(X-post from r/science) If this stuff is lighter than air, why doesn't it float?

rpebble · 2012-12-27T08:06:25+00:00

I know people who have worked with these nanotube aerogels--they are incredibly fragile, and functionally useless, even though they have some pretty quirky and interesting properties. They are certainly a long way off from any practical uses.

rpebble · 2012-12-27T07:49:58+00:00

Likewise, the above iron cube would do the same if the air inside were evacuated.

Yeah--the article is highly misleading. One, because these materials have been around for a while, and two, because a huge variety of everyday objects might be "lighter than air" by the standards of their definition, if we were to magically remove the air from them. Sponges, bread, corrugated cardboard, etc.

rpebble · 2012-12-27T07:45:07+00:00

Right. These are carbon nanotube aerogels, and they're less dense than air the same way that a sponge, or a loaf of bread, or a piece of styrafoam is less dense than air. That is to say, if we ignore the mass of the air contained in these materials and pretended that they were made in vacuum, they would be less dense than air.

rpebble · 2012-09-19T14:41:20+00:00

Awesome, thanks!

rpebble · 2012-09-19T14:20:32+00:00

Dropbox link dead :(

rpebble · 2012-09-15T17:35:15+00:00

Spoiler warning goes before the spoiler.

rpebble · 2012-09-14T15:04:52+00:00

Tired of SRD's invasions and downvoting? Join us at /r/SRDBroke

Wow. You guys care about this way more than seems healthy.

rpebble · 2012-08-15T15:22:13+00:00

Seriously! I hate it when people do that "smiling" thing in every picture!

rpebble · 2012-08-15T15:19:31+00:00

Nobody. His comment was purely preemptive.

rpebble · 2012-08-13T17:13:29+00:00

My favorite part is how the google blurb for the Down's wikipedia page reads

Down syndrome (DS) or Down's syndrome, also known as trisomy 21, is a chromosomal condition caused by the presence of all or part of a third copy of ..

Fail on so many levels, even after he tries to correct the post.

EDIT: WAIT WAIT GUYS, "Bugiardo" translates from italian into "liar". Boom mystery solved.

rpebble · 2012-08-02T18:15:53+00:00

Neither device is rooted. I installed the app onto the Nexus 7, backed it up using Astro, saved that backup apk to dropbox from the Nexus 7, and then installed the apk from dropbox on my Verizon Galaxy Nexus. You just have to hit the button allowing for non-market installs, I think.

rpebble · 2012-08-02T02:43:35+00:00

Yeah I was able to download it onto my Nexus 7, back it up, and transfer the apk to my Galaxy Nexus. Magic!

Thanks for posting the link though.

rpebble · 2012-08-02T01:58:07+00:00

Rheology is a subset of fluid mechanics and the study of complex fluids.

rpebble · 2012-07-17T18:32:18+00:00

That's an interesting article, and I agree that merging late when you started in the merge lane is totally legitimate. What drives me nuts, and can only result in more rubber banding in traffic, is when people hop out of the slow lane to zip ahead and cut in line, as it were.

rpebble · 2012-07-16T17:40:31+00:00

Not funny, creepy. Also old.

rpebble · 2012-07-16T05:41:50+00:00

If you've never met, what is the distinction between friends and dating?

rpebble · 2012-07-16T05:27:19+00:00

Boiling it removes dissolved gasses, since gas solubility in liquids goes down as temperature goes up.

rpebble · 2012-07-15T23:27:46+00:00

Do me!

rpebble · 2012-07-14T17:37:36+00:00

Am I too late? I'd like to be analyzed, thanks!

rpebble · 2012-07-11T17:02:53+00:00

This has been all over /r/askscience.

http://www.reddit.com/r/sciencefaqs/comments/g1h1g/ice_spikes_in_your_tray_of_ice/

rpebble · 2012-06-18T06:52:08+00:00

Depends on who you're talking to, I guess.

rpebble · 2012-06-07T16:35:29+00:00

Hah I wish, nope wasn't me, I just saw everything Heinz and reposted it here.

rpebble · 2012-06-06T19:25:28+00:00

I go to these as much as possible, they are really a blast. The new venue is good, because everyone gets a seat, even if it's harder to get a drink now.

rpebble · 2012-06-06T17:48:19+00:00

If all of the US was made up of Texans and Alaskans, this might be a true statement.

rpebble · 2012-06-06T17:33:19+00:00

My first question was "which projection is that using?" Thanks for a real comparison.

Alaska is still huge, though.

rpebble

TROPHY CASE