One of the most important aspects of anything Pokemon related is catching Pokemon in capsules called Poke Balls. These Poke Balls are orbs that fit in the palm of your hand and seemingly impossibly have the ability to hold any Pokemon inside of them and summon them from inside at will. The Poke Balls carry Pokemon around inside of them, even if the Pokemon are much larger than the Poke Balls they are being contained in. When capturing Pokemon inside of Poke Balls, a few laws of physics come into play.

The Conservation of Mass

The biggest problem with Poke Balls is that they can contain any Pokemon of any size and weight, meaning that even the heaviest Pokemon can be stored inside of a Poke Ball. Celesteela, for example, weights 2204.4 lbs, or 999.9 kg. Celesteela, of course, can be captured inside of a Poke Ball, so what happens to all of Celesteela's mass when it is stored inside this very small object?

Well, the law of conservation of mass states that mass in an isolated system is neither created or destroyed. This means that when a Pokemon is captured, the Pokemon (and all of its mass) is either completely stored inside of the Poke Ball or the Pokemon's mass must be removed from the system. Removing some of the Pokemon's mass, however, means that the Pokemon is no longer the same Pokemon it was to start with, as part of its body has now been removed. This means that in order for the Pokemon to remain the same upon being capture in a Poke Ball, all of its mass must be stored within this approximately orange sized sphere. 

Image Credit: 
1. ​​​https://i.embed.ly/1/display/resize?key=1e6a1a1efdb011df84894040444cdc60&url=http%3A%2F%2Fmedia.tumblr.com%2Ftumblr_m8egzo85aY1qg6d88.gif&width=810
2. http://cdn.bulbagarden.net/upload/8/89/797Celesteela.png
3. https://img.clipartfest.com/a558e0068087554731e0a9477dc3cfdb_-red-arrow-up-wild-shark-red-arrow-image_2304-1296.png