Cool. Positronium 'atoms' are made up of an electron and a positron.
"Researchers are [...] actively seeking tricks to make sources of positronium atoms that live longer. In a paper published today in the journal Physical Review A, the AEgIS collaboration at CERN describes a new way of making long-lived positronium."
Suppose you were trying to invent a bright orange powder that could easily dye clothes and be hard to wash off. Using your knowledge of quantum mechanics you'd design this symmetrical molecule where an electron's wavefunction can vibrate back and forth along a chain of carbons at the frequency of green light. Absorbing green light makes it look orange! And this molecule doesn't dissolve in water.
Yes: you'd invent turmeric!
Or more precisely 'curcurmin', the molecule that gives turmeric its special properties.
The black atoms are carbons, the white are hydrogens and the red are oxygens.
Read on and check out what pure curcurmin looks like.
@johncarlosbaez@b3nb3n@mc I vividly remember the moment in grad school twenty-odd years ago when it suddenly hit me that conjugated carbon-carbon double bonds are a hallmark of dyes "#chromophores" (as well as fluorescent molecules "#fluorophores"). Because they happen to have #electrons of just the right energies to absorb visible #photons! (Or ultraviolet photons, and then emit visible photons.)
One of my many post-undergrad "WHY oh WHY DIDN'T THEY MENTION THIS IN #OrganicChemistry?!" moments.