If you're looking for architecture, try Toronto. We have the CN Tower, which was the world's tallest free-standing structure for several decades (and still might be; I'd have to doublecheck). We have plenty of other strange architecture as well - City Hall looks enough like an alien city that it was featured as one on ST:TNG, and Robarts Library in the University of Toronto was built with wierd threefold symmetry (the only right angles in the place are vertical).
If you're looking for science, try the Ontario Science Centre in Toronto, and Science North in Sudbury (though between that and the giant nickle, that's all there is to see in Sudbury that I'm aware of).
For more tech, maybe email University of Toronto, York University, Waterloo University, and other places and see if you can schmooze a tour of the engineering or physics laboratories. I managed to get a tour of a lab with a "T3" laser by a friend-of-a-friend route ("Table-Top Terawatt"; a laser that uses the "chirped pulse" method to stuff a few joules of energy into a 100-femtosecond pulse).
It may also be worthwhile taking a tour of ATI while you're in the country, though if I recall correctly they were in Montreal, Quebec (which is also a great place to visit; just remember that "pedestrian == fodder" as far as the motorists are concerned).
Lastly, if you're literally into backpacking, try Algonquin Park. Rent a canoe for even more fun - there are routes that can take weeks to paddle through. For something shorter and closer to Toronto, Mono Cliffs Provincial Park has a very beautiful set of trails that you can easily spend a day walking through.
Okay for the last 20 years they've been working on this. WHY are they not looking into solid state storage?
Because "solid state storage" to date has meant either battery-backed RAM, which is extremely expensive per gigabyte, or experimental optical or electro-optical approaches that aren't anywhere close to production.
There are plenty of companies within 2 years will have drives that will blow away current drives in speed and capacity. One such company is using nanotech to offer 1 terabit per cm2. And it'll run at 10x the speed of current memory.
Check through science magazines for the last 20 years or so, and you'll see many announcements in this vein. Believe them when they're going into full-scale production at the advertised density. Not before, and not with prototypes that lack on any front.
There needs to be a more efficient way to copy/move/edit giant (video) files before this becomes practical... a RAID setup in every computer is not the answer, faster (exponentially) solid state storage media is.
Data transfer, be it from a hard drive's platter or from a RAM chip, is a fundamentally serial operation. You have an interface of fixed size (number of bus lines, or number of platters with read heads on them), and are modulating in time to transmit data.
While there's a big gap between the two - it's easier to vary bus signals quickly than to run a platter past a read head at warp factor 9 - the disparity is by no means growing exponentially. Bus speeds started slowing down relative to transistor speeds at least a decade ago.
That, and even with current speeds transmitting a video clip takes much less time than recording it did.
Essentially, as I understand it, with longitudinal recording the poles of the bits are pointed flat on the surface. Imagine a bar magnet. Put the long flat end of the bar on the platter. That's longitudinal recording.
With perpendicular recording the bar magnet would be standing on it's end.
Ah.
Now I vaguely recall someone trying to market floppy drives that did that, about a decade ago.
Any numbers on what the minimum size of a domain is in each scenario? One of the papers the other posters linked put the maximum density increase at about a factor of 4, which is consistent with domain size not changing much (just orientation).
I wonder, will magnetic storage (in any number of dimensions) ever get eclipsed by non-magnetic ones like these?
Maybe.
The disadvantage optical schemes have is that the size of a bit's worth of storage medium is the size of a wavelength of light. While magnetic media have limits too, the ultimate density limit for EM devices is the size of a small cluster of atoms (or even one atom) - much, much denser.
While holographic schemes store bits in a distributed manner instead of in individual buckets, the limit ends up being the same (proof is beyond the scope of this reply; think "Fourier transforms").
My own bet is that storage of the future will be through some kind of electrical scheme that lends itself to chemical self-assembly (picture a 3D tangle of polymer spaghetti where every crossing of strands can store one bit of information). Magnetic storage has enough of a lead that it will take quite some time for any alternative to catch up, though.
I don't have a website handy, but as I understand it, when you're doing high-speed transfers, it's far easier with serial than parallel because you don't have to worry about the bits all getting there at the same time.
You can get around this to a large extent by having self-clocked encoding on each of the signal lines, and a data buffer at the end to line things back up (or a series of delay-locked loops to literally line the signals back up).
The popular parallel connectors (and buses) don't do this, though, and cross-talk is still a problem no matter what.
...engineers are working with software developers on a way to dramatically reduce power consumption by maximizing the number of 0-bits in memory.
The grain of truth to this joke: There is a well-known technique that reduces the number of 1s in words transmitted on a bus by inverting words that are more than half 1 (and setting an extra bit indicating that the word has been inverted). The idea is to reduce the number of transitions on the bus lines, as a change in state is what dissipates power.
Could someone explain (/point me to a website) as to what this paragraph means?
"We always have concerns about new connectors and backplane designs but those problems are minimized in a serial environment where the wiring is point-to-point,"
"Connecting devices fast is a lot easier when there's only two of them."
a crackdown on file-sharing. If they take that away from us, then whats the point of having that much space?
Legitimate content.
It's easy enough to end up with tens of thousands of photographs on your machine if you're in the habit of carrying a digital camera around. Now, think about what happens when you snap video clips the way you currently snap photographs.
This is already happening. With cameras being integrated into phones, it's growing even more.
How much extra storage will this give me on the same number and size of platters?
According to the article, it will increase it by about a factor of 5-10, going from 100-200 Gbit/in^2 as an approximate upper bound to standard storage to something in the range of 1 Tbit/in^2.
They also said that the number may actually be too small, given that light from some parts of the Universe hasn't had time to reach us yet. So it may be impossible to determine the total size of the Universe.
The total size of the universe may even be infinite. At any given time, we can only see the parts close enough for light emitted in the past to reach us, but to the best of my knowledge there is no restriction on the dimensions of the universe as a whole (perhaps an astrophysicist can enlighten me if I'm mistaken?).
One question I've always had is: when we look back in time to the creation of the Universe, we see light from that time. So the light has been traveling for 15 billion years to get to us. But if that light has been traveling that whole time toward us, how did we get here first?
It took the long route.
Light that was emitted substantially after the big bang would have been emitted from objects already quite far away from us. This gives more than enough time for it to reach us.
As the universe expands, more space is added between any given points in the universe. Thus, light emitted from an object that was initially quite close to us could find itself traversing a surprisingly large distance before finally reaching us. This is why light from the very early universe took so long to reach us, if I understand correctly.
they had an article about a newly developed radiation suit - using various organic salts embedded in the textile, you can get (for the same price as lead) just as good radiation protection with what appears to be a thick cloth. It is definently not as bulky as lead, and I believe it also allows water to evaporate from your body.
It's as bulky (and as heavy) as lead (more bulky, in fact, as there's less lead per unit volume). It's just a lot more flexible, which makes it far more practical to wear.
Yes, you can create open generic CPU, and everybody would be able to build an alarm clock or server out of it. Yet if you have a chip for alarm clock that is proprietary, but suits just fine alarm clock builders, 10 times smaller, 5 times cheaper, consumes 13 times less energy, what would you choose?
Being proprietary vs. being non-proprietary and being generic vs. being specialized are unrelated qualities.
The question is not whether you'd use a non-proprietary generic processor or a proprietary specialized processor to build that alarm clock. The question is whether you'd use a proprietary or non-proprietary alarm clock chip to build the alarm clock.
The original poster also appears to be confused about the word "proprietary". A proprietary design is one that someone owns. The design of Intel microprocessors is proprietary - just try fabbing your own chips from copies of Intel's masks and see how far you get. x86 clones exist because, while the implementation is proprietary, the instruction set and behavior are still _documented_, and these documents are available for anyone to view. While you can't build your own copy of an Intel processor, you can build another one that does the same thing as far as programs are concerned (possibly better than Intel's does, possibly not).
Similarly, whether or not you can write your own software for a device has no relation to whether the device's design is proprietary - it relates to whether the device's programming specs are public or not.
I can't help but wonder if a high tech civilization using fission, fusion, antimatter and who knows what.... would generate high levels of nutrino flux and if results from detectors such as these could be used as a device to detect such?
While a civilization using any of several varieties of nuclear power could produce substantial neutrino emissions, these would be swamped by the neutrinos emitted by their parent star.
Also, the fusion reactions proposed for power production do not produce substantial numbers of neutrinos. Neutrino production occurs in Weak-force interactions, which tend to have cross-sections lower than the Strong-force interactions that dominate the various fusion schemes involving D, T, and/or He3. The sun produces neutrinos because to get hydrogen (p) turned into helium (2p + 2n) you need Weak-force interactions to produce the neutrons. Thus, plain hydrogen fusion produces neutrinos because there are no fusion paths that _don't_ (this is also one of the reasons why fusing plain old hydrogen is very difficult).
The idea behind SETI is to search for alien transmissions in bands where there is relatively little ambient noise. Neutrino emission isn't such a case.
Only if you assume the infrastructure will be used only for the purpose of building powersats and will be thrown away immediately afterwards.
a) It has a finite maintenance lifetime. Even the most aggressively designed self-maintaining plant (which makes the design at least another order of magnitude more complicated) requires specialty parts that must be produced on Earth.
b) It produces power satellites at a limited rate. The power satellites produced over the lifetime of the plant may very well weigh _less_ than the lunar mining/smelting/fabrication/launch facility. It's straightforward to make solar collectors light weight, either by using thin-film cells or aluminized mylar concentrating mirrors or both. Your lunar facility, on the other hand, will be _heavy_, as it must deal with very large amounts of bulk material, and be spread over a very large area (especially the mass driver used for launch).
Do the math - figure out how many satellites you need for your target market and their mass. Then figure out how big a mining facility you need to build them within a reasonable length of time (as both your satellites and your production facility have finite lifetimes).
Lunar material supply is only practical if you need very large amounts of relatively non-specialized material in space. This means "giant space station" or "city on the moon", neither of which would pay for itself, and so neither of which is currently planned by the private sector.
Is this a stupid analogy or what? This can be said about any type of light detector. This is like saying a digital camera works like a light bulb in reverse... duh? So these "modules" are just simply really sensitive digital cameras networked together.
Not quite. These are photomultiplier tubes, designed to detect single photons. A photon strikes a photosensitive material, generating an electron. This electron is accelerated down a high-voltage tube, knocking additional electrons free from electrodes, creating an electron cascade that can be detected.
The electron cascade may or may not be detected using camera-like photosensors (using a phosphor screen to turn the electron cascade back into light) (nightvision goggles do something like this, photon-counting tubes may measure the charge transfer directly).
When I first read about these things I thought it had something to do with solid glass spheres that for some reason, in combination with the ice, had optical properties that allowed them to capture neutrinos.
Ice is used because it's reasonably transparent. That's about it. Neutrino detection in this detector seems to be purely based on scattering of neutrinos against other particles with enough energy to produce Cherenkov light as the other particles fly off. How they plan to focus exclusively on muons is beyond me. With electron neutrinos you'd mainly get electron scattering as opposed to direct synthesis of muons. While mu neutrinos could produce muons via Weak-force interactions, they'll have scattering interations as well, and you have plenty of electron neutrinos present too.
No, they're just cameras. Why make it sound more complex than it really is?
Cameras produce images. Photomultiplier tubes don't (they just indicate that a photon hit the tube). Determination of the path of the neutrino is done by looking at the timing of photon events in many detectors in the array, and looking at which detectors registered events at all.
Aside from improving the two you already mentioned with new technology to make them more compellingly profitable, why not pick and choose exactly which asteroid components would be 1) most easily extractable and refinable once located and 2) most valuable when already in orbit per unit of mass.
Ah, so you *are* assuming that the materials will be used in space.
What makes you think there's a market up there?
Supplying metals, hydrocarbons, and dirt for space construction assumes that we have something very large we want to construct. Anything not "very large" would be cheaper to construct with Earth-supplied materials, as you wouldn't have to lift the production facilities.
Supplying air is useless - we can already recycle this at perfect efficiency given power.
Supplying water is similarly not useful - it would cost less to lift a distillation rig than it would to send a water extractor out to whatever your proposed source is.
Food cannot be found among the asteroids - it's either lifted from earth, or (should we ever build a very large station) grown in situ as part of the organics recycling process.
What is this market that you're trying to supply? I certainly don't see one that exists at present, or that can be predicted to exist without making some shaky assumptions.
Your criticism also managed to dismiss small unit resource extraction and space-based fabrication remarkably quickly. Don't make the relatively common mistake of assuming that a smelting system in space will even slightly resemble a smelting system on earth (especially in mass). Important differences include lack of gravity, unimpeded access to the sun, a lack of ambient oxygen or nitrogen to assist or interfere in reactions... A space-based small unit asteroid processing system will look rather unfamiliar to any modern expert in ore extraction and material processing.
You still have to either haul your asteroid into Earth orbit, or send all of your refined material back in transfer orbits. Good luck on making that, combined with your facility lift costs, less than the cost of just lifting material from Earth. If the destination is Earth, good luck making it cheaper than terrestrial mining and refining.
You are also assuming that your hypothetical solar furnace smelter can work in closed-loop mode without significant weight addition. If it can't, you're stuck - you need to send up all of your smelting reagents, or you need to send up an organics refinery to process hydrogen, carbon, or some other suitable substance out of your asteroid - which now has to contain hydrocarbons, which drops the ore yield for the asteroid you pick.
I am confident that a practical asteroid mining facility will cost much more than you are assuming. Do a detailed design and cost breakdown for yourself if you don't believe me.
Start reading NASA reports about automated lunar factories (circa 1981), then use some of those ideas as starting points
I will believe the cost and complexity estimates for fully automated lunar mines/smelters/factories when someone manages to build a fully automated terrestrial factory with the same capabilities. Until then, I stand by my assertation that they'll be extremely expensive and have a very heavy set of starting components.
Automated lunar factories have been proposed far earlier than 1980. It's one of those things that'll be really cool if it's finally built, but for which the cost and complexity estimates have been going up every time a new study is done.
If you're building something Really Huge in space, it's cost effective to think about building mines and factories on the moon (probably manned, as that _reduces_ the cost and complexity). For anything smaller than "really huge", you're better off lifting the materials from Earth.
Sounds like you were figuring on the cost of buying and lifting the solar cells into orbit using something like the Shuttle at $4000/pound and $10/watt.
Whereas you are proposing to lift a fully automated lunar mining facility, refinery, and solar cell fabrication facility *and* parts for a railgun into a lunar transfer orbit.
If Bell's figures are correct, then the OSV will be so overweight that the available rocketry will be unable to lift the cargos it is designed for, into orbit.
You appear to be saying that the OSV will be successful because it has to be.
Bell says that the OSV will be unable to perform if it is a winged design. All of the assertations that it will fail depend on a winged design being adopted. Neither you, nor Bell, provide a convincing proof that the design will be winged, and NASA has a very strong incentive to produce a more conservative capsule design (a non-working design will leave them with a non-working vehicle when the last shuttles disintegrate or are grounded).
Why would NASA not produce a capsule design?
Regarding the continued use of the shuttle: if the Shuttle is all they have in 2010, they will need to continue using it or else give up going into space. No matter what you or anyone else says now. Bell thinks this is the most likely outcome so presents it almost like a straightforward prediction.
Or take option c), and keep paying the Russians to launch things and slide them a bit more money to increase the number of space station supply launches.
We've lost two shuttles in 20 years. If NASA wants to keep using them, they're going to have to start building new ones as we lose more.
The rest is extrapolation based on what must happen *if* NASA don't recognize and act on the above quickly enough. It's no good bitching about it: the OSV just won't work and unless NASA drops it quickly (and they aren't) they will indeed be continuing to rely on the Shuttle for longer than they had planned. 2010 deadlines notwithstanding.
You're making the same assumption he is - that the OSV designed by NASA will be an expensive, impractical design. Given the constraint that it has to work, I don't see this as a foregone conclusion.
He *still* presents as fact - not a what-if scenario - this allegation, along with the allegation that NASA will use the shuttle for cargo indefinitely.
We appear to agree on reasonable solutions to the problem, but not on what the author of the article is asserting.
That's the thing... for launch vehicles, chemical propellants are the best that there is. Unless you count an elevator concept... which is technically propellantless. It's not broken technology, it's the laws of physics.
He may have been referring to air-breathing designs (which give you some of your fuel mass from the atmosphere) or to designs that receive power from the ground (and typically use air as reaction mass), like laser launchers, or to designs that use a ground-based accelerator to boost projectiles (which limits trajectories, but there are ways around that).
All of these approaches have problems, and it's questionable if they'd be cheaper than fuel+oxidizer chemical rockets, but the point is that other options do exist.
The still DO need a shuttle, and quite urgently, because the soyuz -progress can't carry enough stuff to keep them alive up there, even wit their reduced crew of two
Money is not the issue. If you can't call out at least three ways to make substantial revenues ($x > $1 * 10e10) from space in less than five minutes of trying, then you aren't smart enough to be commenting on the issue. The problem is getting permission from the US government to go after it, which it currently isn't giving.
Care to list these?
Last time I checked, the ESA wasn't limited by the US government's wishes regarding space launches.
The old favourite money-maker was solar power satellites. You'll have an interesting time convincing me that the cost of building these amortized over their lifetime is less than the cost of the same amount of power generated on earth, even without considering the cost of the receiver arrays on Earth.
The new favourite money-maker is finding a metal-rich asteroid, towing it into Earth orbit, and mining it. The problem is that this requires an *incredibly* huge investment - you have to bring high-Isp engines big enough to move an asteroid out of Earth's gravity well. This is assuming that you still plan to do the smelting on Earth - smelting in space requires you to haul up even more equipment. I am very skeptical of the investment paying off, as metal ores aren't exactly expensive here on earth (it's one of those "make it up in volume" proposals).
The new (or at least, new-again) favourite is the space elevator. The problem is that unless you have a good reason to haul *lots* of cargo into space, the elevator won't be profitable to build. It too will have to amortize its costs over a relatively short investment window, and it will need to be maintained. The costs of construction and maintenance must be amortized into the lift price for cargo. The amount of cargo that _can_ be transported is limited by the amount of time taken to lift it to geosync (not LEO - it won't have enough transverse velocity to stay in orbit). The total amount of cargo that can be on the elevator is at most comparable to the mass of the elevator itself, and probably much less (the elevator without cargo really pushes materials limits even with magical defect-free long-chain nanotubes). This limits throughput, putting a lower limit on cost of lift even under the best of conditions. In practice, unless there's a good reason to put things in space, volume will be even lower (driving costs up even more if you want to pay back the investment cost, which lowers volume again...).
You're not the only one who's put a lot of thought into ways of making money from space. As far as I can see, most of them presuppose a reason to be in space en masse in the first place.
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If you're looking for architecture, try Toronto. We have the CN Tower, which was the world's tallest free-standing structure for several decades (and still might be; I'd have to doublecheck). We have plenty of other strange architecture as well - City Hall looks enough like an alien city that it was featured as one on ST:TNG, and Robarts Library in the University of Toronto was built with wierd threefold symmetry (the only right angles in the place are vertical).
If you're looking for science, try the Ontario Science Centre in Toronto, and Science North in Sudbury (though between that and the giant nickle, that's all there is to see in Sudbury that I'm aware of).
For more tech, maybe email University of Toronto, York University, Waterloo University, and other places and see if you can schmooze a tour of the engineering or physics laboratories. I managed to get a tour of a lab with a "T3" laser by a friend-of-a-friend route ("Table-Top Terawatt"; a laser that uses the "chirped pulse" method to stuff a few joules of energy into a 100-femtosecond pulse).
It may also be worthwhile taking a tour of ATI while you're in the country, though if I recall correctly they were in Montreal, Quebec (which is also a great place to visit; just remember that "pedestrian == fodder" as far as the motorists are concerned).
Lastly, if you're literally into backpacking, try Algonquin Park. Rent a canoe for even more fun - there are routes that can take weeks to paddle through. For something shorter and closer to Toronto, Mono Cliffs Provincial Park has a very beautiful set of trails that you can easily spend a day walking through.
Enjoy.
Okay for the last 20 years they've been working on this. WHY are they not looking into solid state storage?
Because "solid state storage" to date has meant either battery-backed RAM, which is extremely expensive per gigabyte, or experimental optical or electro-optical approaches that aren't anywhere close to production.
There are plenty of companies within 2 years will have drives that will blow away current drives in speed and capacity. One such company is using nanotech to offer 1 terabit per cm2. And it'll run at 10x the speed of current memory.
Check through science magazines for the last 20 years or so, and you'll see many announcements in this vein. Believe them when they're going into full-scale production at the advertised density. Not before, and not with prototypes that lack on any front.
There needs to be a more efficient way to copy/move/edit giant (video) files before this becomes practical... a RAID setup in every computer is not the answer, faster (exponentially) solid state storage media is.
Data transfer, be it from a hard drive's platter or from a RAM chip, is a fundamentally serial operation. You have an interface of fixed size (number of bus lines, or number of platters with read heads on them), and are modulating in time to transmit data.
While there's a big gap between the two - it's easier to vary bus signals quickly than to run a platter past a read head at warp factor 9 - the disparity is by no means growing exponentially. Bus speeds started slowing down relative to transistor speeds at least a decade ago.
That, and even with current speeds transmitting a video clip takes much less time than recording it did.
Essentially, as I understand it, with longitudinal recording the poles of the bits are pointed flat on the surface. Imagine a bar magnet. Put the long flat end of the bar on the platter. That's longitudinal recording.
With perpendicular recording the bar magnet would be standing on it's end.
Ah.
Now I vaguely recall someone trying to market floppy drives that did that, about a decade ago.
Any numbers on what the minimum size of a domain is in each scenario? One of the papers the other posters linked put the maximum density increase at about a factor of 4, which is consistent with domain size not changing much (just orientation).
I wonder, will magnetic storage (in any number of dimensions) ever get eclipsed by non-magnetic ones like these?
Maybe.
The disadvantage optical schemes have is that the size of a bit's worth of storage medium is the size of a wavelength of light. While magnetic media have limits too, the ultimate density limit for EM devices is the size of a small cluster of atoms (or even one atom) - much, much denser.
While holographic schemes store bits in a distributed manner instead of in individual buckets, the limit ends up being the same (proof is beyond the scope of this reply; think "Fourier transforms").
My own bet is that storage of the future will be through some kind of electrical scheme that lends itself to chemical self-assembly (picture a 3D tangle of polymer spaghetti where every crossing of strands can store one bit of information). Magnetic storage has enough of a lead that it will take quite some time for any alternative to catch up, though.
I don't have a website handy, but as I understand it, when you're doing high-speed transfers, it's far easier with serial than parallel because you don't have to worry about the bits all getting there at the same time.
You can get around this to a large extent by having self-clocked encoding on each of the signal lines, and a data buffer at the end to line things back up (or a series of delay-locked loops to literally line the signals back up).
The popular parallel connectors (and buses) don't do this, though, and cross-talk is still a problem no matter what.
...engineers are working with software developers on a way to dramatically reduce power consumption by maximizing the number of 0-bits in memory.
The grain of truth to this joke: There is a well-known technique that reduces the number of 1s in words transmitted on a bus by inverting words that are more than half 1 (and setting an extra bit indicating that the word has been inverted). The idea is to reduce the number of transitions on the bus lines, as a change in state is what dissipates power.
Could someone explain (/point me to a website) as to what this paragraph means?
"We always have concerns about new connectors and backplane designs but those problems are minimized in a serial environment where the wiring is point-to-point,"
"Connecting devices fast is a lot easier when there's only two of them."
a crackdown on file-sharing. If they take that away from us, then whats the point of having that much space?
Legitimate content.
It's easy enough to end up with tens of thousands of photographs on your machine if you're in the habit of carrying a digital camera around. Now, think about what happens when you snap video clips the way you currently snap photographs.
This is already happening. With cameras being integrated into phones, it's growing even more.
How much extra storage will this give me on the same number and size of platters?
According to the article, it will increase it by about a factor of 5-10, going from 100-200 Gbit/in^2 as an approximate upper bound to standard storage to something in the range of 1 Tbit/in^2.
Does anyone have a link to a description of this that's more detailed than "stacking bits on end"?
Are they using platters with trenches and storing information on the sidewalls?
Are they using some means of reading and writing at many depths within the platter without disturbing other layers?
The article says the technology has been under investigation for 20 years, so presumably there's a forest of technical literature on it.
They also said that the number may actually be too small, given that light from some parts of the Universe hasn't had time to reach us yet. So it may be impossible to determine the total size of the Universe.
The total size of the universe may even be infinite. At any given time, we can only see the parts close enough for light emitted in the past to reach us, but to the best of my knowledge there is no restriction on the dimensions of the universe as a whole (perhaps an astrophysicist can enlighten me if I'm mistaken?).
One question I've always had is: when we look back in time to the creation of the Universe, we see light from that time. So the light has been traveling for 15 billion years to get to us. But if that light has been traveling that whole time toward us, how did we get here first?
It took the long route.
Light that was emitted substantially after the big bang would have been emitted from objects already quite far away from us. This gives more than enough time for it to reach us.
As the universe expands, more space is added between any given points in the universe. Thus, light emitted from an object that was initially quite close to us could find itself traversing a surprisingly large distance before finally reaching us. This is why light from the very early universe took so long to reach us, if I understand correctly.
they had an article about a newly developed radiation suit - using various organic salts embedded in the textile, you can get (for the same price as lead) just as good radiation protection with what appears to be a thick cloth. It is definently not as bulky as lead, and I believe it also allows water to evaporate from your body.
It's as bulky (and as heavy) as lead (more bulky, in fact, as there's less lead per unit volume). It's just a lot more flexible, which makes it far more practical to wear.
unfortunetely, as we all know, when you start removing quality out of a project, the chances of that project succeeding become less and less.
The idea (for space probes at least) is that being able to launch more probes for the same amount of money makes up for the increased failure rate.
Yes, you can create open generic CPU, and everybody would be able to build an alarm clock or server out of it. Yet if you have a chip for alarm clock that is proprietary, but suits just fine alarm clock builders, 10 times smaller, 5 times cheaper, consumes 13 times less energy, what would you choose?
Being proprietary vs. being non-proprietary and being generic vs. being specialized are unrelated qualities.
The question is not whether you'd use a non-proprietary generic processor or a proprietary specialized processor to build that alarm clock. The question is whether you'd use a proprietary or non-proprietary alarm clock chip to build the alarm clock.
The original poster also appears to be confused about the word "proprietary". A proprietary design is one that someone owns. The design of Intel microprocessors is proprietary - just try fabbing your own chips from copies of Intel's masks and see how far you get. x86 clones exist because, while the implementation is proprietary, the instruction set and behavior are still _documented_, and these documents are available for anyone to view. While you can't build your own copy of an Intel processor, you can build another one that does the same thing as far as programs are concerned (possibly better than Intel's does, possibly not).
Similarly, whether or not you can write your own software for a device has no relation to whether the device's design is proprietary - it relates to whether the device's programming specs are public or not.
[/soapbox]
I can't help but wonder if a high tech civilization using fission, fusion, antimatter and who knows what.... would generate high levels of nutrino flux and if results from detectors such as these could be used as a device to detect such?
While a civilization using any of several varieties of nuclear power could produce substantial neutrino emissions, these would be swamped by the neutrinos emitted by their parent star.
Also, the fusion reactions proposed for power production do not produce substantial numbers of neutrinos. Neutrino production occurs in Weak-force interactions, which tend to have cross-sections lower than the Strong-force interactions that dominate the various fusion schemes involving D, T, and/or He3. The sun produces neutrinos because to get hydrogen (p) turned into helium (2p + 2n) you need Weak-force interactions to produce the neutrons. Thus, plain hydrogen fusion produces neutrinos because there are no fusion paths that _don't_ (this is also one of the reasons why fusing plain old hydrogen is very difficult).
The idea behind SETI is to search for alien transmissions in bands where there is relatively little ambient noise. Neutrino emission isn't such a case.
Interesting idea, though.
I think my way is cheaper.
Only if you assume the infrastructure will be used only for the purpose of building powersats and will be thrown away immediately afterwards.
a) It has a finite maintenance lifetime. Even the most aggressively designed self-maintaining plant (which makes the design at least another order of magnitude more complicated) requires specialty parts that must be produced on Earth.
b) It produces power satellites at a limited rate. The power satellites produced over the lifetime of the plant may very well weigh _less_ than the lunar mining/smelting/fabrication/launch facility. It's straightforward to make solar collectors light weight, either by using thin-film cells or aluminized mylar concentrating mirrors or both. Your lunar facility, on the other hand, will be _heavy_, as it must deal with very large amounts of bulk material, and be spread over a very large area (especially the mass driver used for launch).
Do the math - figure out how many satellites you need for your target market and their mass. Then figure out how big a mining facility you need to build them within a reasonable length of time (as both your satellites and your production facility have finite lifetimes).
Lunar material supply is only practical if you need very large amounts of relatively non-specialized material in space. This means "giant space station" or "city on the moon", neither of which would pay for itself, and so neither of which is currently planned by the private sector.
Is this a stupid analogy or what? This can be said about any type of light detector. This is like saying a digital camera works like a light bulb in reverse... duh? So these "modules" are just simply really sensitive digital cameras networked together.
Not quite. These are photomultiplier tubes, designed to detect single photons. A photon strikes a photosensitive material, generating an electron. This electron is accelerated down a high-voltage tube, knocking additional electrons free from electrodes, creating an electron cascade that can be detected.
The electron cascade may or may not be detected using camera-like photosensors (using a phosphor screen to turn the electron cascade back into light) (nightvision goggles do something like this, photon-counting tubes may measure the charge transfer directly).
When I first read about these things I thought it had something to do with solid glass spheres that for some reason, in combination with the ice, had optical properties that allowed them to capture neutrinos.
Ice is used because it's reasonably transparent. That's about it. Neutrino detection in this detector seems to be purely based on scattering of neutrinos against other particles with enough energy to produce Cherenkov light as the other particles fly off. How they plan to focus exclusively on muons is beyond me. With electron neutrinos you'd mainly get electron scattering as opposed to direct synthesis of muons. While mu neutrinos could produce muons via Weak-force interactions, they'll have scattering interations as well, and you have plenty of electron neutrinos present too.
A good introduction to neutrino detection is at http://www.sno.phy.queensu.ca/sno/sno2.html (Sudbury Neutrino Observatory page).
No, they're just cameras. Why make it sound more complex than it really is?
Cameras produce images. Photomultiplier tubes don't (they just indicate that a photon hit the tube). Determination of the path of the neutrino is done by looking at the timing of photon events in many detectors in the array, and looking at which detectors registered events at all.
Aside from improving the two you already mentioned with new technology to make them more compellingly profitable, why not pick and choose exactly which asteroid components would be 1) most easily extractable and refinable once located and 2) most valuable when already in orbit per unit of mass.
Ah, so you *are* assuming that the materials will be used in space.
What makes you think there's a market up there?
Supplying metals, hydrocarbons, and dirt for space construction assumes that we have something very large we want to construct. Anything not "very large" would be cheaper to construct with Earth-supplied materials, as you wouldn't have to lift the production facilities.
Supplying air is useless - we can already recycle this at perfect efficiency given power.
Supplying water is similarly not useful - it would cost less to lift a distillation rig than it would to send a water extractor out to whatever your proposed source is.
Food cannot be found among the asteroids - it's either lifted from earth, or (should we ever build a very large station) grown in situ as part of the organics recycling process.
What is this market that you're trying to supply? I certainly don't see one that exists at present, or that can be predicted to exist without making some shaky assumptions.
Your criticism also managed to dismiss small unit resource extraction and space-based fabrication remarkably quickly. Don't make the relatively common mistake of assuming that a smelting system in space will even slightly resemble a smelting system on earth (especially in mass). Important differences include lack of gravity, unimpeded access to the sun, a lack of ambient oxygen or nitrogen to assist or interfere in reactions... A space-based small unit asteroid processing system will look rather unfamiliar to any modern expert in ore extraction and material processing.
You still have to either haul your asteroid into Earth orbit, or send all of your refined material back in transfer orbits. Good luck on making that, combined with your facility lift costs, less than the cost of just lifting material from Earth. If the destination is Earth, good luck making it cheaper than terrestrial mining and refining.
You are also assuming that your hypothetical solar furnace smelter can work in closed-loop mode without significant weight addition. If it can't, you're stuck - you need to send up all of your smelting reagents, or you need to send up an organics refinery to process hydrogen, carbon, or some other suitable substance out of your asteroid - which now has to contain hydrocarbons, which drops the ore yield for the asteroid you pick.
I am confident that a practical asteroid mining facility will cost much more than you are assuming. Do a detailed design and cost breakdown for yourself if you don't believe me.
Start reading NASA reports about automated lunar factories (circa 1981), then use some of those ideas as starting points
I will believe the cost and complexity estimates for fully automated lunar mines/smelters/factories when someone manages to build a fully automated terrestrial factory with the same capabilities. Until then, I stand by my assertation that they'll be extremely expensive and have a very heavy set of starting components.
Automated lunar factories have been proposed far earlier than 1980. It's one of those things that'll be really cool if it's finally built, but for which the cost and complexity estimates have been going up every time a new study is done.
If you're building something Really Huge in space, it's cost effective to think about building mines and factories on the moon (probably manned, as that _reduces_ the cost and complexity). For anything smaller than "really huge", you're better off lifting the materials from Earth.
Sounds like you were figuring on the cost of buying and lifting the solar cells into orbit using something like the Shuttle at $4000/pound and $10/watt.
Whereas you are proposing to lift a fully automated lunar mining facility, refinery, and solar cell fabrication facility *and* parts for a railgun into a lunar transfer orbit.
I think my way is cheaper.
If Bell's figures are correct, then the OSV will be so overweight that the available rocketry will be unable to lift the cargos it is designed for, into orbit.
You appear to be saying that the OSV will be successful because it has to be.
Bell says that the OSV will be unable to perform if it is a winged design. All of the assertations that it will fail depend on a winged design being adopted. Neither you, nor Bell, provide a convincing proof that the design will be winged, and NASA has a very strong incentive to produce a more conservative capsule design (a non-working design will leave them with a non-working vehicle when the last shuttles disintegrate or are grounded).
Why would NASA not produce a capsule design?
Regarding the continued use of the shuttle: if the Shuttle is all they have in 2010, they will need to continue using it or else give up going into space. No matter what you or anyone else says now. Bell thinks this is the most likely outcome so presents it almost like a straightforward prediction.
Or take option c), and keep paying the Russians to launch things and slide them a bit more money to increase the number of space station supply launches.
We've lost two shuttles in 20 years. If NASA wants to keep using them, they're going to have to start building new ones as we lose more.
The rest is extrapolation based on what must happen *if* NASA don't recognize and act on the above quickly enough. It's no good bitching about it: the OSV just won't work and unless NASA drops it quickly (and they aren't) they will indeed be continuing to rely on the Shuttle for longer than they had planned. 2010 deadlines notwithstanding.
You're making the same assumption he is - that the OSV designed by NASA will be an expensive, impractical design. Given the constraint that it has to work, I don't see this as a foregone conclusion.
He *still* presents as fact - not a what-if scenario - this allegation, along with the allegation that NASA will use the shuttle for cargo indefinitely.
We appear to agree on reasonable solutions to the problem, but not on what the author of the article is asserting.
That's the thing... for launch vehicles, chemical propellants are the best that there is. Unless you count an elevator concept... which is technically propellantless. It's not broken technology, it's the laws of physics.
He may have been referring to air-breathing designs (which give you some of your fuel mass from the atmosphere) or to designs that receive power from the ground (and typically use air as reaction mass), like laser launchers, or to designs that use a ground-based accelerator to boost projectiles (which limits trajectories, but there are ways around that).
All of these approaches have problems, and it's questionable if they'd be cheaper than fuel+oxidizer chemical rockets, but the point is that other options do exist.
The still DO need a shuttle, and quite urgently, because the soyuz -progress can't carry enough stuff to keep them alive up there, even wit their reduced crew of two
Um, launch twice as many?
Money is not the issue. If you can't call out at least three ways to make substantial revenues ($x > $1 * 10e10) from space in less than five minutes of trying, then you aren't smart enough to be commenting on the issue. The problem is getting permission from the US government to go after it, which it currently isn't giving.
Care to list these?
Last time I checked, the ESA wasn't limited by the US government's wishes regarding space launches.
The old favourite money-maker was solar power satellites. You'll have an interesting time convincing me that the cost of building these amortized over their lifetime is less than the cost of the same amount of power generated on earth, even without considering the cost of the receiver arrays on Earth.
The new favourite money-maker is finding a metal-rich asteroid, towing it into Earth orbit, and mining it. The problem is that this requires an *incredibly* huge investment - you have to bring high-Isp engines big enough to move an asteroid out of Earth's gravity well. This is assuming that you still plan to do the smelting on Earth - smelting in space requires you to haul up even more equipment. I am very skeptical of the investment paying off, as metal ores aren't exactly expensive here on earth (it's one of those "make it up in volume" proposals).
The new (or at least, new-again) favourite is the space elevator. The problem is that unless you have a good reason to haul *lots* of cargo into space, the elevator won't be profitable to build. It too will have to amortize its costs over a relatively short investment window, and it will need to be maintained. The costs of construction and maintenance must be amortized into the lift price for cargo. The amount of cargo that _can_ be transported is limited by the amount of time taken to lift it to geosync (not LEO - it won't have enough transverse velocity to stay in orbit). The total amount of cargo that can be on the elevator is at most comparable to the mass of the elevator itself, and probably much less (the elevator without cargo really pushes materials limits even with magical defect-free long-chain nanotubes). This limits throughput, putting a lower limit on cost of lift even under the best of conditions. In practice, unless there's a good reason to put things in space, volume will be even lower (driving costs up even more if you want to pay back the investment cost, which lowers volume again...).
You're not the only one who's put a lot of thought into ways of making money from space. As far as I can see, most of them presuppose a reason to be in space en masse in the first place.