Tree Gaps and Orchard Problems - Numberphile
Why Mathematics Stack Exchange recommends it
Mathematics Stack Exchange users link it when someone wants an intuitive, visual feel for lattice points, rational slopes and why you can or cannot see through a forest.
Recommended by 3 people across 3 different months, 2018 to 2020.
What it is
A Numberphile video in which Ben Sparks explains the orchard problem: how far you can see through a regularly planted grid of trees, and how the size of the trees affects whether lines of sight exist. It uses lattice points and slopes of lines through the origin, with a GeoGebra demo, filmed by Brady Haran.
What people said
Strong rec Graviton · 2020-08 · Mathematics Stack Exchange · on “When you can look through a forest?”
There's a highly-related Numberphile video called Tree Gaps and Orchard Problems [this video] . I highly recommend taking a look. You're definitely not the only one with such curiosities!
Recommends Larry B. · 2018-01 · Mathematics Stack Exchange · on “Prove that any point I pick on the plane will lie on a line defined by integer coordinates and $(0,0)$?”
Here's a proof, which lulu hinted at in the comments: Suppose I have the point $(\pi, \sqrt{2})$, and there were a line $y = mx $ that it lies on. That line would need slope $m = \frac{\sqrt{2}}{\pi}$. What lattice point can we choose with that kind of slope? We can't choose any, since, for all lattice points $(a,b)\in\mathbb{Z}^2$, the resulting slope is a rational number $\frac{b}{a}\in\mathbb{Q}$, and $m$ is irrational. You might have tried a simpler proof, where "the lattice points go on forever", by noticing that the line $y = mx$ maps the real line onto the plane. The number of lines can be enumerated; the space of lines has the same cardinality as $\mathbb{R}^1\times\mathbb{N}^2$, whi
Recommends badroit · 2020-06 · Mathematics Stack Exchange · on “Intuitive, possibly graphical explanation of why rationals have zero Lebesgue measure”
With respect to "with very little background in math", this video might help to achieve a related intuition: [this video] ?