PhD stands for philosophiae doctor - teacher of philosophy.
The following assumes there is a limited, finite mental capacity for humans:
"Philosophers are people who know less and less about more and more, until they know nothing about everything. Scientists are people who know more and more about less and less, until they know everything about nothing." (quote from somebody smart)
Therefore PhD in science is an oxymoron. Actually, no it's not. You can both know everything about nothing, and nothing about everything, at the same time. You can have limit(x->infinity)x*1/2x+1/2x*x=1, or infinity*0+0*infinity=1, a finite number.
Yeah, from what I understand, paypal charges neither you nor the receiver any processing fee, instead they collect interest on the money while it's in their hands, for those 2-7 days between deposit and withdrawal. It doesn't become available to be withdrawn right away, unless you're posting it directly to someone else's paypal account, in which case paypal will freely toss it around internal accounts, as long as they keep it on hand. So, they make money on interest they collect, which means they loan out some kind of average balance they have, which means they operate like a bank - banks hold your money, and pay you interest, or let you at least have free checking, and they cover their costs by taking risks with your money, just like paypal does. The more risks they take, the bigger the profits, or bigger the failures. I assume paypal takes "secure" risks such as only buying government bonds (gov't money is guaranteed, the money can always be printed, even if it's inflated away to no worth, you can always be sure to get the numerical equivalent of dollars you're owed), cd's, etc. each with low interest, but fairly low risk.
Duh. That's a nice logical catch for dilettantes. I was thinking of a situation where the resolving power between the different frequencies was absolute. As if you got 900 Mhz worth of ticks or wavetrains that can be say amplitude modulated both on the 900.00001 channel and the 900.00002 channel, and the two channels "don't interfere." I was thinking of modulation as a simple on off of a wavetrain, staying at the assigned frequency. But sine-waves are not digital square waves, and are not that simple as on off. With a sine wave cut a single wave-train out, and you suddenly got a Fourier series with multiple frequencies on your hand. In fact you can't do anything to sine waves without changing frequencies. And sine waves are the pure form of waves that travel, square waves are simply Fourier composites of sine waves, and will quickly break up into components. The fact is that you simply can't modulate a signal without consuming nearby frequencies. It's not very intuitive, but this is what escaped me. Even with AM modulation, that seemingly only changes the amplitude of the sine wave, but not the frequency, there are two sidebands, dependent on the modulation frequency. If the modulation frequency is a 1 KHz pure sine tone, the AM sidebands would be at 899.999 and 900.001 MHz. Alas, the frequency of the modulating signal that can be put onto these 900.00001 channels is 100 Hz. The kind of digital signals such a 100 Hz modulation can carry is on the oder of 100 baud, very slow. So yeah, you can't gain bandwidth by talking both on the 900.00000001 MHz frequency channel and the 900.00000002 MHz channel, because any meaningful modulation of the signal changes the frequency far outside those tight ranges. Duh. I used to have this concept in my head when skimming through books, but until now I never really had my own rig where I'd try to do something cool like this, to try to get more bandwidth, even as a thought experiment, and get this concept of you can't hard etched into my memory. It's kind of like trying to construct a perpetuum mobile - the laws of physics forbid it, and if you think you got a way around it, like so many people before you thought, think again. That 2nd kind of perpetuum mobile, that extracts energy from a single heat reservoir, such as the air, or the sea, though, is still a bit up in the air, and may one day be created by a sufficiently efficient Maxwell's demon. The theory has already been expanded to include information itself in the concept of entropy, and to show that none of the Maxwell demons/nanotech Brownian ratchets can be efficient enough.
Every room using IRDA or light networks should have a no smoking sign.
Bandwidth is important, and will be the driver for this technology. Sure, people like signals that penetrate walls and obstacles, but those waves have limited frequency, and eventually you have to go to directional/line-of-sight high frequency signals. Kind of like satellite vs. VHF. VHF goes through everything almost, but has only 13 conventional 100 MHz TV channels. UHF can carry more channels, but it's less penetrating. And satellite signals can carry thousands of channels, but require line of sight. People don't bother with satellite signals? Sure they do. Eventually. Not in 1956, but yes in 2000. IRDA and light is not for 2010, or even 1991, but yes for 2020.
You could even make a lightbulb fixture/splitter with IRDA adapter/repeater on one end, lightbulb the other. I had a smoke alarm like that, with a lightbulb adaptor, but the rechargeable battery in it was a supercapacitor, and it was always too low a voltage very fast, and it would keep beeing every three minutes, unless you turned the light on, and it'd keep beeping for a while even after that. Really annoying. Should have had a 9V recheargable battery. But the same idea goes for an IR repeater, make it a light fixture, and please, supercaps go bad so fast, use a 9V rechargeable battery, even if it has to be bought separately.
Why is it obsolete technology? I put lightbulbs/fluorescent/led up into little domes in the ceiling, and that's still not obsolete technology, so why not put IR repeaters up there too?
Is there really a use for this? Light is the future. Light will eventually be able to carry channels with 10 Gbit/s, 100 Tbit/s, 100 exabit/s, and so on, which will not be possible to do on the frequencies that Wifi uses, per channel, unless technology shows up to resolve a certain set of frequencies into even smaller individual subdivisions, such as 900.000001 MHz, 900.000002 MHz, and successfully carries uninterfering data on each of those frequencies. Even GHz microwave is quite directional and severely decaying with distance compared to say VHF bands, so whatever issues you face with light, as you have to increase frequencies to carry data faster, all your electromagnetic waves will have issues similar to issues with light.
Persistence of vision kicks in above 25 Hz, and some people can still sense an 85-100 Hz refresh on CRT monitors with their periferal vision, but anything vibrating at a higher frequency is oblivious to the eyes. I'm guessing stuff transmitting in the GBit/s range is operating near 1GHz or close to it, which is well above the 100 Hz flicker you can see. If anything, the laser hitting you in the eyes, especially if it's infrared and invisible, might be the problem.
One of the issues becomes the data interference from multipath reflection, that used to be a problem with nondirectional rabbit ear antennas in television. The speed of light is 3x10^8 m/s, the frequency we talk about is 1x10^9/s, so that gives a wavelength for the modulated signal of 0.3 m, or about 1 foot. So path differences on this order or greater cause interference - light reflected off the far corner carrying the old databit comes in 10 nanoseconds later than the light reflecting from the nearby wall, carrying the current databit. This of course can be avoided if the path is restricted, such as aiming to a white spot on a wall, and then focusing a telescope with full magnification zoom onto that spot. This should be cheaper than running cables, however people walking through the room blocking line of sight have to be considered, and the ease of knocking the computer table/devices out of alignment. But a homing-zooming type wide viewfield webcam setup that finds you 10 different dots on the wall, and tells you to pick the one talking to you in software, then zooming in onto that dot, and keeping homed in onto it, that could be done. Or something transparent and automated, such as in a netcafe, you get assigned a new ID/key combo, and you type that in, and the computer goes from dot to dot, and shoots a reply dot 2 cm to the left of the dot, to try to establish handshake, and tries each dot iteratively til it finds the one belonging to it.
I think even now there is a way to listen to people having conversations by the modulation the window puts onto a reflected infrared laser light. There is already technology that extracts info from laser dots on a wall.
Still, software can do something about weeding out some of the multipath noise. Or even just focus on a small area of the wall, but broadcast the reply. In a spatially broadcast and not limited to a dot reply world everyone shares the same channel, and from the encoded info the master router station has to decipher which packet came from who. Less bandwidth, but also less hardware, as the router has to have a laser aiming for each of the channels onto a separate spot on the wall. Also, I haven't talked about repeaters, that go around doors and rooms and staircases, possibly being blocked by people walking there. With staircases pulling a wire through the floor might be more straightforward. Or a combo - dot on the wall within a room, and short cabling intra-floor or throught he walls.
It's not the tv shows. Even without the tv shows, as long as people have a roof over their heads and have theirs stomachs filled, as long as there is some sense of security, there is not gonna be revolts. Why would there be? Even if you lose your job you can go on welfare and get a place to sleep and food. If anything, the only people I imagine feeling totally rebellious are military personnel, fighting a bullshit war they don't believe in, but as long as there is a voluntary army, kind of a mercenary army, where you don't have to be there unless you sign up to take orders, in exchange for pay, scolarships and early retirement, and to feel useful defending your country and people, rebellion is unlikely too. If there was mandatory conscription, and people shipped off overseas against their own will, now you're talking. One can say faced with the choice of going on welfare and getting your expenses nitpicked by govt bureaucrats vs. signing up for the military because there are no jobs, well, it's not mandatory, but halfway there. Everyone likes to feel useful, like they are living for or doing something worthwhile. Though often we have to settle for total useless and bs activities just to deal with the circumstances, such as paying bills, and one can call those things "entertainment" to those who are willing to pay for something you absolutely feel useless doing. Money comes from other people, one way or another you have to please another person to get it, it's entertainment of someone else one way or another, unless you're on welfare. Even then it's pleasing someone else to know that you're not suffering.
Actually, the better palace than Kilimanjaro is Ecuador, Peru, and Colombia where one could build a couple km steep sloping maglev starting deep in the ocean and stopping at the peaks of the Andes. It looks like the steepest long length zone in the world close to the euqator. There is another of course another zone in Africa, and another in eastern Indonesia, just north of Australia.
One more thing: in the initial scenario, with a 42000 km long cable on 300 km apogee/perigee difference ellipsoid orbit satellite, if one could tug the cable while the satellite was dropping it, and then hang the weight on it while the satellite was raising it, it might be a way to resupply the energy to maintain orbit, just like pushing a swing on the way down is a way to make it swing more intensely. Of course one can always try to raise the swing as it goes up, just enough, but with a cable, pushing the satellite up doesn't work, because it's not a stick, it's a cable that can pull but not push. The problem is of course having a 42000 km cable that can sustain its own weight, which needs a strength to weight material that does not exist, at least we don't know of it yet.
The other way, with a "comet" satellite on a severely ellipsoid orbit, with a 300 km closest approach (6700 km radius perigee), and 42000 km apogee, the satellite is almost in a direct free fall toward the Earth, just barely not hitting it, and a direct ascent away to the great heights, once it swings around, just like comets do around the Sun. On the way down, it could send ahead a cable with a faster speed than itself, and as that cable comes to the Earth, it could be captured and tugged on. Then it would release the cable end as the motion becomes severly tangential about the surface, and a second end of a spring loaded cable, rocket propelled to meet up with it on the way up, could be sent up. Rocket propelling a small weight cable is cheaper than propelling a kiloton of cargo. The more massive the comet-satellite, the more weight it can tow back up to 42000 km. The problem with this scenario is no longer the cable material science, but the speeds involved. The satellite travels near the escape velocity when in the vicinity of Earth, which is 11 km/s. That's Mach 36, 36 times faster than the speed of sound, and the fastest spy plane, the Blackbird, which could outrun Soviet bullets shot after it as a normal evasive procedure, only traveled at Mach 3. Helicopter blades at the tip can be made to go much faster than Mach 3, and similarly, a big winding cylinder spinning extremely fast, capturing the downshot cable, might be able to tug the satellite. As long as the motion is along the length of the cable through the atmosphere, heating will be significant at the 15 km/s, but not as significant as a sideway drag. Though good luck trying to coordinate such a capture, or building such a spinning winder, and winding cable up on it, at 15 km/s tangential speed. That too seems much past the technological abilities.
Using stages of satellites with short cables, with nearby satellites orbiting fast, and farther ones orbiting slower, there is still a problem. With 7.7 km/s tangential speed at 380 km altitude for the ISS, or 7.6 km/s at 600 km for the Hubble telescope, compared to the 0.4655 km/s surface speed at the equator, the tugging from the ground or the atmosphere for the lowest stage satellites is still the same problem as with the 11 km/s comet-satellite. It is too fast.
That leaves rockets, or cannons to go through the atmosphere. A cannon can shoot up cargo to 300 km hitting the comet satellite spring attachment right at the perigee through a spring capture, which might turn into some spinning yoyoing concotion at 11 km/s, which quite some centrifugal force, unless a very long cable is used, but the comet-satellite, and cargo could fly up spinning together. This way even if the cargo does not attain escape velocity, it has a way to get up there. And I was wrong about not burning fuel in space, as long as it is burned at a very low point to impart speed. Because if you burn it all low, at 300 km altitude, while going 11 km/s, that's better than burning it at 11km/s in the atmosphere, because there is no air drag in vacuum. One could shoot up rockets with just enough speed to reach 300 or even 100 km, and then ignite the rockets, where they don't have to fight air drag. If the cannon, or maglev rollercoaster shoots up the
I feel like there is something unintuitive I'm missing here, such as the Coriolis force. Suppose we have a massive enough asteroid, a couple hundred thousand ton in weight, orbiting geosynchronously but past the 42000 km just enough to provide a centrifugal pulling force of 1 ton, and we let it lift this exact 1 ton to 300 km, by making the orbit elliptical to a 300 km difference. Or more exactly, the average load is 1 ton, more on the ascent, say 2 tons, and none on the descent. Under this scenario, you could move the whole earth and billions of tons up to the 300 km mark, without seemingly any energy input, just relying on the "escape velocity" of the asteroid. This would be like a perpetuum mobile doing work, which is forbidden.
Basically, what's missing is the conservation of angular momentum. If you ever watch olympic ice skating performers, when they spin, they use a trick to make themselves spin faster, by pulling their arms in closer to the center. Same with circus acrobats. One might ask how does a force that drives and object in perpendicularly, cause a horizontal rotation increase. But it does, and only if there is an intial rotation already present. If there was no rotation, pulling an object close or far from the center does not affect rotational speed, does not get it started. But if there is initial rotation, pulling your arms in speeds up the rotation, and most importantly, letting them back out slows the rotation.
There are 3 fundamental laws of motion: 1. conservation of momentum, an mv quantity, 2: conservation of energy, and mv2 quantity, 3: conservation of angular momentum, m*omega*r type quantity.
This is what's happening in case of the space elevator, because Coriolis forces are easy to forget about in thought experiments. Initially there is an angular momentum present, represented by the mass of Earth rotating about the asteroid-earth center of gravity, probably 1 cm for the earth, and 42000 km for the asteroid, depending on the mass and distance from Earth of the asteorid. Basically the Earth is in the center, and all its mass is rotating at a radius smaller than 6500 km. Now as you start taking weight up, the same thing happens as in case of the ice skaters releasing their hands: the rotation slows down due to the appearance of coriolis forces. So a counterweight would keep losing speed as it lifts, and thus the system's rotational kinetic energy would be transformed into gravitational potential energy, unless, unless of course both the energy is conserved, and the angular momentum - which means a solar panel motor doin the lifting, and once the stuff is off, spin some of it up enough to restore your angular momentum, and send it away from the station up there, either into just outer space, or down to the Earth. This replenishing of angular momentum after a lift, by compensating amount of counterrotation discarded, is needed on any space station doing the lifting.
By the way whenever I say tons per minute, technically simply the tons matters, not the per minute part. At any given time to maintain equilibrium, irrespective of minutes or hours, at any given second there should be a fixed amount of force balancing the centrifugal force. However the tons per minute can be applied if you use a dynamic equilibrium: suppose you let the satellite do lifting for 1 hour each day, and you let it lift 24 tons,instead of the steady 1 ton for 24 hours it was meant and designed to do. Then suppose, for the remaining 23 hours you allow it to gain altitude from the uncompensated centrifugal force fly off. One has to be careful, because there is no proportionality, such a ton per minute value is not fixed, because it depends on the actual height obtained, and the forces farther away are radius squared weaker than at a radius closer to the center of the Earth. In a small localized domain however, the proportionality and constancy of weight force stands. Say I'm 90 kgs(200 lbs) at sea level, but only 90 kgs* 6400^2/(6400+8.848)^2= 89.75 kgs on top of the 8.848 km Himalayas protruding from the 6400 km radius Earth. The weight is constant inside a room, or even in a city, but over severely varied altitudes, it's not, and that quarter kilogram can add up as error over time. Still, the tons per minute can be adjusted to whatever is necessary to compensate for a given lifting schedule and orbit height scenario. There may be some dummy weights lifted through a certain number of stages, then held onto and lifted together with the next cargo, then even dropped into free fall to burn up in the atmosphere or fall into an ocean, instead of handing over to the next stage, if needed to keep things in sync.
You could have many stages of orbiting satellites reeling in cargo with short pieces of cable currently available to material science technology. Then as they fly by the cable to the next stage up, they can hand the cargo over. The orbit could be maintained by providing just the right amount counterpull over time, the tons per minute lift, even if dummy weights, to keep the satellites from gaining height and flying off into outer space. The very first stage, the lifting of weights over the dense high pressure atmosphere would still have to be done the conventional rocket way. In case of dummy weights, some of the dummy weight could be used fuel to push the satellites back down into correct orbit - if they can lift the fuel for free, powered by solar panel energy to lift, then why not? If you don't want to provide combustible fuel, then they still need some mass they can accelerate and eject upward to keep themselves down, and they can use the solar panel energy for that.
I just thought of this: using fuel to restore orbit at 42000 km vs. using fuel to lift is almost the same thing. Especially when that fuel has to be taken up so high. The whole problem with rockets is, that to get so high, you need fuel, and to have the fuel, you have to lift the fuel too, and the majority of the fuel is wasted to lift the rest of the fuel. But you can drop stages halfway there. If you have to take fuel up all the way to 42000 km first, and then burn it there, that's nonsense, that's like not dropping stages, but first lifting all the fuel, wasting all that energy to lif it, then burning it up there so you can reel something up. That is absolute nonsense from an energy frugality standpoint. This was a logical catch I didn't think of. The whole point of the space elevator is to not have to lift fuel. The less gravitational potential energy you have to impart to any kind of fuel, the better off you are.
You can have fuel to do corrections in orbit, but not as a major orbit restoration/lifting ingredient. The lifting should be done by solar panels, or similar non heavy energy, such as electricity sent through the cable without lifting weight, or microwave radiated energy from the surface. The pull force would be provided by the object being past the geosynchronous 42000 km point, and gaining altitude slowly, unless it is pulled down as it lifts something else, just in the right equilibrium. The lift capacity per minute would be determined by the weight of the counterweight, and the distance past the 42000 km mark. You cannot do something in lower orbit than that, because the end of the cable would drag through the atmosphere too fast, wasting energy. However if you use rockets to lift something to 300 km, then the elevator to take over and lift to 20000 km or such, then the elevator does not have to be geostationary and could go faster at a lower altitude, because the end of the cable would not be hanging into the atmosphere. Unfortunately all of these cases require very long cables with strengths unavailable to material science.
The moon is orbiting in an elliptical orbit with Earth in one of the focal points, with an apogee (largest distance from Earth) of roughly 405,000 km, and perigee (closest approach) of 363,000 km. The center of gravity of the two object system is such that the moon orbits around it an average of 380,000 km, while the Earth 4700 km.
A circular geosynchronous orbit would be 42,000 kms away, which is one tenth the Earth/Moon distance.
Moreover altitudes over 100 km are recognized as space flight, with the first manned one, Vostok 1 piloted by Yuri Gagarin, obtaining an apogee of 330 km and perigee of 170 km above ground.
If the geosynchronous orbit is elliptical, only the semi major axis is 42000 km, and the minor axis can be anything. If the orbit is allowed to be slightly elliptical, with a say 300 km difference between apogee and perigee, then the counterweight object, depending on how massive, and how far past the 42000 mark it is, could do the lifting of cargo just above the atmosphere. Then a second object could fly by on an extremely elliptical orbit, with an apogee of 42000km, and perigee of 300 km above surface (meaning 6400 km + 300 km from the center of Earth), and swoop up the cargo. The higher the altitude it has to do this capture, the lesser the slowdown and energy loss due to atmospheric friction, and also somewhat smaller the impact forces from the swooping capture. Some 2 km long spring absorbing the shock slowly might work. Most likely the cargo would have to be dropped into freefall before capture, so that the cable is not shocked by the impact. The flyby object could have a remote controller to effect and coordinate the dropping and capture once it's close enough. The cargo would contain enough extra propellant to both compensate the fast flyby objects frictional energy losses, and the counterweight's energy losses, and restore orbits to both.
Note that one still has to have a 42000 km long cable, because if an only 300 km cable is used, the flyby speed near the perigee is so great, that any cable dipped into the viscous atmosphere would create immense frictional energy losses. But the stirring speed due to the change in orbiting speed and relative orbit position because of an eccentric orbit at 42000 km would probably be acceptable.
Both the ultra-long spring dampening fast flyby object and the counterweight past the 42000 km mark would take the portion of the cargo meant for them as orbit replenishment fuel. The rest of the cargo would be at 42000 km fairly quickly with minimal energy expenditure.
Of course there is always the option of winding the cable, powered by solar panel energy, but that is either very energy intensive requiring storage batteries, or slow, if only small amount of solar panels are available. Things change once there is a space solar array that beams energy down to Earth in microwave, because then one has enough energy available up there too, and winding is preferred compared to flyby drop-capture. But in the meantime, energy can cheaply be supplied from Earth as propellant, and the fast height raising work being done by the centrifugally/inertially stored energy, and the orbit raised back/sped up again slowly til there is enough kinetic energy built up to do another lift. Though kinetic energy is not that energy dense compared to batteries, it's cheap, other than the expensive complications of coordinating a flyby capture.
Now if one can only find a cable that can sustain its own weight at 42000 km.
Maybe it does not have to be 42000 km. Instead of drop catch, the object coming in at 300 km would catch a surface to space rocket propelled end of a cable attached to a ground cargo, with a 2km long spring attachment to lessen the sudden tugging forces, and acceleration at takeoff. Then it would fly with this cargo up to 42000 km and hand it over to the geostationary object, while dampening or maybe not dampening the spring vibration. It would burn some propulsion fuel for it's downward acceleration back to Earth so i
Otherwise a very important reason for sex is procreation, raising children and future generations, and neither a cat nor a robot can help you with that, though in some not so distant future a robot might, when dna copying in a jar is developed, with 100% cloning or random mutations introduced on purpose. Biotech is scary.
Presentations are the most important "value" created in today's business world, as far as employment dollars spent go. Lower on the scale there are lots of workers, but their hourly wage is very low, and higher up there is not enough people, even if they earn a lot. The bulk of employment money goes to middle managers tweaking powerpoint slides to present at meetings that take up the bulk of the time. The purpose of presentattions is to dumb down and simplify concepts so they can be effectively conveyed to wide audiences who otherwise don't have a clue. Being an expert, and knowing the very fine details, as described in scientific papers that present the full set of actual measurement data is no longer important, as far as job success goes, but one has to be very good at giving succinct and summarizing presentations. No longer do you find ad hoc vivid conversations one on one between experts addicted to a topic caught up discussing the details for hours with a twinkle in their eyes, but you have a lot of time management software scheduled and accepted mandatory summons to meetings where people neither want to be there, nor are they interested, but it brings them a paycheck, so they have to do it. Self interest is amazing.
I've been thinking about this some more, and with a turbine part at 3000C it would be difficult to find bearings that last. So the shaft would have to be extended long far from the hot zone and cooled before support. Most turbines in power plants are in the horizontal plane, but if one put them vertical, they would only have to be supported on the cold end of the shaft, the rest spinning like a top. There would be precession forces in a gravitational field on the top in case the shaft is not properly aligned vertical, but that could be stabilized with a long extending shaft on top, but this time a pin-like one, because the forces necessary to guide and keep the turbine into a vertical direction are much smaller than when full support of the weight is needed. Imagine a turbine with a 10 meter diameter axle, whose hot end is at 3000C, but from the center of the 10 meter dia axle there is a 3 inch segment protruding through a very long hole with tight clearance, and cold gas is blown through that hole at a flowrate of 1000:1, so it does not affect the temperature inside the turbine in the hot zone. By the way some of these concepts are applicable for lower temperatures too, even for 1500C turbines.
That's the only thing they know how to do: embrace, extend, extinguish. Like the Borg, they only know how to assimilate. Why do you think Slashdot carries a Borg icon for MS?
Well, software is hard work, and who likes to work for free, especially on things that you don't believe in nor enjoy doing? Do you? Wouldn't you rather spend your time partying than coding? And how else are you gonna extort money from software, by any other way than making it into intellectual property and have your users agree to a eula that criminalizes attempts to decompile or trying to figure out what makes it tick?
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PhD stands for philosophiae doctor - teacher of philosophy.
The following assumes there is a limited, finite mental capacity for humans:
"Philosophers are people who know less and less about more and more, until they know nothing about everything. Scientists are people who know more and more about less and less, until they know everything about nothing." (quote from somebody smart)
Therefore PhD in science is an oxymoron. Actually, no it's not. You can both know everything about nothing, and nothing about everything, at the same time. You can have limit(x->infinity)x*1/2x+1/2x*x=1, or infinity*0+0*infinity=1, a finite number.
Yeah, from what I understand, paypal charges neither you nor the receiver any processing fee, instead they collect interest on the money while it's in their hands, for those 2-7 days between deposit and withdrawal. It doesn't become available to be withdrawn right away, unless you're posting it directly to someone else's paypal account, in which case paypal will freely toss it around internal accounts, as long as they keep it on hand. So, they make money on interest they collect, which means they loan out some kind of average balance they have, which means they operate like a bank - banks hold your money, and pay you interest, or let you at least have free checking, and they cover their costs by taking risks with your money, just like paypal does. The more risks they take, the bigger the profits, or bigger the failures. I assume paypal takes "secure" risks such as only buying government bonds (gov't money is guaranteed, the money can always be printed, even if it's inflated away to no worth, you can always be sure to get the numerical equivalent of dollars you're owed), cd's, etc. each with low interest, but fairly low risk.
Duh. That's a nice logical catch for dilettantes. I was thinking of a situation where the resolving power between the different frequencies was absolute. As if you got 900 Mhz worth of ticks or wavetrains that can be say amplitude modulated both on the 900.00001 channel and the 900.00002 channel, and the two channels "don't interfere." I was thinking of modulation as a simple on off of a wavetrain, staying at the assigned frequency. But sine-waves are not digital square waves, and are not that simple as on off. With a sine wave cut a single wave-train out, and you suddenly got a Fourier series with multiple frequencies on your hand. In fact you can't do anything to sine waves without changing frequencies. And sine waves are the pure form of waves that travel, square waves are simply Fourier composites of sine waves, and will quickly break up into components. The fact is that you simply can't modulate a signal without consuming nearby frequencies. It's not very intuitive, but this is what escaped me. Even with AM modulation, that seemingly only changes the amplitude of the sine wave, but not the frequency, there are two sidebands, dependent on the modulation frequency. If the modulation frequency is a 1 KHz pure sine tone, the AM sidebands would be at 899.999 and 900.001 MHz. Alas, the frequency of the modulating signal that can be put onto these 900.00001 channels is 100 Hz. The kind of digital signals such a 100 Hz modulation can carry is on the oder of 100 baud, very slow. So yeah, you can't gain bandwidth by talking both on the 900.00000001 MHz frequency channel and the 900.00000002 MHz channel, because any meaningful modulation of the signal changes the frequency far outside those tight ranges. Duh. I used to have this concept in my head when skimming through books, but until now I never really had my own rig where I'd try to do something cool like this, to try to get more bandwidth, even as a thought experiment, and get this concept of you can't hard etched into my memory. It's kind of like trying to construct a perpetuum mobile - the laws of physics forbid it, and if you think you got a way around it, like so many people before you thought, think again. That 2nd kind of perpetuum mobile, that extracts energy from a single heat reservoir, such as the air, or the sea, though, is still a bit up in the air, and may one day be created by a sufficiently efficient Maxwell's demon. The theory has already been expanded to include information itself in the concept of entropy, and to show that none of the Maxwell demons/nanotech Brownian ratchets can be efficient enough.
Every room using IRDA or light networks should have a no smoking sign. Bandwidth is important, and will be the driver for this technology. Sure, people like signals that penetrate walls and obstacles, but those waves have limited frequency, and eventually you have to go to directional/line-of-sight high frequency signals. Kind of like satellite vs. VHF. VHF goes through everything almost, but has only 13 conventional 100 MHz TV channels. UHF can carry more channels, but it's less penetrating. And satellite signals can carry thousands of channels, but require line of sight. People don't bother with satellite signals? Sure they do. Eventually. Not in 1956, but yes in 2000. IRDA and light is not for 2010, or even 1991, but yes for 2020.
You could even make a lightbulb fixture/splitter with IRDA adapter/repeater on one end, lightbulb the other. I had a smoke alarm like that, with a lightbulb adaptor, but the rechargeable battery in it was a supercapacitor, and it was always too low a voltage very fast, and it would keep beeing every three minutes, unless you turned the light on, and it'd keep beeping for a while even after that. Really annoying. Should have had a 9V recheargable battery. But the same idea goes for an IR repeater, make it a light fixture, and please, supercaps go bad so fast, use a 9V rechargeable battery, even if it has to be bought separately.
Why is it obsolete technology? I put lightbulbs/fluorescent/led up into little domes in the ceiling, and that's still not obsolete technology, so why not put IR repeaters up there too?
How many homes don't have windows? you can always put up a curtain for privacy reasons over the window.
Is there really a use for this? Light is the future. Light will eventually be able to carry channels with 10 Gbit/s, 100 Tbit/s, 100 exabit/s, and so on, which will not be possible to do on the frequencies that Wifi uses, per channel, unless technology shows up to resolve a certain set of frequencies into even smaller individual subdivisions, such as 900.000001 MHz, 900.000002 MHz, and successfully carries uninterfering data on each of those frequencies. Even GHz microwave is quite directional and severely decaying with distance compared to say VHF bands, so whatever issues you face with light, as you have to increase frequencies to carry data faster, all your electromagnetic waves will have issues similar to issues with light.
That brings the question to mind as to why regular wifi does not suffer from multipath reflection? It probably does.
Persistence of vision kicks in above 25 Hz, and some people can still sense an 85-100 Hz refresh on CRT monitors with their periferal vision, but anything vibrating at a higher frequency is oblivious to the eyes. I'm guessing stuff transmitting in the GBit/s range is operating near 1GHz or close to it, which is well above the 100 Hz flicker you can see. If anything, the laser hitting you in the eyes, especially if it's infrared and invisible, might be the problem. /s, so that gives a wavelength for the modulated signal of 0.3 m, or about 1 foot. So path differences on this order or greater cause interference - light reflected off the far corner carrying the old databit comes in 10 nanoseconds later than the light reflecting from the nearby wall, carrying the current databit. This of course can be avoided if the path is restricted, such as aiming to a white spot on a wall, and then focusing a telescope with full magnification zoom onto that spot. This should be cheaper than running cables, however people walking through the room blocking line of sight have to be considered, and the ease of knocking the computer table/devices out of alignment. But a homing-zooming type wide viewfield webcam setup that finds you 10 different dots on the wall, and tells you to pick the one talking to you in software, then zooming in onto that dot, and keeping homed in onto it, that could be done. Or something transparent and automated, such as in a netcafe, you get assigned a new ID/key combo, and you type that in, and the computer goes from dot to dot, and shoots a reply dot 2 cm to the left of the dot, to try to establish handshake, and tries each dot iteratively til it finds the one belonging to it.
One of the issues becomes the data interference from multipath reflection, that used to be a problem with nondirectional rabbit ear antennas in television. The speed of light is 3x10^8 m/s, the frequency we talk about is 1x10^9
I think even now there is a way to listen to people having conversations by the modulation the window puts onto a reflected infrared laser light. There is already technology that extracts info from laser dots on a wall.
Still, software can do something about weeding out some of the multipath noise. Or even just focus on a small area of the wall, but broadcast the reply. In a spatially broadcast and not limited to a dot reply world everyone shares the same channel, and from the encoded info the master router station has to decipher which packet came from who. Less bandwidth, but also less hardware, as the router has to have a laser aiming for each of the channels onto a separate spot on the wall. Also, I haven't talked about repeaters, that go around doors and rooms and staircases, possibly being blocked by people walking there. With staircases pulling a wire through the floor might be more straightforward. Or a combo - dot on the wall within a room, and short cabling intra-floor or throught he walls.
It's not the tv shows. Even without the tv shows, as long as people have a roof over their heads and have theirs stomachs filled, as long as there is some sense of security, there is not gonna be revolts. Why would there be? Even if you lose your job you can go on welfare and get a place to sleep and food. If anything, the only people I imagine feeling totally rebellious are military personnel, fighting a bullshit war they don't believe in, but as long as there is a voluntary army, kind of a mercenary army, where you don't have to be there unless you sign up to take orders, in exchange for pay, scolarships and early retirement, and to feel useful defending your country and people, rebellion is unlikely too. If there was mandatory conscription, and people shipped off overseas against their own will, now you're talking. One can say faced with the choice of going on welfare and getting your expenses nitpicked by govt bureaucrats vs. signing up for the military because there are no jobs, well, it's not mandatory, but halfway there. Everyone likes to feel useful, like they are living for or doing something worthwhile. Though often we have to settle for total useless and bs activities just to deal with the circumstances, such as paying bills, and one can call those things "entertainment" to those who are willing to pay for something you absolutely feel useless doing. Money comes from other people, one way or another you have to please another person to get it, it's entertainment of someone else one way or another, unless you're on welfare. Even then it's pleasing someone else to know that you're not suffering.
Actually, the better palace than Kilimanjaro is Ecuador, Peru, and Colombia where one could build a couple km steep sloping maglev starting deep in the ocean and stopping at the peaks of the Andes. It looks like the steepest long length zone in the world close to the euqator. There is another of course another zone in Africa, and another in eastern Indonesia, just north of Australia.
One more thing: in the initial scenario, with a 42000 km long cable on 300 km apogee/perigee difference ellipsoid orbit satellite, if one could tug the cable while the satellite was dropping it, and then hang the weight on it while the satellite was raising it, it might be a way to resupply the energy to maintain orbit, just like pushing a swing on the way down is a way to make it swing more intensely. Of course one can always try to raise the swing as it goes up, just enough, but with a cable, pushing the satellite up doesn't work, because it's not a stick, it's a cable that can pull but not push. The problem is of course having a 42000 km cable that can sustain its own weight, which needs a strength to weight material that does not exist, at least we don't know of it yet.
The other way, with a "comet" satellite on a severely ellipsoid orbit, with a 300 km closest approach (6700 km radius perigee), and 42000 km apogee, the satellite is almost in a direct free fall toward the Earth, just barely not hitting it, and a direct ascent away to the great heights, once it swings around, just like comets do around the Sun. On the way down, it could send ahead a cable with a faster speed than itself, and as that cable comes to the Earth, it could be captured and tugged on. Then it would release the cable end as the motion becomes severly tangential about the surface, and a second end of a spring loaded cable, rocket propelled to meet up with it on the way up, could be sent up. Rocket propelling a small weight cable is cheaper than propelling a kiloton of cargo. The more massive the comet-satellite, the more weight it can tow back up to 42000 km. The problem with this scenario is no longer the cable material science, but the speeds involved. The satellite travels near the escape velocity when in the vicinity of Earth, which is 11 km/s. That's Mach 36, 36 times faster than the speed of sound, and the fastest spy plane, the Blackbird, which could outrun Soviet bullets shot after it as a normal evasive procedure, only traveled at Mach 3. Helicopter blades at the tip can be made to go much faster than Mach 3, and similarly, a big winding cylinder spinning extremely fast, capturing the downshot cable, might be able to tug the satellite. As long as the motion is along the length of the cable through the atmosphere, heating will be significant at the 15 km/s, but not as significant as a sideway drag. Though good luck trying to coordinate such a capture, or building such a spinning winder, and winding cable up on it, at 15 km/s tangential speed. That too seems much past the technological abilities.
Using stages of satellites with short cables, with nearby satellites orbiting fast, and farther ones orbiting slower, there is still a problem. With 7.7 km/s tangential speed at 380 km altitude for the ISS, or 7.6 km/s at 600 km for the Hubble telescope, compared to the 0.4655 km/s surface speed at the equator, the tugging from the ground or the atmosphere for the lowest stage satellites is still the same problem as with the 11 km/s comet-satellite. It is too fast.
That leaves rockets, or cannons to go through the atmosphere. A cannon can shoot up cargo to 300 km hitting the comet satellite spring attachment right at the perigee through a spring capture, which might turn into some spinning yoyoing concotion at 11 km/s, which quite some centrifugal force, unless a very long cable is used, but the comet-satellite, and cargo could fly up spinning together. This way even if the cargo does not attain escape velocity, it has a way to get up there. And I was wrong about not burning fuel in space, as long as it is burned at a very low point to impart speed. Because if you burn it all low, at 300 km altitude, while going 11 km/s, that's better than burning it at 11km/s in the atmosphere, because there is no air drag in vacuum. One could shoot up rockets with just enough speed to reach 300 or even 100 km, and then ignite the rockets, where they don't have to fight air drag. If the cannon, or maglev rollercoaster shoots up the
I feel like there is something unintuitive I'm missing here, such as the Coriolis force. Suppose we have a massive enough asteroid, a couple hundred thousand ton in weight, orbiting geosynchronously but past the 42000 km just enough to provide a centrifugal pulling force of 1 ton, and we let it lift this exact 1 ton to 300 km, by making the orbit elliptical to a 300 km difference. Or more exactly, the average load is 1 ton, more on the ascent, say 2 tons, and none on the descent. Under this scenario, you could move the whole earth and billions of tons up to the 300 km mark, without seemingly any energy input, just relying on the "escape velocity" of the asteroid. This would be like a perpetuum mobile doing work, which is forbidden.
Basically, what's missing is the conservation of angular momentum. If you ever watch olympic ice skating performers, when they spin, they use a trick to make themselves spin faster, by pulling their arms in closer to the center. Same with circus acrobats. One might ask how does a force that drives and object in perpendicularly, cause a horizontal rotation increase. But it does, and only if there is an intial rotation already present. If there was no rotation, pulling an object close or far from the center does not affect rotational speed, does not get it started. But if there is initial rotation, pulling your arms in speeds up the rotation, and most importantly, letting them back out slows the rotation.
There are 3 fundamental laws of motion:
1. conservation of momentum, an mv quantity,
2: conservation of energy, and mv2 quantity,
3: conservation of angular momentum, m*omega*r type quantity.
This is what's happening in case of the space elevator, because Coriolis forces are easy to forget about in thought experiments. Initially there is an angular momentum present, represented by the mass of Earth rotating about the asteroid-earth center of gravity, probably 1 cm for the earth, and 42000 km for the asteroid, depending on the mass and distance from Earth of the asteorid. Basically the Earth is in the center, and all its mass is rotating at a radius smaller than 6500 km. Now as you start taking weight up, the same thing happens as in case of the ice skaters releasing their hands: the rotation slows down due to the appearance of coriolis forces. So a counterweight would keep losing speed as it lifts, and thus the system's rotational kinetic energy would be transformed into gravitational potential energy, unless, unless of course both the energy is conserved, and the angular momentum - which means a solar panel motor doin the lifting, and once the stuff is off, spin some of it up enough to restore your angular momentum, and send it away from the station up there, either into just outer space, or down to the Earth. This replenishing of angular momentum after a lift, by compensating amount of counterrotation discarded, is needed on any space station doing the lifting.
By the way whenever I say tons per minute, technically simply the tons matters, not the per minute part. At any given time to maintain equilibrium, irrespective of minutes or hours, at any given second there should be a fixed amount of force balancing the centrifugal force. However the tons per minute can be applied if you use a dynamic equilibrium: suppose you let the satellite do lifting for 1 hour each day, and you let it lift 24 tons ,instead of the steady 1 ton for 24 hours it was meant and designed to do. Then suppose, for the remaining 23 hours you allow it to gain altitude from the uncompensated centrifugal force fly off. One has to be careful, because there is no proportionality, such a ton per minute value is not fixed, because it depends on the actual height obtained, and the forces farther away are radius squared weaker than at a radius closer to the center of the Earth. In a small localized domain however, the proportionality and constancy of weight force stands. Say I'm 90 kgs(200 lbs) at sea level, but only 90 kgs* 6400^2/(6400+8.848)^2= 89.75 kgs on top of the 8.848 km Himalayas protruding from the 6400 km radius Earth. The weight is constant inside a room, or even in a city, but over severely varied altitudes, it's not, and that quarter kilogram can add up as error over time. Still, the tons per minute can be adjusted to whatever is necessary to compensate for a given lifting schedule and orbit height scenario. There may be some dummy weights lifted through a certain number of stages, then held onto and lifted together with the next cargo, then even dropped into free fall to burn up in the atmosphere or fall into an ocean, instead of handing over to the next stage, if needed to keep things in sync.
You could have many stages of orbiting satellites reeling in cargo with short pieces of cable currently available to material science technology. Then as they fly by the cable to the next stage up, they can hand the cargo over. The orbit could be maintained by providing just the right amount counterpull over time, the tons per minute lift, even if dummy weights, to keep the satellites from gaining height and flying off into outer space. The very first stage, the lifting of weights over the dense high pressure atmosphere would still have to be done the conventional rocket way. In case of dummy weights, some of the dummy weight could be used fuel to push the satellites back down into correct orbit - if they can lift the fuel for free, powered by solar panel energy to lift, then why not? If you don't want to provide combustible fuel, then they still need some mass they can accelerate and eject upward to keep themselves down, and they can use the solar panel energy for that.
I just thought of this: using fuel to restore orbit at 42000 km vs. using fuel to lift is almost the same thing. Especially when that fuel has to be taken up so high. The whole problem with rockets is, that to get so high, you need fuel, and to have the fuel, you have to lift the fuel too, and the majority of the fuel is wasted to lift the rest of the fuel. But you can drop stages halfway there. If you have to take fuel up all the way to 42000 km first, and then burn it there, that's nonsense, that's like not dropping stages, but first lifting all the fuel, wasting all that energy to lif it, then burning it up there so you can reel something up. That is absolute nonsense from an energy frugality standpoint. This was a logical catch I didn't think of. The whole point of the space elevator is to not have to lift fuel. The less gravitational potential energy you have to impart to any kind of fuel, the better off you are.
You can have fuel to do corrections in orbit, but not as a major orbit restoration/lifting ingredient. The lifting should be done by solar panels, or similar non heavy energy, such as electricity sent through the cable without lifting weight, or microwave radiated energy from the surface. The pull force would be provided by the object being past the geosynchronous 42000 km point, and gaining altitude slowly, unless it is pulled down as it lifts something else, just in the right equilibrium. The lift capacity per minute would be determined by the weight of the counterweight, and the distance past the 42000 km mark. You cannot do something in lower orbit than that, because the end of the cable would drag through the atmosphere too fast, wasting energy. However if you use rockets to lift something to 300 km, then the elevator to take over and lift to 20000 km or such, then the elevator does not have to be geostationary and could go faster at a lower altitude, because the end of the cable would not be hanging into the atmosphere. Unfortunately all of these cases require very long cables with strengths unavailable to material science.
The moon is orbiting in an elliptical orbit with Earth in one of the focal points, with an apogee (largest distance from Earth) of roughly 405,000 km, and perigee (closest approach) of 363,000 km. The center of gravity of the two object system is such that the moon orbits around it an average of 380,000 km, while the Earth 4700 km.
A circular geosynchronous orbit would be 42,000 kms away, which is one tenth the Earth/Moon distance.
Moreover altitudes over 100 km are recognized as space flight, with the first manned one, Vostok 1 piloted by Yuri Gagarin, obtaining an apogee of 330 km and perigee of 170 km above ground.
If the geosynchronous orbit is elliptical, only the semi major axis is 42000 km, and the minor axis can be anything. If the orbit is allowed to be slightly elliptical, with a say 300 km difference between apogee and perigee, then the counterweight object, depending on how massive, and how far past the 42000 mark it is, could do the lifting of cargo just above the atmosphere. Then a second object could fly by on an extremely elliptical orbit, with an apogee of 42000km, and perigee of 300 km above surface (meaning 6400 km + 300 km from the center of Earth), and swoop up the cargo. The higher the altitude it has to do this capture, the lesser the slowdown and energy loss due to atmospheric friction, and also somewhat smaller the impact forces from the swooping capture. Some 2 km long spring absorbing the shock slowly might work. Most likely the cargo would have to be dropped into freefall before capture, so that the cable is not shocked by the impact. The flyby object could have a remote controller to effect and coordinate the dropping and capture once it's close enough. The cargo would contain enough extra propellant to both compensate the fast flyby objects frictional energy losses, and the counterweight's energy losses, and restore orbits to both.
Note that one still has to have a 42000 km long cable, because if an only 300 km cable is used, the flyby speed near the perigee is so great, that any cable dipped into the viscous atmosphere would create immense frictional energy losses. But the stirring speed due to the change in orbiting speed and relative orbit position because of an eccentric orbit at 42000 km would probably be acceptable.
Both the ultra-long spring dampening fast flyby object and the counterweight past the 42000 km mark would take the portion of the cargo meant for them as orbit replenishment fuel. The rest of the cargo would be at 42000 km fairly quickly with minimal energy expenditure.
Of course there is always the option of winding the cable, powered by solar panel energy, but that is either very energy intensive requiring storage batteries, or slow, if only small amount of solar panels are available. Things change once there is a space solar array that beams energy down to Earth in microwave, because then one has enough energy available up there too, and winding is preferred compared to flyby drop-capture. But in the meantime, energy can cheaply be supplied from Earth as propellant, and the fast height raising work being done by the centrifugally/inertially stored energy, and the orbit raised back/sped up again slowly til there is enough kinetic energy built up to do another lift. Though kinetic energy is not that energy dense compared to batteries, it's cheap, other than the expensive complications of coordinating a flyby capture.
Now if one can only find a cable that can sustain its own weight at 42000 km.
Maybe it does not have to be 42000 km. Instead of drop catch, the object coming in at 300 km would catch a surface to space rocket propelled end of a cable attached to a ground cargo, with a 2km long spring attachment to lessen the sudden tugging forces, and acceleration at takeoff. Then it would fly with this cargo up to 42000 km and hand it over to the geostationary object, while dampening or maybe not dampening the spring vibration. It would burn some propulsion fuel for it's downward acceleration back to Earth so i
Otherwise a very important reason for sex is procreation, raising children and future generations, and neither a cat nor a robot can help you with that, though in some not so distant future a robot might, when dna copying in a jar is developed, with 100% cloning or random mutations introduced on purpose. Biotech is scary.
Presentations are the most important "value" created in today's business world, as far as employment dollars spent go. Lower on the scale there are lots of workers, but their hourly wage is very low, and higher up there is not enough people, even if they earn a lot. The bulk of employment money goes to middle managers tweaking powerpoint slides to present at meetings that take up the bulk of the time. The purpose of presentattions is to dumb down and simplify concepts so they can be effectively conveyed to wide audiences who otherwise don't have a clue. Being an expert, and knowing the very fine details, as described in scientific papers that present the full set of actual measurement data is no longer important, as far as job success goes, but one has to be very good at giving succinct and summarizing presentations. No longer do you find ad hoc vivid conversations one on one between experts addicted to a topic caught up discussing the details for hours with a twinkle in their eyes, but you have a lot of time management software scheduled and accepted mandatory summons to meetings where people neither want to be there, nor are they interested, but it brings them a paycheck, so they have to do it. Self interest is amazing.
I've been thinking about this some more, and with a turbine part at 3000C it would be difficult to find bearings that last. So the shaft would have to be extended long far from the hot zone and cooled before support. Most turbines in power plants are in the horizontal plane, but if one put them vertical, they would only have to be supported on the cold end of the shaft, the rest spinning like a top. There would be precession forces in a gravitational field on the top in case the shaft is not properly aligned vertical, but that could be stabilized with a long extending shaft on top, but this time a pin-like one, because the forces necessary to guide and keep the turbine into a vertical direction are much smaller than when full support of the weight is needed. Imagine a turbine with a 10 meter diameter axle, whose hot end is at 3000C, but from the center of the 10 meter dia axle there is a 3 inch segment protruding through a very long hole with tight clearance, and cold gas is blown through that hole at a flowrate of 1000:1, so it does not affect the temperature inside the turbine in the hot zone. By the way some of these concepts are applicable for lower temperatures too, even for 1500C turbines.
Lots of haphazard things these days. Somebody is going crazy... Let's think about that for a sec.....
That's the only thing they know how to do: embrace, extend, extinguish. Like the Borg, they only know how to assimilate. Why do you think Slashdot carries a Borg icon for MS?
I was half asleep when I wrote that, I think I fell asleep before I hit submit.
Well, software is hard work, and who likes to work for free, especially on things that you don't believe in nor enjoy doing? Do you? Wouldn't you rather spend your time partying than coding? And how else are you gonna extort money from software, by any other way than making it into intellectual property and have your users agree to a eula that criminalizes attempts to decompile or trying to figure out what makes it tick?