THE SEMMES BRANCH LIBRARY, COMANCHE LOOKOUT PARK SCALE MODEL SOLAR SYSTEM
SSMSS
There now .wav files for the scale model solar system, short descriptions of each marker you can download to your mp3 player or phone. There is also a map of the park and podcasts for the Madison High School Science Department nature trail on the Friends of Comanche Lookout Park podcast page. markgoll@wt.net
WELCOME TO THE SCALE MODEL SOLAR SYSTEM PAGE.

The solar system is a big place, and hard to see. Planets are not always visible, and you have to know where to look, and sometimes you need a big telescope to see them. So, the scale model solar system lets you see the size of our celestial neighborhood and experience a trip to the planets by just taking a short walk.
From this web site you can download a short information brochure, .doc, a map .jpg, information links, and .wav files. Note the orange cone in the photographs, this marks the location of the planet. The 523 section of the library has books on the solar system.
This link leads to a NASA web site about the planets.
Going out the front door, turn right and the Sun marker is located in the grass next to the sidewalk. It is a yellow disk 7 inches in diameter(although the Sun is actually mostly white). 1/8,000,000,000th of the size of the real Sun. 90% of the mass of the solar system is in the Sun, and 90% of its mass is at the very center. The surface we see of the sun is really very thin hot gas, a plasma, 5000 deg C. The Sun is a million times larger than the Earth, but only 1/3 as dense. Standing at the sun, look along the sidewalk to see Mercury. In the inner solar system each next stop will be shown from where you are now standing.

Mertcury, the innermost planet. The small dot, as depicted on the brochure, gives you an idea how small Mercury is compared to the Sun. Standing at Mercury, you can see the Sun as it would appear in the sky. Mercury takes 88 days to go around the sun, and 59 days to rotate, a 3/2 resonance lock. Because of this odd resonance, and the ellipitical orbit, some parts of Mercury are hotter, some parts colder, and the poles never get direct sun light..

Next is Venus. Note that the dot representing venus has actual size, about 0.067 inches in diameter. Venus is covered with clouds, and hotter than Mercury. It rotates very slowly and in the retrograde direction.

Next is Earth, my favorite planet. It's nice that it's set in the green grass. We all live on this small dot. The Moon is also on the marker, a small dot. Standing at Earth, your view of the scale model solar system and the real solar system are the same. Note that the planets Mercury and Venus always stay near the Sun, making them hard to see and keeping them in the morning and evening skys.

Next is Mars. Mars is small, cold and dry. Look back at the inner solar system, these are the terrestrial planets, planets with solid surfaces or dirt. From here the distances get longer, Cross the bridge and you're in the realm of the asteroids. The dust in the air is about right for the size of these motes. Walk down the side walk and turn right at the junction to get to Jupiter.

Jupiter. Note that even at this small scale Jupiter is still a big planet. The dot is nearly 5/8ths in diameter. Also on the display are the four dots for the four large moons of jupiter. These four moons are easily visible in a small telescope and can be seen to move from hour to hour. The largest Jupiter moon is larger than the planet Mercury. 1000 earths could fit in Jupiter, and it's 318 times heavier. Jupiter has a very powerful magnetic field and is surrounded by intense radiation. All of the outer bodies of the solar system, except Pluto, are gas giants. They have no solid surface. They are composed mostly of hydrogen with some helium.

Just across from the bullitin board, turning right at the junction is Saturn. This is a "Gods eye view", so we look down on the rings. Also visible is a small dot for Saturn's big moon Titan which is also bigger than Mercury. Saturn is less dense than water. A small telescope will display the rings and they tilt from year to year. This is the end of the "classical planets", bodies which deserve the name planets, greek for wanderer. Now you walk a lot farther and enter the realm of the outer solar system. Those bodies which can only be seen with a telescope.

The name of this planet is Oron. Since its discovery in1781 by William Herschel it has had a name problem. The name "Uranus" has never been popular, Really folks, would you drive a car named Uranus, or burden a child with that moniker?.... So now the new Hebrew name for the planet is Oron, and should be used by all. It's a big cold gas ball, bluish green, with no big moon.

Neptune. Another bluish gas ball. Also the large moon Triton, but there has been a lot of vandalism on this marker.

Pluto. Just beyond the culvert. Included because Clyde Tombaugh, Pluto's discoverer, was a big supporter of amatuer astronomy. Note that this marker has also been vandalized by those whose skulls are a continuing source of a good hard vacuum.

Beyond here is the Keiper belt and Ort cloud of comets. Nearly 130 objects have been discovered so far. It's a half mile back to your car. As you've probably noticed there is a scooter in each photo, I ride down hill to go home. :-)
THE SCALE MODEL ATOM
The scale model solar system takes something very large and brings it down to a reasonable size(1/(8*10^9)). But what about something very very small, like the hydrogen atom? Most of our solar system is in fact hydrogen. If we use the same seven inch disk that represents the Sun, and scale the hydrogen atom's Proton up to that size, ((35*10^13)/1), the electron becomes a small visible dot (.) about the size of the scale model Mercury, but located about 12 miles away.
By comparison there is much much more empty space inside an atom than in our solar system. A scale model electron for the seven inch Sun/Proton, is a small marker with the letter "e" (e is for electron) and a dot (.) for the hydrogen atom electron; IS currently located at the Brook Hallow branch The San Antonio Public Library, just outside the front door, to the right, back in the corner.
Quantum mechanics says that this stationary electron cannot exist, but we can suspend the rules of physics for a little while, but, our electron will jump to another location. Where???, cannot be predicted with any accuracy. Since it takes time for the light to travel from the marker to your eye, you see the electron in the past, and Heisenberg says that all things can be known about the past. It's the future that is uncertain.
If you would like to see a scale model hydrogen atom on your computer screen go to the atom. This is one of the largest web pages on the internet!