Thoughts at a Time of Thanks

We are having a wonderful time here in Washington, DC with Cindy's family. With encouragement from Bill, I am posting a thought for the day that my manager at work sent out to us before we left for the Thanksgiving weekend. Enjoy, with hopes that your thanksgivings are full of things to be thankful for!

Thought for the day: Everything travels at lightspeed through spacetime. Light travels only through space, not at all through time, so photons don't age. To them everything happens at once! Be happy you are not a photon. Rocks and similar stuff travel only through time, pretty much not at all through space. Be happy you are not a rock.
The rest of us travel mostly through time and a little bit through space, the latter usually more on Thanksgiving than at other times. Our travel is timelike and we mostly age. Be happy for the spacetime you can savor.

Finished Building My New Rear Wheel

Two years ago, I built a front wheel for my bike. I got a hub, spokes, nipples, and a rim and put them together into a wheel. It was fun to learn how the spokes, which are in tension, put the rim into compression, which is a structurally more stable configuration. Then the way the spokes from either side of the hub pull the rim in the transverse direction and when tightened from both sides of the hub they can change the radial displacement of the rim.

This past winter (2007) I started to build a rear wheel. It is slightly more complicated, since the cassette - the sprockets on the rear wheel - offset the spokes on that side of the wheel and make them asymmetric compared with the spokes on the other side. I have built the wheels in the basement shop of my friend Robert from work (same Robert as from previous posts). He was very helpful in guiding me through the process and for giving me access to the shop 24/7.

I laced the spokes in a 3X pattern, which means each spoke crosses over three other spokes as it goes from the hub to the rim. There are also 2X, 1X and radial spoke patterns, but since I am so heavy, I went with the 3X design to optimize strength.

I have 9 sprockets in the cassette, which is referred to as a 9-speed bike, though I have two chain rings in the front, which gives me 18 gear combinations. The largest three sprockets in the cassette are made of titanium, which is why they look a little duller than the others. The six other sprockets are made of steel.

I will break the new wheel in on the roller trainer I picked up from a garage sale recently. It is getting too cold to ride outside lately, though I got in a short ride with Charlene and Robert today.

More about the ordeals with the trainer in a future post.