It's not just the size of the connector, it's the size you have to devote to an unknown future upgrade board.
Just look at the amount of empty space inside the average tower PC. You can't add that much upgrade flexibility to a laptop without ballooning its size.
Laptops are optimized for low size and weight. Desktops are optimized for upgrade flexibility. This naturally leads to two distinctly different products. Even hard drives and memory, which you can usually upgrade on a laptop, use different form factors in a laptop.
I agree. I doubt it's possible for a lens to focus on something at its surface. That would be infinitely close.
Maybe a laser diode would work. The system would have to project images onto the retina, rather than rely on the eye's lens to focus on a display at its surface.
Of course we're trying to outguess the optical experts designing the system. I'm sure they have a solution in mind. I just wish the article managed to explain what they're up to.
It's both shorter and simpler to go left. It's the next left after the left. If you go straight you get there also, but it's the third right and about twice as far. I do occasionally go that way myself for variety.
If you go on that street and keep on turning right, you'll be stuck in an infinite loop.
Of course, even in a regular grid if you keep turning right you'll go in circles forever. But in your case you'll be doing it on the same street.
There's a street near my house that does the same thing, it loops back and crosses itself. Directions to my house could include "turn left at the intersection of Alloway and Alloway". It only crosses itself once, so it's a unique landmark. But its simpler to just say "make the first left" in my case.
I think the most important question is what would mass adoption of solar power due to our power grid. Non-solar generated electricity would go through the roof, for starters - causing the adoption rate to increase - again causing rates on non-solar energy to increase - until at some point the power companies wouldn't be able to afford to operate their grids anymore.
Less demand shouldn't cause the price of electricity to increase. A reduction in the amount of expensive peak power should improve the situation a good deal.
We'll still need the power grid to give us power at night, or after whatever batteries we have run out. The first thing that will change is the laws that give you credit for the excess electricity your solar panels generate. With mass adoption of solar the grid will have to stop acting as a free battery (i.e. buying power from you at the same retail rate it sells for).
I suspect that this laser will be the kind that blinds everyone in line of sight.
More like the sort of laser that vaporizes everyone in sight. Not sure whether we're talking terawatt or petawatt though. Something in that range probably.
"MW class PLP rockets will be capable of launching small payloads with weights in the order of kg, such as nanosatellites or small parts for space stations, into LEO in a single stage reusable platform, or of accelerating them to unprecedented high speed for rapid-outcome deep space exploration. The scaling of PLP to higher power will be capable of accelerating spacecraft to near light speed."
So if it takes megawatt class lasers to launch a kilogram it will take gigawatts to launch tonnes. Which I find odd because I seem to recall figuring in the past that it takes a gigawatt of photons just to get a few newtons of thrust. So there is something going on here besides pure light pressure thrust.
As I understand it, lung tissue isn't a one way passage for oxygen and carbon dioxide, it simply equalizes the partial pressures of these two gasses between the air in the lungs and the bloodstream. Used venous blood has excess carbon dioxide and depleted oxygen relative to inhaled air, so the CO2 gets dumped and O2 gets picked up.
In the case of a lung full of vacuum both CO2 and O2 would be dumped into the lungs. Pretty well cleaning out any and all gasses from the bloodstream, making the blood delivered by the arteries useless. I wonder if you'd last longer if your heart simply stopped right away.
"The time of consciousness after loss of cabin pressure is reduced due to offgassing of oxygen from venous blood to the lungs. Hypoxia is the most immediate problem following a decompression."
Not only does vacuum mean truly zero air in your lungs, but your lungs are now working in reverse and dumping all remaining oxygen in your bloodstream into the vacuum. In just five or ten seconds the blood supplied to your brain is completely devoid of oxygen. That's what gets you.
It's true that slow and steady thrust will build up over time. The study says that a thruster given ten years would give a speed change less than a thousandth what the nuke could give. This should come as no great surprise since it really all comes down to the amount of energy as momentum you can apply to the asteroid. Nuclear weapons just contain many magnitudes more energy than any alternative. You just need to find a way to convert that energy to momentum, and even a wasteful conversion is likely to beat all other methods hands down.
Now if you can discover the threatening object soon enough and get an accurate enough projection of its trajectory, you may not need a lot of momentum to turn a collision into a near miss. In that case the other methods may work well enough. The study indicates that if we started on Apophis now with decades of lead time, we could get it moved enough with thrusters. If in 2029 the close pass put it on a collision course in 2036 we'd have no feasible option besides nuclear at that point.
Capturing an asteroid is thousands or millions of times harder than deflecting it. If you have years or decades notice you only have to nudge the asteroid by a small fraction of a meter per second, if you want to capture it into earth orbit you're going to have to slow it by some kilometers per second.
Since we're debating the feasibility of even nudging an asteroid off a collision course, capturing one is right out.
Few NEO asteroids are even a billionth the mass of the moon, so it's not going to have any appreciable affect on the tides. Tidal effect is proportional to mass divided by distance cubed (IIRC). That distance cubed factor means getting it closer really increases the effect, but for a rocky object to raise the same tides as the moon it has to be close enough to look the same size as the moon. For Apothis that would require being inside Earth's atmosphere, not a good place for orbiting an asteroid.
So society drives technological innovation, yes, but it absolutely depends on the right innovation coming along at the right time, and there is a certain amount of serendipity in that.
I have to disagree with you there, as I'm sure the author of the article would. Nothing depends on the "right" innovation coming along. Our technological society is an amalgam or whichever innovations came along and fit reasonably well together. This is not the best of all possible technological worlds, it's just good enough to make do. I think this is exactly what the author is getting at: no need to worship the latest break through gadget, it's not as important as you think it is.
He mentioned pneumatic delivery tubes and postulated an alternative technological path where they caught on completely and packages zipped across the city in moments. That's quite imaginable and would be pretty handy, but not as indispensable as some of it's users would no doubt claim it to be.
It's probably modded as funny by those who catch it as a Monty Python reference.
Surely you've heard Monty Python's lumberjack song? There is also a skit where an office worker, probably an accountant, talks about wanting to be a lion tamer, but is completely unprepared for the reality of facing an actual lion.
There is comedy inherent in office workers who dream of exciting occupations they are totally unsuited for. Computer programers didn't really exist when Monty Python was writing their comedy skits. Otherwise maybe they wouldn't have picked on accountants so much.
Have you noticed how hydroelectric power is always on big dams placed on white water type rivers? Ever see one in a swamp or on a sluggish river? That's because you need a good head of water to make it worth doing.
Sewers don't have that sort of water pressure involved. They are deliberately designed to slope gradually from the source to the treatment plant, with just enough drop to keep the sewage moving.
A bit a research finds that it takes 10 gallons per minute drooping 1 foot to generate a single watt of power. That's why serious power requires lots of water dropping a good distance.
You're making me wonder where all my power goes. 20 khw a day can't all be explained by lighting, refrigerator, microwave and computers. I suppose that the gas heating still uses a good deal of electricity just for the blower. I did notice the other day that the master bath sports eight 60 watt decorator bulbs. That's 480 watts just to light a bathroom, for heavens sake. Luckily those lights aren't on much.
Also, doing a little Google search, I found a bike that claims to generate 400 watts [los-gatos.ca.us], and a pedal device that claims to generate up to 1000 watts [emediawire.com]. Of course, I have no idea how sustainable those powers are.
That second link describes a system of springs that output at up to 1000 watts, but doesn't mention how long it takes to wind it. The first link does mention human output rates. It claims 425 watts as "burst output" only, with a 30 min average of 150 watts. Later it says "assuming you can crank out 125 watts for an hour, which is very ambitious". He also describes 130 watts as strenuous exercise.
Regarding your refrigerator, a consumer site I found claims: "A typical new refrigerator with automatic defrost and a top-mounted freezer uses less than 500 kWh per year". That would be about 1.5 kilowatt hours a day right there. I figure I blow another kilowatt hour or two each day just running lights.
So I doubt your electrical use is less than 1 kwh a day. Maybe the dollar figure sticks in your head better. Do you really pay less than 3$ a month for electricity?
While it would be fun to produce electricity by your own effort, it isn't economically practical. With a current price of about 10 cents a kilowatt hour, you'll probably only be able to produce enough electricity to equal one cent per hour. That's going to be an awful lot of hours pedaling before you've paid back the cost of the extra equipment. Probably longer than the lifetime of the equipment.
"I'm a marathon runner, and the amount of electricity I might generate from my daily exercise routine would probably generate all of my electrical needs for that day, with a little extra left over."
You must have a very energy efficient lifestyle then. As I understand it, the amount of energy a person can put out can run a laptop or a light bulb, but that's about it.
From - http://www.windstreampower.com/humanpower/hpgmk3.h tml - "The typical average continuous power that can be generated by pedaling the Human Power Generator is up to about 80 watts." So if I work out for an hour generating an even 100 watts, then I've produced a tenth of a kilowatt hour. But my house consumes about 20 kilowatt hours a day (during a cool season when I don't need the air conditioner, it's triple that in the summer). Human generation would be a drop in the bucket for me. Still, I've always wanted to get one of those things, it would be useful to have in an emergency.
they will sell the electricity to other country/state or province that cant afford the solar panel, Who's paying you to supply the electricity?
Who's paying them to distribute the excess electricity you generate? Power lines don't maintain themselves when there's an ice storm. Who's paying for the generation plants needed to run you house when it's dark and there's no wind and no one in your neighborhood is generating electricity?
There is a value to staying connected to the grid. It's very difficult to make yourself completely energy independent. Yes, you should be paid for supplying excess power to the grid, but your connection to it won't be for free.
According to one of the links, the human eye has an overall luminance vision range of 14 orders of magnitude from starlight to direct sun. You're correct that we can't see all that at once because of the way our eyes adapt to changing conditions, but the article also stated that the eye's instantaneous luminance vision range is five orders of magnitude. So in the same scene we can make out details with a contrast range of 100,000:1. That's why the blacks often look gray on a typical monitor with a contrast range of 500:1.
So, our eyes can see more than current monitors can present in terms of brightness. That's what Brightside is trying to produce: monitors with ten times brighter whites and ten times darker blacks. I'd love to get one of those, but not at the current price. Hopefully they'd be reasonable in a few years.
I get what you're saying. There is a difference between individual fitness and species fitness. In the end it's the fitness of the species as a whole that matters. An important component of a species fitness is its genetic diversity which gives it flexibility to adapt to changes.
Still, I'm not sold on saving every gene we can. Some of the nasty mutations are best removed from the gene pool. But I agree it's impossible to predict what future use a seemingly undesirable change could have. In combination with some other change it might become a great advance.
A ring/linear hybrid doesn't help the situation much. For a linear track with constant acceleration the first half of the velocity comes in the first quarter of the track. Going to mach 5 in a ring and then from 5 to 25 in a linear track only reduces the linear track length by 4%. You might as well build the whole thing straight.
For your 5 km diameter track, if you put human endurance at 10 g, you get a maximum speed of about 500 m/s. That's 1/16 orbital speed, less than mach 2. If you quadruple the size to 20 km you double the maximum speed to 1 km/s, an eighth of what you need. Want to guess how large it needs to be to achieve orbital speed with only 10 g of centripetal acceleration?
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It's not just the size of the connector, it's the size you have to devote to an unknown future upgrade board.
Just look at the amount of empty space inside the average tower PC. You can't add that much upgrade flexibility to a laptop without ballooning its size.
Laptops are optimized for low size and weight. Desktops are optimized for upgrade flexibility. This naturally leads to two distinctly different products. Even hard drives and memory, which you can usually upgrade on a laptop, use different form factors in a laptop.
I agree. I doubt it's possible for a lens to focus on something at its surface. That would be infinitely close.
Maybe a laser diode would work. The system would have to project images onto the retina, rather than rely on the eye's lens to focus on a display at its surface.
Of course we're trying to outguess the optical experts designing the system. I'm sure they have a solution in mind. I just wish the article managed to explain what they're up to.
It's both shorter and simpler to go left. It's the next left after the left. If you go straight you get there also, but it's the third right and about twice as far. I do occasionally go that way myself for variety.
Of course, even in a regular grid if you keep turning right you'll go in circles forever. But in your case you'll be doing it on the same street.
There's a street near my house that does the same thing, it loops back and crosses itself. Directions to my house could include "turn left at the intersection of Alloway and Alloway". It only crosses itself once, so it's a unique landmark. But its simpler to just say "make the first left" in my case.
Less demand shouldn't cause the price of electricity to increase. A reduction in the amount of expensive peak power should improve the situation a good deal.
We'll still need the power grid to give us power at night, or after whatever batteries we have run out. The first thing that will change is the laws that give you credit for the excess electricity your solar panels generate. With mass adoption of solar the grid will have to stop acting as a free battery (i.e. buying power from you at the same retail rate it sells for).
More like the sort of laser that vaporizes everyone in sight. Not sure whether we're talking terawatt or petawatt though. Something in that range probably.
From the BAE Institute website (not the article):
"MW class PLP rockets will be capable of launching small payloads with weights in the order of kg, such as nanosatellites or small parts for space stations, into LEO in a single stage reusable platform, or of accelerating them to unprecedented high speed for rapid-outcome deep space exploration. The scaling of PLP to higher power will be capable of accelerating spacecraft to near light speed."
So if it takes megawatt class lasers to launch a kilogram it will take gigawatts to launch tonnes. Which I find odd because I seem to recall figuring in the past that it takes a gigawatt of photons just to get a few newtons of thrust. So there is something going on here besides pure light pressure thrust.
As I understand it, lung tissue isn't a one way passage for oxygen and carbon dioxide, it simply equalizes the partial pressures of these two gasses between the air in the lungs and the bloodstream. Used venous blood has excess carbon dioxide and depleted oxygen relative to inhaled air, so the CO2 gets dumped and O2 gets picked up.
h tml
In the case of a lung full of vacuum both CO2 and O2 would be dumped into the lungs. Pretty well cleaning out any and all gasses from the bloodstream, making the blood delivered by the arteries useless. I wonder if you'd last longer if your heart simply stopped right away.
from http://www.sff.net/people/Geoffrey.Landis/vacuum.
"The time of consciousness after loss of cabin pressure is reduced due to offgassing of oxygen from venous blood to the lungs. Hypoxia is the most immediate problem following a decompression."
Not only does vacuum mean truly zero air in your lungs, but your lungs are now working in reverse and dumping all remaining oxygen in your bloodstream into the vacuum. In just five or ten seconds the blood supplied to your brain is completely devoid of oxygen. That's what gets you.
It's true that slow and steady thrust will build up over time. The study says that a thruster given ten years would give a speed change less than a thousandth what the nuke could give. This should come as no great surprise since it really all comes down to the amount of energy as momentum you can apply to the asteroid. Nuclear weapons just contain many magnitudes more energy than any alternative. You just need to find a way to convert that energy to momentum, and even a wasteful conversion is likely to beat all other methods hands down.
Now if you can discover the threatening object soon enough and get an accurate enough projection of its trajectory, you may not need a lot of momentum to turn a collision into a near miss. In that case the other methods may work well enough. The study indicates that if we started on Apophis now with decades of lead time, we could get it moved enough with thrusters. If in 2029 the close pass put it on a collision course in 2036 we'd have no feasible option besides nuclear at that point.
Capturing an asteroid is thousands or millions of times harder than deflecting it. If you have years or decades notice you only have to nudge the asteroid by a small fraction of a meter per second, if you want to capture it into earth orbit you're going to have to slow it by some kilometers per second.
Since we're debating the feasibility of even nudging an asteroid off a collision course, capturing one is right out.
Few NEO asteroids are even a billionth the mass of the moon, so it's not going to have any appreciable affect on the tides. Tidal effect is proportional to mass divided by distance cubed (IIRC). That distance cubed factor means getting it closer really increases the effect, but for a rocky object to raise the same tides as the moon it has to be close enough to look the same size as the moon. For Apothis that would require being inside Earth's atmosphere, not a good place for orbiting an asteroid.
I have to disagree with you there, as I'm sure the author of the article would. Nothing depends on the "right" innovation coming along. Our technological society is an amalgam or whichever innovations came along and fit reasonably well together. This is not the best of all possible technological worlds, it's just good enough to make do. I think this is exactly what the author is getting at: no need to worship the latest break through gadget, it's not as important as you think it is.
He mentioned pneumatic delivery tubes and postulated an alternative technological path where they caught on completely and packages zipped across the city in moments. That's quite imaginable and would be pretty handy, but not as indispensable as some of it's users would no doubt claim it to be.
It's probably modded as funny by those who catch it as a Monty Python reference.
Surely you've heard Monty Python's lumberjack song? There is also a skit where an office worker, probably an accountant, talks about wanting to be a lion tamer, but is completely unprepared for the reality of facing an actual lion.
There is comedy inherent in office workers who dream of exciting occupations they are totally unsuited for. Computer programers didn't really exist when Monty Python was writing their comedy skits. Otherwise maybe they wouldn't have picked on accountants so much.
Have you noticed how hydroelectric power is always on big dams placed on white water type rivers? Ever see one in a swamp or on a sluggish river? That's because you need a good head of water to make it worth doing.
Sewers don't have that sort of water pressure involved. They are deliberately designed to slope gradually from the source to the treatment plant, with just enough drop to keep the sewage moving.
A bit a research finds that it takes 10 gallons per minute drooping 1 foot to generate a single watt of power. That's why serious power requires lots of water dropping a good distance.
You're making me wonder where all my power goes. 20 khw a day can't all be explained by lighting, refrigerator, microwave and computers. I suppose that the gas heating still uses a good deal of electricity just for the blower. I did notice the other day that the master bath sports eight 60 watt decorator bulbs. That's 480 watts just to light a bathroom, for heavens sake. Luckily those lights aren't on much.
Also, doing a little Google search, I found a bike that claims to generate 400 watts [los-gatos.ca.us], and a pedal device that claims to generate up to 1000 watts [emediawire.com]. Of course, I have no idea how sustainable those powers are.
That second link describes a system of springs that output at up to 1000 watts, but doesn't mention how long it takes to wind it. The first link does mention human output rates. It claims 425 watts as "burst output" only, with a 30 min average of 150 watts. Later it says "assuming you can crank out 125 watts for an hour, which is very ambitious". He also describes 130 watts as strenuous exercise.
Regarding your refrigerator, a consumer site I found claims: "A typical new refrigerator with automatic defrost and a top-mounted freezer uses less than 500 kWh per year". That would be about 1.5 kilowatt hours a day right there. I figure I blow another kilowatt hour or two each day just running lights.
So I doubt your electrical use is less than 1 kwh a day. Maybe the dollar figure sticks in your head better. Do you really pay less than 3$ a month for electricity?
For varying values of "might as well".
While it would be fun to produce electricity by your own effort, it isn't economically practical. With a current price of about 10 cents a kilowatt hour, you'll probably only be able to produce enough electricity to equal one cent per hour. That's going to be an awful lot of hours pedaling before you've paid back the cost of the extra equipment. Probably longer than the lifetime of the equipment.
"I'm a marathon runner, and the amount of electricity I might generate from my daily exercise routine would probably generate all of my electrical needs for that day, with a little extra left over."
You must have a very energy efficient lifestyle then. As I understand it, the amount of energy a person can put out can run a laptop or a light bulb, but that's about it.
From - http://www.windstreampower.com/humanpower/hpgmk3.h tml - "The typical average continuous power that can be generated by pedaling the Human Power Generator is up to about 80 watts." So if I work out for an hour generating an even 100 watts, then I've produced a tenth of a kilowatt hour. But my house consumes about 20 kilowatt hours a day (during a cool season when I don't need the air conditioner, it's triple that in the summer). Human generation would be a drop in the bucket for me. Still, I've always wanted to get one of those things, it would be useful to have in an emergency.
they will sell the electricity to other country/state or province that cant afford the solar panel, Who's paying you to supply the electricity?
Who's paying them to distribute the excess electricity you generate? Power lines don't maintain themselves when there's an ice storm. Who's paying for the generation plants needed to run you house when it's dark and there's no wind and no one in your neighborhood is generating electricity?
There is a value to staying connected to the grid. It's very difficult to make yourself completely energy independent. Yes, you should be paid for supplying excess power to the grid, but your connection to it won't be for free.
"Let there be light." (Bomb #20 - Dark Star)
You forgot:
Imagine a Beowulf cluster of these.
According to one of the links, the human eye has an overall luminance vision range of 14 orders of magnitude from starlight to direct sun. You're correct that we can't see all that at once because of the way our eyes adapt to changing conditions, but the article also stated that the eye's instantaneous luminance vision range is five orders of magnitude. So in the same scene we can make out details with a contrast range of 100,000:1. That's why the blacks often look gray on a typical monitor with a contrast range of 500:1.
So, our eyes can see more than current monitors can present in terms of brightness. That's what Brightside is trying to produce: monitors with ten times brighter whites and ten times darker blacks. I'd love to get one of those, but not at the current price. Hopefully they'd be reasonable in a few years.
I get what you're saying. There is a difference between individual fitness and species fitness. In the end it's the fitness of the species as a whole that matters. An important component of a species fitness is its genetic diversity which gives it flexibility to adapt to changes.
Still, I'm not sold on saving every gene we can. Some of the nasty mutations are best removed from the gene pool. But I agree it's impossible to predict what future use a seemingly undesirable change could have. In combination with some other change it might become a great advance.
A ring/linear hybrid doesn't help the situation much. For a linear track with constant acceleration the first half of the velocity comes in the first quarter of the track. Going to mach 5 in a ring and then from 5 to 25 in a linear track only reduces the linear track length by 4%. You might as well build the whole thing straight.
For your 5 km diameter track, if you put human endurance at 10 g, you get a maximum speed of about 500 m/s. That's 1/16 orbital speed, less than mach 2. If you quadruple the size to 20 km you double the maximum speed to 1 km/s, an eighth of what you need. Want to guess how large it needs to be to achieve orbital speed with only 10 g of centripetal acceleration?