To quote wikipedia: This can occur if the atmospheric pressure exerted on the substance is too low to stop the molecules from escaping from the solid state.
Atmospheric pressure is not as important as the partial pressure of the substance at its surface. That is, in this case, the vapour pressure of water which is practically zero on Mars. Therefore water, if it is not locked down in crystalline form, cannot exist in liquid form because it cannot form an equilibrium with its surroundings to form a 'triple point' (solid/liquid/vapour phase temperature).
It also depends, as far as I understand, on the interaction between molecules of the substance. If it is too weak, the range of temperatures at which the substance can be liquid is narrow (or practically zero). It's a fairly wide range for water, though.
I didn't study the topic beyond that and it was years ago.
Thanks for your considered reponse. I appreciate it.
I submitted a patch to the web server, and if a company modifies the webserver to suit their needs, I would love for them to be required to share their change with the world. The GPL is all about this flow of ideas.
Motives can be important, I guess, but the law generalizes. In my case I plan to release my software to the public as a sourceforge project or something, but not in the form it is now (since it's a veritable mess and very customized for the people who asked me to do it). So I don't want it public yet.
In spirit, I accept that the GPL wants me, basically, to release my code to the outside.
I think, though, it's poor form for commercial entities to go ahead designing and releasing GPL based software without thinking ahead and accepting that they have to supply source code to their paying customers.
I'm still a bit confused about it, but it seems like they have to provide the sourcecode for the entire thing, except for stand-alone proprietary programs running 'separately' from everything else, and provided they aren't using GPL libraries.
It's interesting to me because I am using GPL stuff for one of my projects, but at this stage it's straightforward since the only people I distribute it to are my departmental staff who can have the source code no-worries, but it gets interesting because the software is then usable by the public to whom I don't wish to distribute the code (basically because of security fears).
Is the end-user - at a public terminal - entitled to the same rights under GPL as the owner of the computer on which the software runs?
That and clarifying on distributing, under which license you ship, is the minimum for GPL So your software should clearly state somewhere obvious (eg: the about-box) that it is using GPL sources, right? And then state how to go about getting hold of the source code.
Re:Simplest Solar Powered Lighting
on
DIY Solar Resources?
·
· Score: 3, Informative
Is a skylight in the roof. Next simplest is a marketed gadget called, I think, "SolaTube". That's for when you have a ceiling as well as a roof.
I would certainly take that approach. The fewer steps of energy conversion, the better.
If I ever get prosperous enough to afford it, I will be converting our home to renewable (off the paid electricity grid). Probably a gradual process but I have to say investing in simple things like skylights, insulation, solar hot water heating has the best long term pay-off, since there is practically zero maintenance involved.
I mean they're not going to put sensors everywhere in the city to track them everywhere but I bet they could sell the data of routes people take and sell the stats to businesses. That or follow "suspicious" people who haven't even committed a crime.
I mean, nobody who is about to commit a crime is going to make sure they aren't traced by stealing a bike or maybe using a false credit card or possibly thinking for three seconds before they commit the crime.
If it's a rental vehicle, it's no different from a taxi.
You can bet they will be tracking everyone with it, but so what?
I know this is slashdot, but would it kill maybe 3 or 4 people to actually RTFA before going off on rants? If it would accidentally kill 3 or 4 people, I think it would happen much more often. But no, to RTFA means you will end up making an insightful comment somewhere far down a thread where chances of upward moderation dwindle.
Furthermore, what are most of the palestinians (since they speak Arabian) referred to? Mostly they're not referred to.
I get mad when I here bullshit of this kind. I get mad when I read such terrible spelling. But apart from that you make some valid points.
I hope that is not the case.:) No amount of advice and no amount of insulation can stop a determined idiot from short circuiting something. But yeah, we're assuming this guy is not a few short of a dozen.
My point is that working with a low-voltage system doesn't necessarily make you safer. Yeah, considering people don't even switch the light off before climbing a metal ladder and replacing the bulb, using the socket to help them balance.
The fact that you think low current 120/240v is dangerous, but very high current 12/24V is safe
I didn't say either was safe. I just said it does not require an electrician by law (AFAIK - but of course it's as far as I know).
With amateur-installed T-Bars, I would fully expect the frame of your house to start slowly roasting itself in short order, if you're lucky, and not using quite enough current, it might not catch fire until the next heavy rain.
These are for lighting systems not ovens or dish-washers or other things.
Why are you assuming that the designer was so stupid as to design a system that could not cope with the designated load? What are fuses for?
This allows for typical residential AC wiring practices to be used, which vastly simplify the situation. It'll save time, money, and headaches in the long run, though the system will initially be a fair bit more expensive. Even an on-the-cheap installation is really anything but cheap. You're right. But we were talking about lighting (not microwave ovens, washing machines and other high-load devices). I don't know what the best solution for things like dish-washers and washing machines is, but smallish solar panel arrays tend to be a bit inadequate for it (and deep cycle batteries don't like being drawn).
Is there any other technology battery-wise for a project like this that is feasable?
I discussed this exact type of project (in a farm setting) with a civil engineer who did the same thing. He found that using excess energy (also from wind power) by pumping water up an incline was more efficient than batteries. He used two dams at different parts of a hill which worked well. Also shared the power storage with a neighbour since the dams were large enough and this reduced the infrastructure cost.
Low voltage power wiring can be more dangerous than regular 115/220 VAC. The return current (black) is usually a single large wire running down the axis of the circuit and is far from the active wires which by and large are thinner. So short circuits are unlikely except at the wall socket. Battery arrays, as is written pretty much everywhere, should be stored away from the building in a separate ventilated and locked enclosure.
DIY project for wiring your house? Yeah, if you wish to invalidate your insurance and burn down your house.
Nobody is saying you have to do it at AC 110V (or 240V / 220V). AFAIK running 12V or 24V cabling through your house does not require an electrician, and to achieve low resistance you can use T-bars or other large metal structures (or just some automotive copper) for return currents to avoid voltage drops, or alternatively transport the energy via AC/240V (might need professional work for that).
Just have smaller, cheaper inverters at specific locations for the high voltage/AC appliances such as fridges, computers etc.
Unfortunately, this would imply that there is a problem with an OSS piece of software (which will quickly be fixed). Which is why it wasn't reported as such on/.
.. lucrative business models based on existing wired and 2.5G/3G infrastructures
Now there's an understatement. I would call the business model 'ludicrous' rather than lucrative. 3G is priced way out of reasonable range for any serious use.
Nobody pretends that wireless broadband will be available in mountain crevices, but 3G has been quite disappointing IMO.
As for $50/$100 plans, that will depend on competition, which in Australia, at least, is totally lacking.
What of us gamers running win boxes that are rock solid? Sadly they are refusing to make any more PC's out of stone, so you'll just have to settle for plastic-solid.
Is a faster system going to improve the generally rubbish weather forecasts of "it might rain today"? No, but someone is going to get a lot of grant money to implement it.
Slashdot Mirror
To quote wikipedia: This can occur if the atmospheric pressure exerted on the substance is too low to stop the molecules from escaping from the solid state.
Atmospheric pressure is not as important as the partial pressure of the substance at its surface. That is, in this case, the vapour pressure of water which is practically zero on Mars. Therefore water, if it is not locked down in crystalline form, cannot exist in liquid form because it cannot form an equilibrium with its surroundings to form a 'triple point' (solid/liquid/vapour phase temperature).
It also depends, as far as I understand, on the interaction between molecules of the substance. If it is too weak, the range of temperatures at which the substance can be liquid is narrow (or practically zero). It's a fairly wide range for water, though.
I didn't study the topic beyond that and it was years ago.
PS. Iodine is another substance that sublimates.
Thanks for your considered reponse. I appreciate it.
I submitted a patch to the web server, and if a company modifies the webserver to suit their needs, I would love for them to be required to share their change with the world. The GPL is all about this flow of ideas.Motives can be important, I guess, but the law generalizes. In my case I plan to release my software to the public as a sourceforge project or something, but not in the form it is now (since it's a veritable mess and very customized for the people who asked me to do it). So I don't want it public yet.
In spirit, I accept that the GPL wants me, basically, to release my code to the outside.
I think, though, it's poor form for commercial entities to go ahead designing and releasing GPL based software without thinking ahead and accepting that they have to supply source code to their paying customers.
That's not insightful, that's funny!
OTOH.. that's not funny, it's insightful!
Just tried the GPL quiz. I did poorly I must say.
I'm still a bit confused about it, but it seems like they have to provide the sourcecode for the entire thing, except for stand-alone proprietary programs running 'separately' from everything else, and provided they aren't using GPL libraries.
It's interesting to me because I am using GPL stuff for one of my projects, but at this stage it's straightforward since the only people I distribute it to are my departmental staff who can have the source code no-worries, but it gets interesting because the software is then usable by the public to whom I don't wish to distribute the code (basically because of security fears).
Is the end-user - at a public terminal - entitled to the same rights under GPL as the owner of the computer on which the software runs?
I would certainly take that approach. The fewer steps of energy conversion, the better.
If I ever get prosperous enough to afford it, I will be converting our home to renewable (off the paid electricity grid). Probably a gradual process but I have to say investing in simple things like skylights, insulation, solar hot water heating has the best long term pay-off, since there is practically zero maintenance involved.
I mean, nobody who is about to commit a crime is going to make sure they aren't traced by stealing a bike or maybe using a false credit card or possibly thinking for three seconds before they commit the crime.
If it's a rental vehicle, it's no different from a taxi.
You can bet they will be tracking everyone with it, but so what?
Mod parent up - this comment needs discussion because it's very interesting indeed!
I didn't say either was safe. I just said it does not require an electrician by law (AFAIK - but of course it's as far as I know).
With amateur-installed T-Bars, I would fully expect the frame of your house to start slowly roasting itself in short order, if you're lucky, and not using quite enough current, it might not catch fire until the next heavy rain.
These are for lighting systems not ovens or dish-washers or other things.
Why are you assuming that the designer was so stupid as to design a system that could not cope with the designated load? What are fuses for?
I discussed this exact type of project (in a farm setting) with a civil engineer who did the same thing. He found that using excess energy (also from wind power) by pumping water up an incline was more efficient than batteries. He used two dams at different parts of a hill which worked well. Also shared the power storage with a neighbour since the dams were large enough and this reduced the infrastructure cost.
Nobody is saying you have to do it at AC 110V (or 240V / 220V). AFAIK running 12V or 24V cabling through your house does not require an electrician, and to achieve low resistance you can use T-bars or other large metal structures (or just some automotive copper) for return currents to avoid voltage drops, or alternatively transport the energy via AC/240V (might need professional work for that).
Just have smaller, cheaper inverters at specific locations for the high voltage/AC appliances such as fridges, computers etc.
.. lucrative business models based on existing wired and 2.5G/3G infrastructuresNow there's an understatement. I would call the business model 'ludicrous' rather than lucrative. 3G is priced way out of reasonable range for any serious use.
Nobody pretends that wireless broadband will be available in mountain crevices, but 3G has been quite disappointing IMO.
As for $50/$100 plans, that will depend on competition, which in Australia, at least, is totally lacking.