The Living Boundary
Investigate why skin can hold water in, why sweat does not always cool, and why an unchanged touch becomes less noticeable. Follow growth in hair and nails using interactive skin models. Eight investigations for ages 12 and up.
Library
A living boundary
Lesson 1
The Splinter That Didn't Bleed
A shallow splinter can make your forearm bleed but not your palm. How can the same depth reach blood in one place and miss it in another?
StartLesson 2
The Wall Made of Dead Cells
Your body is full of water, but your skin does not keep leaking it into dry air. How can its thin outer layer hold so much water in?
StartHeat and touch
Lesson 3
Sweat That Cannot Cool
Someone is soaked in sweat and still getting hotter. What decides whether the sweat cools them?
StartLesson 4
Pale Fingers, Red Face
Your skin turns pale in the cold and red after a run. What changes beneath it?
StartLesson 5
The Sock You Stopped Feeling
Your socks still press on your skin, but you stop noticing them. Why?
StartThe structures we grow
Lesson 6
Short and Prickly, Long and Soft
Why does short stubble feel stiff and prickly while longer hair bends easily?
StartLesson 7
After a Shave
Eyebrow hairs stay short, while hair on your head can grow much longer. How can hairs made of the same material end up at such different lengths?
StartLesson 8
The Nail That Remembers
A mark on a fingernail moves towards the tip over several weeks. How could its position give a clue to when it first formed?
StartReview and assessment
Lesson 9
Test: The Living Boundary
Review the course ideas by applying them to new situations, with kind feedback after every answer.
Locked till you take the prior lesson