Re: 'Effect' vs 'Affect'
"Affect" and "effect" are both nouns and both verbs, with different meanings in several cases.
• You may have an effect upon Something. (noun)
• That Something will have been affected by you. (verb)
• You may effect a change. (verb) — The change will have been effected. (verb)
• You may affect your wife's emotions. (verb)
• Your psychologist may observe that you have a strange affect. (noun)
The last one is rarely heard as it's a term of art. The former four are all common uses, though the first, second and fourth are probably the more common. It's not a 'color/colour' thing in the sense of US vs British English, but you will observe incorrect usages much more frequently in US content simply because of their appalling standards of general education. Even their president has poor language, grammar and spelling skills. Mind you, he is as dumb as a stump.
That all said, you could argue for some leeway in sentences like:
"The Earth's gravity Æffects the Moon's orbit."
The Moon orbits Earth because of Earth's gravity, so it must be correct to write "Earth's gravity effects the Moon's orbit", insofar as the orbit is actually created by—brought into existence because of—Earth's gravity.
But the shape of the Moon's orbit is also modified by Earth's gravity, so it must also be correct to write "Earth's gravity affects the Moon's orbit", insofar as the orbit is modified, or changed by Earth's gravity.
I mention this just to confuse folks and revel in the sheer unadulterated weirdness of English language.
You're all very welcome ;-)