Evidence is often “indirect” and reasoning to an object or event is often “inferential”  “Conventional” and common sense view:  Evidence is directly observable  Quarks? Evolution? The Big Bang?  Lederman: evidence for “unobservable” objects  Atoms (for a long time)  Subatomic particles and the “Higgs boson” (today)  Methods  Thought experiments/conceptual analysis (Democritus)  Combination of thought/conceptual analyses and empirical study/evidence  “Conventional” and common sense view:  Evidence is directly observable  Quarks? Evolution? The Big Bang?  Lederman: evidence for “unobservable” objects  Atoms (for a long time)  Subatomic particles and the “Higgs boson” (today)  Methods  Thought experiments/conceptual analysis (Democritus)  Combination of thought/conceptual analyses and empirical study/evidence

Evidence is often “indirect” and reasoning to an object or event is often “inferential”  Justification?  As with Lederman’s invisible soccer ball, such objects or events, or theories that include them, are able to explain what is observable  And often bring together what might otherwise seem like disparate phenomena  Molecules (prior to their being “observed”):  Indirect evidence (expansion, heat conduction, surface tension)  Can be marshaled under the familiar laws of motion  Justification?  As with Lederman’s invisible soccer ball, such objects or events, or theories that include them, are able to explain what is observable  And often bring together what might otherwise seem like disparate phenomena  Molecules (prior to their being “observed”):  Indirect evidence (expansion, heat conduction, surface tension)  Can be marshaled under the familiar laws of motion

Evidence is often “indirect” and reasoning to an object or event is often “inferential”  Gould: evidence for “unobservable” processes  Natural selection (the mechanism)  Evolution (the end result)  Signs of history  Jury rigging and “contrivances”  “Imperfections”  Rudimentary or vestigial organs  Traits as “artifacts” of natural processes (e.g., natural selection)  Gould: evidence for “unobservable” processes  Natural selection (the mechanism)  Evolution (the end result)  Signs of history  Jury rigging and “contrivances”  “Imperfections”  Rudimentary or vestigial organs  Traits as “artifacts” of natural processes (e.g., natural selection)

Evidence is often “indirect” and reasoning to an object or event is often “inferential”  Democritus’ thought experiment  Imagine a knife of polished bronze and very sharp.  Begin to cut up a piece of cheese, first in half, then in half again, and so forth, until there are only tiny pieces.  If I were tiny enough to see the pieces and could continue cutting, I would eventually reach something that is not able to be cut, that is indivisible.  Democritus’ thought experiment  Imagine a knife of polished bronze and very sharp.  Begin to cut up a piece of cheese, first in half, then in half again, and so forth, until there are only tiny pieces.  If I were tiny enough to see the pieces and could continue cutting, I would eventually reach something that is not able to be cut, that is indivisible.

Evidence is often “indirect” and reasoning to an object or event is often “inferential”  The Big Bang and the Hubble Telescope