The late Harold DuBose of Spectra-Physics, repeatedly used 555's as power inverters in the electronic design of a frequency stabilized ring dye laser. He liked the strength of the output transistor.
Readit Newsaj7 commented on Doin' It with a 555: One Chip to Rule Them All aashvik.com/posts/555-rev... · Posted by u/MonkeyClub
What would be most interesting is using optical illusions to help decode how brain visual processing is done.
The kind of older tourist visiting a foreign religious site is definitely going to be relatively indoctrinated regardless of their origin country. But yes, many Americans are indoctrinated. They also tend to be dominant in wide swaths of US geography and highly motivated by their indoctrinators to vote, thus maximizing their electoral impact.
Many other Americans are pretty open-minded to new facts, even today. Unfortunately this kind is relatively geographically concentrated in urban or academic communities, and many of them are also discouraged from voting by being fully aware of how desperate and hard-to-fix the US political situation is, thus minimizing their electoral impact.
In Israel, virtually every Christian relic is fake. Some are hundreds of years old, but nevertheless fake. This is not a comment on Christianity as a religion. Religions need relics, and if they can’t find them, they are created. This is operating in modern times. I was working as a contractor for Intel Israel. They took everybody on a day trip. To an LDS temple to “see the organ” (what else?). An American LDS church. Needed a place in Israel to “represent.” Now wait 100 years. You wait. I have things to do.
aj7 commented on I wanted a camera that doesn't exist, so I built it medium.com/@cristi.baluta... · Posted by u/cyrc
I've got two of those tap guides, one for US and one for metric. They're great. Also for drilling since I don't have a drill press at home.
I've examined cheap taps under a microscope. Maybe they are of varying quality, but the ones I got had burrs all along the cutting edges. A tap that I borrowed from a machine shop was flawless in comparison. So maybe the middle ground is caveat emptor.
Another trick for tapping is to use something pointy in the drill chuck to center the tap after drilling, assuming you've clamped down your workpiece in a drill press or mill. This works for really big taps when you don't have a guide for them. Likewise the tailstock of a lathe can be used for this purpose.
All good advice above. I’ve tapped 1000’s of holes and haven’t broken a tap in 50 years, and I have nothing to add to the above. Berkeley Physics Dept. student machine shop training.
aj7 commented on Some ecologists fear their field is losing touch with nature nature.com/articles/d4158... · Posted by u/Growtika
> It's remarkable how many smart people think that science can be done without data.
It’s so important that we write these down, so when these people have forgotten why they’re not making any progress and they’re searching for answers, they’ll find what we wrote down and say “ohhh, we had too much hubris thought we were smarter than everyone else and didn’t listen to how important actually going outside is.”
And in a similar vein, you can’t learn much about investing without actually risking some capital.
I remember my 1982 Toyota Corolla wagon had an obvious cut-out in the plastic interior, that was just a hair wider than a 4x8 sheet. I still miss that car.
Try buying a compact Toyota pickup without the extra row of seats. The last one was made in 2015. They sell for more than the price of new for mileage < 100k.
aj7 commented on The likely cheapest home-made Michelson interferometer guille.site/posts/3d-prin... · Posted by u/LolWolf
I’m an optomechanical engineer and I’m sorry. I’m not impressed. In a Michelson, the single most important requirement is that the optical path lengths of the two arms do not drift with respect to each other, either in length or angle. Having that path length determined by a fused deposition polymer is about the LAST choice I would make. I have a suggestion. Fused quartz rods are relatively cheap. Buy some 6mm rods and a thin diamond blade to cut them to size. Use the 3D printer to make plate-like parts, ‘replicating’ a cage structure. The polymer parts should be used only for components PERPENDICULAR to the optical path. You could even experiment with using embedded rods to stabilize the plates in various directions. So much of hobbyist activity amounts to a kind of adult coloring or copying. Rather, at your own level, try to be a scientist.
Does anyone know of a lens that can make a laser look like a spotlight?
Look up “beam expanding telescope.”
aj7 commented on Akin's Laws of Spacecraft Design (2011) [pdf] ece.uvic.ca/~elec399/2014... · Posted by u/tosh
I have found that my best designs, few and far between, enter a period where they get simpler as they are completed. And my worst or failed designs keep getting more complex as I go on.
I did my calculus homework on the subway.