Prologue 4

Part 1: Curiosity about living things that comes to mind even while sleeping

1 Is there really a separate stomach for dessert? 11
2 Why do animals have different eyes? 17
3 Why does it itch when I'm still? 23
What if people's skin was a different color than it is now? 29
5 Will a nap make me feel refreshed or tired? 35
6. There are creatures that change gender? 41
7. Humans are animals, so why do they have less hair? 47
8 How will ecosystems change when wildfires occur? 53

Part 2: Odd and Quirky Physics Curiosities

9 What happens if a spaceship runs out of fuel in space? 61
10 Can you talk underwater? 67
Why does falling hurt less when using the 11th method? 73
12 Why do LED lights last longer than fluorescent lights? 79
13 How does a bouncy ball bounce higher than other balls? 87
14 Why does the north pole of a compass point to the north? 93
15 Why does ice stick to your tongue? 99
16 How do you control direction and speed when riding a surfboard? 105

The more you watch Part 3, the more you become immersed in the curiosity of chemistry.

17 What are the ions in sports drinks? 113
Why does my hair stay soft even after rinsing? 121
19 Why do boiled eggs become hard? 127
Why does dry ice smoke when placed in water? 135
21 Why should batteries be disposed of separately in a waste battery bin? 141
22 Why does drinking water when something is spicy make it even spicier? 147
23 Why do old books turn yellow? 153
24 What's the principle behind finding invisible bloodstains at crime scenes? 159

Part 4: Useful Earth Science Curiosities to Know

25 If we breathe too much, won't the Earth's oxygen supply deplete? 167
Why does the river freeze from the top down? 173
27 Why do clouds have different shapes? 179
28 Is it really so rare to see a bolt from the blue? 185
29 Why do earthquakes occur? 191
30 If you keep digging in bare ground, will water come out? 197
31 Were the stars in the sky from the beginning? 203
32 What would happen if the Earth rotated in the opposite direction? 209

Reference 216

A world of science that connects everyday life with simple curiosity!

Why do humans, though animals, have so little hair? _Curiosity about living things that comes to mind even while sleeping
What happens when a spaceship runs out of fuel in space? _Absurd and quirky physics curiosities
Why does drinking water make spicy food even spicier? _The more you look, the more you become fascinated by the chemistry.
Is it really rare to see a bolt from the blue? _Useful Earth Science Curiosities to Know

Curious Science Discovered in Everyday Life
A fun science story that I was curious about when I thought about it.

1.54 million subscribers, 290 million cumulative views
Korea's largest science channel, 'Samulgungi Miscellaneous Knowledge', is now available as a book!
Curious Science Discovered in Everyday Life

“Why does it itch when I'm still?” “Why does falling hurt less if I use a falling technique?” “Why do old books turn yellow?” “If I breathe more, won't the Earth's oxygen deplete?”

'Samulgungi', an abbreviation for 'a story that was so trivial that I couldn't ask, but was curious', is a science channel that uses animation to easily and funnily explain the trivial curiosities that cross our minds in everyday life and the not-so-trivial scientific principles behind them.
The biggest science channel in Korea, 'Samulgungi', which surpassed 1 million subscribers in just one year since its launch and now has a whopping 1.54 million subscribers as of May 2023, is distinguished by its novel and unique questions and solid scientific explanations to support them.
As if captivated by the unexpected questions that make you curious about things you weren't curious about, you click on the video and discover scientific concepts and principles explained in a delightful way, organized through meticulous research and expert advice.
In recognition of this sincerity and high quality, 'Samulgungi' has established itself as a 'trusted and watched' science channel recommended by teachers, students, various media, and education offices, and has proven its excellence by winning the Korea Foundation for the Advancement of Science and Creativity's Outstanding Science and Culture Content and the Youth Recommended YouTube Channel Award.
Recently, thanks to its popularity, it has established itself as an unrivaled science channel by providing videos to public transportation such as Seoul and Gyeonggi buses, Seoul Subway Line 2, and Kakao T taxis.

The 'Samulgungi' book series published by Arte Publishing faithfully translates the concept of the 'Samulgungi' channel into a book, but goes through a meticulous editing process to provide readers with a fascinating reading experience by allowing them to understand scientific concepts and principles that are easily missed in videos at a glance.
Immerse yourself in the world of science relevant to everyday life, guided by YouTube's curiosity solver, Gungi, through the "Samulgungi" series, which naturally leads subscribers to become readers.

Topics that are 200% curious and not covered in the video
A reliable science textbook written by current science teachers
Scientific concepts and principles that are easily missed in textbooks at a glance

Volumes 3 and 4 of "Stories I Was Curious About But Never Asked About" were planned and supervised by YouTuber "Samulgungi," and four current science teachers participated as writers, providing fresher, richer content and more friendly and colorful explanations.
Four teachers belonging to the educational research group 'People Who Make Exciting Science', which is centered around science teachers in the Seoul and Gyeonggi areas, selected 32 questions that students are most curious about and confused about among those not covered on the channel and organized them into themes of 'physics, chemistry, biology, and earth science', a system we are familiar with.


The surprising charm of 'Samulgungi' is that even the most trivial question contains reasons and scientific principles that are by no means trivial.
For example, to understand “Why do humans, though animals, have less hair?”, we need to understand the sharp debate among scientists surrounding human origins, and to answer “How do we control direction and speed when riding a surfboard?”, we need to understand the structure of water waves and the forces acting on objects, such as gravity, rotational force, and lift.
The four authors, who actually meet students in school settings, explain essential scientific concepts and principles in an easy and fun way based on simple explanations of phenomena, and naturally highlight common misconceptions that are easily overlooked in textbooks.
As you follow the charm of the novel questions, the delightful and clear explanations that never leave a dull moment, the lively illustrations, and the quirky and cute character Gung-i, you will discover the surprising fact that science is hidden everywhere in the world, from the smallest leaf to the far reaches of space.


“There is no unimportant question in the world!”
Meet the world with a small question

To ancient people who had little knowledge of nature, nature was an object of the unknown and fear.
However, in the process of finding answers to the trivial question, “Why does the sun rise and set?” that suddenly crossed people’s minds while looking up at the sky as usual, people came to understand the universe and time, and in the process of exploring the question, “Why do rivers flow to the sea?” they came to know the forces that act on the Earth and the cycle of matter.
We consider curiosity that is not directly related to real-world tasks or immediate tasks as "trivial," but in the history of science, such trivial curiosity can be the starting point for great discoveries that mark a turning point in the development of human civilization.
I hope that readers of this book will not pass up the curiosity that began with trivial things after they close the book, and thus experience the great joy of broadening their perspective on the world.