Hacker News new | past | comments | ask | show | jobs | submit | dekhn's comments login

He did- he selected the lowest value, ignoring all the multiples.

Not ignoring the multiples; the multiples verify the result.

If you calculate the charge of one at 1e and you measure 2.5e, something went wrong. All values must be a multiple of the lowest.


I don't think many people today would be able to propose the Michelson Morley experiment and then actually do it. It was truly heoric (and Michelson was a genius).

We did this oil/water experiment in freshman physics or chemistry lab. It was rushed, everybody just did the minimum, the teachers barely explained any of it, and then we moved on.


I agree. The Michelson Morley experiment reminds me of some difficult algorithms: simple only in hindsight, and implementation is _hard_ to do correctly.

People still win Nobel prizes (LIGO, for example) using interferometers. It’s arguably the single greatest invention in experimental physics.

Some powder is added to the water, which covers the surface of the water but not the oil patch (which is circular). Then the oil patch diameter is measured.

This was how we did this when we replicated this experiment in high school. I guess from the other responses here that this wasn't common?

When we did it in high school (70's) we just used compound that had a long chain (soap?) and only one end dissolved in the water. It was very easy to measure and calculate the size of the molecule . We had a series of these simple experiments. Another I recall was measure the speed at which certain volatile compounds moved through the air.

I definitely learned that all science doesn't have to involve complex equipment.


The original way was to cover the surface of a round bowl with oil. It certainly makes a lot more sense to me than trying to measure a floating disk of oil.

Congratulations Android, you've successfully recapitulated the evolution to desktop windowing. Took you only 15 years!

it never gained any real adoption inside google or outside, because it was a lot of work just to get even the most basic bindings. it was really just created because the authors hated swig.

I started with this but ended up designing my own system around a vertical 4040 aluminum extrusion post and various 3d-printed components including an XY stage (often costs $10K or more) and a Z stage (for focus). It was quite challenging to get everything to line up in a single optical axis and keep the dust out but the results have been quite good- I wrote my own software after trying to get micromanager to work, and can do large acquisitions (25x75mm, AKA a single microscope slide) as well as real-time object-detector based tracking.

It's remarkably hard to equal or best a $150 scope from Amscope in terms of optical quality, it's automating their stages that is tricky.


diatoms are fairly easy to collect in the wild, from moss and other moist areas of your yard. https://www.mccrone.com/mm/the-collecting-cleaning-and-mount... http://www.microscopy-uk.org.uk/mag/artjun15/sb-Diatom-Arran...

they are quite small and mostly transparent which makes good observation challenging.


any human differs less than 1 % (although it really depends on how you count differences). It would make sense to store one reference, and then everybody is stored as a delta relative to that (https://en.wikipedia.org/wiki/CRAM_(file_format) and https://en.wikipedia.org/wiki/Compression_of_genomic_sequenc...)

I was unable to find a scientific article explaining the data source in detail. Likely, they uploaded the reference genome.

I don't understand this comment- gcode never had loops, branching, or variables. And most folks use more capable controllers now based on ESP32 or whatever.

Update: I guess gcode does have loops, branching and variables: https://www.fictiv.com/articles/cnc-machining-macros-subprog...


Actually, in LinuxCNC dialect the gcode does have many features most machines will not understand.

This is why these machines can drill and helical-tap plates with thousands of holes with ease. Also, some folks will cut gear-profiles with a slitting saw, and 4th rotary axis...

https://www.youtube.com/watch?v=HI27vSoxCeo

Trying to pull these things off in a CAD/CAM package is usually a fools errand the old guys prank kids with... oh that sounds easy... lol =3


To be fair those features are pretty irrelevant these days. They really are a relict of times when gcode was handwritten. A skill i learned not even 10 years ago in high school.

cnc vendors are still bringing out new machines with new conversational g-code features though

really? got a link to that, im kinda curious.

i mostly see it on the 'titans of cnc' channel on youtube, but i don't have any of their videos on the topic bookmarked. take a look if you can stomach the shouty macho. in less arrogant alternatives, here's an abom79 video i have bookmarked: https://www.youtube.com/watch?v=-EyAWZuY7I4

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: