Viking Sunstones and Mummy Health Secrets

Today on SciShow news, dead person wisdom is helping enrich our understanding of the natural world - how did Vikings manage to be such awesome navigators? And is heart disease inherent in human beings? Scientists think mummies may have the answer.

Crash Course Ecology: Predators

Community Ecology II: Predators - Crash Course Ecology #5

Hank gets to the more violent part of community ecology by describing predation and the many ways prey organisms have developed to avoid it.

Facts about Human Evolution

Hank brings you the facts, as they are understood by scientists today, about the evolution of humans from our humble primate ancestors. On the way to becoming Homo sapiens, game-changing evolutionary breakthroughs led to the development of many hominin species, now all extinct. Hank will introduce us to these species & the breakthroughs responsible for their development, and help us understand the awesome ways in which they led to us.

Veritasium: Trees Are Freaking Awesome!

Trees create immense negative pressures of 10's of atmospheres by evaporating water from nanoscale pores, sucking water up 100m in a state where it should be boiling but can't because the perfect xylem tubes contain no air bubbles, just so that most of it can evaporate in the process of absorbing a couple molecules of carbon dioxide. Now I didn't mention the cohesion of water (that it sticks to itself well) but this is implicit in the description of negative pressure, strong surface tension etc.

SciShow: The Science of the Cinnamon Challenge

Hank explains the science behind the "cinnamon challenge," and reveals why it is nearly impossible to complete.

Do not attempt the cinnamon challenge! Instead, why not just watch some videos of the thousands of YouTubers failing at it! That's what we at SciShow call doing it "the Smart Way."

Like SciShow:

Follow SciShow:

Watch John try the cinnamon challenge on Crash Course World History:


scishow, science, chemistry, cinnamon, cinnamon challenge, impossible, mouth, saliva, mucus, enzymes, bark, cellulose, water, volatile organic compound, VOC, dangerous, medical, powder, breath, central nervous system, gasp, gasping, pharynx, larynx, trachea, lungs, sensitive, tissue, alveoli, immune system, white blood cells, inflammation, pneumonia, scarring, choking, coumarin, liver damage, internet, poison control center, emergency, call, hank green

CrashCourse Biology: Archaea, Bacteria & Protists

Hank veers away from human anatomy to teach us about the (mostly) single-celled organisms that make up two of the three taxonomic domains of life, and one of the four kingdoms: Archaea, Bacteria, and Protists. They are by far the most abundant organisms on Earth, and are our oldest, oddest relatives.

Like Crash Course?

Follow Crash Course!

References for this episode can be found in the Google document here:

Table of Contents
1) Archaea 03:23
a) Methanogens 04:02
b) Extremophiles 04:24

2) Bacteria 05:24:2

3) Gram Positive 06:50
a) Proteobacteria 07:15
b) Cyanobacteria 07:30
c) Spirochetes 07:42
d) Chlamydias 07:52

4) Protists 08:12
a) Protozoa 09:03
b) Algae 09:54
c) Slime Molds 11:13

CrashCourse: The Reproductive System

The Reproductive System: How Gonads Go - CrashCourse Biology #34

Hank lets us in on the meaning of life, at least from a biological perspective - it's reproduction, which answers the essential question of all organisms: how do I make more of myself? So, sex, how does it work?

Like CrashCourse:

Follow CrashCourse:

Table of Contents

1) Gametes: Ova and Sperm 2:27

2) Sex Determination 4:59

3) Secondary Sexual Characteristics 6:48

4) Female Reproductive Structures 7:25

a) Uterus & Oviducts 7:40

b) Endometrium (Menstruation) 7:57

c) Cervix & Vagina 8:32

5) Male Reproductive Structures 8:45

a) Scrotum, Sminferous Tubules & Epididymas 8:59

b) Penis 9:37

c) Vas Deferens to Eurethra (Emission) 10:13


Campbell Biology, 9th ed.

crash course, crashcourse, biology, science, reproductive system, reproduction, asexual, sexual, eukaryote, genome, offspring, sex cell, sex, animal, gamete, ovum, egg, ovule, sperm, hermaphrodite, genitals, male, female, behavior, production, storage, delivery, courtship, fertilize, gonads, organ, sex determining chromosome, nipple, estrogen, testosterone, puberty, secondary sex characteristics, breasts, human, ovary, fallopian tube, menstrual cycle, ovulation, uterus, cervix, vagina, testes, penis, erection, coitus, semen, emission, ejaculation, vas deferens, prostate gland

IDTIMWYTIM: Bird or Dinosaur?

Hank fixes those of us who are probably wrong about what is and is not a dinosaur... and gives a refresher to those of us who do know this already.

LIke SciShow on Facebook!

Follow SciShow on Twitter!


Crash Course Biology: Your Immune System

Your Immune System: Natural Born Killer - Crash Course Biology #32

Hank tells us about the team of deadly ninja assassins that is tasked with protecting our bodies from all the bad guys that want to kill us - also known as our immune system.

Like CrashCourse -

Follow CrashCourse -

Table of Contents

1) Innate Immune System 1:45

a) Mucous Membranes 2:54

b) Inflammatory Response 3:44

c) Leukocytes 4:45

2) Open Letter 6:33

a) Natural Killer Cells 6:56

b) Dendritic Cells 7:57

3) Acquired Immune System 8:36

a) Antibodies 9:08

b) Lymphocytes 9:48

c) Cell-Mediated Response 10:17

d) Humoral Response 13:00


Campbell Biology, 9th ed.

This video uses the following sounds from

"Pigs-01.flac" by Erdie

"straw slurp.wav" by dparke4

"Disgusting Slop.wav" by Ighuaran

"Sonar Ping.wav" by digifishmusic

"Swishes.wav" by Pogotron

"swing.mp3" by morgantj

crash course, crashcourse, biology, immune system, anatomy, physiology, human, health, microscopic, pus, pathogen, bacteria, body, organism, virus, immunity, innate, acquired, animal, vertebrate, germ, skin, mucous membrane, digestive tract, mucus, inflammatory response, mast cells, histamine, allergic, allergy, infection, phagocyte, macrophage, natural killer cell, lymphocytes, white blood cells, antigen, t cell, humoral response

Crash Course Biology: The Excretory System

The Excretory System: From Your Heart to the Toilet

Hank takes us on the fascinating journey through our excretory system to learn how our kidneys make pee.

Like CrashCourse on Facebook:

Follow CrashCourse on Twitter:

Campbell Biology, 9th ed.

Table of Contents:
1) Homeostasis & Osmoregulation 00:00
2) Urea & Uric Acid 01:30
3) Kidneys 02:49
4) Nephron 03:40
5) Glomerulus 4:15
6) Bowman's Capsule 04:25
7) Proximal Convoluted Tubule 04:49
8) Biolography 06:16
9) Loop of Henle 07:36
10) Distal Convoluted Tubule 09:23
11) Collecting Ducts 09:57
12) Ureters, Bladder & Urethra 10:45

3 Sad Surprises: The Human Genome Project

Hank tells us three surprises about human DNA which we learned because of the Human Genome Project.

Like SciShow on Facebook:

Follow SciShow on Twitter:

Find out more about the Human Genome Project at and about the National Human Genome Research Institute at

human genome, human genome project, genetic code, genetics, gene, DNA, evolution, base pairs, bases, adenine, cytosine, thymine, guanine, disease, cure, surprise, protein coding, non-coding DNA, sequencing, sequence, functional genomics, comparative genomics, virus, tail, embryo, junk DNA, epigenetics, biology, science, scishow, hank green

CrashCourse Biology - The Nervous System

Hank begins a series of videos on organ systems with a look at the nervous system and all of the things that it is responsible for in the body.

Like CrashCourse on Facebook:

Follow CrashCourse on Twitter:

References for this episode can be found in the Google document here: