Caption: "Vantablack grown on tinfoil."

"Vantablack is substance made of vertically aligned carbon nanotube arrays and is the blackest artificial substance known, absorbing up to 99.965 % of electromagnetic radiation (EMR) in the visible band (fiducial range 0.4--0.7 μm)" (Wikipedia: Vantablack: slightly edited).

Actually, the carbon nanotubes act a bit like tiny Purcell's hohlraums trapping the light that enters them by multiple reflections until it is dissipated to waste heat (see Wikipedia: Vantablank: Properties).

Note carbon nanotubes may be pose a health concern (see Wikipedia: Toxicology of carbon nanomaterials: Carbon nanotubes).

Despite appearances, vantablack is NOT dark energy.

Credit/Permission: © Surrey NanoSystems 2014 (uploaded to Wikimedia Commons by User:Anna Frodesiak, 2014) / 2008) / CC BY-SA 3.0.
Image link: Wikimedia Commons: File:Vantablack 01.JPG.
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