DNA contains coding and control regions. Changes to the coding regions are rare, most of the evolutionary stuff is happening within those control regions instead. Mutations there are more likely to result in interesting effects by affecting the way genes activate and interact, while the coding regions do the heavy lifting.

Losing some feature could be as simple as a mutation that permanently switches off the control region of a gene, even if the gene itself and the interactions formerly coded around it still work. Over time, those accumulate mutations and degrade, since they are not useful and therefore evolution doesn’t preserve them, but they are still there. For example, we have an inactivated gene that used to make an enzyme that would break down uric acid. So we get gout, but our ancestors didn’t.

Underrated comment.

The atmosphere is just about 10 kg/m^2 in sectional density; the manhole cover was very likely higher than that, wouldn’t that mean the cover’s mass should have come out at the other side, intact or not?

I’m a beta-lactam antibiotic.

Good for many tasks, but rapidly becoming useless.

I mainly use it to get a general direction/names/sources when I want to learn about someting but don’t know where to start. So far it’s the only use case for which I’ve found it reliably useful.

It starts out as a tube and folds into its final shape, but I’m suprised it can be reversed, holy crap…

I fully intend to go on with the project! Right now it’s not good enough to be interesting, but the results so far are too promising to not give it a chance.

Thank you! :)

I managed to get 4 piezo elements to work, limited by the FPGA. This was actually enough for some reasonable horizontal resolution since I used a phase array configuration, so the downside was the electronics had to generate very precisely timed pulses. The fourth prototype had 10 working elements thanks to replacing the MCU-FPGA duo with just a more powerful FPGA and using conductive glue to more reliably connect the elements themselves.

It was configurable to use any even divisor of 120 MHz, but in practice anything over 1 MHz would not even make it out of the acoustic lens due to the low voltage and low quality impedance matching layer. And much lower frequencies are barely useful anyways, so the true working range was narrow.

For the acoustic lens, I used the parametric design software OpenSCAD, with an equation for aberration-free lenses I had found somewhere and saved long before (will find it if you want) and the speed of sound in the different materials.

Well, one thing I’ve noticed in most measures that involve mental things (mood, performance…) is that lots of things seem to be cyclical. For example, mood is often alternating (more so in my case), but productivity and burnout also tend to repeat predictably as long as the routine doesn’t change.

Also, I’m maximally performant in tasks when most stable (good sleep, moderate mood, medication, no drugs…), but maximally productive when in a better mood.

Of course!

I wanted to test whether a cheap piezo buzzer could be used as a crude ultrasound probe. It worked, so I tried to upgrade it into full-blown ultrasound imaging. The third iteration of that did produce an image, using a piezo buzzer cut in sections, a cheap FPGA, a MCU, custom PCB and mostly 3D printed pieces (acoustic lens, etc.). Aside from the expected low resolution, turned out that it wouldn’t image anything beyond about 1 cm.

I did make a fourth iteration of the device, much smaller and theoretically much better. But life happened and I never finished the coding part.

I track lots of things, all the time; my body composition, performance at specific tasks… As for experiments, I’ve done a few:

• Tried to see if I could 3D print small channels and fill them with metal using electroplating (couldn’t).
• I also made a DIY ultrasound imaging device and tested it. Did actually produce some images, but it wouldn’t penetrate very far in tissues.