Classification of Things

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Classification of Things

• Dr. Harold Williams
• Montgomery College Planetarium
• http//Montgomerycollege.edu/Departments/planet/

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Who, Why, What, Where, When, and How

• Who and What are classification questions
• Who and Why are Religious questions
• What, Where, When, and How are Scientific
  Questions
• Who, Why, What, Where, When, and How are
  Philosophical Questions
• Classification spans both Religion and Science by
  asking Who and What!

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Some Common Classifications in Science

• Periodic Table of the Elements
• Particle Physics and the Standard Model
• Fundamental Interactions of Physics
• Electron Orbitals or Probability Distributions,
  the Auf Bau
• Geological Time Scales
• Biology and the Tree of Life
• Spectral Classification of the Stars
• Hertzsprung-Russell Diagram and Luminosity
  Classes as well as spectral classifications
• Types of Star Clusters
• Types of Galaxies

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Big Bang made 75 H, 25 He stars make
everything else
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Fundamental Particleshttp//en.wikipedia.org/wiki
/Elementary_particles
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What are the fundamental building blocks of
matter?
Proton
Neutron
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Quarks
Proton
Neutron

• Protons and neutrons are made of quarks
• Up quark (u) has charge 2/3
• Down quark (d) has charge -1/3

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Fundamental Forces according to the Wikipedia

• Electromagnetism http//en.wikipedia.org/wiki/Elec
  tromagnetic_interaction
• Weak Nuclear Force http//en.wikipedia.org/wiki/We
  ak_interactions
• Electroweak http//en.wikipedia.org/wiki/Electrowe
  ak_interaction
• Strong Nuclear Force http//en.wikipedia.org/wiki/
  Strong_interaction
• Gravity http//en.wikipedia.org/wiki/Gravity

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Electrons in Atoms, Auf Bau

• In quantum mechanics an electron in an atom does
  not orbit in the usual sense
• We can know only the probability of finding an
  electron at a particular spot

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The Geological Time Scale
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Tree of Life

• Mapping genetic relationships has led biologists
  to discover this new tree of life.
• Plants and animals are a small part of the tree.
• Suggests likely characteristics of common
  ancestor.

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Lines in a stars spectrum correspond to a
spectral type that reveals its temperature
http//en.wikipedia.org/wiki/Spectral_type
(Hottest) O B A F G K M
(Coolest)
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Remembering Spectral Types
(Hottest) O B A F G K M (Coolest)

• Oh, Be A Fine Girl, Kiss Me
• Oh, Be A Fine Guy, Kiss Me
• Oh, Be A Fine Gay, Kiss Me
• Only Boys Accepting Feminism Get Kissed
  Meaningfully

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Pioneers of Stellar Classification

• Annie Jump Cannon and the calculators at
  Harvard laid the foundation of modern stellar
  classification

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H-R diagram depicts Temperature Color
Spectral Type Luminosity Radius
Luminosity
Temperature
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What are the two types of star clusters?
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Open cluster A few thousand loosely packed
stars http//en.wikipedia.org/wiki/Open_clusters

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Globular cluster Up to a million or more stars
in a dense ball bound together by gravity
http//en.wikipedia.org/wiki/Globular_cluster
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What are the three major types of galaxies?
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Hubble Ultra Deep Field
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Hubble Ultra Deep Field
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Hubble Ultra Deep Field
Spiral Galaxy
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Hubble Ultra Deep Field
Spiral Galaxy
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Hubble Ultra Deep Field
Elliptical Galaxy
Elliptical Galaxy
Spiral Galaxy
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Hubble Ultra Deep Field
Elliptical Galaxy
Elliptical Galaxy
Spiral Galaxy
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Hubble Ultra Deep Field
Elliptical Galaxy
Elliptical Galaxy
Irregular Galaxies
Spiral Galaxy
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A better name

• Spiral galaxies might be better named by calling
  them Disk galaxies!
• Some Disk galaxies have no or little spiral
  structure, but they are still have disks.

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Hubbles galaxy classes
Spheroid Dominates
Disk Dominates
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Categories

• http//en.wikipedia.org/wiki/Categories_28Aristot
  le29
• Categories By Aristotle Written 350 B.C.E
  Translated by E. M. Edghill another one.
• Categories List