The heavy appeal of liquid metals

Liquid metals are so outside our usual experience that it’s hard not to see them as some sort of otherworldly, almost magical substance. No liquids we routinely encounter are metallic in the least, and any molten metals we see are normally glowing hot and thus viewed at a distance. Perhaps it’s mercury’s poisonous reputation we have to thank for that – my only lab experience of liquid metals was confined to the inside of thermometers, safe in the knowledge there was a mercury spill kit somewhere nearby in case of accidents. That the futuristic – and deadly – T-1000 in the second Terminator film was made of a mimetic polyalloy (or ‘liquid metal’, as Arnold Schwarzenegger so memorably intoned) was no coincidence.