
New carbon nanotube-metal hierarchical material is 10x darker than Vantablack - bookofjoe
https://pubs.acs.org/doi/10.1021/acsami.9b08290
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the8472
[https://sci-hub.tw/10.1021/acsami.9b08290](https://sci-
hub.tw/10.1021/acsami.9b08290)

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anon1m0us
Can someone please explain to me the race to the blackest black?

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exabrial
Painting your car in it to avoid lidar

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EGreg
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-...](https://www.quora.com/Lets-say-Im-a-rich-racer-who-wants-to-coat-my-
car-in-Vantablack-Would-it-be-expensive)

~~~
BoorishBears
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...](https://www.cnet.com/roadshow/news/bmw-x6-vantablack-paint-color-
lidar/)

~~~
jdc
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.

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lgats
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/](https://www.stealthveil.com/faq/)

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all_blue_chucks
Well this is certainly bad news for anyone who invested $35k in a vantablack
wristwatch: [https://www.h-moser.com/en/collection/1801-1200-endeavour-
pe...](https://www.h-moser.com/en/collection/1801-1200-endeavour-perpetual-
moon)

~~~
contravariant
It's a bit weird to demonstrate the colour of vantablack by adding a shine to
it.

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tempestn
I was thinking the same thing. You can see how they must have felt a black
circle on a screen doesn't look too impressive, but this is a rather backwards
way of dealing with that. (I would have added shine to the background and
watch body but not the face...)

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SamReidHughes
There is a piece of domed sapphire in front of it with an imperfect anti
reflective coating.

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gibolt
It is stated to be an order of magnitude better across the broad spectrum than
other broad absorbers.

I wonder if there are any narrow bands that it specifically excels at compared
to existing materials, and how big the difference is.

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robocat
This is the relevant graph I think:

[https://i.ibb.co/129RQK9/Screenshot-20190915-124224-2.png](https://i.ibb.co/129RQK9/Screenshot-20190915-124224-2.png)

~~~
kzrdude
They are potentially misleading by connecting the dots in that way. (The
classic, it implies data where there is nothing.)

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umvi
But can the human eye tell the difference?

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2_listerine_pls
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...](https://petapixel.com/2016/07/25/human-eye-sensitive-can-detect-
single-photon-light/)

~~~
perl4ever
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.

~~~
2_listerine_pls
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.

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samstave
Serious question:

How do these materials both perform against radar?

Will we be seeing them as stealth paints on planes or satellites?

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big_chungus
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.

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

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tempestn
And at headlights otherwise. But if your car has popup headlights and no front
plate, and you paint it vantablack, you'd probably be close to invisible to
police LIDAR (laser) guns. I'm not sure what the reflectivity of this stuff in
the radio spectrum is though.

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ianai
What are the hopeful uses for making ever more absorbing black materials?

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WizardAustralis
While not the most technology advanced use, I think this stuff could make for
a great solar powered water heater.

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tedunangst
Are the incremental improvements over regular black paint meaningful?

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cordite
Could such a material be put behind (and be protected by) glass and still have
the desired properties?

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ironfootnz
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.

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DoctorOetker
solar panels are way more efficient than 3.333... % , so no, _nothing_ can be
30x more efficient than solar panels these days.

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christopoulos
Maybe we now can get true black on an LCD screen?

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2_listerine_pls
LCDs don't work like that, they block the back-light with polarization:

[http://soft-matter.seas.harvard.edu/index.php/Phase_transiti...](http://soft-
matter.seas.harvard.edu/index.php/Phase_transitions_in_liquid_crystals)

