Discussion of astronomy, astrophysics, and cosmology

We had a great walk in Bradley Palmer State Park today (August 17). The temperature was in the low seventies with clouds, some sun, and no rain.

We will meet next at 1:45-3:45 Saturday, August 24, at the Hamilton-Wenham Public Library, 14 Union Street, South Hamilton. Our discussion will cover, not necessarily in the order appearing below, as much of the following as time permits:
• Clock time, solar time, sidereal time, leap seconds
• Spring and neap tides
• The equatorial plane, the plane of the ecliptic, the galactic plane
• The obliquity of Earth’s axis, the eccentricity of Earth’s orbit, the equation of time, the analemma
• Orbits, barycenters, occultations, Doppler shifts, exoplanets
• Precession of the equinoxes
• The asteroid belt, Kuiper belt, Oort cloud, comets
• Red dwarfs, brown dwarfs, white dwarfs, blue giants, red giants, supernovae, neutron stars, pulsars, quasars, magnetars, black holes
• Distances to various planets, stars, galaxies
• LIGO, gravitational waves
• Dark matter, dark energy
• Cosmic microwave background
• Big Bang, inflation, eternal inflation, parallel universes
• Cosmological constant
• Celestial navigation

We won't have time to explore all of these topics in detail. If you have a special interest in certain topics, please let me know what they are, and we will work them in.

I look forward to seeing you.

Don