Dark Matter!!

[Jim Horn]

Dark matter and dark energy can't be measured but only deduced by measuring other things? Would that be like most observations in physics? I can't see magnetic fields but only deduce them by their effect on current flow through a coil (if varying), moving a compass needle, etc. Similarly, we know *something* is bending the light of distant galaxies and such. Refraction and other Newtonian explanations fail. The only successful-so-far known cause is gravity. But the gravity caused by the observed mass of things is insufficient. So either there's lots of missing mass from our observations -or- we don't measure the mass properly from known observations of electromagnetic spectra -or- there's mass that isn't involved with those spectra. The latter case has gotten the descriptive name of dark matter (and, correspondingly, dark energy).

Can we therefore never measure those? We couldn't measure voltage, current or magnetic fields centuries ago but we've learned a lot since then. Perhaps in the future what we now call dark matter or energy will be known to be akin to neutrinos, (entirely hypothetical) tachyons, or the heretofore unmeasured mass of souls. I don't know what the answer will be but I can't rule out the hypothesis, which is what it is.

Great comment, though, Joe! Lots of food for thought (nom, nom, nom)...