Is there any scientific reason for buttons on the right?

Question

Have you ever noticed that every(or most of them) webdesigner places the buttons on the right?

On the google page, we click on "more" button which is on the right.

Here on Y! the preview and cancel is on the right.

On the webmails services, the "log out" is on the right and so on...

Is there any scientific reason for that?

Answer 1

Western User Interface design 101:

People that use western and Cyrillic languages read from top to bottom, left to right.

We prefer to see contents first (left top), followed by interface elements (right bottom).

Answer 2

Probably due to most people being right handed and mouse pointer is already in that area of screen.