PDA

View Full Version : OT: 2 questions for "intersting stuff" people who know



GAU-8
03-02-2007, 09:28 PM
1. of course theere has been flying toys, years before there was ever any aircraft. much like the (chinese ? ) top with feathers on the top of it. but just curious...were PAPER AIRPLANES ever around before aircraft? im sure it wasnt called an "airplane"..maybe a paper dart, or something like that. just made me wonder..

2. it has been long known that spiders silk is stronger than steel in such things as tensile strength an such. im sure its used somewhere in the world for its own use, but...

is there any applications that spiders silk is being used in some form of industrial/ product or something? even if used in microscopic size. more or less a steel replacement. or are the properties other than its tensile strength flawed for everyday usage. i.e. short lifespan, brittle when cold, disfigures when warm, too many loose spiders in the spider silk room, man has artificial spider silk that gets the job done..etc etc.

GAU-8
03-02-2007, 09:28 PM
1. of course theere has been flying toys, years before there was ever any aircraft. much like the (chinese ? ) top with feathers on the top of it. but just curious...were PAPER AIRPLANES ever around before aircraft? im sure it wasnt called an "airplane"..maybe a paper dart, or something like that. just made me wonder..

2. it has been long known that spiders silk is stronger than steel in such things as tensile strength an such. im sure its used somewhere in the world for its own use, but...

is there any applications that spiders silk is being used in some form of industrial/ product or something? even if used in microscopic size. more or less a steel replacement. or are the properties other than its tensile strength flawed for everyday usage. i.e. short lifespan, brittle when cold, disfigures when warm, too many loose spiders in the spider silk room, man has artificial spider silk that gets the job done..etc etc.

FritzGryphon
03-02-2007, 09:50 PM
On spider silk, I've read that it performs well under all the conditions you mention. Good in all environmental conditions, lasts a long time, resists fatigue, etc.

It's been used in small applications even in WWII, one example being for crosshairs on periscopes.

It could be used for everything from body armor and arrestor cables, to building construction, were it not so rare and expensive. Artificial production is still very arduous, and the silk is of poorer quality than natural stuff.

WB_Outlaw
03-02-2007, 10:26 PM
Spider silk proteins are produced in the milk of genetically engineered goats. Once the proteins are seperated out of the milk, silk is produced using almost the same process a spider uses. The last I heard, the proteins are extruded through a nozzle with many microscopic holes in it. The nozzle is similar to a spider's spinnerets but, as FG said, the quality of the silk is very much inferior to even steel in terms of tensile strength. They were working on different nozzles so they may be producing better silk by now.

Sometimes reality is stranger than fiction.

--Outlaw.

GAU-8
03-03-2007, 09:35 PM
so what about paper airplanes? if so, did they have a specific name (like paper flyer, or paper dart)? and by chance was this used to explore future of flight by looking at the simple dynamics of the paper planes?

R_Target
03-03-2007, 10:49 PM
My guess would be that they were derived from early kites. Check this out: Paper Plane History (http://paperplane.org/History/history.html).

x6BL_Brando
03-04-2007, 02:16 AM
I was round at a friend's house helping to build a model of a stone viaduct. Stupidly, I plunged the point of my scalpel deep into the ball of my thumb producing a puncture that just wouldn't stop bleeding.

That is, until my friend's mother went into an understairs cupboard and grabbed a handful of spiders' web. She rolled the fibres into a small pad and pressed it over the wound adjuring me to hold it there. After a few minutes the pad had turned into a smooth & dry scab which stopped the blood and protected my thumb for days until it eventually wore away after about a week of normal hand-washing.
Spider web contains a large amount of the blood clotting agent, keratin, and that's why the flow stopped - while the strength of the silk must be why the artificial scab endured so long. It worked so well that I was able to go back to using my thumb within half an hour. I've used this method many times now for patching small cuts.

B

Altocirrus
03-04-2007, 04:23 AM
Ouch! I'll have to add some cobwebs to my first aid kit.

If you've got a spare half an hour, have a listen to this radio programme:

http://www.bbc.co.uk/radio4/science/rams/materialworld_20061109.ram

It highlights some of the potential applications of spider's silk. And there's some stuff on aerial photography too.