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New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

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Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#61

Post by marcosdumay »

ironfootnz wrote: post #51

O wonder if they could use this to absorb sun light and transform into heat and generate electricity. Looking into the absorption rates in the chart, it’s clear that it would be 30x more efficient than solar panels these days.

For heating a surface you'll want a material that absorbs the solar spectrum, but is extremely reflective on the heat spectrum. Optimizing the material absorbtivity does not lead to much gain, while optimizing the reflectivity leads to huge results.

This material absorbs every spectrum, what makes it really bad for that application.

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#62

Post by perl4ever »

2_listerine_pls wrote: post #9
umvi wrote: post #7

But can the human eye tell the difference?

If we were to shine a light into vantablack in a dark room ~0.04% would be reflected but it would be enough make the object visible. So, it is possible to differentiate both paints in those conditions. https://petapixel.com/2016/07/25/human-eye-sensitive-can-det...

Somebody went and took a picture of the vantablack car that wasn't set up to make it look dark and showed it appeared to be a dull gray. There's a very high degree of latitude in how you take pictures of something, and the 0% brightness level in the output can be anything you like. The human eye is adaptive, as well, so it probably wouldn't be all that impressive in person either.

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#63

Post by samstave »

kart23 wrote: post #29
samstave wrote: post #15

Serious question: How do these materials both perform against radar? Will we be seeing them as stealth paints on planes or satellites?

https://worldbuilding.stackexchange.com/questions/76278/woul... google my friend. There are other specially formulated paints that aim to absorb the correct wavelength.

Awesome read, thank you

Now I’m envisioning a system where the spy drone sows down significantly and little machanized graphene “hairs” stand up all over its body to absorb any wavelengths of radar it wants to avoid...

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#64

Post by samstave »

awodol wrote: post #23
big_chungus wrote: post #17

Earlier quoted context omitted.

Follow-up serious question: if I paint my car with this stuff, can a policeman tag me with his radar gun? If I wear clothes impregnated with it, would it confuse a "smart" surveillance camera? I'm also thinking if I used it as war paint, a facial recognition cam would probably be awfully confused by what appears to be a hole in my face.

For the car case, usually police shoot their radar at your license plate since it's a flat reflective surface anyways.

Do the black and yellow California plates still possess reflective properties?

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#65

Post by lgats »

jdc wrote: post #42
BoorishBears wrote: post #40

Earlier quoted context omitted.

It can be done for limited production, but it doesn't fully hide from LIDAR https://www.cnet.com/roadshow/news/bmw-x6-vantablack-paint-c...

From the CNET article: >> Typically, the lidar unit can spot things from more than 328 feet away. >> In this case, the company said the darkest of dark BMWs would need to be about 72 feet away before the lasers and ambient light register the moving black hole.

LIDAR is most effective at a distance from the license plate, headlight, and chrome reflective parts of a car. There is a laser absorbing product called VEIL made specifically for reducing these reflections.

https://www.stealthveil.com/faq/

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#66

Post by 2_listerine_pls »

perl4ever wrote: post #62
2_listerine_pls wrote: post #9

Earlier quoted context omitted.

If we were to shine a light into vantablack in a dark room ~0.04% would be reflected but it would be enough make the object visible. So, it is possible to differentiate both paints in those conditions. https://petapixel.com/2016/07/25/human-eye-sensitive-can-det...

Somebody went and took a picture of the vantablack car that wasn't set up to make it look dark and showed it appeared to be a dull gray. There's a very high degree of latitude in how you take pictures of something, and the 0% brightness level in the output can be anything you like. The human eye is adaptive, as well, so it probably wouldn't be all that impressive in person either.

The car looked gray because it had a protective coating on top, thus you get some amount of diffuse/specular reflection from the camera's flash and surroundings.

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#67

Post by Ao7bei3s »

gabrielbln wrote: post #53
anon1m0us wrote: post #31

Can someone please explain to me the race to the blackest black?

Oh god. We developed the blackest tshirt in the world. So I know much more about this subject than what is possibly good for my mental health lol I made a comparison video about the ultra blacks that are freely available https://youtu.be/ElVzQ2M6vh0 Regarding VB and the MIT stuff, they are hi-tech and useful for optical applications like space telescopes. Interestingly, the creator of Vantablack told me that there ar…

How quickly does it wash out?

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#68

Post by samstave »

big_chungus wrote: post #17
samstave wrote: post #15

Serious question: How do these materials both perform against radar? Will we be seeing them as stealth paints on planes or satellites?

Follow-up serious question: if I paint my car with this stuff, can a policeman tag me with his radar gun? If I wear clothes impregnated with it, would it confuse a "smart" surveillance camera? I'm also thinking if I used it as war paint, a facial recognition cam would probably be awfully confused by what appears to be a hole in my face.

Id like a baseball cap, painted with vanta black, but with a cheese-cloth style net also painted with vanta black, which can be worn down like a bee-keepers hat, such that facial recognition cant be used against me.

Also, i am anouncing right now my freedom to destroy any facial recognition cameras i come across. Its my fist amendment right to not be supressed with facial recognition because i am free to say anything i want, and using facial recognition is a violation of my first amendment rights.

Re: New carbon nanotube-metal hierarchical material is 10x darker than Vantablack

#69

Post by OrgNet »

BoorishBears wrote: post #40
EGreg wrote: post #37

Earlier quoted context omitted.

Haha would this even be legal? Nevermind - it’s not even feasible https://www.quora.com/Lets-say-Im-a-rich-racer-who-wants-to-...

It can be done for limited production, but it doesn't fully hide from LIDAR https://www.cnet.com/roadshow/news/bmw-x6-vantablack-paint-c...

because that ultra-black looks blue? https://www.youtube.com/watch?v=7tVaJVtxMYE&t=0m11s
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