It's not all bad. Does anyone remember how a couple months ago it would take 30 mins to emerge --sync, with the disk crunching the whole time (at least on my machine)? Now it takes like a minute. That was a pretty sorely needed change.
But I do agree that Gentoo seems more intricate and less stable than 3 years ago. Some of this intricacy must be related to increasing flexibility and power? But I don't use my box for anything different than I did 3 years ago, and I'm becoming increasingly glum at the thought of spending the whole frickin weekend updating my machine and debugging problems with the update! I am this -><- close to just buying a Mac and roughing it out with the beautifully integrated suite of built-in apps.
This process has never been tested beyond the laboratory workbench. There are a large number of very significant hurdles to getting such a system operational on the Martian surface. Among them - insulation; Mars has enough atmosphere that MLI won't work, and this means large, bulky and difficult to handle tanks for receiving the output product. Another is filtering the input feed (to get rid of the atmospheric dust), as well as keeping the filters themselves clean. Etc... Etc... No obvious showstoppers I admit, but some very definite steep hurdles.
It's true that Zubrin's book is idealistic (I was rolling my eyes a few times). Nevertheless it is a very elegant idea. By producing the fuel for the return journey on Mars itself we eliminate in one stroke all the Battlestar Galatica-size fleets of ships necessary to transport the fuel, and construction and staging areas in orbit and on the Moon etc. It is insane that people are talking about the Moon as a stepping stone to Mars.
Instead of blowing wads of cash on the ISS for no apparent reason we could be doing engineering on the problems you outline. Seems much more practical IMHO.
This is a myth. We only need to send 6 tons of liquid hydrogen and a small reactor. In a 2-step process you can use this to create 108 tons of fuel.
1. CO2 (from atmosphere) + 4 H2 (from Earth) -> CH4 (rocket fuel) + 2 H20
2. 2 H20 (from 1) -> 2 H2 (feed back into 1) + O2 (oxygen for rocket fuel)
You fly to Mars with just enough fuel to get you there, create your own fuel from the Martian atmosphere, and fly back. To make things less risky, we send the first one unmanned, so there's a return vehicle on the surface of Mars all fueled up when humans arrive.
The 300 tons is only if you insist on bringing the fuel for your return journey along with you.
This is clearly described in The Case for Mars by Robert Zubrin. Surprised more people haven't read that.
The wording varies between manufacturers, but sunlight is around 5500K. So if you want to stimulate a warm sunny day get ~5000K bulbs and a LOT of them. If you don't have enough it won't look like sunlight.
If you could focus the light from a typical 32W T8 3000-lumen bulb on a square foot of space, that would be 3000 foot-candles and a bright sunny day is about 10000 foot-candles. So there's no hope of matching the intensity of sunlight but after a certain point you can trick your psychovisual system into thinking it's close. I use 6 3000-lumen bulbs in a small room and it seems nice and bright. And the quality of the light is much better than incandescent, which looks yellow and sickly to me now.
I also toyed with the idea of getting Solux bulbs which have a reflector that transmits some of the light to make the reflected light close to 5500K (the visible spectrum is also very similar to true sunlight, unlike fluorescent, obviously). But it would take approximately 5x more wattage to equal the light level I have now with fluorescent, which equals a lot of heat.
http://www.hushtechnologies.net/ has lots to choose from with no fans. I would have paid the price premium a couple years ago if I'd known how noisy my Shuttle would be.
Sorry but my impression of Paris was exactly the opposite. Narrow sidewalks, and many of them have fruit stands or whatnot on the side. And MANY people, all dodging each other (or mopeds) on the sidewalk. And LOTS of dog excrement, despite the measures they have in place to clean it up. I just can't see using a Segway on the sidewalks of Paris, unless you take it out at 3am.
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It might be more correct to say they occur far too *often*.
But I do agree that Gentoo seems more intricate and less stable than 3 years ago. Some of this intricacy must be related to increasing flexibility and power? But I don't use my box for anything different than I did 3 years ago, and I'm becoming increasingly glum at the thought of spending the whole frickin weekend updating my machine and debugging problems with the update! I am this -><- close to just buying a Mac and roughing it out with the beautifully integrated suite of built-in apps.
Much less than the amount of CH4 the astronauts produce along the way.
Back of envelope calculation
- Density of H atoms in solar system ~ 1 atom/cm^3
- Distance Earth to Mars ~ 1 AU = 23000 Earth radii = 23000 * 6400 km = 10^13 cm
- Area swept by spacecraft ~ 100 m^2 = 10^8 cm^2
- Volume swept by spacecraft = 10^21 cm^3
- Number of H atoms = 10^21
- Avogadro's constant = 10^24
- Number of H atoms in moles = 0.001
Mass of H atoms = 0.001 gramsInstead of blowing wads of cash on the ISS for no apparent reason we could be doing engineering on the problems you outline. Seems much more practical IMHO.
1. CO2 (from atmosphere) + 4 H2 (from Earth) -> CH4 (rocket fuel) + 2 H20
2. 2 H20 (from 1) -> 2 H2 (feed back into 1) + O2 (oxygen for rocket fuel)
You fly to Mars with just enough fuel to get you there, create your own fuel from the Martian atmosphere, and fly back. To make things less risky, we send the first one unmanned, so there's a return vehicle on the surface of Mars all fueled up when humans arrive.
The 300 tons is only if you insist on bringing the fuel for your return journey along with you.
This is clearly described in The Case for Mars by Robert Zubrin. Surprised more people haven't read that.
Sorry I meant "simulate" a warm sunny day, not "stimulate". Hopefully no one will notice my Freudian slip.
If you could focus the light from a typical 32W T8 3000-lumen bulb on a square foot of space, that would be 3000 foot-candles and a bright sunny day is about 10000 foot-candles. So there's no hope of matching the intensity of sunlight but after a certain point you can trick your psychovisual system into thinking it's close. I use 6 3000-lumen bulbs in a small room and it seems nice and bright. And the quality of the light is much better than incandescent, which looks yellow and sickly to me now.
I also toyed with the idea of getting Solux bulbs which have a reflector that transmits some of the light to make the reflected light close to 5500K (the visible spectrum is also very similar to true sunlight, unlike fluorescent, obviously). But it would take approximately 5x more wattage to equal the light level I have now with fluorescent, which equals a lot of heat.
http://www.hushtechnologies.net/ has lots to choose from with no fans. I would have paid the price premium a couple years ago if I'd known how noisy my Shuttle would be.
Sorry but my impression of Paris was exactly the opposite. Narrow sidewalks, and many of them have fruit stands or whatnot on the side. And MANY people, all dodging each other (or mopeds) on the sidewalk. And LOTS of dog excrement, despite the measures they have in place to clean it up. I just can't see using a Segway on the sidewalks of Paris, unless you take it out at 3am.