If the earth is moving

[nohorn]

If the earth is spinning and in orbit, why don' t humans or other animals sense or detect movement? Would we/they if anything slowed down?

[ChuckFickens]

people and animals can not detect movement, all they can detect a change in movement (direction or velocity), if you think about being in a car, you don't feel like you are moving at a steady speed on a motorway, but you can feel if the car brakes, accelerates or turns.

if the earth was to slow down gradually then nobody would notice the change in movement as it would be below the threshold that we can detect (we would notice the days getting longer fairly quickly though)

If the earth was to suddenly stop then we would most certainly be able to detect the change.

[jake-the-peg]

This is a common misconception you cannot tell when you are moving at a fixed speed only when you experience acceleration or deceleration.

This is one of the two concepts that special relativity is based on (The other is that the speed of light is a fixed maximum).

Of course because we are moving in a circle there is an acceleraion it's just that the circle is so big we don't notice it.

You'd actually have to speed up the Eath's rotation, not slow it down for it to affect us.

Please don't though some of us get dizzy easily.

[wildwood]

Perhaps we don't actually sense the traveling through space because the atmosphere travels with the planet???

Just a thought.

[wildwood]

As an matter of interest and I've never found out if it's true....

I remember a looooooong time ago at school someone asked what would happen if the Earth stopped spinning and the teacher's reply was "if it stopped at midday we would fry in 12 hour and at the other side of the planet life would freeze".

[R1Geezer]

If it stopped suddenly we'd all die from deceleration 1000mph to 0 in 1 second = Hovis.

[jake-the-peg]

Well Wildwood it's an interesting question because planets ten to become orbitally locked like the moon and permanently face the body they are orbiting.

For a long time it was thought that Mercury was like this and that one side was frozen and one side was amazingly hot. Radar measurements subsequently found that not to be the case but I'm sure that was what your science teacher was thinking of.

However there is a complication in the case of the Eath because unlike mercury it has seas and a significant atmosphere.

I have no dought that the night side of the Eart would become cold and the sun side hot but there would also probably be a lot of strong winds and currents transporting energy from one side to the other too wich might make it less extreme than you might think

[jonboy35]

We do detect movement! But only against really fixed objects like the stars crossing the sky each night.. Our own star (the sun) appears to cross the sky (as you know!) once a day. It is fixed (relatively!) and we are the ones moving. Everything else moves along with us. Other evidence of earth movement is hurricanes going anti clockwise in the northern hemisphere and oppositely in the southern hemisphere--and yes the water in the kitchen sink really does prefer to do the same down the plughole as do (rare) rotating ice disks seen on nearly frozen streams. Cannot give web references but they do exist..