4 ms·

What do you mean by directly? Gravity is only sensed via an interaction between fluids and fine hairs in your inner ear. By that definition, we can also detect

• panda-giddiness 4y ago
  On the contrary, I'd be perfectly content classifying our probing of gravity/acceleration indirect, too. For completeness I include gravity because it's the only other fundamental interaction we arguably directly sense (inner ear fluid and fine hairs are part of the same sensory organ, unlike our skin and the sun). But I still suspect we would be able to sense gravity without inner ear fluid, even if only slightly. When we vigorously shake our head, the fluid flows against the hairs, so naturally the electromagnetic force and/or Pauli exclusion is mostly responsible for sensing. However, even absent any inner ear fluid, the hairs should still bend due to gravity -- I just don't know how appreciable the effect is.
  • jamesrom 4y ago
    > For completeness I include gravity because it's the only other fundamental interaction we arguably directly sense (inner ear fluid and fine hairs are part of the same sensory organ, unlike our skin and the sun). Not sure why the organ doing the sensing matters. I'm talking about thermoreceptors in the skin, obviously. But just to be clear, I'm saying that you're actually sensing electromagnetic force in your inner ear _caused by_ gravity. Not gravity itself. Even if the hairs bend due to gravity alone, that force upon the sensory receptors is an electromagnetic one. But if you consider that 'direct' then you must also consider sensing of the weak force, as 'direct'. Whether it be via thermoreceptors or your retina. tldr gravity : bending hairs :: weak interaction : radium glow