“Science: we are not concerned with where a new idea comes from – the sole test of its validity is experiment” (Richard Feynman)
“The most important hypothesis in all of biology, for example, is that everything that animals do, atoms do. In other words, there is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics” (Richard Feynman)
“The most we can know is in terms of probabilities” (Richard Feynman)
“Nature and Nature’s laws lay hid in night:
God said, Let Newton be! and all was light” (Alexander Pope)
“hypotheses non fingo” (Isaac Newton)
Methodology: Observe, reason, experiment
A law is an approximation to the truth. It is valid until proven otherwise.
Classical physics is a good approximation to describe reality under the following conditions:
-Matter moves at speeds less than about 1% the speed of light
-Objects are large enough so that they can be seen by the use of a microscope
-Gravitational fields are weak (such as the one of the planet Earth)
In Dutch ‘Wiskunde’ means ‘the science of what is certain’ (the term was coined by the Flemish mathematician Simon Stevin 1548-1620). Stevin is known for the law of the equilibrium on an inclined plane.
Probability is founded on certain criteria:
-Observations are repeatable
-Observations appear to be equivalent at a different time or place
-An estimate is made after a set of finite observations
Eudoxus (c. 390– c. 337 BC), a student of Plato, believed planets had a perfect circular motion around the Earth. However the Ancient Greeks knew that the velocity of the planets could vary (Kepler realised planets had an elliptic motion). Eudoxus tried to rationalise this by explaining that planets followed certain spheres.
Plato had also suggested that the elements were associated with the Platonic solids (cube, dodecahedron etc)
Galileo’s insights were on free fall motion (without air resistance, two objects of unequal weight will fall at the same speed if thrown from the same height) and uniformly accelerated motion. However his account was just a description of motion, not an explanation of the causes. Kinematics is the description of motion, dynamics is about the causes: the two together form mechanics.
For Kepler geometry was the pattern God’s mind used to create the Universe.
Kepler’s epitaph “I measured the skies, now the shadows I measure. Skybound was the mind, earthbound the body rests”.
Kepler, a mystic, believed in the musica universalis.
In January 2002, a dull star in an obscure constellation suddenly became 600,000 times more luminous than our sun, temporarily making it the brightest star in our Milky Way galaxy.
HISTORY FROM BIG BANG TO HUMANITY:
-The universe has no edge, no center.