Light travels at a finite speed, with the speed depending upon the medium. With mirages, the medium is air. In air, the speed of light is only slightly less than it is in a vacuum, and the speed of light in air depends upon the temperature of the air. Simply put, the speed of light is slightly greater in warmer air than it is in cooler air. In physics, we usually express this behavior reciprocally as the index of refraction, n:

This is also why objects of different size and density fall down with the equal speed in vacuum chamber. Where is the "mass" law in this case? Mass has disappeared? No, it never existed! They fall with equal speed only because there is no air around them which could slow down their motion. They are attracted to the bigger density of the earth under them.

“A SOLAR eclipse is the result simply of the moon passing between the sun and the observer on earth. But that an eclipse of the moon arises from a shadow of the earth, is a statement in every respect, because unproved, unsatisfactory. The earth has been proved to be without orbital or axial motion; and, therefore, it could never come between the sun and the moon. The earth is also proved to be a plane, always underneath the sun and moon; and, therefore, to speak of its intercepting the light of the sun, and thus casting its own shadow on the moon, is to say that which is physically impossible.
48) On a ball-Earth Santiago, Chile to Johannesburg, South Africa should be an easy flight all taking place below the Tropic of Capricorn in the Southern hemisphere, yet every listed flight makes a curious re-fueling stop in Senegal near the Tropic of Cancer in the North hemisphere first! When mapped on a flat Earth the reason why is clear to see, however, Senegal is actually directly in a straight-line path half-way between the two.
INCREASE to such an extent beyond the equator (going southwards) that hundreds of vessels have been wrecked because of the false idea created by the untruthfulness of the charts and the globular theory together, causing the sailor to be continually getting out of his reckoning. With a map of the Earth in its true form all difficulty is done away with, and ships may be conducted anywhere with perfect safety. This, then, is a very important practical proof that the Earth is not a globe.
65.) The Rev. D. Olmsted, in describing a diagram whish is supposed to represent the Earth as a globe, with a figure of a man sticking out at each side and one hanging head downwards, says "We should dwell on this point until it appears to us as truly up," In the direction given to these figures as it does with regard to a figure which he has placed on the top! Now, a system of philosophy which requires us to do something which is, really, the going out of our minds, by dwelling on an absurdity until we think it is a fact, Cannot be a system based on God's truth, which never requires anything of the kind. Since, then, the popular theoretical astronomy of the day requires this, it is evident that it is the wrong thing, and that this conclusion furnishes us with a proof that the Earth is not a globe.

97) NASA and modern astronomy say the Earth is a giant ball tilted back, wobbling and spinning 1,000 mph around its central axis, traveling 67,000 mph circles around the Sun, spiraling 500,000 mph around the Milky Way, while the entire galaxy rockets a ridiculous 670,000,000 mph through the Universe, with all of these motions originating from an alleged “Big Bang” cosmogenic explosion 14 billion years ago. That’s a grand total of 670,568,000 mph in several different directions we’re all supposedly speeding along at simultaneously, yet no one has ever seen, felt, heard, measured or proven a single one of these motions to exist whatsoever.

Astronomers tell us that, in consequence of the Earth's "rotundity," the perpendicular walls of buildings are, nowhere, parallel, and that even the walls of houses on opposite sides of a street are not! But, since all observation fails to find any evidence of this want of parallelism which theory demands, the idea must be renounced as being absurd and in opposition to all well-known facts. This is a proof that the Earth is not a globe.