Big Book of Science

The Big Book of Science is a collection of writings on general science, written before the Great War. There are at least 997 pages in the Big Book of Science, as in Vault 101 when taking the G.O.A.T, on the black board you can see "turn to page 976 in Big Book of Science". Students also "need to study page 997" according to the same blackboard.

Fallout, Fallout 2
A set of books containing information about different scientific fields. Time will pass while reading. If used in inventory screen, rather than used in weapon slots, time will not pass until the inventory screen is exited.

Note that in Fallout 2, Chemistry Journals look identical to Big Books of Science, and are (almost) completely useless.

Fallout 3
Reading improves the player's Science skill by 1 (by 2 with the Comprehension perk). Per the name, this book is the largest book in the game, several times larger than any other skill book and matching The Wasteland Survival Guide in dimensions while being thicker overall.

Fallout
 

Fallout 2
 

Fallout 3
 

Fallout Tactics
 

Fallout 3

 * A special version of this book specific to the Wasteland Survival Guide quest exists in the game's code, but it unused. It is identical to the standard Big Book of Science and grants the same bonus when used.  It is unclear why this specific version was created.
 * It is possible to obtain infinite copies of the book because the Ant Researcher in Shalebridge Tunnels respawns every 73 hours. This resets his inventory and the book can be taken from him multiple times. It may be difficult to find him at times. The Ant Researcher is hostile to both you and the "friendly" ants, but usually does not fight, resulting in his retreat, sometimes glitching into areas of the cave you cannot reach. If you are playing the PC version and you do not want to (literally) spend hours waiting 73 in-game hours every time for the Ant Researcher to respawn, you can use the console to select the corpse of the Ant Researcher and use the resurrect command. This will not only bring the him back to life, but also reset his inventory. Although if you are using Console Commands, then you may as well just add the books to your inventory.
 * If you intend to pick up all 25 skill books (and not use the above bug), you'll have to buy the Scientist Theme for your Tenpenny Tower suite. Only 24 books are available if you choose not to (or if you have the Megaton House).

El gran libro de la ciencia