I thought it'd be about Lie groups!

https://en.wikipedia.org/wiki/Root_system

I thought it'd be about the superuser account.

HN is like Forrest Gump's box of chocolates: you never know what you might get!

They usually are. It’s a process akin to archaeology where they have to carefully wash away the dirt from the root system, measuring as they go. The problem with this method is that it's hard to reconstruct the entire 3d structure of bigger plants like trees so a lot of the root drawings on the site don’t accurately show how deep they go. It’s much easier with small plants where the researcher can control the soil used.

Modern methods like xray CT or ground penetrating radar can do it nondestructively in the field but they’re usually expensive to set up compared to just sending some grad students to dig.

Collection history page has a photo for part of the process https://images.wur.nl/digital/collection/coll13

A few ways. This particular project is doing it by hand and very tedious.

The traditional way of transplanting large trees while keeping the root system intact is with a hydrovac. A machine the size of a jet engine that liquifies the soil with water and then vacuums it up. [1]

More recent developments have tried using an AirSpade which doesn’t use water but compressed air to blow apart and then suck the soil without making a slurry which is better as the soil can be redeposited in the same hole rather than discarded[2]

[1] https://youtube.com/shorts/HinwD5-Q2xA

[2] https://youtu.be/B3XomJ6Z1I4

For plants, and trees too I guess, you can just grow your own, dig it up after a while, and inspect for yourself.

Today I finished picking tomatoes from my tomato plants and pulled them up to avoid them rotting in the field as the temperature goes down. It was curious to see how the root systems varied both between the two tomato varieties I had planted, the location of the plant in relation to surrounding grass, and the type of soil they ended up in.

no wonder the damned things keep coming back!

Whats the units?

My dad told me that one year his school held a contest over the summer to see who could get the longest dandelion root.

Always good to have a weed puller in your toolshed. A stand-up puller, specifically, that operates as a lever, allowing it to first grab deeply and then through a rotation of the handle it pulls out quite a bit of the root system. A lifesaver if you have a rain garden which is really just a synonym for weed garden.

Isn't reproduction the point? The roots exist to obtain water, nutrients, minerals; leaves gather energy from the sun; this is used to grow fruit, or whatever is used for reproduction

The answer to pretty much every biological "why" question is: because it reproduced. It seems simplistic, but really, a thing is here and alive because its ancestors reproduced.

Your version of the question has surprising perspective- I think you are asking what the "it" of the plant is. That's an interesting personification of a plant. I think it points to the fact that plants may be safer underground- for anchoring, for not being eaten, for getting shielded from harsh elements.

just start

I expected *nix file system diagrams of some sort :) but this might be even better