BeigeJournal

I went to Wisconsin’s Pike Lake State Park on Saturday, where among other things I walked the Astronomy Trail, which is a scale-model of the solar system. That the outer solar system is big is the lesson one learns on the 930 meter hike. The scale is 1:6.3 billion. The inner solar system is cozy. Mercury, at 0.4 AU, is 9 meters from the sun, a 5 second walk at 1.7 m/s (6.25 km/h). Venus is another 8 meters and around five seconds, then Earth at 7 meters and four seconds, and Mars, 12 meters and about 8 seconds. Then we enter the outer solar system. The asteroid belt appears 30 meters from mars, 17 seconds of walking. Jupiter, 5.2 AU from the sun, is 35 seconds of walking from the asteroids. A minute to walk 100 meters brings us to Saturn. 2:10 and 230 meters to Uranus. 2:28 and 250 meters to Neptune. 2:04 and 220 more meters brings us to Pluto, the end of the trail, 930 meters and 8:56 from the sun. At this scale Proxima Centauri, 4.2 light years from Earth, is 6300 km away, approximately the distance from Milwaukee to the Canary Islands. The Andromeda galaxy, at around 2.4 million light years, would be 240 astronomical units, six times the distance to Pluto. Using 15 billion light years as the edge of the observable universe puts that at 2.3 light years, almost half way to Proxima Centauri.

Pluto is 5.4 light hours from the sun. I walked the distance in just under nine minutes on the trail, which would be just over 36 times the speed of light in a naive calculation. If I’ve done my time dilation calculations correctly, traveling at 99.963% of the speed of light would produce enough time-dilation to make the elapsed “ship time” nine minutes. Going that fast inside a solar system full of dust and debris would be…problematic.