution.
This is my option 1. You can force a current along the wire, using up electrical power, and push the satellite up to a higher orbit. Alternatively, you can tap the electrical current induced in the wire and accept that the forces resulting will drop the satellite into a lower orbit.
There are two possible connections with "particles". One is the electrons in the tether which will be pushed up or down it. The other is the tenuous upper fringes of the atmosphere which form the return part of the current carrying loop. Electrons are sprayed out of one end of the tether and gathered in at the other by specially designed electrodes.
Just to clarify a bit. There are a few different things you can do with tethers once you've mastered the art of winding and unwinding them, building tethers resistant to single-point breakage, and so on.
1. Trade off electrical power for orbital altitude. You can do this either way, running as either a motor or a dynamo.
2. Dangle an object in the upper fringes of the atmosphere. This is an area which is normally hard to study, as you can't stay in orbit long, but it's too high to fly a plane or balloon. A big orbitting spacecraft dangling a small instrument package on a tether can be a useful combination.
3. Rotating tethers can be used to tranfer orbital momentum between different satellites in various possibly useful ways. The most extreme case has one end of the tether actually touching the ground (with no horizontal velocity) every rotation. You just grab hold and get lifted up into orbit, or even launched out of Earth orbit -- of course you have to land enough matter to keep the tether spinning.
4. stabilization. Even quite a short (100m) tether will be stabilized by Earth's tidal forces and can be used to keep a satellite pointed in a certain way
Actually this is a perfectly sensible and serious theory, which has been around for 10 or 15 years, in various guises, it has just suffered from abbrevation and simplification.
Regarding the comparisons, if you take any fundamental particle in the universe which actually has both mass and charge and place an identical particle at rest 1m away from it, the electrostatic force between them exceeds the gravitational by many orders of magnitude. If you want a theory that explains both electromagnetism and gravity as aspects of the same thing (which is generally considered desirable) then it has to explain this huge discrepancy.
Regarding the dimensions, imagine a 1mm^2 two-dimensional creature living on the outer surface of a garden hose. It has two very different dimensions: along, which is practically infinite (althoiugh explorers may claim to have reached the mythical "tap" and "spout") and around, in which you can go only a few dozen body-lengths before you get back to your starting point.
Actually an even closer analogy would be to imagine creatures living on the hose big enough to actually wrap round it in places. Fundamental particles are supposed to be entangled with the extra dimensions in this way.
Slashdot Mirror
Trains and planes both have very efficient engines, and expend almost all their thrust overcoming air resistance. Trains also lose a little in rolling resistance and some to turbulence because they are close to the ground. Planes move faster, and must waste some thrust on lift, but travel through less dense air. Trains have denser air at slower speeds, and can pull more people behind one front cross-section (in other words they are longer). Cars are way less efficient in all respects, but move much more slowly.
Even disregarding the details of the California regime there are factors that make electricity an
area where standard market forces don't work well:
1. at the end user level it is a natural monopoly. Few houses or even factories have more than one incoming power cable, so whoever owns that or the equipment upstream has to be regulated in some way.
2. electricity is (almost) impossible to store on this scale, so the supply and demand have to balance second by second.
3. new capacity takes a very long time to plan and build (even disregarding regulatory issues)
4. The costs to the user of a supply interruption
are huge.
I'm really astonished at New Scientist giving this one house room.
From the article, it appears simply to be a high-tech version of the trick where you can propel yourself forward in a boat, or on some kind of wheeled cart, by moving slowly in one direction and then quickly in the other. The slow movement is not sufficient to overcome static friction, and nothing moves, while the rapid "jolt" does overcome friction and the boat or cart moves.
In other words, the whole effect depends on friction, and would not work in space. This is one of the oldest and commonest kinds of erroneous or fake perpetual motion or reactionless propulsion systems.
Steve Linton
Actually I thought it was interesting how slow the P4 was EVEN WITH these optimizations. On most of the scores it only narrowly beat the 1GHz Athlon, so would probably have narrowly lost to the 1.2GHz version.
It really does appear that we're going to have to wait for Northwood and the new socket, and/or see whether Intel can ramp up the clock speed faster than AMD can before the P4 will offer much.
Costs to land something are far lower than costs to launch it. If you want to land lumps of asteroidal iron, nickel or gold, you just sculpt it into a vaguely aerodynamic shape, attach some small steering rockets and a simple electronics package and point it into the atmosphere aimed at your favourite desert. Atmospheric braking would get it down to a few times the speed of sound, at which speed it should stay mostly in one piece as it comes in, and then you just drive out to the middle of the crater and start carving.
Offshore stations do have an impact on the shoreline "behind" them. You would not want to put too many of them off one stretch of environmentally sensitive coastline. Still, there's lots of coastline, much of it already developed.
It's rewritable, although it might be like flash RAM, where you have to zero it in quite large chunks. To erase an area, you warm it with a laser until the surface flows, and surface tension flattens out all the little scratches which mark the bits.
As far as I know, you can do this as often as you like.
It isn't as slow as it sounds, because the areas involved, and the amounts and distances flowing are so tiny.
I don't see why it should be especially over-sensitive. The pins would be suspended over a rotating disk, just as a magnetic head is now, and held at constant (small) altitude by a feedback loop and a piezo. The feedback loop is also the sensor. I imagine the feedback loop would be running at hundreds of KHz or even a few MHz, so most external shocks would be so slow that the signal processing software wouldn't even see them.
Basically, the heads are so small and working so fast, that external movement will no more disrupt them than a gently rocking ship disrupts your eye-tracking when you read a book.
The control and sensing electronics would be susceptible to interference just as a current magnetic devices are, but shielding is easy.
Writing is also safe enough. Think of using a pen on shipboard (not in a gale).
Steve
Actually I suspect it will be fine. At any visible scale, there will be just one head, flying over the disk in the normal way. At a microscopic scale, the head has a comb with 1024 tiny tines. Each tine is constantly adjusted to remain at a fixed height over the disk, by an individual feedback loop, and a piezo-electric actuator (a crystal that stretches or shrinks under electrical control). There are NO moving parts in the usual sense, just a few that stretch or bend. By reading off the activity in the feedback loop, and a fair bit of signal processing, the exact shape of the underlying surface can be read. In laboratory AFMs this is to literally atomic precision. I imagine the AFM disk would sacrifice a little of this for robustness.
Writing is accomplished by pushing the tine down a little further and scratching the (plastic) surface. Re-writing by heating a small area slightly with a laser so that it softens and surface tension flattens it.
Steve
Actually this has been proposed, at least by SF writers, and more for Jupiter's moons (or for Mars) than for Titan, but the idea is the same.
A body without (much) internal heat anywhere in the Solar System is heated by solar radiation, which is mainly visible light. In equilibrium it re-radiates that energy mainly as infrared (the colder it is, the longer the wavelength). If you can surround it with something that is transparent to visible light, but opaque, or reflective, to infrared, then it can;t radiate the heat away and gets hotter. CO2 has such properties to a modest extent. Various rather exotic gasses much more so. It has been computed that adding 1 part per million of some of these gasses to Mars's atmosphere would warm the equator of Mars to the temperatures of the arctic on Earth.
Titan would be a much bigger problem, and it might be more efficient to use some more direct heating method, but the greenhouse effect has its part to play.
The nature of gamma rays is rather well understood -- they are simply electromagnetic waves of very short wavelength.
The nature of gamma ray bursters is much less well understood. Assuming that they are as far away as we think, and that they are emmitting their enegergy more or less in all directions, not beaming it at us, then they are VERY energetic! Each GRB during its burst is brighter than the whole of a normal galaxy
This battery technology has high power/weight and mediocre energy/weight. To me that sounds ideal for applications where you have a steady low-power energy source and want short bursts of much higher power from time to time. Where is this, we ask:
1. Small planetary exploration robots: charge slowly off the solar cells, then use a burst of power to move/dig/analyze/transmit, then go back to sleep and recharge.
2. Similar story for remote sensing -- run the sensors and slowly charge the battery of a small solar cell, then use a burst of power to run the radio transmitter and report
Steve
Your options for storing hydrogen are basically four:
1. as a gas under high pressure. This requires a rather sttong, and so heavy tank, and the pressure translates into quite a lot of energy when its released, so there is potential for the tank to explode, or rocket out of the wreck of the car. Also, if all the hydrogen vented suddenly, mixed with some air and then got a spark, you could have a fairly serious flash-over.
2. as a liquid at very low temperatures (possibly combined with moderate pressure). Now your tank needs to be a vacuum flask and your car will slowly vent hydrogen when it's not being driven. If the hydrogen spills it will freeze anything it hits (you for instance) and boil off very rapidly (very low specific heat) leading to an explosion hazard nearly as bad as 1.
3. adsorbed onto a surface,usually under moderate pressure. Metals dusts are one of the best choices of surface, but there might be others. This is attractive if the hydrogen/metal weight ratio can be controlled, and if a reasonably large proportion of the gas can be recovered without too big a variation in the pressure.
4. In chemical combination with something. You can, I think, make methane (and water) from carbon dioxide, hydrogen and possibly some energy. Burning the methane (in a fuel cell or a flame) yields carbon dioxide and water. The net effect is hydrogen + oxygen -> water, with the carbon being recycled. In this model, your power station makes methane (and oxygen) from water, atmospheric CO2 and energy, and your car burns the methane with atmospheric oxygen. If this could be made efficient enough it's quite nice. Similar cycles could probably be concocted using methanol as the "hydrogen carrier".
To me 1 & 2 are really not attractive for cars, although enough engineering might make them workable. 3 & 4 are much more appealing if they can be made efficient.
I imagine a big part of it was not the computer technology, which is indeed, not really cutting edge any more, but the cryptanalytic methodology, which is much slower to change. Computers now can search 10^9 cases per second (say) now insteaqd of 10^3 then, but the analysis of operation procedure, message formats, procedural errors, etc. that gets you down to this many cases probably dates much less quickly.
A few years ago there was a landmark action. The first files relating to UK covert foreign intelligence work (spying) EVER were declassified. They turned out to relate almost exclusively to the Napoleonic wars. I believe they are considering declassifying some Crimean and Boer war material sometime this century.
The problem is that it needs different data structures, and possibly the different algorithms would actually need different interfaces.
This is rubbish. It may not work economically, but optically, the following setup works:
At the top, a large (say 10m x 6m elliptical) optically flat mirror, mounted steerably. This reflects light from the chosen area of the sky, so that it comes straight down the barrel of the LMT.
Next a small flat secondary mirror, say 1m x 50cm elliptical, suspended above the LMT, on its axis, just below the focal point, tilted permanently at 45degree. The back of this mirror, and it's mount need to be very black. This mirror moves the focal point of the LMT (where you want to put your cameras, etc.) off to one side, out of the way.
Optically this works, and you replace the problem of steering a parabolic glass mirror, with the problem of steering a rather large optical flat. The latter problem is certainly easier (ie cheaper) but I'm not sure how much cheaper.
Finally the LMT.
The details of even the proposed pathfinder mission (I can't find any details for the main mission) are fairly mind-blowing. The pathfinder is effictively an X-ray telescope with a 450km (300 mile) focal length. This is two spacecraft flown in formation at this distance with their relative positions and angles controlled and sensed to hideous precision.
Of course pointing the telescope at a new target takes a while.
I think this could work, but it has to be done sensibly. In the UK we have specialist family courts, and various kinds of specialist commercial courts. The judges are still judges, meeting theusual criteria for the job, but, since they work in the specialized courts, they build up a general background knowledge in their area.
A tech court judge would not be expected to know everything about every topic they would be called upon to judge, but they would be in a better starting position to understand when one or other side tried to explain the technical background of their argument. The tech courts might also have special rules or procedures, for example allowing the court to appoint neutral expert assessors, or allowing more streamlined procedures for complex technical submissions. They would also be an expert on the most relevant areas of the law
Could be worth trying, but needs to be done sensibly.
Basically you have two ingredients (muonic tritium and a deuterium nucleus) and you need to bring them together very carefully with exactly the right sized bump. If you do then, with luck, they go bang, producing an enegetic alpha particle, an energetic neutron and an energetic muon. You would then need to
a) recover the energy from the alpha particle
b) use the neutron to breed more tritium (lithium blanket
c) catch the muon and reuse it (quite a lot of times)
Probably the way to do this is in quite high vacuum, so that you can have cold beams of uT and D atoms coming in and reacting, largely unaffected by the energetic reaction products flying outwards to be caught somewhere. The hardest part of this would be stripping the muons off the alpha particles, separating them, cooling them and recycling them quickly enough and with enough efficiency, but it might be possible.
Use the slashdot system, but don't tell people whether they have moderator status or not. Just let everyone moderate and ignore the actions of those who don't currently have the status.
One cannot prove that the universe was not created yesterday out of nothing, with all our memories and all its other internal records made consistent. On the other hand, such a theory has very little predictive power, since the next thing you look at might be the one thing that is not consistent. One cannot prove that the behaviour of gravity will not change tomorrow to cause the Earth to crash into the Sun.
Scientists always have to choose among the theories that fit the available evidence. Then they seek more evidence to test their choices. Experience leads to some "meta-theories" about which choices seem to work out better:
* simplicity -- once you have the right language (usually mathematics) then theories that derive lots of behaviours from a few simple rules seem to do well
* predictive value -- theories that don't let you make predictions about experiments not yet performed are not much use.
* mediocrity -- theories that have our location, our species or our epoch in the history of the universe as somehow special do not seem to do well
* aesthetics -- a bit of a two-edged sword, but brilliant and experienced scientists often seem to develop an effective intuition for which theories are "beautiful enough" to be true.
Anyway, returning to the question of evolution. All reasonably simple theories consistent with the biology that we observe seem to have
+ Mendelian inheritance, with minor modifications
+ Malthusian pressure resulting in not all
juvenile creatures actually breeding
+ mutations
A consequence of this is the sort of evolution by natural selection that can be seen going on over short timescales in (for instance) butterflies adjusting their camouflage to smoke polution, or cod breeding at younger ages under fishing pressure.
The next question is what happens if this process goes on over geological timescales (assuming for the moment the basic theories about the age of the Earth and the basic geological processes acting). Here, you will find more divergence among theorists about details, but most surviving theories do have species emerging, diverging and dying out, matching the fossil record. Recent theories suggest this may be less gradual and more jerky than earlier theories, with processes like the isolation of small populations on islands playing a larger role.
Finally, you can ask whether processes like these have been taking place in past, and if so, how the existing range of species fit in, which brings me back to where I came in: you cannot disprove creation yesterday, or one second ago. On the other hand, teh available records, mainly fossils, but also ice cores and other things, are really quite consistent with the broad thrust of evolution.
This is my option 1. You can force a current along the wire, using up electrical power, and push the satellite up to a higher orbit. Alternatively, you can tap the electrical current induced in the wire and accept that the forces resulting will drop the satellite into a lower orbit.
There are two possible connections with "particles". One is the electrons in the tether which will be pushed up or down it. The other is the tenuous upper fringes of the atmosphere which form the return part of the current carrying loop. Electrons are sprayed out of one end of the tether and gathered in at the other by specially designed electrodes.
Just to clarify a bit. There are a few different things you can do with tethers once you've mastered the art of winding and unwinding them, building tethers resistant to single-point breakage, and so on.
1. Trade off electrical power for orbital altitude. You can do this either way, running as either a motor or a dynamo.
2. Dangle an object in the upper fringes of the atmosphere. This is an area which is normally hard to study, as you can't stay in orbit long, but it's too high to fly a plane or balloon. A big orbitting spacecraft dangling a small instrument package on a tether can be a useful combination.
3. Rotating tethers can be used to tranfer orbital momentum between different satellites in various possibly useful ways. The most extreme case has one end of the tether actually touching the ground (with no horizontal velocity) every rotation. You just grab hold and get lifted up into orbit, or even launched out of Earth orbit -- of course you have to land enough matter to keep the tether spinning.
4. stabilization. Even quite a short (100m) tether will be stabilized by Earth's tidal forces and can be used to keep a satellite pointed in a certain way
Actually this is a perfectly sensible and serious theory, which has been around for 10 or 15 years, in various guises, it has just suffered from abbrevation and simplification.
Regarding the comparisons, if you take any fundamental particle in the universe which actually has both mass and charge and place an identical particle at rest 1m away from it, the electrostatic force between them exceeds the gravitational by many orders of magnitude. If you want a theory that explains both electromagnetism and gravity as aspects of the same thing (which is generally considered desirable) then it has to explain this huge discrepancy.
Regarding the dimensions, imagine a 1mm^2 two-dimensional creature living on the outer surface of a garden hose. It has two very different dimensions: along, which is practically infinite (althoiugh explorers may claim to have reached the mythical "tap" and "spout") and around, in which you can go only a few dozen body-lengths before you get back to your starting point.
Actually an even closer analogy would be to imagine creatures living on the hose big enough to actually wrap round it in places. Fundamental particles are supposed to be entangled with the extra dimensions in this way.