Wormhole - Wikipedia

Before we jump into anything else, let it be known that there has to be a fuel source of some sort in order for the Portal gun to function.

Even when viewing the Portal Guns in games or TV shows, there is always a substance that allows the Portal Gun to work. Although we have no idea what that substance could be, we could loop it under the term, Exotic Matter. 

Exotic Matter is a type of matter that is unknown to the human race yet which could have abstract/unique properties.

Suppose that we are able to acquire a potential fuel source for this Portal Gun. What would the actual portal even be made out of?

This is where Wormholes come into play.

Wormholes are essentially interdimensional gateways between two different points across the fabric of spacetime. In simpler terms, it allows you to travel from one end of the universe to another really really fast.

I know that we have already made a lot of assumptions today, but let's make one more for the sake of simplicity; The Exotic Matter mentioned earlier can stabilize this hypothetical Wormhole.

Why would the wormhole need to be stabilized? The reason is that wormholes themselves are very unstable, and for the theoretical ones that could exist in our universe, they would collapse after mere milliseconds of being open. This is obviously a problem, because if they are not open, then we do not have a portal to travel through.

Before we get to the final product, there are a couple of key things to keep in mind.

In order for the portal to appear wherever you shoot it, that essentially means that there has to be a wormhole everywhere. 

One idea is that there are wormholes being formed and collapsed so fast that they are never able to materialize. However, if we were to use our stabilizing Exotic Matter to stabilize one of these wormholes, then we have essentially created a portal gun. 

The only outstanding problem is that there is no way to determine where exactly we will land.

Although there are still some questions as to how practical this Portal Gun would be, it is officially complete! 

Granted it might not be the most useful invention ever created, it is certainly interesting to delve into the specifics and really try to understand all of the factors that would help construct such a device. 

Science Fiction in general has many different concepts like this, and every single one is worth the time to investigate.

Although this series of ideas only outlined one of the potential ways that a Portal Gun could be possible, there are some other ways that they could exist.

I would describe them all, but that takes the fun out of it!

If this was an interesting read for you, I highly suggest scouring the internet for different articles about Portal Guns or YouTube videos that detail the science behind them!

It is a great way to pass the time, and it sheds a lot of light as to what is really possible in our universe, and what is simply MAKE BELIEVE!