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Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

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Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#31

Post by has2k1 »

graycat wrote: post #2

Use for a skyhook ? A skyhook is what? Dirt cheap way to mass into earth orbit. How? Put a weight on a string, attach the string at, maybe, the equator of earth, put the weight into orbit, and let the centrifugal force of the weight keep it in orbit and keep the string tight. Then to put mass into orbit, let it crawl up the string from electric power conducted from earth in the string. Main problem: Getting a suffici…

I have encountered the term in another context.

> A "skyhook" is an imaginary device for hanging an object from the sky. The word originated in a sarcastic remark by a frustrated pilot of a reconnaissance plane in the First World War, when told to stay in the same place for an hour: "This machine is not fitted with skyhooks," he replied.

From, "The Evolution of Everything: How New Ideas Emerge" by Matt Ridley

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#32

Post by hwillis »

graycat wrote: post #30
hwillis wrote: post #16

Earlier quoted context omitted.

Main problem is more that there is no advantage to a skyhook if you're just putting things into orbit. Every kilo you lift with a skyhook pulls it down and it has to be used to de-orbit that mass, or lifted up by rockets or thrusters etc. Unlike an actual space elevator, or orbital ring, or launch loop, it doesn't hold itself at altitude. Also, there's really no need for the tether to be conducting. For one, you coul…

I was being very simple. I used skyhook as informal and humorous and did not know that it had a technical meaning in this context. I was thinking more of what is commonly called a space elevator but did not look up the details, e.g., synchronous orbit or some such. Really I was just commenting on the spider silk with carbon fibers that might add some of the needed strength and also permit sending power to whatever wa…

Oh, I figured you meant it. In that case carbon fiber is stronger, more conductive, and cheaper. Why bring up space elevators if you have no interest in saying or learning something about them?

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#33

Post by krige »

Is graphene even a thing? Last I checked it was still a magical hypothetical substance made with pencil shavings and duct tape (that's an exaggeration but only a mild one). Every now and then I see news about graphene being the next big thing, like, very soon, but the results I see fail to prove that it's even an actual substance, and the evidence is the lab that made it swearing that it's totally a thing.

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#35

Post by ieatkittens »

jimnotgym wrote: post #9
azernik wrote: post #5

Earlier quoted context omitted.

A skyhook is generally a space elevator that doesn't go all the way to the ground, and so doesn't have to be quite as precise about orbital velocity and the like.

I thought a skyhook was one of those things you send the apprentice kid to the stores for, like tartan pain, spirit level bubbles, long stands and a weight with no point? Maybe even a left handed screwdriver...

Wifi cable

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#36

Post by mrfregg »

george_ciobanu wrote: post #34

Plot twist: Silk worms leave study disgusted with shity new taste of food.

"...by spraying fresh mulberry leaves with SWNTs or GR solutions...containing SWNTs with solution concentration of 0.2 and 1.0 wt % and GR at the concentration of 0.2 and 2.0 wt %" I'd be surprised if they tasted anything at all, if they can taste :)

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#37

Post by wastedhours »

mrfregg wrote: post #36
george_ciobanu wrote: post #34

Plot twist: Silk worms leave study disgusted with shity new taste of food.

"...by spraying fresh mulberry leaves with SWNTs or GR solutions...containing SWNTs with solution concentration of 0.2 and 1.0 wt % and GR at the concentration of 0.2 and 2.0 wt %" I'd be surprised if they tasted anything at all, if they can taste :)

Interesting that they're not dangerous - had a pot of SWNTs and the warning labels against breathing them in were 4x larger than the container itself! Same with getting them on your hands, thought it was due to them creating lots of micro-cuts - guess the low concentration makes that less likely?

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#38

Post by mirimir »

> Zhang’s team tested conductivity and structure after heating the silk fibers at 1,050°C (1,922°F) to carbonize the silk protein, and unlike untreated silk, the carbon-enhanced silk conducted electricity.

After that much heat, would this silk be useful for making fabric?

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#39

Post by WJW »

hwillis wrote: post #28
Fjolsvith wrote: post #25

Earlier quoted context omitted.

If there was a big counterweight out at the far end of the cable, and it was sufficiently long enough, wouldn't the centrifugal force acting on the weight counteract the kilos lifted?

No, that doesn't work for anything less than a space elevator or the other devices I mentioned. A space elevator is tied down to the earth, and constantly trying to fly off into space. A skyhook is basically nothing more than a LEO satellite with a very, very long rope hanging off it. If you pull on the rope, you pull the satellite down since there is no centrifugal force besides the inertia keeping it in orbit. If y…

While the energy imparted to the object being leunched is the same, you would be able to use high-ISP thrusters like ion engines to boost the counterweight back up. They can't be used lower down though, due to not having enough thrust for use in the atmosphere. This would have the advantage of raising the average ISP during the launch, thus having to use less propellant overall.

It might even be possible to use tether-based propulsion for the counterweight, which wouldn't need any propellant at all but push against the Earths' magnetic field.

Re: Graphene-Fed Silkworms Produce a Super-Strong Silk That Conducts Electricity

#40

Post by Already__Taken »

wastedhours wrote: post #37
mrfregg wrote: post #36

Earlier quoted context omitted.

"...by spraying fresh mulberry leaves with SWNTs or GR solutions...containing SWNTs with solution concentration of 0.2 and 1.0 wt % and GR at the concentration of 0.2 and 2.0 wt %" I'd be surprised if they tasted anything at all, if they can taste :)

Interesting that they're not dangerous - had a pot of SWNTs and the warning labels against breathing them in were 4x larger than the container itself! Same with getting them on your hands, thought it was due to them creating lots of micro-cuts - guess the low concentration makes that less likely?

Nanoscale things are considered dangerous because they happily pass straight through cells. Not something you want to find out is a problem.

/notascientist

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