Dr. Stone Wiki
Dr. Stone Wiki

Eyes of Science (科学の眼 Kagaku no Me) is the thirty-ninth episode of the Dr. Stone anime, and the fourth episode of the third season.


"Why-man" suddenly sent an eerie message to Senku and the others. Senku, Ryusui, Chrome, Gen, and Ukyo, the five generals of the Kingdom of Science, began a strategic meeting to find out their true identities. To counter the invisible enemy, Taiju creates radar and sonar, which are the eyes of science, and thinks of exposing Why-man. Having learned about the nature of the radar, which can see both the sky and the sea, Chrome thinks of something...

Plot Details[]

Everyone wonders from who or what that signal may be but Taiju states they should leave that to Senku and focus on the things they can do. Kohaku agrees too that they should leave this matter to the five most clever people in their kingdom, Senku, Gen, Ukyo, Ryusui, and Chrome.

Ukyo summarizes the things that happened until now. Ryusui, however, doesn't think that the "Why-man" was the one that petrified him since it's been 3700 years since the petrification unless he had petrified himself too. Chrome wonders why they assume that Why-man is an enemy but Senku explains that if he ends being a friend, they would have just over prepared. Gen states that Why-man for sure isn't appreciating them as when Senku tried to speak with him, he ignored him and the signal stopped. Ukyo finds the situation scary as an unidentified, unseen enemy can come from anywhere. Senku then gets an idea and states they will see the unseen with the eyes of science.

Gen and Yo not impressed by Senku's display

Gen and Yo not impressed by Senku's display.

Senku takes some of Chrome's sphalerite he collected and asks the muscle group to mash them to powder. Then, in a conical flask, he then adds some water to dissolve it, creating a fluorescent paint. Kaseki guesses that they will be turning the flask in a giant vacuum tube. When they are ready and turn it on, Senku explains that they are using electrodes to accelerate electrons emitted by heat and hit the bottom of the flask, making it lights up. With this, they have obtained a cathode ray tubes display. Gen and Yo aren't impressed as Senku used to make more complicated stuff. Senku then explains that the dot will turn into an image when they nudge the beam in a precise rate, from left to right, top to bottom, which is how the old cathode ray tube TV's worked. He also shows them that using a sheet of crystal on which he applies voltage causes it to vibrate, and by using two sheets like a sandwich, the electrons passing between them make a perfect curve and turn the dot into a straight line. For the vertical curve, Senku connects the antenna to the top-bottom sandwich. Seeing the result, Ukyo is surprised that he didn't figure out earlier that this is a radar with which they will be able to see the unseen enemy.

Ryusui catching some fish

Ryusui catching some fish.

Senku and few others then go into the sea to test it. While looking at the sonar radar, Chrome starts to figure it and states there is something in the water. Senku laughs and explains he also wanted to make the sonar for another reason. As their voyage will be long, they need to find food locally. Ryusui then throws the net, catching a large amount of fish. Senku is thankful of Why-man as thanks to him, he now knows what they are looking for.

Back on land, Francois turns the fish into fine dishes. While they enjoy it, Kohaku is surprised that the sonar and radar can see the fish, and Ryusui states that they can see anything. Hearing that, Ginro wonders if it can see through clothes. Trying to explain, he wonders for a scientific reason. They quickly understand what he wants to do, and Senku states that the closest thing to that is an X-ray, but you will see more than just through the clothes. Ginro tries to say that Chrome is also thinking about it, but seeing him, Kaseki states that Chrome is probably coming up with some fun projects. Ukyo wonders how they will power the radar, and Senku explains that they will be using large engines that will be generating power. Kaseki gets excited to build then; however, Senku explains that they will need a large amount of steel and oil.

Chrome creating a metal detector

Chrome creating a metal detector.

Suika and Kohaku are gathering iron at the river, but the amount is too small. Meanwhile, Chrome is wondering if they can use the radar to see through dirt to find iron. He starts experimenting and quickly finds out that his experimentation works. He then runs excited to a mountain where they used to catch lighting with Senku and starts searching for iron. He ends up finding a strong signal in a cave and quickly calls Senku, who sees that Chrome has made a metal detector. They find a large iron deposit and quickly turn it into a mine to harvest it. Since the iron is quite heavy, they have some trouble carrying it out and wonder how they will take it to their kingdom. Senku then states that they have a hundred people in the village and will make a distribution network.

Mixing gravel and scum left from cooking oil, Senku creates asphalt and make a road from the mine to the river. They transport the iron with a car to a boat at the river which will then carry it to the kingdom. Senku also makes mine carts and railroad to carry the iron outside the mine.








Inventions and Discoveries[]

  • Cathode Ray Tubes
  • Radar and Sonar
  • Metal Detector
  • Mine
  • Asphalt
  • Mine Cart

Anime to Manga Differences[]

  • The Gorilla squad making a road

    The Gorilla squad making a road.

    Following Chapter 97, the first five pages of Chapter 98 where the Power Team starts constructing asphalt pave roads and Gen driving the iron load to the river was placed between the scenes of Senku opening the network and Ryusui's imperial education.



Site Navigation[]

[v  e]
Story Arcs
Prologue Saga
Stone Formula Arc
Chapters 1234
Episodes 12
Vs. Tsukasa Arc
Chapters 56789101112
Episodes 345
Ishigami Village Saga
Kingdom of Science Arc
Chapters 131415161718192021222324252627282930313233
Episodes 5678910111213
Village Games Arc
Chapters 34353637383940
Episodes 131415
Village Origins Arc
Chapters 4142434445
Episodes 1617
Stone Wars Saga
Vs. Hyoga Arc
Chapters 4647484950
Episodes 1819
Communications Arc
Chapters 5152535455565758596061626364656667686970717273747576777879808182
Episodes 20212223242526272829303132333435
Source of the Petrification Saga
Age of Exploration Arc
Chapters 8384858687888990919293949596979899 100
Episodes 35Ryusui3637383940
Treasure Island Arc
Chapters 101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138
Episodes 4142434445464748495051525354
The Truth of the Petrification Saga
New America City Arc
Chapters 139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169
Episodes 555657
South America Arc
Chapters 170171172173174175176177178179180181182183184185186187188189190191192193
New Stone World Arc
Chapters 194195196197198199200
Globetrotting Arc
Chapters 201202203204205206207208209210211212
Stone to Space Saga
Moon Mission Arc
Chapters 213214215216217218219220221222223224225226227228229230231232