. "Planck's constant"^^ . "0"^^ . . . "the constant of proportionality relating the energy of a photon to its frequency; approximately 6.626 x 10^-34 joule-second"@en-us . . "13591123-n"^^ . . "Planck's constant"@en-us . "113591123"^^ . . "112825875"@en-us . "0"^^ . . . . . "h"@en-us .