I thought most of the effect of actual greenhouses was due to stopping convection?
I’d need a bigger jar. My nonexistent fucks are too big to fit in that.
Brings to mind the only exchange from Adaptation I really enjoyed:
KAUFMAN: Then when you walked away, she started making fun of you with Kim Canetti. . . . How come you looked so happy?
DONALD: I loved Sarah, Charles. It was mine, that love. I owned it. Even Sarah didn’t have the right to take it away. I can love whoever I want.
KAUFMAN: She thought you were pathetic.
DONALD: That was her business, not mine. You are what you love, not what loves you. That’s what I decided a long time ago.
Reminds me: need to develop a glass ablation method that systematically reduces the intensity at the edges, anti-aliasing with the laser, to cut down that chipping.
The letters are individually cut, not on a clear backer.
The chipping is apparently the property of the material. What I saw being done with it is some coating, or using a wet tissue to increase the thermal gradients between the part hit with the laser and left alone, so the glass cracks over a shorter distance.
It’s probably micro thermal shock. Like when you take hot glass and dunk it in cold water. So I bet by carefully modulating the laser power, you could also cause the shock to travel a shorter distance and get finer lines.
Likely yes, but I’d guess that you’d need a higher laser power for shorter time, and that’d require a pulsed laser instead of the CW tubes.
The shorter wave-length light pases through the glass and hits stuff (plants) which heat up giving off longer wave-length IR which the glass reflects so it stays inside. So, for the most part, energy that goes in, stays in. (See also sun-powered distillation.)
When I played with my friend’s 40w CO2, we were ablating glass at around 50% power, with plenty left over. The lines on letters were actually pretty sharp, with no modulation at all. Not sharp like laser printer sharp. Sharp like drawn with a felt pen. It was sort of the “overall effect” that had issues. So what I did was ran the piece then re-ran it again. There is no depth to the etching whatsoever. I’m looking at the piece right now. You can feel the rough surface, but it is very shallow.
A different friend has a 60W laser with one of those improved controllers we were talking about. He etched granite, something like 10 passes and got about a mm relief. It was very impressive.
I’m dreaming of the day I have a laser like that. I would be perfectly happy with about a 100W CO2 in my garage…
My eggnog-addled brain read that as “Scalia’s Jar”, which would be appropriate given the number of fucks that said Justice obviously gives…
I’m familiar with the greenhouse effect. The point is that it’s not the primary source of heating in an actual greenhouse. That is primarily due to convection. I looked it up here:
However, R. W. Wood in 1909 constructed two greenhouses, one with glass as the transparent material, and the other with panes of rock salt, which is transparent to infrared. The two greenhouses warmed to similar temperatures, suggesting that an actual greenhouse is warmer not because of the "greenhouse effect" as described in the previous paragraph, but by preventing convective cooling, not allowing warmed air to escape.
They go on to say that it is now thought to be non-negligible, but is still not the primary source of a greenhouse’s warmth.
The Nightmare Chemical? There are protein synthesis people who have no problem with it, but they’re weirdos anyway.
Depends on the amount. Don’t bathe in it.
A quart of it gives me slight willies. A couple drops, very much not so.
Edit: Got some years ago, played with it with wax-masked glass etching, and survived to tell the tale. It’s a fun thing, should get more.
What, yah mean something I learned as a child turns out not to be true?!?
Would be interesting to re-conduct that experiment with modern instrumentation and see if in fact the effect under the rock salt panes was really the same, just affecting different ranges of wavelengths from glass.
Tired of the “My account of f---- to give is overdrawn” [insert your own ‘f— to give’ variation here] It’s not funny or original anymore. Let’s move on.
So, not tired yet of giving a fuck?
If you have access to a sand- or bead-blaster and a suitably resistant template, this would be easy-peasy to create. If not, there is absolutely nothing wrong with the current execution.
I am not going anywhere near a container of HF unless there is a shitload of calcium gluconate closer on hand.