robryk @robryk@qoto.org
I enjoy things around information theory (and data compression), complexity theory (and cryptography), read hard scifi, currently work in infosec, am somewhat literal minded and have approximate knowledge of random things. I like when statements have truth values, and when things can be described simply (which is not exactly the same as shortly) and yet have interesting properties.
I live in the largest city of Switzerland (and yet have cow and sheep pastures and a swimmable lake within a few hundred meters of my place :)). I speak Polish, English, German, and can understand simple Swiss German and French.
If in doubt, please err on the side of being direct with me. I very much appreciate when people tell me that I'm being inaccurate. I think that satisfying people's curiosity is the most important thing I could be doing (and usually enjoy doing it). I am normally terse in my writing and would appreciate requests to verbosify.
I appreciate if my grammar or style is corrected (in any of the languages I use here).
Joined Nov 2020
How do shops end up with such anti-discounts for volume orders? I don't expect this is intended, so why isn't a sanity check against such cases a common thing?
Court arguments can be hilariously entertaining (because judges are very good at cutting through bullshit) and frustrating (because it's supposed to be pure eristics from both counsels and because many problems are caused by lack of precision in the law) at the same time. I just got entertained by a discussion about differences between kinds of delivery and about excluded middle: https://youtu.be/cuWVWUaNdqc?t=1486
What are the advantages of through-hole PCBs over wire wrapping?
I can see many advantages of wire wrap (though I've never used it, so I might be mistaken):
- due to wire shape, unwanted capacitances are kept much smaller in wire wrap (compared to e.g. a 2-layer PCB),
- it should be about as labor-intensive to wire wrap through-hole components as it is to solder them (TTBOMK you can't reflow through-hole components, so you need to spend some time per pin),
- no need for explicitly making multi-layer PCBs: the problems of routing, possibly stacking layers (for >2 layer ones), coating vias, etc. just go away.
The only advantage of through-hole PCBs I can see is that they're more durable mechanically and thinner.
Am I missing something obvious?
Let's say that you have two electrodes in vacuum and apply a potential difference to them. This will cause electrons to sometimes be "pulled out" of one of them. How will that impact the temperature of both electrodes?
I would expect the negative electrode to be heated by incoming electrons: after all they've had at least ~0 kinetic energy after leaving the positive electrode, so they bring in extra kinetic energy due to the potential difference.
I'm not sure what should happen to the positive electrode. On one hand, I would intuitively expect ones that have higher kinetic energy of thermal motion to be more likely pulled out, which would decrease the temperature (because we're skimming the top of the kinetic energy distribution, which should decrease the expected value). On the other hand, that would mean that this mechanism is a heat pump that should work regardless of the current temperatures of the electrodes, which is obvious violation of 2nd law of thermodynamics.
Where am I being foolish?
I started thinking about this after reading that one should not apply DC to fluorescent tubes, "because otherwise one filament cools off while the other overheats, evaporates and darkens one end of the tube" (http://ludens.cl/Electron/Fluolamp/fluolamp.html).
I enjoy things around information theory (and data compression), complexity theory (and cryptography), read hard scifi, currently work in infosec, am somewhat literal minded and have approximate knowledge of random things. I like when statements have truth values, and when things can be described simply (which is not exactly the same as shortly) and yet have interesting properties.
I live in the largest city of Switzerland (and yet have cow and sheep pastures and a swimmable lake within a few hundred meters of my place :)). I speak Polish, English, German, and can understand simple Swiss German and French.
If in doubt, please err on the side of being direct with me. I very much appreciate when people tell me that I'm being inaccurate. I think that satisfying people's curiosity is the most important thing I could be doing (and usually enjoy doing it). I am normally terse in my writing and would appreciate requests to verbosify.
I appreciate if my grammar or style is corrected (in any of the languages I use here).
Joined Nov 2020
