3.Hubble Legacy, 30 years of Discoveries and Images, Jim Bell, Kindle Edition,2021, Sterling.
4. Quote Francis Bacon "As for myself, I found that I was fitted for nothing so well as for the study of Truth; as having a mind nimble and versatile enough to catch the resemblances of things...and at the same time steady enough to fix and distinguish their subtler differences; as being gifted by nature with desire to seek, patience to doubt, fondness to meditate, slowness to assert, readiness to consider, carefulness to dispose and set in order; and as being a man that neither affects what is new nor admires what is old, and that hates every kind of imposture."
5. Quote René Descartes "If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things."