I'm designing an alien civilization that has achieved wormhole travel. Their devices are used by every member of their society and are usually located on their wrist. They type the coordinates of their destination, then shoot a small projectile in the air before opening a wormhole. The wormhole can be any size, and can get someone anywhere in the universe in an instant.

However, in their society they still have other means of transportation like hyperloops, spaceships, space elevators and even sea ships. Now my question is, why would a civilization that has such means of instant transportation still use other means of transportation?

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    $\begingroup$ I hear some people have a crippling fear of transporter psychosis... $\endgroup$
    – forest
    Jan 1, 2019 at 8:53
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    $\begingroup$ Almost everybody in the USA that travels to Alaska does so by air (or by cruise ship). Flying is far faster, much easier, and cheaper than driving. Yet every other year, I drive up. I am not afraid to fly. I just really enjoy the drive. You get to see so many things that are not visibile from the air. In your universe, people will still occasionally want to see what lies between their start and their destination. $\endgroup$ Jan 1, 2019 at 14:52
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    $\begingroup$ How safe is teleportation in your world compared to other methods of travel? How expensive? $\endgroup$ Jan 1, 2019 at 20:36
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    $\begingroup$ This is presumably fast. This mean that not using it demonstrates you have plenty of time to spare, for instance a demonstration of wealth. "Only working people must teleport"- $\endgroup$ Jan 2, 2019 at 4:00
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    $\begingroup$ There is an issue that is not relevant to your wormhole based teleporter, but which I've always wondered about for the Star Trek version. If a transporter scans you so perfectly that it can reassemble a perfect duplicate far away, then in the process it learns all your secrets. Your passwords, your biometrics, your guilty little sins, national security information -- everything. It's a security nightmare. High ranking officers should actually be prohibited from using transporters. $\endgroup$
    – Securiger
    Jan 2, 2019 at 10:36

18 Answers 18


Entertainment There are days when absolutely nothing will make you happy other than the sound of a Harley Davidson motorcycle polluting the atmosphere in style.

To Impress People One of my favorite scenes from the book The Stars My Destination is when the protagonist, hiding in plain sight via enormous wealth (and in a world with mental teleportation, not unlike your story!), arrives at a social function in a railroad engine. People stood and stared as workers laid track to the door of the mansion so the train could drive up and drop its passengers. Think about it. Dang.

Because the Line's Busy Do you remember the good old days when the smallest emergency guaranteed you could't get through on your cell phone... or your land line...? It's nice to think your population of (I'm suggesting) 9.2 billion can open 9.2 billion simultaneous wormholes — but the reality is they can't (and shouldn't). Too many wormholes in too close a proximity causes bad things to happen. (And probably would in real life. That, or the current existence of one wormhole guarantees through the magic of physics that no other wormholes within a specified distance can be opened.) So, whadaya do when everybody's using the line? You get on your Harley, of course....

Because the Destination is Popular Even if your world allows any arbitrary number of wormholes to open in close proximity... that doesn't mean there's enough landing space for everyone! The 100th Marvel Movie (The Runaways save the world!) is opening at the Odeon and you absolutely must see it on opening night! The problem is, so do a number of people representing at least 700% of the actual number of seats in the theater. The result? Thousands of people trying to arrive in the same 500 square foot space — all at the same time. Gratefully, your tech simply won't allow the wormhole to form if there's not enough physical space to deposit you. So, you jump on your bicycle and hope like crazy you can beat at least 1,000 of those people to the theater! (BTW, if you think about it, this would be a very common problem at any goods distribution facility. It doesn't matter how big or small you can make the wormhole... there simply is only so much wormhole transit space to go around. Everybody else gets to use trucks.)

Your Wonder Woman Wormhole Bracers... Broke There ain't no such thing as perfection. It's pretty rare that the wrist controls for the wormholes break, but when your little brother swung the tree branch at you... well... Dad's not gonna be happy paying another \$1,000 for a new cell phone set of Wonder Woman Wormhole Bracers. Bzzz, thank you for playing. Your consolation prize is you get to walk. (You can add to this one taking away your allowance, privileges, grounding you literally, or any other means of imposing reality on the unappreciative teen mind.)

There's Too Many People Near You You know what the basic problem with a rave is? They're packed! And in this city, raves are packed for miles. Oh, yeah! We're talking Zaphod Beeblebrox on tour! Woot! And you can't just open a wormhole in the middle of all that. You'd cut a dozen people in half as the event horizon formed. At least a dozen.

OK, to be honest, congestion (which at least three of these are talking about) will be a major reason why people don't use them.

You Can't Afford the Tech I don't own a \$1,000 cell phone, do you? Some people do, others take the bus. That's the circle of life.

Because Security Disabled the Destination And last of all — The folks over at Fort Knox takes a dim view of people trying to open wormholes into their vaults. I suspect there are all kinds of government, military, corporate, institutional, judicial, and who knows what else locations that absolutely, positively do not want your wormhole to open anywhere other than where they permit. Which can easily be believed to be "nowhere on this site." Prisons come to mind. There will always be the need for transport into and out of locations where security is a big deal.


I forgot one (or more)...

It Takes Longer to Teleport Do you remember that fabulous opening scene from the movie The Gods Must Be Crazy! (That really dates me!) where the woman gets in her car to drive 100 feet down the road to post a letter or some such? Yeah. Humans can be stupid. But she did it because it was faster than walking and cost her nothing to get in the car and fire it up. But, what if your wormhole has a minimum allowed distance? Or the time to form the wormhole is substantially (aka, minutes, remember the movie) longer than hopping on your bicycle? Then again, humans are creatures of habit! Maybe this isn't a good enough reason after all....

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    $\begingroup$ The congestion problem seems like the biggest problem... what happens if you open a wormhole inside another wormhole? No exact idea, but I bet there’s a lot of energy released as radiation. Even if the destination is sparsely used, you have to be absolutely sure no one is going to the same destination at the same time. And anyone who uses a regularly scheduled wormhole is a target for assasination... from anywhere. That’s quite a suspect pool. $\endgroup$
    – SRM
    Jan 1, 2019 at 2:55
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    $\begingroup$ Related to the security point: defeating traceability. Your character wants to commit a murder, but knows that all wormhole journeys are logged. The cops will be so busy subpoenaing records and checking alibis of people who teleported in and out of the murder location, they won't even think that the murderer might have travelled by bike. $\endgroup$ Jan 1, 2019 at 12:05
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    $\begingroup$ I'm just imagining a high-security bank preventing you from simply teleporting in by redirecting all teleports directly to a prison cell. Would be quite the shocker to the would-be bank robber. $\endgroup$
    – forest
    Jan 1, 2019 at 12:38
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    $\begingroup$ How easy is it to discover the coordinates for place you don't know about yet? $\endgroup$
    – Ellesedil
    Jan 2, 2019 at 21:00
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    $\begingroup$ @root1657 Very possible. It may even cause damage to the spacetime continuum itself over time even if it is so power efficient than the power source can fit on your wrist. $\endgroup$
    – forest
    Jan 3, 2019 at 1:21
  • Energy expensive. Make a wormhole is a very energy hungry operation.
  • Expensive. Maybe it doesn't consume much energy, but the technology or the item itself is very expensive, not everybody can afford it.
  • Disbelief, Insecurity. Did you know that planes are statistically speaking the safest transport? They are in order of magnitudes safer than cars, but still, people have fear of planes, like your people have fear of wormholes. Maybe the first wormhole devices were quite dangerous and two or three great catastrophes occur with them. Now they are safe but some people got traumatized by the events and still not trust in them.
  • Luxury. Wormhole travel is instantaneous, but what if the user wants to rest while travelling? It's like cruisers trips, people go there also to rest, relax and get fun, in addition to travel from A to B. Some people love driving cars...
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    $\begingroup$ Not just fear of flying. I do have a pilot's licence and owned a plane for years, but I won't fly commercial for anything much short of a life-or-death emergency, because it's just too darned unpleasant. Maybe the same is true of wormhole travel? $\endgroup$
    – jamesqf
    Jan 1, 2019 at 4:12
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    $\begingroup$ @jamesqf, oooh, I like that idea. What if the wormhole is negatively charged and it's like walking through a room full of static electrticity? I hate that prickly/itchy feeling. That's a good point! $\endgroup$ Jan 1, 2019 at 17:57
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    $\begingroup$ @JBH Possibly also - you have a non-zero chance of static discharge between electronics and wormhole which may destroy the transistors (if not cause problems like anything with metal in MRI or microwave depending on properties of unobtinabium). You need a laptop for your business trip - you need to fly or get a loaner at your destination. Have a pacemaker? You cannot use wormhole. Etc. $\endgroup$ Jan 1, 2019 at 20:20

Because wormhole travel involves destruction of the physical body, or deformation sufficiently traumatic that it raises the problem of the Teleportation Paradox.

If wormhole travel deforms or even destroys the brain (or analogous organ that produces consciousness in these aliens) then, there is a school of thought that this this process thereby kills the traveler. What emerges at the other end, then, is a copy, clone, or facsimile of the traveler, but not - in a very meaningful way (which you will have to articulate) - the same traveler who actually opened the wormhole. So, as with Captain Kirk and the Enterprise transporter, the traveler actually is killed with every single usage, even though they do not realize it.

In your world, this was actually confirmed through a catastrophic experimental failure that occurred in the beta testing of the wormhole technology. This was hushed up for obvious reasons.

Therefore, politicians, diplomats, aristocrats, intellectuals, high-ranking clergy, and similar persons do not actually engage in wormhole travel, even though they display the devices on their wrists. They take taxis and hyperloops and so on. That other people use these ordinary physical modes of travel is basically a coincidence (for reasons given in other answers), or perhaps, they've actually come to understand the way the technology works; or, they just intuitively distrust it for philosophical or religious reasons.

Said high-rankers might keep the devices on their wrists for ornamental reasons, or they might actually use them in an emergency e.g. the wearer has information known to nobody else that they are willing to die in order to transport elsewhere.


Transporter phobia

Some people may just be really afraid of using transporters. The idea of your atoms being ripped into pieces and put back together, with no margin of error, is certainly going to be scary for some people, even if it is both the fastest, most efficient, and safest method of travel.

From Star Trek: TNG, there was an episode, Realm of Fear, in which the hypochondriac Lieutenant Barclay was terrified of getting transporter psychosis, a rare disease that only affected those using very old transport technology. Despite constant reassurances, he remained terrified of transporting:

BARCLAY: You know, maybe ignorance really is bliss.


BARCLAY: Well, if I didn't know so much about these things, maybe they wouldn't scare me so much. I can still remember the day in Doctor Olafson's Transporter Theory class when he was talking about the body being converted into billions of kiloquads of data, zipping through subspace, and I realised there's no margin for error. One atom out of place and poof! You never come back. It's amazing people aren't lost all the time.

O'BRIEN: With all due respect, sir, I've been doing this for twenty two years and I haven't lost anybody yet.

BARCLAY: Yes, but you realise if these imaging scanners are off even a thousandth of a percent.

O'BRIEN: That's why each pad has four redundant scanners. If any one scanner fails, the other three take over.

LAFORGE: Reg, how many transporter accidents have there been in the last ten years? Two? Three? There are millions of people who transport safely every day without a problem.

BARCLAY: I've heard of problems. What about transporter psychosis?

O'BRIEN: Transporter Psychosis? There hasn't been a case of that in over fifty years. Not since they perfected the multiplex pattern buffers.

LAFORGE: Reg, transporting really is the safest way to travel.


Disclaimer: I'm a public transportation advocate. I am heavily biased towards public transportation.

If everyone in a society has the ability to instantly go anywhere they wish, there will inevitably be conflicts. If two people want to travel to the same destination, they would need to queue up, or there would need to be some form of other restriction to prevent overloading the destination/having multiple wormholes end up at the same location/etc.

For a more concrete example, take a major event (sporting/etc) where members of society will want to be physically present. Controlling access to the locale when people will travel via personal wormhole would be a mess for both safety concerns (what happens if two people exit a wormhole at the same time and injure one another?) and would be a logistical nightmare as well (how do you organize burst loads of people traveling at the same time to the same location when they arrive at any time and at potentially any location?). The best solution would be to have people gather in multiple locations elsewhere and then travel to the locale in a high capacity mode of transportation. This is logistically simpler since the number of vehicles moving in the vicinity of the locale would be drastically lower than the number of people that would be trying to access the locale directly.

This is independent of the other concerns that have been raised with wormhole transportation in other answers.



The use of this tech is prohibitive for specific journeys. The teleportation in my story works better for living beings than it does on inanimate objects. You're better off shipping commercial goods using traditional means, unless delivery is time sensitive and the object is very expensive. People, on the other hand, usually use teleportation. Ask yourself where it is economical to use other methods vs. using teleportation.

Range and location:

Another facet of my teleportation system is that it is limited by range. Someone traveling around the world would need to make a large number of jumps, and the placing of teleportation systems is limited and specific. Most often, the affluent teleport to a location close to their destination, and then use conventional means to complete the journey. In addition, everything but large cities lack the natural features needed to send and receive teleported material. In short, teleportation acts like an airport. It gets you most of the way there, it's expensive, uncomfortable, and small towns don't have the needed infrastructure.


Last but not least, teleportation in my settings gets exponentially more resource intensive outside of local energy fields. The range limitation is in effect on planet. At interplanetary distances, jumps are no longer subject to the range restriction, but become exponentially more costly. Teleporting to other planets is far, far, more costly than teleporting to other cities, even controlling for distance.


There may be specific disruptive phenomena that make teleportation unreliable. Unreliable meaning that it only works at certain times, requires more energy, or is downright dangerous.


Depending on your concept, maybe only a certain number of people can teleport at a given time. This could be a technological limitation, a legal one, or a social one.

Side effects:

There may be side effects associated with teleportation. Either for the person being teleported, or the entity doing the teleporting. Maybe one can only teleport a certain distance within a certain period of time, or risk certain adverse effects.

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    $\begingroup$ +1 for the side effects! I hadn't thought of that! What if wormhole travel came with a 1:1,000,000 chance of becoming insane? How many individual car trips do we take in a year? 1,500? 2,500? Those are the kinds of odds that are actually realistic (accidents happen!) while letting us believe "it'll never happen to me." (Until your best friend comes out of a tube stark-raving mad, leaving dozens of chalk outlines in a local mall before screaming "Daggaroth!" at the ceiling and collapsing, his eyes and ears bleeding. I'm just sayin' we need to worry about it, that's all.) $\endgroup$ Jan 1, 2019 at 18:03

Any technology has multiple cons, which mean we don't over-use them. Here's a few ideas, based on real-life transportation that we have today:


It sometimes causes temporary but embarrassing side-effects.

Some people are more susceptible than others, and some trips are more likely to trigger it than others (for plot reasons, could be short trips, long trips, or could be when there's too many others transporting nearby... Multiple hops in a short period increase the risk...)

But for some people, the risk of vomiting (or perhaps worse!) to save half an hour isn't worth it, particularly if you're going out for a date...

Environmental concerns

Environmentalists have been complaining for years, but now scientists are admitting, the effects of opening thousands of wormholes per person per year is probably not good for the environment.

This could be small wormholes left behind ("studies show that most devices do not meet the standards, and over 20% of wormholes do not close completely within the regulation 10s after transport. In some cases, wormholes as large as 1mm persisted for over a day after use."), microbes transferring through wormholes affecting the local biosphere, or just 'normal' issues like pollution from the devices or their manufacture... They'll almost certainly require heavy metals etc in manufacture, and perhaps they leak something nasty during use, like cars.

Wear and tear on devices / servicing

Much like a car, your device needs a service every 12 months or 150 hops, whichever is earlier. Only an idiot would skip this, given the risks should it malfunction!


Of course you need insurance on them! The risks of doing something stupid are high... Even if it's just an accident, if you teleport to an inappropriate location, you risk high fines or jail time. So there's insurance. And the insurance is priced on the number of hops you do a month.


Time experience is warped. Although you appear instantly on the other side, to you it feels like it takes hours/days/years/millenniums. Meanwhile all you see is darkness. This goes from mildly inconvenient to downright maddening, i.e. people are coming out completely insane if they’re not sound asleep while entering. It’s not always practical to be asleep when entering so people only use this feature when the travel distance is truly great. Idea partially based on Stephen King's short story "The Jaunt".

Time is warped. Although you appear instantly on the other side, your body actually ages quite a bit. This could be anything from ‘don’t do this every day if you want a long life’ to just aging a year every time you use it.

This option can be in combination with the first point, or just standalone.


To me, this questions echos "Why take the stairs when you could take the elevator?"

Two valid reasons for the stairs in the modern day and age are giving preference to the exercise over convenience and safety of arrival. In the case of teleportation, it's about perception, not reality: people may have the perception that there are health benefits to other means of transportation over wormhole teleportation. With respect to safety upon arrival, there are risks to blindly appearing at a location. In the event of a fire, part of the reason they don't want you to use elevators is because you could unknowingly be placed at the location of the fire and become trapped. With teleportation, who knows what could be a hazard upon arrival. Just because you can teleport anywhere, doesn't mean it is safe nor desirable to do so.

The Luddite Argument: For centuries, people have been opposed to technologies of every kind just because it is new and they do not understand it, or it seems like it poses a threat to their exiting lifestyle. Transit operators and the elderly are prime examples to demographics who may hold preferences to other means of transportation over teleportation.

Planes, Trains, and Automobiles A Rest Factor: teleportation is probably faster in most cases, but it may come at the cost that another means of transportation affords people the opportunity to rest when they are not scheduled so tightly they must teleport. Cost Factor: just because everyone has teleporters and uses them regularly doesn't mean they are free or cheap. Assuming they are a capitalist society, teleportation is probably overseen by a company that charges for their use in some way. Since its convenient, it's pretty easy to see them setting the price point for teleportation close to other means of transportation, including above the cost.

Traceability Wormholes may be really easy to track, so someone on the run from a tracker may find they need to stay hidden by using other methods to travel.


It could simply be an unplesant experience, so people might prefer alternatives when possible. How could it be unpleasant? Well, let me quote from The Hitch Hiker's Guide to The Galaxy on how in Douglas Adams' Universe jumping through hyperspace is quite an unpleasant experience:

The jump through hyperspace is a lot like being drunk.

You might ask, what's so bad with being drunk?

You go ask a glass of water.

(I just quoted this from memory, so the quote might be slightly inaccurate)

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    $\begingroup$ The quote's a conversation, so I don't think you need the "you might ask" and I believe it is "unpleasant" rather than "bad". But I'm determined not to google it to match your own efforts. $\endgroup$
    – Jontia
    Jan 3, 2019 at 16:44

Some ideas that I don't think quite overlap with the current top-ranked answer:

To Keep Control of My Personal Information: As mentioned before, when you teleport you probably have to file the equivalent of a flight plan, show the equivalent of a passport, and so on. So someone on the run from the law would have a reason not to teleport. But never mind the politics — did you know that every time you teleport, the teleporter company actually reads the quantum state of your brain and transmits it to your destination? I don't want Ma Bell reading my brain, thank you! Sure they say they're not keeping a copy of your personal consciousness in their database, but corporations have lied before.

Because Alexa Told Me To: This is almost a duplicate of Because the Destination is Popular and/or It Takes Longer to Teleport, but allowing for interaction with other futuristic technologies. You're asking why someone would decide to do x instead of y — well, most likely it's because they plugged their destination into Google Maps and just did whatever the machine told them. Why did the machine tell me not to take the teleporter today? Maybe it knows that teleporter use organically increases when it rains (Because the Destination is Popular), and rain is predicted for today in my location, so it's telling all its users to take the tube instead. ("Nobody goes there anymore; it's too crowded!") Maybe it's trying to be more ecologically conscious (Environmental concerns) by weighting teleporter travel differently than, say, rideshare. Or maybe — if the zaibatsu that controls the most popular recommendation engine is different from the zaibatsu that controls the most popular teleportation provider — maybe they're leveraging corporate synergy to subtly direct customers away from teleportation and toward some more lucrative alternative.

Because the Mom Group Told Me To: I heard teleportation causes autism.


There was an Isaac Asimov story -- I think it's called "The Door" -- about a little boy who started walking home from school instead of using the teleporter like everyone else. His worried parents had him talk to a child psychologist. The boy takes the doctor on the walk with him, and the doctor learns the boy just likes the outdoors. In fact the doctor starts taking walks himself.



If you instantly travel to a destination, then relative to what do you travel? The roleplaying game Traveller has this as a restriction on teleportation: You arrive with the same orientation and speed as you left.

There's a lot in simple physics that restricts teleportation ranges. If you teleport too much up or down, the instant pressure difference you experience will be quite unhealthy. If you teleport to the other side of the planet, you will arrive upside down. Also, the ground under you will be spinning the wrong way relative to your movement, depending on your latitude possibly quite fast - speed at the equator is 1650 km/h. If you teleport to the other side of the Earth from and to the equator, you are upside down and moving sideways at Mach 2.6

If your teleportation does not account for orientation and relative speed and pressure differences and all the other nasty details of physics, then by those simple laws teleportation is limited to short distances where the difference are manageable.


Your pets. You might be able to overcome the fear of going though a wormhole but your dog runs away at the first sight of a wormhole. So if you want to travel with your pets you have to go the old fashioned way.



Many people will drive big muscle cars from the 1960's- 1990's. Not because it's cheap. Not because it's easy (maintenance is very difficult), but because it's their hobby/something they seek enjoyment out of.

One can imagine that a hyperloop and all other forms of transportation were created before teleportation, as technology advanced slowly.

You can reference nostalgic feelings to justify this:

  • The acceleration of starting in a hyperloop
  • The gentle rocking of a sea-ship
  • The weightlessness of a spaceship
  • The cool, gritty feel of the ceramic heat shields as you wipe the flame-retardant polish on the belly of your entry shuttle before taking off.

Because the cost is per kilogram of matter. Teleportation is fine for individuals, but freight is sometimes transported other ways for cost reasons.


It damages space-time

Like in forest's answer, I'm going to pull from TNG. In the TNG episode Force of Nature, the Federation discovered that high speed warp travel was actually causing subspace emissions (pseudo-science, roll with it) that damaged the structure of local space-time wherever there had been high warp traffic. This was demonstrated when the scientist Serova overloaded her ship's warp core, causing it to effectively tear a hole in space-time. Though she died, her actions had the intended effect of pushing warp-capable civilizations to limit the maximum warp-speed allowed except in the most dire of need.

Now, one way to interpret a wormhole is that you are tearing a hole in two separate points in space-time. Taking inspiration from the plot described above, it's not unreasonable to think this might cause long-term and cumulative damage. If your wormholes do in fact cause that kind of damage, then it seems like a very good reason to use these only in the greatest of need.


You probably want to take a peek at What if a portal is opened from the Mariana trench to the Sahara desert?

Essentially, one of these wrist-mounted devices could destroy the planet.

What happens if you open a wormhole between two places with significantly different air pressures? Highest air pressure is 1084.8 hPa, lowest is 870 hPa, assume a round portal 70inches across, so 665,174 standard cubic feet/minute from https://www.tlv.com/global/US/calculator/air-flow-rate-through-orifice.html.

That works out to 24,894 feet/minute, or 282mph winds. This is as fast as the strongest tornadoes eer measured, and plenty fast enough to demolish buildings, and turn anyone passing through it, or nearby and sucked through it, into a puff of red air and bone-shard shrapnel in the first few seconds.

So even without water, just moving from atmosphere to atmosphere, portals may simply kill people. Unless they can somehow withstand pressure, yet not withstand the pressure of a person walking through them, they are a deadly tool.

Unless you're willing to handwave away air pressure, and the possibility of terrorists dropping one into the ocean, they would need very strong and non-overridable security constraints.

Then there's the obvious violation of the first and second laws of thermodynamics, in that you could get infinite energy from gravity.

One possibility is to have the portal require energy equal to the change in potential (some variation of gravitational, electrical, magnetic, kinetic, etc) between the two points in order to pass through. Then the air molecules on either side would be held at bay, as they would lack the energy.

This would also mean that if you were to portal from one side of the equator to the other, you wouldn't suddenly be moving at 2,000mph counter-spinwards.

Instead, you'd need to do it in a series of hops, and the work required from the walker overall would be the same as the kinetic energy required to change their velocity by 2,000mph over that time. This - preservation of potential - would be plenty to make people prefer other methods of travel if they can.

Though there's still the problem of what happens if two portals are opened to the same target coordinates at the same time, and two people step through into the same spot.


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