Search found 174 matches

by po2141
Wed Mar 03, 2010 4:14 pm UTC
Forum: Science
Topic: A/V Cables, Audiophiles, and Antennas
Replies: 15
Views: 1631

Re: A/V Cables, Audiophiles, and Antennas

Goemon wrote:A poorly designed silver antenna could easily be less efficient than a well designed one made out of spam.


I am skeptical of this....
by po2141
Sun Feb 14, 2010 2:01 am UTC
Forum: Science
Topic: Two sodium-related questions
Replies: 16
Views: 2017

Re: Two sodium-related questions

Well then I guess paramagnetism can be surprisingly strong then.
by po2141
Sat Feb 13, 2010 8:23 pm UTC
Forum: Science
Topic: Two sodium-related questions
Replies: 16
Views: 2017

Re: Two sodium-related questions

Ingolifs wrote:How much response would a paramagnetic material have to the magnetic field such as the one in the stir plate?


Well, what else could possibly be causing it to rotate? Convection currents/boiling?
by po2141
Fri Feb 12, 2010 4:12 pm UTC
Forum: Science
Topic: Two sodium-related questions
Replies: 16
Views: 2017

Re: Two sodium-related questions

Silicon Carbide? that seems unlikely in the given conditions.
by po2141
Fri Feb 12, 2010 10:47 am UTC
Forum: Science
Topic: Two sodium-related questions
Replies: 16
Views: 2017

Re: Two sodium-related questions

Well, its must be the paramagnetism moving the sodium. To figure out what the black stuff could be we need to know what else is in there, have you just synthesised the dmdclsi? I'm enjoying the chemistry-related stuff on here, I'm a chemist myself, but I graduated quite a while ago, and as I don't e...
by po2141
Thu Feb 11, 2010 11:33 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

there's air resistance. Bottom line, its not all going to flash into heat all at once. A nuke releases its total energy in a handful of microseconds and in a volume not much larger than the bomb itself. The cable will have a volume of, ooh lets say, 1e4 cubic metres? And it might take 10 minutes (s...
by po2141
Tue Feb 09, 2010 3:02 pm UTC
Forum: Science
Topic: Chemistry Question (Determination of an Unknown)
Replies: 18
Views: 1934

Re: Chemistry Question (Determination of an Unknown)

How about using XRD to determine the bond length with the metal. If you know the what the metal is and what it is apparently bonded to then you should be able to look up the lengths of various covalent bonds. If it is too long then it should be ionic. Make sense? If it works I think this would fall ...
by po2141
Sat Feb 06, 2010 12:52 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

It's the cable itself that will be accelerating the lift tangentially. this is what concerns me, I just thought it might be problematic. Thats not to say not possible. And I think someone said something about balancing mass going up and down at the same time? I didn't think of that, thats clever. A...
by po2141
Fri Feb 05, 2010 9:06 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

Thats true, I hadn't thought about not having to carry fuel with you. The only problem I have with the whole thing is that you'd need to apply a force to your cargo perpendicular to the cable, in the direction of the earths rotation. Because you arn't just hoisting the cargo up, we are standing on a...
by po2141
Fri Feb 05, 2010 5:59 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

@Eikinkloster Nono, I meant a cable from the earths surface to an anchor at geosync - only the very top of the cable is in orbit - the higher you are the faster you need to be travelling to maintain orbit, until you escape altogether. The lower portions of the cable are not rotating sufficiently fas...
by po2141
Fri Feb 05, 2010 2:59 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

A large portion of the cable (dropped from geosync) is at a sizeable portion of orbital velocity, and with the cable being made out of carbon, alot of it will burn up. I don't get this. If it is geostationary, it is stationary also in relation to the atmosphere, isn't it? It will be subjected to wi...
by po2141
Thu Feb 04, 2010 11:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

Im sure there are more efficient ways of causing havoc on earth that dont involve going into space first. Having said that, there would probably be quite a large economic fallout from disabling a space elevator. And if you think about it, the bottom end would probably be surrounded by a customs-like...
by po2141
Thu Feb 04, 2010 4:38 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

uh-oh...
by po2141
Thu Feb 04, 2010 2:16 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

Stop Having Pun, Guys.


punaccetable...
by po2141
Wed Feb 03, 2010 11:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

Re: centrifugal force Gotcha, rotating reference frame=centrifugal ok(ish). Everything else= an illusion caused by centripetal force. Re: missing atoms Thats pretty much correct, try it yourself with a molecular modeling kit. Re: dangling cable wind? Re: nanotubes again make your own carbon60 and na...
by po2141
Wed Feb 03, 2010 10:49 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

It took about 35 posts for the word to show up, 34 posts before it showed up again, and now another 3 posts before someone (this guy, right here) points out that There is NO SUCH THING as CENTRIFUGAL FORCE Thank you. http://www.xkcd.com/123/ Wait. So can I say "centrifugal" or what?
by po2141
Wed Feb 03, 2010 12:43 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

Easy now, although some overly-flowery language has been used, its obvious he just means that he thinks a "space fountain" might be more practical than a "space elevator". Although IMO, we are talking about technology s far in advance that there aint much to choose between them. ...
by po2141
Wed Feb 03, 2010 10:03 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0697: "Tensile vs. Shear Strength"
Replies: 136
Views: 37506

Re: "Tensile vs. Shear Strength" Discussion

@tacvek: No, tensile strength does not scale up like that, a ribbon or cable would be *significantly* weaker than simply multiplying out the cross-section of one nanotube. Carbon nanotubes are still just made of carbon-carbon bonds, just like alot of things - Nylon for example. Its still pretty stro...
by po2141
Tue Jun 09, 2009 6:18 pm UTC
Forum: Science
Topic: A nuclear chemistry question.
Replies: 5
Views: 911

Re: A nuclear chemistry question.

No, in the np reaction, the nitrogen nucleus absorbs a neutron and emits a proton. The proton essentially being a H+ ion.
by po2141
Tue Jun 09, 2009 10:56 am UTC
Forum: Science
Topic: A nuclear chemistry question.
Replies: 5
Views: 911

Re: A nuclear chemistry question.

Dont forget about the electrons - and the neutrons are uncharged. The neutrons being uncharged, tend not to interact with electrons, so will not break interatomic bonds by themselves. When one of the Ns absorbs a neutron and transmutes to C, it will have a negative charge to it. Now neither the N or...
by po2141
Mon Jun 08, 2009 11:41 pm UTC
Forum: Science
Topic: Do you know what this is? (eye conditions)
Replies: 11
Views: 2100

Re: Do you know what this is? (eye conditions)

I know two seperate people who have different coloured eyes, and get this, they are both girls called Lisa!...
by po2141
Mon Jun 08, 2009 3:42 pm UTC
Forum: Science
Topic: Do you know what this is? (eye conditions)
Replies: 11
Views: 2100

Re: Do you know what this is? (eye conditions)

The paragraph on "hazel" (distinct from "brown" or "amber") eyes on the wiki page on eye colour may explain the perception of green or brown shades under differing conditions - but your eyes cant literally change colour, except gradually over your lifetime.
by po2141
Mon Jun 08, 2009 8:29 am UTC
Forum: Hardware
Topic: Choosing a graphics card
Replies: 26
Views: 2324

Re: Choosing a graphics card

I have seen on the grapevine that there is little between the two cards you mention except that the Radeon supports DirectX 10.1 whereas the nVidia has on-board PhysX, so choose one of those and off you go. I have a GTS250 and it can be run in 3xSLI, I guess thats the same for the GTX260, Im not sur...
by po2141
Thu Jun 04, 2009 11:13 pm UTC
Forum: Hardware
Topic: CPU compatability requirements
Replies: 11
Views: 1391

Re: CPU compatability requirements

@mosc: thats a positive thing for me right? Am I reading that correctly, new processors will fit into some older boards but old processor wont fit into new boards? I checked my BIOS settings, the voltage can be set as low as 0.825V, which is slightly higher than the minimum quoted for the e6700, but...
by po2141
Thu Jun 04, 2009 6:23 pm UTC
Forum: Hardware
Topic: CPU compatability requirements
Replies: 11
Views: 1391

Re: CPU compatability requirements

Hmm, I know, it dosnt look good. From what i can see though, the latest BIOS update came out July 07, a few days before the release of the e6750 and e6850 and with the e6700 released July 06. The description of the latest BIOS does state "support for new CPUs added" but doesnt say which. J...
by po2141
Thu Jun 04, 2009 3:16 pm UTC
Forum: Hardware
Topic: CPU compatability requirements
Replies: 11
Views: 1391

Re: CPU compatability requirements

Yes, I have read that some CPUs would not work because the mobo would shut down rather than supply too much current to the processor.

Can this be affected by a BIOS update?

Also, note that the voltage range of the e6700 contains the range of the older PD930.
by po2141
Thu Jun 04, 2009 2:13 pm UTC
Forum: Hardware
Topic: CPU compatability requirements
Replies: 11
Views: 1391

Re: CPU compatability requirements

They are both socket 775.
by po2141
Thu Jun 04, 2009 1:03 pm UTC
Forum: Hardware
Topic: CPU compatability requirements
Replies: 11
Views: 1391

CPU compatability requirements

I have a question regarding an old(ish) motherboard and a slightly-less old CPU that I want to install. I would like to know if the CPU will work. The "official" list of supported CPUs cannot be relied upon because it does not even list the CPU that my computer shipped with, in fact there ...
by po2141
Tue Oct 16, 2007 12:56 pm UTC
Forum: Science
Topic: Vacuum Zeppelin
Replies: 146
Views: 64957

Re: Vacuum Zeppelin

They have "vacuum dirigibles" in the Iain M Banks books. They use a rigid balloon but instead of the balloon being evacuated they fill it with lot and lots of small, light, thin walled evacuated spheres. That way they can shift the balls en-masse and "pump vacuum" from place to p...
by po2141
Tue Oct 16, 2007 8:02 am UTC
Forum: Fictional Science
Topic: What is the mass of a feather?
Replies: 229
Views: 321016

Re: What is the mass of a feather?

Sana wrote:Just on average. An average feather from an average bird. Whatever that is.

Exactly one few grams.
by po2141
Tue Oct 16, 2007 8:00 am UTC
Forum: Science
Topic: Vacuum Zeppelin
Replies: 146
Views: 64957

Re: Vacuum Zeppelin

For a container to be strong enough to enclose a vacuum in a 1atm environment, it needs the same strength as if it were to survive being submerged in 10m of water with 1atm inside. Submarines do this all the time. Now you just have to make them muchmuchmuchmuchmuch lighter....
by po2141
Mon Oct 15, 2007 12:54 pm UTC
Forum: Science
Topic: How high to drop water balloon from for it to be deadly
Replies: 78
Views: 21265

Re: How high to drop water balloon from for it to be deadly

You could have just said "drop the balloon in a vacuum." Anything is deadly at high enough velocity... really, how come all these photons hitting me don't kill me then? UV rays causing DNA damage in the skin resulting an a malignant melanoma? Gamma rays from background radiation, or more ...
by po2141
Mon Oct 15, 2007 8:23 am UTC
Forum: Science
Topic: How high to drop water balloon from for it to be deadly
Replies: 78
Views: 21265

Re: How high to drop water balloon from for it to be deadly

I saw a viseo on break.com once of some college kids dropping a water balloon the size of a small fridge (about 50-100L is my guess) from the top of a building (looked like 2nd or 3rd floor) onto a hapless passer by. They survived the direct hit though it didnt look pleasant for them. I think much l...
by po2141
Fri Oct 12, 2007 8:25 am UTC
Forum: Science
Topic: Stopping a bullet with induction
Replies: 61
Views: 8885

Re: Stopping a bullet with induction

Of course there would still be violent crime! If such a device were available to civilians then it would be available to criminals too. And I would judge it likely that some kind of countermeasure or defense-penetrating weapon would be concieved before too long, otherwise you would end up with invin...
by po2141
Tue Oct 09, 2007 3:54 pm UTC
Forum: Science
Topic: Favorite home experiments
Replies: 590
Views: 482544

Re: Re:

Hehe. Consider the following reaction: K ( metal ) + HNO 3 --> [products] + BANG. K metal is not something you play with unless you know what you're doing. Agreed! Just adding K(s) to water will cause flames and molten metal to be spat around, adding it to HNO3 will certainly result in a much faste...
by po2141
Tue Oct 09, 2007 2:31 pm UTC
Forum: Science
Topic: Seemingly simple reaction
Replies: 9
Views: 1659

Re: Seemingly simple reaction

this is a bit of an awkwardly asked question. water, H 2 O, exists with a small proportion of it dissassociated into H+ and OH-, the H+ combines with some H 2 O to get H 3 O+, so when it say Na 2 CO 3 + H 3 O+(aq) it just means Na 2 CO 3 + H 2 O. Na 2 CO 3 dissolved in water dissassociates to 2Na+ a...
by po2141
Tue Oct 09, 2007 8:02 am UTC
Forum: Science
Topic: Flash device
Replies: 13
Views: 1791

Re: Flash device

I'm almost certain that air has a break-down voltage (3MV/m @ 1atm), not a wattage, it is the strength of the electric field that causes the breakdown. And you can't have any wattage until current is flowing anyway.
by po2141
Mon Oct 08, 2007 12:25 pm UTC
Forum: Science
Topic: Temperature.
Replies: 26
Views: 2869

Re: Temperature.

Unfortunately I don't possess a flashbulb and have neither the will nor the attention span to buy one, but is this feasible, does the radiation incident on a frying pan contain enough momentum to cause an audible sound? I am severly sceptical.
by po2141
Mon Oct 08, 2007 9:13 am UTC
Forum: Science
Topic: So how much of that kung fu stuff in movies is plausible?
Replies: 87
Views: 16734

Re: So how much of that kung fu stuff in movies is plausible?

Steven Seagal is some kind of very-highly ranked buddhist. Or something. I remember someone saying there are only a couple of people with his status in the world, its something like "enlightened one" or similar. He is also the Sherrif of his home town in america. He also has an album. Its ...

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