Nebula Nebula - November 2016 | Page 11

NEBULA VOLUME 44 I ssue 2 PAGE 11 CYCLE THE SOLAR SYSTEM by Kevin Taylor The Sun (2.42 m diameter) On the 29 th of May 2016, Vad, Eva (aged 6), Nadine and I, went on a bike ride down a disused part of the old East Coast main-line railway. The route (near York), from Riccall to Bishopthorpe cov- ers 6.4 miles. What’s special is that spread along the route is a scale model of our Solar System. The planets along the route are in scale (100 metres of track equals 57 million kilometres of space) both in their relative sizes and dis- tances from one another. This equates to the speed of light to be about 1.16 mph, making cycling about 10 times light speed. This scale would also put Alpha Cen- tauri one and three quarter times around the Earth away! One of Alpha Centauri stars—Proxima Centauri—has been in the recent news with regards to a potentially earth sized planet in the habitable zone. All of these facts and more can be found on the model’s web- site, https://www.york.ac.uk/solar/ Shortly after leaving Pluto I heard a POP-HISSssss noise from the rear end of my bike. Of course I didn’t really need to look to know what had happened. Not be- ing a very good scout, I wasn’t prepared. Fortunately Vad had a puncture repair kit with him (He also offered to ride back to his car and get a spare inner tube. In the spirit of space travel I decided con- tinue with what we had). The puncture was caused by my tyre being worn right through to the inner-tube. Therefore, once re- paired, I could only pump the tire up with enough pressure to stop the rims running on the track— otherwise the inner-tube ballooned out of the hole. I had to hope that it lasted for the rest of the journey, giving a little “Apollo 13” feel to the ride! One thing about the distance scale that was really apparent (you can look up the facts and figures, but it doesn’t compare to the ex- perience of leg power) was just how far away Pluto was from the rest of the planets. If it hadn’t been for the incredible images from last year’s New Horizons photos, one could be forgiven for going along with the new planetary definitions to disqualify Pluto (hopefully this will be reverted). Route Map (by permission of Physics Outreach, University of York) Sometime after Uranus we came across a large contraption on a pole fitted with a satellite dish. A sign read that it was a 1/3rd scale model of the Cassini probe. We Kevin, Vad and Eva with the Earth and Mo on on the cycleway