Chapter 178

* Chapter Cover
* WSJ Cover

**Science Scales Mountains** (科 (か) 学 (がく) は山 (やま) を越 (こ) えて, *Kagaku wa Yama o Koete*) is the one hundred and seventy-eighth chapter of the *Dr. Stone* manga.

## Summary

The chapter begins at the American Colony castle, with Yuzuriha pouring Revival Fluid onto the petrified Joel. It seems that Joel managed to squeeze one last activation out of the Petrification Weapon but now it's fully stopped working. Joel intends to work on the brutal task until he can't work anymore to show off his strength in front of the other men who again remark on his behavior.

In South America, we see the terrain become more mountainous as they go further inland, and they discuss mountain ranges. They eat armadillo after an arrow (presumably from Ukyo) kills one. Senku recaps their plan to find the original petrification device before Stanley can catch them. Francois insists everyone is well-fed for the long journey. Hyoga comments that they must be fast as the airplane will be completed quickly, and until they get under the natural barrier of the Amazon's jungle canopy they won't be safe from it. Taiju asks how long it'll be until they reach it, and Chelsea thinks for a moment before declaring that the forest will be on the other side of the Andes.

Max asks how Chelsea could possibly know that when they didn't know the area they were in would be desert, causing her to explain how the world has probably changed since then. Chelsea's main points are that because of the lack of people, global temperatures decreased which made the Antarctic sea currents start flowing north. This in turn forces warm air to gather in the middle of the Pacific Ocean as cold air from the Arctic gets pulled southwards. The effect is called "La Niña". This also explains the new desert, as the colder seawater means less humidity and rain. With the mountain range blocking the effects of the ocean's temperatures, the final effect is that Chelsea is confident that the other side holds the lush greenery of the Amazon.

In a seeming non-sequitur, Chelsea asks Luna for her weight. Luna reacts badly and lies about her weight, claiming she's 90 pounds (40 kg). Senku explains they need to rebalance the weight distribution on the bikes for maximum efficiency, as they left in a hurry the first time. Luna then realises this is an opportunity to sit near Senku, which Chelsea immediately jumps on and starts loudly whispering about her crush. Luna corrects her and says that they're actually dating, disappointing Max and Carlos.

Flashing back to soon after Senku got shot, Luna tells them that after she asked if he'd become her boyfriend, Senku agrees because he believed it to be "sorta like a political marriage" with the bonus of her two followers joining the Kingdom of Science. Afterwards, no one seems to agree with her that they're actually dating.

As they conversed, Senku had built a scale for figuring out their weights and heights based off his own height and taking 10 cm3 of water as 1 kg. Everyone is measured and weighed and sorted onto different bikes.

They soon hit extremely steep roads and must push the bikes to continue. Stanley says the airplane's repairs have been completed and sets off in the plane, the American radar man flying it. Senku, not wanting to leave anything behind, announces that they'll be building a ropeway to continue.

## Characters in Order of Appearance

* Joel Gear
* Yuzuriha Ogawa
* Minami Hokutozai
* Brody Dudley
* Yo Uei
* Chelsea Childe
* Ryusui Nanami
* Xeno Houston Wingfield
* Francois
* Taiju Oki
* Chrome
* Kohaku
* Senku Ishigami
* Hyoga
* Ukyo Saionji
* Max Adams
* Suika
* Gen Asagiri
* Luna Wright
* Carlos Barrios
* Tsukasa Shishio
* Kaseki
* Stanley Snyder

## Chapter Notes

* Joel is depetrified.
* The petrification device is back to being unusable.
* The reason Ishigami Village has more snow is revealed to be due to global cooling.
* The conversation between Senku and Luna from Chapter 163.
	+ Senku only agreed to be Luna's boyfriend for extra Kingdom of Science members.
* Heights and weights of all the motorcyclists are given.
* A scale is built.
* Xeno's gag has been taken off.
* Stanley's airplane has been fixed and is now in pursuit.
* The new motorcycle groups are:
	+ On the largest motorcycle: Francois (driver), Suika, the boiler (= 201 kg)
	+ Ukyo (driver), Hyoga, Kaseki (= 201 kg)
	+ Carlos (driver), Xeno, Max (= 200 kg)
	+ Gen (driver), Tsukasa, Chelsea (= 200 kg)
	+ Taiju (driver), Kohaku, Luna (= 202 kg)
	+ Ryusui (driver), Senku, Chrome (= 202 kg)

## Trivia

* Hyoga does not pull down his face covering to eat.
* A crescent moon is shown in one of the panels, implying that they've been travelling for around 2 weeks.
* The 'water' they use to create the kilogram weights appears to be at least somewhat made of spit, as Luna is shown spitting into a jar.
* The Americans seem to have no trouble communicating in Japanese as Max and Kohaku converse with no issue.
* In the English translation, Senku says that 10 cubic centimetres of water is a kilogram, however it should be 1000 cubic centimetres, or 103.