Sun up or not

[weecalf]

Ok so we have heard it a thousand time ,Sun up ,I actually think its the mountains or the horizon which go down .As the world turns it actually turns the horizon down .so the sun dont rise it just sits there .Can any one dispell this notion so I can get a nights sleep.

[sandyRoe]

The Sun sits steady. We do the moving.

[weecalf]

So why" sun up"

[sandyRoe]

Because it seems to rise into the sky?

[Buenchico]

'Up' and 'down' are defined by the way that the human brain perceives things.

An experiment:
Stand absolutely still, just before dawn, with your eyes focussed on the horizon and look at what you see. Quite clearly (as your brain perceives it), the sun is going up (since the horizon hasn't moved).

The only way that you can explain it as being 'the horizon going down' is if you accept that you are moving. Of course you really are moving (since you're standing on the surface of a revolving planet) but it's axiomatic, within this experiment, that you're standing "absolutely still". (It's there in the first line above!).

Ergo, if you accept that the horizon is going down you must also accept that you can never stand absolutely still!

[rowanwitch]

And if your brain does work out its the horizon moving have a bucket ready as you might get vertigo

[weecalf]

So can we say sun up and sundown are just optical illusions ?