Water as a liquid isn't stable in vacuum and it evaporates, but UV doesn't decompose it. Comets are water.
Comets are also out in a very dark, very cold place. When they come close to the Sun, water boils off from them, then gets ionized by solar radiation (UV and other bands). That means it decomposes into ions.
Yes, this idea of putting down roots and spreading out petals during the peak of the day could buy you quite a bit. However, it also imposes a much greater requirement for batteries, which brings us right back to the other disappointingly stagnant technology. If only we could come up with a high-power-density battery system with a service life much greater than the current few hundred to few thousand cycles, a lot of things would get a lot better.
The best power density I see for current commercial technology is less than 150 Wh/kg. That means the batteries to store 75kWh of energy would weigh half a ton. If you want a week's worth, that's 3.5 tons, about the weight of, well, a motorhome.
For one, 15kWh is about the average amount a three bedroom house uses in a day. That RV would move just fine off of that...
...just not for long.
Most people don't seem to realize that the typical vehicular engine can produce much more power than the typical household electric service. A generous 200A 240V feed equates to about 64 horsepower. At that power level, you consume 15kWh in a bit less than 20 minutes.
Looking at it another way, an RV will typically get around 10 mpg. That means you're using about 3.3kWh of gasoline per mile (energy content of gas is about 33kWh/gal). Assuming you lose about 80% of that to thermodynamics and other losses not present in an electric power train, you'll still need something like 0.8 kWh per mile, giving you a range of maybe 20 miles per day. And that's neglecting all the other things you'd like to do with the power you collect.
The fold-out panels hold promise; see the comment below.
Adding $70,000 to a high end motor home, that then never needs fuel, grid connection, etc. Even if it just provides say 500 miles of travel a week + complete self sufficiency (ok I still probably need to recycle the waste for clean water) Is well worth considering (would trade my house in as a down payment.)
Good luck with that. A 20% efficient panel will collect maybe 1 KWh/m^2 over the course of a mid-latitude day, on average. A typical motor home will have somewhere around 15 m^2 of roof area. That means you can collect 15kWh per day with today's panels. That's enough to run an electric motor at 20HP for a bit less than an hour. Or, looking at it another way, that's about the energy you get from burning half a gallon of gas.
This is all from the back of a pretty small envelope, as it were -- your panels won't be oriented optimally toward the sun, but you could also cover the sides and ends, so the total-power-intercepted figure shouldn't be too far off. An electric power train is a lot more efficient than an IC engine and power train. But, bottom line, it's not going to be practical to run an RV on any conceivable solar arrangement, unless it's got big dragonfly wings covered with panels, which would run afoul of DOT regulations.
If it costs less than 10 times as much as a 10%-efficient cell, I'm all over it. If it costs 100 times as much, I have no interest, unless I'm really constrained for space and/or weight, or installation costs per square meter are really high.
No, wait. If "99% efficient" means only 1% of the incident radiant energy gets past it or gets re-radiated as heat, I'm all kinds of interested. But, of course, that's not ever going to happen.
First, it's a great achievement just to get the protein appearing sustainably in the right place. More importantly, though, this provides color perception in adult animals whose brains have never received red/green differential stimuli? I never would've guessed that was possible.
It gives me hope that, when we get retinal or cortical implants that can accept more than three bands of color, our brains will actually be able to handle them. Bring on all fifty-seven colors of the rainbow!
Meanwhile, as scientists on an outer planet look our way:
"Rocky planets like the one recently discovered are turning out to be quite common throughout our area of space. Given a dense enough atmosphere, this planet could even support life like ours, although it's hot enough to kill all but the most tolerant extremophiles known. Spectroscopic analysis, though, reveals its deadly nature: much of its surface is covered with molten hydroxic acid, which forms toxic clouds and then falls as corrosive rain. If life-giving ammonia was ever present on the surface, it's long since combined with the abundant free oxygen in the atmosphere. Our chemists are still uncertain what could produce so much free oxygen; fantasists have speculated on forms of life that would metabolize oxygen in the same way that we metabolize hydrogen, but the analogy breaks down quickly as you look more closely at the chemistry involved."
First, it shines a brighter-than-usual light upon the stupidity of "censorship watchdogs".
Second, it antagonizes a company with a lot of money and a lot of public-relations skill. If you're in the censorship business, I'm happy to see you make large, powerful and articulate enemies.
...of whale oil, since it's actually using gasoline, not whale oil, as its fuel. But, hey, whale oil is fuel, and I don't need more than two gallons of it, so my claim is exactly as well-founded as theirs.
Plug-in hybrids are a great idea. But stop already with the stupid and misleading claims about "gas mileage" based on getting most of your energy from the grid.
I don't have firsthand experience, but here's one example study. No mention of what kind of "discomfort" the patients experienced, but I'd expect pins-and-needles sensations. This is from high gradient rate-of-change.
For head motion, again, I don't have first-hand experience, and I'm having a harder time Googling up examples. I have the impression that it's mostly dizziness/vertigo. As I said, I'd assumed that it was an induction effect on axons, but thinking about it more, I wonder if it's diamagnetic force on the fluid in the semicircular canals. 7T isn't enough to levitate, but it's certainly enough to exert force.
For proof that magnetic fields can influence neural activity, you need only look at the burgeoning field of transcranial magnetic stimulation. Those field rates of change are orders of magnitude beyond anything you can coax out of an MR scanner, though.
Oh, but they do get interesting, if you disable the rate-of-field-change safeties that are integrated into clinical scanners. Our lab does high-resolution MR imaging in small animals, and if we don't disable those safeties, we can't get the gradients we need. (In this field, "gradient" refers to a varying magnetic field that's overlaid on the nominally constant and uniform field from the main magnet.)
Even without involving the gradients, if you move your head too quickly near the bore of our 7T magnet, it can have very odd effects. I'm not sure of the mechanism, but I've assumed it has to do with currents induced in axons. They aren't wires, but they are conductive channels, and as Volta showed, they do respond to purely electrical stimulation.
(I hope someone better versed in MR physics will chime in here. I'm just a lowly computer guy, relying on what I've soaked up from my co-workers due to curiosity and overheard discussions.)
That said, if you move a wire through it, you'll generate one hell of an electic field, but only while the strength of the magnetic field through the wire is changing.
Wait, if you move a wire through an unchanging field (perpendicularly), you'll induce a current, right? You'll also induce one if you hold a wire still in a field whose strength is changing.
On a related note, axons are in many ways like long wires. Move around in a high magnetic field, and you'll notice odd effects. It's more of a problem for people than for mice -- our axons run longer, and so inductive effects are stronger.
This was a static field. A static field is like resting your head on the floor. An oscillating field is like beating your head against the floor.
Of course, nothing will stop some people from claiming that strong static magnetic fields cause cancer. Maybe they can fight it out with the people who say that they cure disease.
No, no, not 80x25. Go to the old standard from when every dot was precious -- 5x7 characters in a 6x8 matrix. With six 30" displays, that gives you 1280 columns and 400 rows, or approximately 256 VT100's, with an extra 16 rows of text across the bottom for status bar, function-key labels and whatnot.
Or 500 TRS-80 Mod I displays. Or, for that matter, over 54 green-bar printout pages, or more than an entire box of punch cards.
Oh, nothing could be simpler. You feed them a diet high in soluble fluoride, and lots of intense UV, and they metabolize the stuff into UF6. At the same time, they form into long, columnar biofilms, with flagellae projecting that they use to fan the UF6 into fast circulation. The 235U segregates preferentially to the center, while the 238U goes to the perimeter. All you have to do is separate it out, in lots of stages.
Alternatively, they could bioluminesce at a precise frequency that excites molecules containing 235U, but not 238U.
There are lots of other possibilities. It's just a matter of engineering.
...before the Mac existed. Multiple BARCO monitors, driven by DEC GIGI terminals. You'd send drawing commands to them over 9600-baud hard lines, from a VAX 11/780 with a separate process to control each display. It was... primitive. But it was a multi-screen interactive system, at a time when such things were uncommon to say the least.
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There's a Geneva Convention specifically designed to cause blindness?
Only if you keep doing that with your hand while carefully searching the text for phrases that can possibly be parsed ambiguously.
It's interesting that there's a Geneva Convention on weapons specifically designed to cause blindness , but apparently nothing about deafness.
Water as a liquid isn't stable in vacuum and it evaporates, but UV doesn't decompose it. Comets are water.
Comets are also out in a very dark, very cold place. When they come close to the Sun, water boils off from them, then gets ionized by solar radiation (UV and other bands). That means it decomposes into ions.
Yes, this idea of putting down roots and spreading out petals during the peak of the day could buy you quite a bit. However, it also imposes a much greater requirement for batteries, which brings us right back to the other disappointingly stagnant technology. If only we could come up with a high-power-density battery system with a service life much greater than the current few hundred to few thousand cycles, a lot of things would get a lot better.
The best power density I see for current commercial technology is less than 150 Wh/kg. That means the batteries to store 75kWh of energy would weigh half a ton. If you want a week's worth, that's 3.5 tons, about the weight of, well, a motorhome.
For one, 15kWh is about the average amount a three bedroom house uses in a day. That RV would move just fine off of that...
...just not for long.
Most people don't seem to realize that the typical vehicular engine can produce much more power than the typical household electric service. A generous 200A 240V feed equates to about 64 horsepower. At that power level, you consume 15kWh in a bit less than 20 minutes.
Looking at it another way, an RV will typically get around 10 mpg. That means you're using about 3.3kWh of gasoline per mile (energy content of gas is about 33kWh/gal). Assuming you lose about 80% of that to thermodynamics and other losses not present in an electric power train, you'll still need something like 0.8 kWh per mile, giving you a range of maybe 20 miles per day. And that's neglecting all the other things you'd like to do with the power you collect.
The fold-out panels hold promise; see the comment below.
Adding $70,000 to a high end motor home, that then never needs fuel, grid connection, etc. Even if it just provides say 500 miles of travel a week + complete self sufficiency (ok I still probably need to recycle the waste for clean water) Is well worth considering (would trade my house in as a down payment.)
Good luck with that. A 20% efficient panel will collect maybe 1 KWh/m^2 over the course of a mid-latitude day, on average. A typical motor home will have somewhere around 15 m^2 of roof area. That means you can collect 15kWh per day with today's panels. That's enough to run an electric motor at 20HP for a bit less than an hour. Or, looking at it another way, that's about the energy you get from burning half a gallon of gas.
This is all from the back of a pretty small envelope, as it were -- your panels won't be oriented optimally toward the sun, but you could also cover the sides and ends, so the total-power-intercepted figure shouldn't be too far off. An electric power train is a lot more efficient than an IC engine and power train. But, bottom line, it's not going to be practical to run an RV on any conceivable solar arrangement, unless it's got big dragonfly wings covered with panels, which would run afoul of DOT regulations.
If it costs less than 10 times as much as a 10%-efficient cell, I'm all over it. If it costs 100 times as much, I have no interest, unless I'm really constrained for space and/or weight, or installation costs per square meter are really high.
No, wait. If "99% efficient" means only 1% of the incident radiant energy gets past it or gets re-radiated as heat, I'm all kinds of interested. But, of course, that's not ever going to happen.
Smaller equals faster, and can equal lower power. Both of these are good for cellphones, and lots of other things.
More to the point, this particular advance means fewer individual chips, which means cheaper.
Or maybe "Dueling Banjos". So many ways to make people really want to get out of your way...
First, it's a great achievement just to get the protein appearing sustainably in the right place. More importantly, though, this provides color perception in adult animals whose brains have never received red/green differential stimuli? I never would've guessed that was possible.
It gives me hope that, when we get retinal or cortical implants that can accept more than three bands of color, our brains will actually be able to handle them. Bring on all fifty-seven colors of the rainbow!
...and then run the hot liquid through your radiators.
Meanwhile, as scientists on an outer planet look our way:
"Rocky planets like the one recently discovered are turning out to be quite common throughout our area of space. Given a dense enough atmosphere, this planet could even support life like ours, although it's hot enough to kill all but the most tolerant extremophiles known. Spectroscopic analysis, though, reveals its deadly nature: much of its surface is covered with molten hydroxic acid, which forms toxic clouds and then falls as corrosive rain. If life-giving ammonia was ever present on the surface, it's long since combined with the abundant free oxygen in the atmosphere. Our chemists are still uncertain what could produce so much free oxygen; fantasists have speculated on forms of life that would metabolize oxygen in the same way that we metabolize hydrogen, but the analogy breaks down quickly as you look more closely at the chemistry involved."
First, it shines a brighter-than-usual light upon the stupidity of "censorship watchdogs".
Second, it antagonizes a company with a lot of money and a lot of public-relations skill. If you're in the censorship business, I'm happy to see you make large, powerful and articulate enemies.
...of whale oil, since it's actually using gasoline, not whale oil, as its fuel. But, hey, whale oil is fuel, and I don't need more than two gallons of it, so my claim is exactly as well-founded as theirs.
Plug-in hybrids are a great idea. But stop already with the stupid and misleading claims about "gas mileage" based on getting most of your energy from the grid.
I don't have firsthand experience, but here's one example study. No mention of what kind of "discomfort" the patients experienced, but I'd expect pins-and-needles sensations. This is from high gradient rate-of-change.
For head motion, again, I don't have first-hand experience, and I'm having a harder time Googling up examples. I have the impression that it's mostly dizziness/vertigo. As I said, I'd assumed that it was an induction effect on axons, but thinking about it more, I wonder if it's diamagnetic force on the fluid in the semicircular canals. 7T isn't enough to levitate, but it's certainly enough to exert force.
For proof that magnetic fields can influence neural activity, you need only look at the burgeoning field of transcranial magnetic stimulation. Those field rates of change are orders of magnitude beyond anything you can coax out of an MR scanner, though.
But... but... surely it means that Swine = 1 + (Hysteria / Flu)?
In any event, it means that more Hysteria produces more Swine, and that means more bacon, so, hey, win-win scenario?
Thank you. I don't think I ever saw it explained in quite those terms, and they were apparently just the terms my brain was looking for.
Oh, but they do get interesting, if you disable the rate-of-field-change safeties that are integrated into clinical scanners. Our lab does high-resolution MR imaging in small animals, and if we don't disable those safeties, we can't get the gradients we need. (In this field, "gradient" refers to a varying magnetic field that's overlaid on the nominally constant and uniform field from the main magnet.)
Even without involving the gradients, if you move your head too quickly near the bore of our 7T magnet, it can have very odd effects. I'm not sure of the mechanism, but I've assumed it has to do with currents induced in axons. They aren't wires, but they are conductive channels, and as Volta showed, they do respond to purely electrical stimulation.
(I hope someone better versed in MR physics will chime in here. I'm just a lowly computer guy, relying on what I've soaked up from my co-workers due to curiosity and overheard discussions.)
That said, if you move a wire through it, you'll generate one hell of an electic field, but only while the strength of the magnetic field through the wire is changing.
Wait, if you move a wire through an unchanging field (perpendicularly), you'll induce a current, right? You'll also induce one if you hold a wire still in a field whose strength is changing.
On a related note, axons are in many ways like long wires. Move around in a high magnetic field, and you'll notice odd effects. It's more of a problem for people than for mice -- our axons run longer, and so inductive effects are stronger.
This was a static field. A static field is like resting your head on the floor. An oscillating field is like beating your head against the floor.
Of course, nothing will stop some people from claiming that strong static magnetic fields cause cancer. Maybe they can fight it out with the people who say that they cure disease.
No, no, not 80x25. Go to the old standard from when every dot was precious -- 5x7 characters in a 6x8 matrix. With six 30" displays, that gives you 1280 columns and 400 rows, or approximately 256 VT100's, with an extra 16 rows of text across the bottom for status bar, function-key labels and whatnot.
Or 500 TRS-80 Mod I displays. Or, for that matter, over 54 green-bar printout pages, or more than an entire box of punch cards.
Oh, nothing could be simpler. You feed them a diet high in soluble fluoride, and lots of intense UV, and they metabolize the stuff into UF6. At the same time, they form into long, columnar biofilms, with flagellae projecting that they use to fan the UF6 into fast circulation. The 235U segregates preferentially to the center, while the 238U goes to the perimeter. All you have to do is separate it out, in lots of stages.
Alternatively, they could bioluminesce at a precise frequency that excites molecules containing 235U, but not 238U.
There are lots of other possibilities. It's just a matter of engineering.
...nobody wanted to pay $18K a pop for them.
Read about how they were driven and you'll see one of the reasons they didn't catch on.
I'd love to see super-high-res screens, too, but as presbyopia sets in, it's getting less relevant to my own interests.
That's just... sad, really.
On the brighter side, I suppose you could now drive four DIVEs from a single PC.
...before the Mac existed. Multiple BARCO monitors, driven by DEC GIGI terminals. You'd send drawing commands to them over 9600-baud hard lines, from a VAX 11/780 with a separate process to control each display. It was... primitive. But it was a multi-screen interactive system, at a time when such things were uncommon to say the least.
citation