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Smart fabric heats up under the sun

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Re: Smart fabric heats up under the sun

#11

Post by TuringTourist »

Ekaros wrote: post #3
rokkamokka wrote: post #2

"... enabling the fabric to absorb heat and convert it into warmth" is a fun sentence

"The design requires no external power" Umm, so sunlight is not external power?

I take "external power" to mean power that is not "free" as in humans paid for it. Otherwise the phrase "External power" is meaningless, as all energy comes from somewhere else eventually. (unless you're at some point in time extremely close to the birth of the universe, then we might accept that it's actually internal or at least locally sourced)

Re: Smart fabric heats up under the sun

#13

Post by water9 »

TuringTourist wrote: post #11
Ekaros wrote: post #3

Earlier quoted context omitted.

"The design requires no external power" Umm, so sunlight is not external power?

I take "external power" to mean power that is not "free" as in humans paid for it. Otherwise the phrase "External power" is meaningless, as all energy comes from somewhere else eventually. (unless you're at some point in time extremely close to the birth of the universe, then we might accept that it's actually internal or at least locally sourced)

You bring up an interesting point about the birth of the universe. Doesn’t that violate the principle that energy cannot be created?

Re: Smart fabric heats up under the sun

#15

Post by SapporoChris »

codr7 wrote: post #10

Isn't that like, the default? I would find it more impressive if it didn't.

Yes, I am confident that all materials get warmer when exposed to sunlight. Evaporative cooling might be argued as an exception, however I do not consider it so.

There might be some materials that do not absorb solar radiation, I'm not aware of them.

https://en.wikipedia.org/wiki/Evaporative_cooler

Re: Smart fabric heats up under the sun

#17

Post by viraptor »

> Notably, when exposed to 600 W m−2 irradiation for 600 s, the equilibrium temperature of the photo-thermochromic elastic fiber rises impressively from the ambient 20.0 °C to 53.5 °C.

Does anyone know what's the expected raise from that much energy in basic cotton for comparison?

Re: Smart fabric heats up under the sun

#19

Post by cluckindan »

nine_k wrote: post #16
yapyap wrote: post #12

Stupid fabric also heats up under the sun, as does braindead fabric.

Stupid fabric can only grab a few degrees, while the smart fabric acquires full 30. A genius fabric could likely boil water in the wintertime with sunlight alone!

A wet black sock around a beverage can in direct sunlight will cool down the can as it dries.

Re: Smart fabric heats up under the sun

#20

Post by chowells »

water9 wrote: post #13
TuringTourist wrote: post #11

Earlier quoted context omitted.

I take "external power" to mean power that is not "free" as in humans paid for it. Otherwise the phrase "External power" is meaningless, as all energy comes from somewhere else eventually. (unless you're at some point in time extremely close to the birth of the universe, then we might accept that it's actually internal or at least locally sourced)

You bring up an interesting point about the birth of the universe. Doesn’t that violate the principle that energy cannot be created?

At the very large scale, the universe does not appear to conserve energy. The whole "lambda" in "lambda cold dark matter" is a description of how energy is being added to the universe.
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