The nice thing about science is that, unlike various other belief systems, you don’t have to take it on faith. You can check a substantial fraction of it yourself. This is especially true of basic astronomy.
Nothing more than pre-university geometry, trigonometry, and algebra, along with some star-gazing and a distant friend or two (and/or a little targeted web browsing), is required to
- confirm that the Earth’s a spinning (almost-)sphere,
- estimate the size of the Earth and Moon and the distance between them,
- show the Sun’s larger than the Earth and much further than the Moon, and that the stars are further still,
- verify the other planets orbit the Sun and estimate their relative distances from the Sun and their orbital times,
- infer a relation between these distances and times known as Kepler’s law, and show that a similar Kepler-type law works for objects orbiting the Earth,
- infer from these laws that the same gravity that makes ordinary objects fall does so by creating an inward acceleration, one that follows Newton’s inverse square law, holding certain objects in orbit around the Earth and others in orbit around the Sun
- confirm that the Earth orbits the Sun, by invoking Kepler’s law.
- (Incidentally, this last statement is unambiguous, despite some claims to the contrary, even in Einstein’s theory of gravity.)
- (Incidentally, this last statement is unambiguous, despite some claims to the contrary, even in Einstein’s theory of gravity.)
- estimate (using meteors, surprisingly!) the distance from the Earth to the Sun, and from this, determine all the distances between the Sun and all its planets, and between those planets and their moons.
