Summary by TwinMind · 21m 27s
Summary by TwinMind · 21m 27s
How Many Holes Does a Human Have?
How Many Holes Does a Human Have?
Vsauce
Vsauce
Introduction - Human Body as Doughnut Analogy
- Traditional view: human body like doughnut with central hole (mouth to anus)
- Reality more complex: humans have multiple holes (nostrils, ears, pores, etc.)
- Subatomic level: gaps between molecules, 60 billion neutrinos from Sun pass through thumbnail every second
- At molecular scale, human body just loose constellation of atoms/molecules
Defining Minimum Hole Size
- Established minimum: 20-60 millionths of meter (width of human hair)
- 60 micron wide spaceship could enter pores like giant craters
- Cannot continue through vasculature or slip between molecules
- Creates distinction between different types of holes
Through-Holes vs Blind Holes Classification
- Through-holes: GI tract (mouth to anus) - can thread 60 micron string completely through
- Blind holes: pores, urethras, nipples, ears, hair follicles, birth canals, sinuses
- Can be entered but eventually dead-end at narrow capillaries
- Only permeable by things smaller than single blood cell
- Examples of blind hole limitations:
- Eyeball: blocked by conjunctiva
- Sinuses: dead-end at same ostia entered through
- Ear: airtight eardrum blocks passage at 60 microns
- Total blind holes: millions (counting all pores and hair follicles)
Philosophy of Holes
- "Hole" is colloquial, fuzzy, imprecise term
- Refers to disparate, unreconciled things without single mathematical definition
- Holes might not exist - ontologically parasitic (depend on something else to inhabit)
- Demonstration: bowl → drinking glass → plate transformation
- Shows blind holes can disappear without closing anything
- Through-holes (like doughnut) cannot be removed without cutting/gluing
Human Body's Connected Pathways
- Mouth connects to both blind and through holes
- 60 micron traveler: mouth → esophagus → exit, OR mouth → trachea → dead-end in lungs
- Pharynx: area behind mouth, warms/moistens/filters air
- Nasal pathway: nostril → nasal vestibule → nasal cavity → pharynx → trachea
- Nostrils and mouth connected: string can go mouth/nose → butt
Additional Connected Openings
- Eustachian tube: middle ear to nasal cavity, normally collapsed
- Controls air pressure, opens when swallowing/yawning ("popping ears")
- Not through-hole due to eardrum blockage
- Lacrimal punctum: 4 openings (one near each eyelid)
- 1/3 millimeter wide, drain tears into nasal cavity
- Why nose runs when crying (tears, not snot)
- 60 micron string could thread: punctum → tear ducts → nasal cavity → pharynx → anus
- Total external openings: 8 (2 nostrils, 1 mouth, 1 anus, 4 tear ducts)
Topology and Homeomorphisms
- Topology: studies properties that persist without ripping apart
- Homeomorphism: gentle continuous transformation (stretching/squashing, no cutting/gluing/ripping)
- Coffee cup ↔ doughnut example: both have 1 through-hole
- Blind holes can be erased through homeomorphism (topologists don't count them)
- Through-holes cannot be massaged away
Topological Puzzles and Solutions
- Two-hole donut with rod: can manipulate so rod goes through both holes
- Intertwined loops: can be untangled by inflating bulb section
Mathematical Definition of Homeomorphism
- Bijective function: one-to-one correspondence between points
- Continuous: cuts must be mended perfectly, points return to same neighbors
- Material cannot be added/subtracted
- No smooth sliding along abrupt fissures
Counting Human Body Holes
- Result: Human body has 7 through-holes at 60 micron scale
- Not doughnut, but "seven-hole doughnut"
- Topologically equivalent to 4 pairs of pants sewn together at waists
- "Bodysuit for spider"
- Transformation: legs become nostrils (2) + tear ducts (4) + mouth (1), inflate into head/body shape
Variables Affecting Hole Count
- Piercings: each adds 1+ holes
- 2 holes if piercing goes through existing through-hole
- Supernumerary lacrimal punctum: some people have >4 tear duct openings
- Each additional one adds another hole to standard 7
- Accessory ostia: up to 50% of people have extra holes connecting sinuses to nasal cavity
- Creates additional through-holes
- Most people unaware unless serious sinus problems/extensive scans
Final Answer
- Blind holes: millions (at least 5 million)
- Through-holes: 7 at birth (standard), varies with individual anatomy
- Individual variation due to accessory ostia unknown without medical imaging
- Paradox: can define hole properties rigorously, study Pluto craters, but few know true hole count of own body
