### Why can't we feel the Earth's revolution?

• I googled it and checked a few Q&A and there's only things about "Earth's rotation". But why can't we feel the revolution?

They say we can't feel the rotation because the Earth spins at a constant speed. Okay, I get what happens for the rotation, but isn't it different when it comes to the revolution?

At night we feel the sum of speed of green and blue, whereas at day we should feel the sum of speed of green and minus blue, shouldn't we? In other words, shouldn't we feel the changes in velocity by times?

Speak for yourself. I feel quite dizzy, thank you very much. Also, the fact that we don't all float off into space (I can feel the floor below me as I type), appears to be evidence of something.

The explanation you read about Earth rotation is wrong but the answers should clarify that point as well.

You also cannot feel the Moon or the Sun gravitational force, but the sea can, and you can measure the rise of the tides

• Firstly the speeds are massively different (about 1000 mph (1610 kph) on the equator for Earth's rotation and 70,000 mph (112,654 kph) for the revolution), so the change is not large. Secondly, the green line is far straighter than it appears in your picture (because the orbit is so large) so Earth's motion around the Sun is pretty close to motion at constant velocity, which Einstein tells us cannot change the outcome of any experiment.

Which in turn is a reflection of just how ***weak*** gravity is.

This answer is misleading in that it is not the size of the speeds but any acceleration (change velocity in its speed or direction) that is related to an applied force. When traveling in a circle a force needs to be applied to change the direction of motion. The answers by llama and ap55 are better. However I like the "the green line is far straighter than it appears in your picture (because the orbit is so large) so Earth's motion around the Sun is pretty close to motion at constant velocity". At constant velocity any forces are all balanced out (net force = zero, F=0)

Galileo, not Einstein.

Yeah it didn't take Einstein to realize this...