The force of destruction pulls on the goats. The force of life pulls on the sheep.
And
Egypt pictures the occupation of the goats.
And
What does Egypt need with the Earth? They go somewhere else. So the force of Egypt weakens the force for life. A weak force for life is dangerous for Earth.
But some say the sun won't shine forever on the Earth. Because you know the same thing theorized to happen way out in space happens to this sun? How do you know?
http://www.jehovahs-witness.net/watchtower/bible/220546/1/The-Two-Forces