Veloscope: Bicycle Transportable Telescope
I'm really excited about this aspect of the project, and a few things came together in a last couple of days that allow me to finally talk to you about it with reasonable confidence of it actually working out. Here's an image of the present design:
But before we get too much into the Bicycle Transportable Telescope itself, I should tell you a little bit about what a telescope does, and how it does it. It'll make some other things clearer down the road. First and foremost, the primary job of a telescope (in astronomy) is not to magnify, it is to amplify. In other words, the astronomical telescope makes faint objects brighter.
A telescope does this by virtue of its objective, a piece of glass (either a lens or mirror) whose job it is to collect photons (light). Imagine that you walk out into a steady rain with two containers. One is a test tube 1/4" in diameter. The other is a beaker 8" in diameter. Which one will collect more rain? This is what a telescope does. It collects more photons so faint things appear brighter. You know how when it gets dark your pupil opens up wider? It does this to let more light in, so you can see better in the dark. Imagine your pupil opening up to 8", or a meter, the size of the smallest research telescopes. Imagine the proposed 30 Meter Telescope.
Telescopes also magnify, which is nice. And the larger the objective of a telescope (also known as the aperture) the more fine detail it can resolve. That's why they want to build the 30 Meter Telescope...it'll allow us to start studying the atmospheres of the many planets we are finding orbiting other stars.
The kind of telescope I prefer is called a Newtonian reflector on a Dobsonian mount. Let's parse that out. Reflector means the telescope uses a mirror as its objective. Newtonian refers to dear Isaac Newton, who created this particular kind of reflecting telescope:
The design is devilishly simple. Light enters the tube on the left side here (astronomers mostly look up, so we can call that the "top") and travels down to the right (bottom) of the tube, where the primary mirror is located. It's shaped in a parabola (think satellite dish) and this directs the light back up the tube in a cone, where it meets the secondary mirror. This mirror is flat and positioned at a 45 degree angle. It's just is only to bounce the remaining light cone out the side of the tube, through the focuser and eyepiece and hopefully, into your eye.
Dobsonian refers to a method of mounting a telescope, where, similar to a canon mount, you can move the tube up and down (altitude) and right and left (azimuth). Dobsonian mounts keep the center of gravity fairly close to the ground and have two semicircular side bearings that provide that altitude motions and a single disk bearing on the bottom, like a lazy susan, to provide the azimuth action.
A Newtonian doesn't have to have a tube as shown in the image above. All you need is a structure to hold the mirrors and focuser in place, and there are many ways of doing that. The scope that was in the Epoch Times article is a Newtonian, and if you look carefully you can see the primary mirror at the bottom of the "tube" which is formed by three parallel struts and some wooden rings.
The Bicycle Transportable Telescope will be an 8 inch Newtonian, and I'm really excited about the design. The whole thing should fold up into a box measuring 14x14x9 inches. (If you look at the image I started this update with, it's the small box to the left of the assembled telescope.)
This design comes from a chap named Dan who apparently is a 3d designer by trade. I believe it! Dan placed his travel telescope plans on Google Sketchup, an online 3d modeling library (Google is a many-fingered beast, it has one in just about everything). Here's a short 3d animation based on that model:
I love the hookah and six pack of Corona...
Anyway, the idea behind this is really cool. Basically anyone can download the design to a local shop that can do CNC routing or laser cutting, and that shop can plug in the plans and cut a telescope kit out of a single piece of plywood at fairly low cost. Here's a video of Dan's scope kit being cut out. You don't have to watch the whole thing.
Of course this just yields the wooden parts. Assuming the telescope maker is buying and not making the optics (which is possible if a bit of a time commitment), she (or he) will need to purchase the primary and secondary mirror, hardware (some basic stuff one can buy from a store like Home Depot), and a few other specialty items like a focuser and secondary mirror holder (what we call a "spider").
I've spoken with Dan, and he's game for helping turn his experiment into the prototype Bicycle Transportable Telescope (BTT or VeloScope). We'll use the prototype to test and fine tune the design, and then we'll release it upon the world with a how-two web page and a list of possible components that one would need to complete the kit. The great thing is that the CNC shop would do the really difficult the work...the rest is assemblage and finishing, which shouldn't take much more than a drill, screwdriver and some hex wrenches to complete.
Even better, I found a local shop that does CNC laser cutting and it turns out the owner has read my review articles in Astronomy Technology Today, and he's wicked excited to help out with the project. So pieces are falling into place, and I'm really excited to be able to offer a new kind of telescope to the world...with the help of some do-gooder designers, machinists, and of course, supporters like you. Thanks for joining me in this night ride.