HalverScience Home

Observing at Crystal Lake Recreation Area
A nice dark location where we can see the Milky Way and stars.

Directions to the observing location (pdf):
Map of Crystal Lake Recreation Area

Web Cam to check for clouds:
Even if it is cloudy at Mt. SAC, it can be beautiful weather at Crystal Lake Rec Area, since it is at 5600 foot altitude. (1700 meters). Mount Wilson is just West of Crystal Lake, at a similar altitude, so if the web cams show clear skies we can go.

Chapter 2 - Patterns in the Sky

NASA's "Eyes on the Solar System" and other cool simulations:
(Useful for visualizing the ecliptic plane.)

Chapter 3 - Laws of Motion

For Lab Ch03a Forces and Motion using PhET:

For Lab Ch03c Universal Gravitation using PhET:

For Lab Ch03d Planet Orbits using PhET:

Chapter 4 - Light and Telescopes

For Lab Ch04 Intro to Waves:

Examples of specific photon energies being absorbed and emitted. I plan to use this in the notes. This demo is not a perfect fit to the notes because it uses molecules instead of atoms. But the concepts are the same. Like atoms, molecules absorb particular photon energies and then reemit them.

Another example of specific photon energies being absorbed and emitted. This demo is also not a perfect fit. The problem is that it's only for hydrogen. Also it only builds an emission spectrum. It shows an absoption spectrum, but it's too small to see clearly. One cool thing is that it shows how physicists understood the atom at various points in history. The most accurate, modern version is the Schrodinger version. Go with this for accuracy. I like the deBroglie version which is pretty good.

Design your own telescope, microscope, optical device using this free optical design software. You download it to your computer. Run as Java code.

Chapter 5 - Formation of Stars and Planets

For Lab Ch05a Blackbody Radation with PhET:

For Lab Ch05b Detecting Planets:

For WS05-3 Doppler Shift watch this video:

Summary of the Nebular Theory of how planetary systems are formed:

Halverson's note: This video is OK conceptually, but the artwork is flawed. Big black dots represent dust and gas and the protostar is much too large relative to the accretion disk.

Supercomputer animation of a molecular cloud contracting and becoming a cluster of protostars:

More info on StarForge: https://starforge.space/

Amazing supercomputer simulations of the formation of the solar system:

Notice the how the protoplanets make rings of empty space in the accretion disk. This has been seen by JWST around other protostars. Notice how Jupiter and other planets fling hundreds of minor planets into deep space. This is one way the anglar momentum of the solar system was greatly reduced, and it allowed the planets to migrate from way far out to their current obits.

Chapter 6 - The Inner Solar System

For WS06-2 Formation Temperatures of the Planets:
Scroll down to Solar System Characteristics and select Planet Formation Temperatures Plot Be sure to click the View by Flash Emulator button. (Don't click the advertisments which say "Start here" or "Open")

Useful simulation of solar system:
Useful feature: COMPARE SIZE. Click on a planet then click on "Compare Size" at the bottom. Works best if you click on Earth first.

Older but more controllable simulation of solar system:

Chapter 10 - Measuring the Stars

For Worksheet 10-1 "Parallax" here is the distance chart needed to identify the origin of the mysterious object, based on its distance from us:

For Lab 10-2 HR Diagram the preferred software is downloaded and installed on your computer. It's the NAAP Labs, which you can get here:
OR you can use this slightly buggy web page:

Easy video explanation of parallax distances:

Chapter 11 - The Sun

Just for fun - a TV program from my childhood: The Thunderbirds.
This episode is about rescuing astronauts who get too close to the Sun.

Video showing magnetic field lines from ordinary magnets. (Skip ahead to 1 min 47 sec for horseshoe magnet)

For Lab 11-1 Sunspots go to Spaceweather Live:
Later for this lab you will need the data for October 17, 2014 which is here:

Chapter 12 - Low-Mass Stars

Artist's impression of two white dwarf stars merging and creating a Type 1a supernova.
(A type 1a SN is when the carbon core collapses under its own weight and the sudden fusion of carbon to iron releases a huge amount of energy.)

This video hosted by Wikimedia. The original video and explanations are from the European Southern Observatory here:

Artist's impression of a "vampire star", a white dwarf taking material from a normal star until it becomes a type 1a supernova.

This video hosted by Wikimedia. The original video and explanations are from the European Southern Observatory here:

Chapter 13 - High-Mass Stars

Video about the rebound effect that makes supernova explosions so powerful.

For Lab 13-1 Time Dilation:

Videos about falling into a black hole. Amazing.
The detailed explanations about how to think about black holes are worth studying. I learned a lot!

For Lab 13-2 Black Holes:
Extreme example of gravitational lensing. How many lensed galaxies can you find?
The black hole simulation

Free book, in PDF format, about Special Relativity:
Free book, in PDF format, about General Relativity:
These books, by MIT professor Edwin F. Taylor and Princeton professor John Archibald Wheeler are excellent! Definitly worth looking at, even if you aren't planning to be an astronomer.

Chapter 14 - Measuring Galaxies

For homework Ch14 number 8 here is the video to watch. Balloon analogy to expanding Universe:

Mount Wilson project or field trip

Before visiting Mount Wilson watch this Huell Howser video (one hour):

Read the history of Mount Wilson. What did Hubble do with the giant telescopes?

Griffith Observatory project or field trip

Since parking at Griffith Observatory is $10 PER HOUR (expensive!), here is the LA City bus to the observatory:

Griffith Observatory hours:

Moon Project

Moon rise and set times, phases:
Sun rise and set times:

Telescope Project

Make your own telescope: