# Physics of movement

The earth spins on it's axis at approximately 2 mi/sec(795 mi/hr), it
spins around the sun at approximately 18.5 mi/sec(67,000 mi/hr), and
the sun along with all of the planets spins around the center of the
galaxy at 144 mi/sec(1/10th the speed of light. So how come we don't
feel all of that motion?

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mathman
We don't sense velocity with our bodies, only change in velocity.

mistersmith said:
144 mi/sec(1/10th the speed of light.
The speed of light is 186,282 mi/sec, and 144 mi/sec is nowhere near 1/10th of that.

Phobos
Staff Emeritus
Gold Member
mathman said:
We don't sense velocity with our bodies, only change in velocity.
example...flying in an airplane. You don't feel the motion while traveling at a few hundred miles per hour (turbulence aside) but you do feel the change in velocity (acceleration) when taking off.

Staff Emeritus
Gold Member
Dearly Missed
Suppose you were blindfolded and sat in a chair at the north pole. In 24 hours you would turn through 360 degrees, in one hour through 15 degrees. Do you suppose that without some exterior visual cue you could "feel" that speed of rotation? And everywhere else than the poles, the experienced earthly rotation is less; at the equator it's zero - parallel transport! And all the other rotation speeds you cite are less than the earth's, 360 degrees in a year? 360 degrees in umpty billion years? Man when you turn your head to one side you do 90 degrees in half a second; that's 648,000 degrees per hour, for comparison.

Phobos said:
example...flying in an airplane. You don't feel the motion while traveling at a few hundred miles per hour (turbulence aside) but you do feel the change in velocity (acceleration) when taking off.
can this be considered as an example for inertia?

J77
Plus the atmosphere spins at pretty much the same rate as the Earth, that helps in not feeling anything...