Browsing through a bunch of old papers I found a few notes on a technology which I meant to use in some novel but dropped it because it wasn’t feasible.  Now, you might be wondering, we are talking fantasy, right?  What could possibly not be feasible? Well, the point is, we are not talking fantasy, we are talking science-fiction and though it is fiction, it is not magic, it still has to be possible.

I don’t think I need to tell anybody what scientists call ‘wormholes’, they are in all sort of novels, movies or TV series. Basically, a sort of tunnel that instantly gets you from point A to point B anywhere in the universe.  In science-fiction it is usually used to allow interstellar and even intergalactic travel possible because, otherwise, it would take so long that there would not be any story possible.

I wanted to explore it as the scenario for a story, not just as an excuse to allow impossibly short interstellar travel times. Make those wormholes an everyday thing.  What would happen if every morning you could simply walk to your neighborhood portal and then go through a wormhole to instantly show up downtown a few blocks from your office? How would such a network of zillions of portals connecting everywhere with everywhere else affect city life?

The first obvious thing is that why would you bother living in the city? You could commute from your Mediterranean beachside home to your South Pole lab just as easily as going around the corner.  Instead of ordering pizza, you could have your lunch break in Naples savouring the real thing.

That is when fantasy starts coming in.  In the real world there is a catch, there is always a catch.  Putting it that way ‘there has to be a catch‘,  might not be a very scientific assessment but the truth is the real world imposes limitations, otherwise it is just fantasy and it would be no different than snapping your fingers to move from one place to another.

One first limitation I meant to impose is that the portals would be paired.  You can’t enter a portal and pop up in any other portal.  Portals would be permanently paired.  Thus, to get from point A to point B you might have to cross several portals.  There would be end-nodes in the neighborhoods and connecting stations of various sizes so you can transfer from one portal to another.  So, that would impose some real-life limitation.  Travel would not be instant from wherever to anywhere else, you would have to jump several times, walking through the concourses of the several intermediate stations and perhaps queuing at each portal.

Still, there has to be some cost somewhere, not necessarily an economic cost but in the real world nothing comes for free.  Otherwise, you would be creating something out of nothing.

For example, the Poles are colder than the Equator.  In the cold, the air gets denser so there is higher atmospheric pressure.  Then you could set up a series of portals in the Arctic paired with sets of portals in the Stadiums for the 2022 World Cup in Qatar and let the cold Arctic air, at higher atmospheric pressure, to flow on its own to cool down the fields.  It would save a lot of electricity for the air conditioners the Qataris should install to achieve the same. That saving means you would be having air conditioning for free.  Unfortunately, the world doesn’t work like that.

What if you had a portal at the top of a high building paired with one in the basement.  You drop a hose on the side of the building and connect it to both portals so it all makes a loop.  Then you fill it with water.  The water would fall down the hose due to gravity, enter the portal in the basement, instantly come out of the one on at the top, enter the hose and drop once again.  You could put a turbine somewhere and get a lot of power for nothing.  That simply can’t happen.

There has to be some cost to get through the portal.  Would it depend on the distance? The distance from the top of the building to its basement might not be that big, but there is a difference in gravity potential, would that be the cost?   But then, if I put a cost so that generating power out of a hose down a building is uneconomical, I would make interstellar travel unaffordable. Would it depend on the weight (mass) of the object transferred?  What about the cool Arctic air?  If the portals are at the same height, there would be no gravitational gain, and the air is relatively light so if cost depended on weight, it should be cheap to cool down the whole of Qatar.

So, I kept thinking about usage examples and I could not figure out a reasonable cost structure for the system.  Besides, I had no story to tell in that scenario. But the further I dug into it, the less realistic I found it.

That is what makes science-fiction different from fantasy, there has to be some real-world science in it.  Otherwise, it is just magic.