Does gravity have a speed?

http://www.physlink.com/ae352.cfm

How do we see things upright if the image formed on the retina

in our eye is an inverted one?

http://www.physlink.com/ae353.cfm

What is the Pascal's law?

http://www.physlink.com/ae339.cfm

What causes high tide and low tide and why?

http://www.physlink.com/ae338.cfm

If the size of the universe is infinite and the speed of light

is constant, are there places light has not reached?

http://www.physlink.com/ae336.cfm