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Comment by gaze | Hacker News Reader

This write-up and project is from the same guy that discovered superconductivity in bilayer twisted graphene. Pretty impressive.

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I don't know how uncommon that is, but more than 14k citations at age 25, most of which as first author sounds pretty darn impressive.

Not knocking his efforts, but I guess its on a par to writing some code or making something which is used by many people.

Probably underestimates it. Not my field, I don't know of this guy but a few hundred citations is you write a library that everyone uses and similar academic recognition and academic platinum for tenure on the background of other publications. 300 000 is the equivalent of writing the Linux kernel or sqlite.

https://www.nature.com/news/the-top-100-papers-1.16224

Right - that’s impressive

It really isn't -- unless you're talking something like bzip2 or some extremely nontrivial thing.

I once went through quite an experience. Used to work with a guy that was awarded a big prize in his field. I think one day he got tired of being treated as "some kind of genius", as he said. He started to discuss a topic one day, listening to my answers and questions back and forth. At the end the discussion hit a point where we could not go further. He then told me: "if you then submitted this as a proposal, were lucky enough to have it granted and just answered the last question you asked me with a simple experiment, you would receive the same prize as I did".

That guy was great.

And a genius lol. Don’t tell him I said that

You're probably being intentionally vague here to avoid "naming names", but I'd love to hear the actual details of this story: the topic under discussion, the interrogation that lead up to the "point where [you] could go no further", what the last question was, and what a simple experiment to answer it would look like.

That really is knocking his efforts. How is that constructive?

i've written code used by at least a billion people over fifteen years. i'm nobody and it was nothing. so definitely not on par

Aside from pure curiosity and or research purposes... Is there any everyday/practical apps/uses for something like this, for the avg joe? Building something for 500 that would normally be 10k, already has me intruiged.

You could run Quality Control on your amazon chemical purchases if you were willing to put in time to find methods using spectrophotometery in this wavelength range.

I brought this up in a comment in another thread. I found this page because I wanted to see whether it was feasible to monitor nutrient concentration in an aeroponic solution. Typically the solution circulates between the tank and the root box, so the concentration in nutriments will decrease gradually. Near-IR isn't enough to figure out these details I believe (I'm not a scientist), but it is enough to get a fingerprint of the nutrition "equilibrium". These solutions are probably the most technical aspect of aeroponics, so I wanted to use commercial solutions bundled as three bottles you're supposed to mix in various proportions. I think that if you explore the concentrations space using such a spectrometer you may be able to train a model to interpolate the concentrations from spectrographs measured in "production".

Anyway I think this is best to address the shortcomings of circulating the solution, for instance use a tiny tank, circulate for a few hours/days, refill, dosing as you go. A spectrometer would be still be cool in order to get real-time concentration diffenrential for each solution component. Identifying individual chemical species could be accomplished I think using far-IR spectroscopy with a model trained on data measured using more expansive spectrometry techniques.

I haven't grown anything yet, I want to build a sap flow sensor first.

https://edaphic.com.au/products/sap-flow-sensors/

https://dynamax.com/products/transpiration-sap-flow/dynagage...

this sounds like a relatively cheap project.

* any microcontroller with multiple ADC channels, for example ESP32 if you want it to be wireless as well...

* a heat generator (can be as simple as a transistor)

* a few thermistors, which you will have to calibrate (pretty easy if you have access to a thermometer, an electric kettle and ice, basically dunk the thermistor in a glass, put the thermometer in the glass, have the microcontroller output measurement number, and measurement value over serial port, now heat water to boiling point, make a table with a first column pre-entered with the thermometer gradation, then pour it in the glass, each time it passes a gradation you look at the scrolling list of values and note it in the second column of your table. Now you have a monotonically decreasing list of measurements, some of them marked as a thermometer gradation passing. Make a preadsheet and use the value of the fixed resistor in the voltage divider [the other resistor was your thermistor] together with the standard NTC or PTC formulas, then fit the free variables of the formula to the data... An acquaintance of me was starting to brew beer had all the components, but didn't know how to calibrate it, so I helped him out. Doesn't take long if you set your mind to it and properly prepare.)

Perhaps the difficulty is in the mechanical fabrication such that you thermally isolate from the phloem (which you puncture) and selectively measure temperature in the xylem?

Perhaps standard thermistors are too large. so an alternative would be a tiny diode, whose IV curve is temperature dependent. Added benefit is lower thermal mass, although I was surprised at the response time of the thermistor once calibrated (and filtered to result in step transitions when putting in and out of hot water and icy water).

EDIT: just making sure, what I'm trying to say is, don't be intimidated, and break up the task in smaller tasks, go ask for some help on ##electronics or so when you have sketched an initial plan, and listen to their feedback.

I read a lot of articles of this nature, not necessarily in this specific subject area, and may be guilty of writing some myself. I rarely build anything exactly to its original plans, but I take away bits and pieces, theory, and techniques, and re-combine them for my own purposes.

The value of the whole thing hanging together as a product is that you know the person has worked out the bugs of the individual parts, to the point where the whole thing is testable and reproducible.

This is actually true of the scientific literature as well. People rarely reproduce entire research projects, but often borrow bits and pieces and adapt them for their own use.

I used to work doing software for fruit sorting machines and we had a NIR Spectrometer to work out the sweetness of fruit, so when I'd go to actual sorting sites, especially in California which have these machines on a massive scale, I'd use it to sort out the biggest sweetest pieces of fruit.

That sounds super interesting. How does it work?

I don't know enough to know if this one would work for this kind of usage but cheaper and easily accessible spectrometers would be amazing for harm reduction and drug testing usages.

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