big314mp

As for testing it, the quintessential grade school test for oxygen is to take a burning splint of wood and blow it out so that only an ember remains at the end. Stick the burning end of the splint into a container that you think has pure oxygen. If the splint relights (full on flame, not just get brighter), then you have oxygen. I'm surprised that no one has suggested electrolysis yet. Run an electric current from a battery through salt water, and it will split the water into hydrogen and oxygen. Capture the oxygen in a small tube, then do the above test.

Is this for a demonstration of some sort? If so, what if you used some temperature sensitive ink as a coating on the tube? As the warm water passes, it will heat the tube, causing the ink to change color.

no worries. It was an interesting to chew on though.

clearly I didn't think very far I like i_a's idea, since there are off the shelf devices that will send a text message with their location at certain intervals. A google search will pull up several.

Well, in a nutshell, you need to find the proton concentration and plug that into the formula that kaeroll gave. Have you learned the ICE method? Use that to find the proton concentration.

Am I missing something, because this sounds like a slightly re imagined calutron from the Manhattan project, and that took a long time to produce significant product.

I think we did an experiment like this in high school and found that glucose passed through the dialysis membrane quite easily. I don't know any specifics on the characteristics of the particular dialysis membrane we used though.

This is a fairly straightforward relation, since the tighter an atom holds its own electrons (i.e. the smaller it's radius), the tighter it will grab on to some other atom's electrons (it's electronegativity). I think your equation could be simplified to: r*e = C I have no idea what C would be however.

Didn't NASA do something like this using aerogel to capture solar wind particles in space? If I recall, the premise was that a canister opened, solar particles struck the gel, and were trapped. Eventually the canister was resealed and returned to Earth. Where it smashed into the ground when it's parachute failed to open, but that's neither here nor there. Some sort of moist filter (hepa filter soaked in some sort of media?) attached to a small fan to suck air through the filter should be able to trap bacteria and keep them alive until they get back to the ground. You'd need to find some sort of way to seal up the filter after a predetermined collection time. As for height, would a sizeable weather balloon attached to fishing line help? Have the canister attached to the fishing line, and the canister attached to the balloon via some sort of breakable connection. Once the balloon reaches a certain height, the device starts to collect. Once the max height is reached, the fishing line yanks the collection device off of the balloon. Then you follow the line to the collection filter.

I think your first issue is that you are (I suspect) using a 32bit operating system, which reads a maximum of just under 4GB. The OS isn't seeing the last stick. However, if you go into the BIOS, it should show all 4 gigs. As to the swap file, its not that big of a deal. Swap files exists to cache data off of ram when the ram gets used up. You have maxed out the ram, so I doubt the swap file is being heavily used. A test you can do, however, is watch the hard disk light when your friend is working. If the hard drive light is constantly on, then the swap file is being used heavily. Of course, the other reason the hard disk light would be on, would be if you are copying lots of from the hard disk into the ram. If you are loading large image files off of the hard disk, it could be just that the disk is taking a while to find all of the data. Defrag the disk to see if that helps at all. Finally, the processor/mobo seem a little dated for heavy duty photo editing, so it could be that the computer is just too slow. You can us msconfig and services.msc (typed into the "run" prompt) to cut down on background processes, to try and free up some resources. You could also try overclocking some if it is available on your mobo. Merged post follows: Consecutive posts merged The reason they recommend having it on a different drive, is that the page file acts as "pseudo-ram". There will (if you are short on ram, which I doubt you are) be lots of read/write operations performed on the swap file. By placing the swap file on a physically different disk, you use one disk for uploading system files, and another disk for the page file. Basically, it's a form of load balancing to improve performance. However, as you surmised, an external disk would be horribly slow. Not to mention the myriad problems that would happen if the external disk were unplugged while the machine were on. As to #2, I can't answer that, but I suspect that there is only one paging file at any given time. Merged post follows: Consecutive posts mergedForgot a couple of diagnostic tests: 1) To see if CPU is the hold up, open up the task manager and look at the CPU utilization. If it is running at 100% continuously, then it probably is. 2) To see if there is sufficient ram, look at the "commit charge" box. One of the things listed is "peak". This is the peak amount of "ram" (in quotes, because if the physical ram is exceeded, then the swap file is called in to meet the demand) that the system has used since the last reboot. If this number is larger than the total amount of ram in the machine, then ram could be the hold up. Both of these can be found in the "performance" tab of the task manager.

A salt water + small amount of electricity combo should corrode the steel quite well. That combo is the bane of coastal boat owners...

The closest you are gonna get to that would be a "hearts and minds" type of campaign to convince the Palestinian public that Israel won't go away, so they might as well learn to get along. Of course, I find that possibility laughably distant, given the current state of the region. And what are we ever going to do with those red faced attackers

The different gravity analogies that you list are all compatible. The object will circle in slowly when it is at a distance. Once it gets close enough, however, the gravitational field (or spacetime curvature if you prefer) changes so quickly that the object becomes shredded. It all depends on how fast the gravitational field strengthens, which is a function of distance to the black hole (among other things, like mass).

This sounds stupid, but what if you take the speed of light and divide it by the planck time? Something like the fastest velocity divided by the shortest time ought to give some sort of "planck acceleration." Or am I just digging a mathematical hole here?

I believe you're thinking of falafel

I'm gonna have to agree with YT. http://en.wikipedia.org/wiki/Hypnagogia#Sensory_phenomena http://en.wikipedia.org/wiki/Hypnic_jerk I'm thinking that you are just more conscious of the "jerk" when you are falling asleep.

*clicks thumbs up symbol* This is a good idea. Sometimes its nice to be able to compliment a good post non-anonymously.

So I'm guessing the premise is to create a double slit type pattern of fringes, and then make sure a dark fringe lines up with the earth. I found the article, btw: http://www.sciam.com/article.cfm?id=geoengineering-how-to-cool-earth&page=5 The way it's described makes me think the physics is a bit faulty though.

It's kind of funny to see this thread resurrected Cap'n, I was just curious about the process. If I actually found out, it would destroy my fantasies about secret admirers on the internet

In a recent SciAm article (last month, I think) there was an article on geo-engineering. One proposal was to use perforated disks of a clear material arranged in a cloud between the earth and the sun. The premise was that light passing through the perforations would travel slightly faster than light passing through the disk material. The light would then destructively interfere on the other side, thereby reducing the amount of light falling on the Earth. My question is: What happens to the energy carried by the light? It obviously can't be destroyed, but where does it go?

Fair enough. I was just thinking that since you can prove that you paid for a decal, then you might be able to get a replacement decal.

Just because it smells like alcohol, doesn't mean that all of the alcohol that you added is still there. A large portion of it can evaporate, leaving behind very little, and yet it will still smell of alcohol. And don't drink it.

Just watch the seal around the edge of the windshield. The adhesive there might be damaged by some of the solvents you are thinking of. Maybe you could try an iron box with an extension cord for heat. If you live in the US, go to a hardware store, and tell them your problem. There is a device that holds a blade, sort of like a sharp putty knife, that will help you peel it off. I suppose there is some sort of reason you can't just get another one to stick on the back?

Well, I'm assuming the bottle was mostly full of alcohol when you started the experiment. How much fluid was left when you found it again?

And welcome to SFN!