Monday, April 14, 2014

Cutting Glass Circles

I've been organizing the barn lately and came across a box that had a pair of really cool 6.25" gauges that a friend had given me.  They're pressure gauges from an ammonia refrigeration system.  I'd been meaning to mount them on the wall, but one of them was missing the glass when I got them, so I had put them in a box until I could find a glass for it.  I looked online for circular gauge glass, but the only glass circles I could find were ridiculously expensive.  So I wound up buying a circle glass cutter off ebay for about $7.  It came from China, so I had to wait about 2 or 3 weeks for it to arrive, but the price was right and I was in no hurry.  I found a good video on youtube of a guy demonstrating how to use just such a tool to cut a circle out of glass.  I've had the cutter for a while and was a little apprehensive about trying it, thinking I would probably fail 2 or 3 times before finally getting a good piece of glass without breaking it, but instead I found out that it was amazingly quick and easy to cut a circle out of glass (if you have the right tool).

I mean it was REALLY easy (and quick).

If you need to cut a circle out of glass, buy a cutter and go for it.






All I did was watch the 3 minute video below and do exactly what the guy in the video does.



https://www.youtube.com/watch?feature=player_embedded&v=1T_sb-tPdx4


And here is a picture of the finished product, followed by a picture of both gauges mounted on the wall.

The one on the left is the one I replaced the glass in.







Thursday, April 10, 2014

the electron theory

I'm reading a delightful book right now called, "Surely You're Joking, Mr. Feynman!"  It's a bunch of little stories from the life of phyicist Richard Feynman, as told by Richard Feynman.

I came across an interesting little idea on page 70.

Feynman says, "The electron is a 'theory' that we use; it is so useful in understanding the way nature works that we can almost call it real."

I think most people count that it IS real, and so it's good to have some clarification that it isn't, quite.

At first it might seem unsettling to think that the electron is more of an idea than a real thing; this might make our world seem less solid, less concrete.  But his pointing this out is comforting to me because it helps make sense of something else I learned about the electron back in college.  An idea that has never set well with me.

In college they told us that the electron has mass.  They told us they can do experiments to measure the mass of an electron, but any experiment they can think of, to measure the radius of an electron, always comes back with the answer of "zero".

How the crud do you have a physical object that has a measureable mass but has a diameter of zero?

This is a uncomfortable idea.  But if you think about the electron as more of a model to explain the experimental results that we see, and less as a physical, solid thing, it leaves some fudge factor in there for what's really going on... something that we haven't discovered...or don't understand...yet.



Wednesday, April 2, 2014

Slide Gate Lever

We have a double gate going into our back yard.  Nothing fancy, just something I put together that would meet the dual purposes of letting a car into the back yard and keeping the dogs IN the back yard.  Over time the gates kind of warped opposite directions from one another such that, when they were latched together at the top, the bottoms didn't meet together real well.  Eventually the dogs figured out there was enough flex to the gates that they could worm between them at the bottom and get out of the yard.  To prevent this we had a crappy little piece of vinyl siding trim that we had snatched up out of the yard and slid through the bottoms of both gates, securing them together and preventing the dogs from flexing them open at the bottom.  This solution was pretty flimsy and needed an upgrade.  As I was preparing to cut a decent piece of real wood to replace the vinyl siding, the thought came to me to do something more creative, something with a lever that would make it more convenient to open and shut the gate without having to bend over to move the slide.

I mean, if you have to create something, you may as well create something cool, right?

Below you can see what I came up with.  It's simple, but fun, and I like it.