When the poet Paul Valery once asked Albert Einstein if he kept a notebook to record his ideas, Einstein looked at him with mild but genuine surprise. "Oh, that's not necessary," he replied . "It's so seldom I have one."
Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve.
Karl PopperAustrian-British philosopher of science and social and política e falsificationism and for criticism of Plato, Hegel and Marx as totalitarian opponents of open society1902 - 1994
Who is more humble? The scientist who looks at the universe with an open mind and accepts whatever it has to teach us, or somebody who says everything in this book must be considered the literal truth and never mind the fallibility of all the human beings involved?
Carl SaganAmerican astrophysicist, cosmologist and author1934 - 1996
Philosophers, for example, often fail to recognise that their remarks about the universe apply also to themselves and their remarks. If the universe is meaningless, so is the statement that it is so. If this world is a vicious trap, so is its accuser, and the pot is calling the kettle black.
Alan WattsBritish American author and lecturer1915 - 1973
Watts, A. (1968). The Wisdom of Insecurity. Vintage.
Imagine we could accelerate continuously at 1 g — what we're comfortable with on good old terra firma — to the midpoint of our voyage, and decelerate continuously at 1 g until we arrive at our destination. It would take a day to get to Mars, a week and a half to Pluto, a year to the Oort Cloud, and a few years to the nearest stars.
Carl SaganAmerican astrophysicist, cosmologist and author1934 - 1996
Pale Blue Dot: A Vision of the Human Future in Space