For this question I'm assuming a utterly infeasible technological breakthrough suddenly makes wormholes technology possible. However there is a major catch, the 2D "windows" as they're called don't allow through matter or gravitational pull. The "windows" can be opened for about a half a million USD. Once opened these portals stay open indefinitely unless closed.

Opening a portal requires a large amount of energy, and the use of expensive and bulky machines on one end of the wormhole, with only a small machine and energy on par with a car battery required on the other end. The portals are flat windows that look like portals, however were you to walk up to one you would pass through it unaffected. The portals size can be as small as a millimeter or as large as 2,600 meters, any larger would require using multiple portal machines and linking them together. A portal can have any shape with the smallest definition being a millimeter, however portals are totally flat. Each side of the flat portal corresponds to a side of the other end of the portal. Each of the two connected portals must be the exact same shape and size.

Portals will continue moving as the machine that created them was, at the moment it created the portal, other than controlling its initial motion you can't move portals except as detailed below. This means if the machine was orbiting the earth the portal will continue this motion, even though it isn't itself a object and has no mass. Portals also continue accelerating or decelerating as the machine was when it created it, however while portals can continue accelerating indefinitely they will slow acceleration such that they approach, but never reach the speed of light.

A portal on earth will not slowly drift, since slight changes in planetary motion such as the lengthening of days is effectively counted as deceleration thus the portal undergoes the same slowing, this only holds true for motions that continue at the same rate of acceleration/deceleration as when the portal was created. The end of the portal which requires the expensive machinery to create can be kept linked to the machines so that it moves with them, however this means you can't use those machines to make further portals.

Weapon note: To prevent the scenario of potential apocalyptic destruction, due to someone launching a portal through the sun. I have decided that a wormhole will collapse if more than about the equivalent of a kiloton of TNT worth of energy tries to pass through it in a second, though most energy that can pass through it in a second is equivalent to a ton of tnt. Since the portal only allows through at most a ton of tnt, any additional energy is reflected back when it hits the portal. This is still a lot of energy so it still has a lot of weapon potential. Keep in mind, as far as I know all energy would be in the form of photons.

TLDR: It's a portal that only lets light through.Well actually other details of it are more complicated, so read the whole question before answering.

What uses would be implemented for such a technology assuming it essentially appeared in our world overnight?

The most obvious thing I can think of using it for is as a source of near infinite energy, you could get one end of the portal in an orbit much closer to the sun and use the energy to boil massive amounts of water (also may be useful for desalinization). Using it to allow faster than light communication is an obvious application as well (though given our current technology that's not super useful).

  • $\begingroup$ They will be used for scientific research, exploring the weird physics that lets them exist. Lots of other things are bound to arise from the research, since physics will have to be rebuilt from the ground up. $\endgroup$
    – Mike Scott
    Commented Dec 21, 2015 at 19:39
  • $\begingroup$ Yes but like with many questions, the macguffin that lets these portals exist may not be able to be exploited in other areas. $\endgroup$ Commented Dec 21, 2015 at 19:45
  • 3
    $\begingroup$ Do these wormholes allow any frequency EM radiation to pass through or just visible spectrum EM? $\endgroup$ Commented Dec 21, 2015 at 22:19
  • 2
    $\begingroup$ What you describe in your question isn't quite what I was thinking from the title, but it reminds me of the Stephen Baxter/Arthur C. Clarke collaboration The Light of Other Days, which might be a good read if you're thinking about the topic. It "explores the development of wormhole technology to the point where information can be passed instantaneously between points in the space-time continuum". $\endgroup$
    – DCShannon
    Commented Dec 21, 2015 at 22:23
  • 2
    $\begingroup$ With two pairs of these, one end of each accelerating away from the earth at near-light speeds, you could transmit information backwards in time. $\endgroup$ Commented Dec 21, 2015 at 22:31

8 Answers 8


Colonization of other moons and planets

You could open up portals around a bunch of bodies in our solar system to increase insolation and make teraforming more viable.

Titan would be a real possibility for teraforming, with a thick atmosphere, water, etc. The problem is that it is really really cold.
It’s 72 kelvin on Titan, which is about the temperature of liquid nitrogen.

Throw a few portals around it and you could raise the temperature to a habitable level.

Mars could benefit from more light, since it has about 44% of the Earth’s solar constant. This would make growing things easier, and could restart the water cycle.

Also, since it allows photons, that means that radio waves will go through. So communication with the rovers on Mars or space probes gets a lot faster.

The fact that they keep accelerating up to lightspeed is also useful, in that you could create one that is heading toward another star, and one end you look through here on Earth, and it becomes something like an infinite zoom telescope. You'd want to have some high speed cameras on it, as it would pass by the intended star pretty fast.


Energy Collection As user867 pointed out, with enough of these you could make a Dyson Swarm/Dyson Bubble for energy collection.

  1. Launch a portal generator into a solar orbit.
    It doesn't have to be that close of an orbit either. The Dyson Sphere concept uses a orbital distance of 1 AU (the same distance as Earth orbits). These portals could be a lot closer, maybe inside the orbit of Venus, but you wouldn't need to be inside the orbit of Mercury. It would probably take some computer simulation to decide on the best orbital distance to portal size to maximize the collection while staying below the shutdown point.
  2. Create a small portal to be used for energy transfer through far field wireless power transmission (microwave or laser perhaps).
  3. Beam enough power to create a large portal to start harvesting the suns energy, which could used for solar power (it could even work at night!), thermal to drive a normal steam dynamo plant, or both.
  4. Take the power generated and beam it to the generator to create another portal, increasing the amount of power generated.
  5. Repeat until there are enough portals to enclose the sun. It could be helpful to avoid putting portals in the plane of the ecliptic so that earth and the other planets still get the same amount of light.

Some portals might get knocked out if they are overloaded by solar flares, but with several portal generators working to make new portals this would be a minor problem. At some point the amount of energy collected basically lets you create portals for almost nothing.

\$500,000 is a little high for a radio mast, but there are a few things that might make it worth the cost (if the cost hasn't been driven down by the previous point).
Towers used for television, cell phones, radio, and other communication can cost \$200,000 - \$300,000 to put up, plus the cost of land (expensive in cities) and running hard lines (expensive in rural areas).
By using portals, you can essentially put a transmitter in any location at any altitude, while all the hardware is in an easily accessible, easy to maintain location on the ground.

Google has been playing around with using balloons as wifi transmitters, and others have been looking into satellites as a way to have global wifi internet access. A portal is cheaper than a satellite, and is easier to maintain and upgrade, since all the hardware is on the ground still.

Also, as Jan Dvorak pointed out, for replacing the normal backbone infrastructure, portals would be way cheaper than undersea cables, and you would never need to worry about them being cut.

As the technology matures and portals get cheaper and cheaper, at some point you'll see an ISP offering PTTH (portal to the home) internet instead of fiber.

  • $\begingroup$ Yeah using the portals to shine bright sunlight on things would be a pretty good use. However given how small the portals are relative to the size of a planet this would only work for enclosed greenhouses. As I said in the question this is referring to a tech level equal to our own, since the resources necessary to make enough portals to matter on a planetary scale are greater than what we can currently muster i'm not sure your question exactly fits $\endgroup$ Commented Dec 21, 2015 at 18:17
  • 1
    $\begingroup$ A 2600 meter portal in a low orbit is going to be pretty big in the sky. For example a failed advertising group had plans to put billboards in orbit around earth. Their 1000 meter billboard would have had the same apparent size as the moon. Coincidentally, the moon and sun are the same size in the earths sky. So a 2600 meter portal would be as big, if not bigger than the sun as seen from Earth. In the question you already state that one end could be put close to the sun to generate heat for electricity. Why not heat for teraforming? $\endgroup$
    – AndyD273
    Commented Dec 21, 2015 at 18:36
  • $\begingroup$ I just didn't really think that compared to the total surface area of mars that people could make enough portals to warm mars, but then again the windows could be shining enough light to equal a ton of tnt a second so it's pretty energy dense. I wish someone with physics knowhow could come in and clear up some questions regarding the energy scales involved. $\endgroup$ Commented Dec 21, 2015 at 19:31
  • 2
    $\begingroup$ You know, with enough of these, you could build a functional Dyson Sphere. $\endgroup$
    – user867
    Commented Dec 21, 2015 at 23:31
  • 1
    $\begingroup$ Interestingly since the max energy allowed through doesn't depend on the size of the portal it would be in your best interest to make a bunch of millimeter sized portals and place them very close to or slightly inside the sun (don't know where they wold have to be to get the max energy but get less than a kiloton of energy.) $\endgroup$ Commented Dec 22, 2015 at 16:55

High-frequency trading communications platform.

HFT relies heavily on super-low-latency internet connections -- so much so that companies will rent office space that is physically closer to trunk exchanges, just to get an edge:

[...] each mile adds about eight microseconds of latency. There is so much money to be made that any expenditure on research and infrastructure to shave those microseconds is worth it.

It's already been posited that we could use neutrino-based communication, passing through the mass of our planet, to execute faster trades. Half a million would be chump change to acquire near-instantaneous, globally-spanning communications.

Telesurgery would be another interesting application, which likewise requires a low-latency connection.

Really, anything requiring very low-latency communications, which can be accomplished with fiber-optic (photon-based) hardware, and which is valuable enough to invest the initial half-million dollars in. It would also have potential for high-bandwidth applications -- half a million for a wormhole and some fiber-optic repeaters is still a lot cheaper than laying undersea cable (\$28,000-$90,000 / km), and a lot easier & cheaper to repair & upgrade.

More speculatively, a photon-emitting wormhole could be used not only to maintain real-time communications with space exploration hardware (as AndyD273 mentioned in their answer), but also to help power them (looks like bowlturner thought of this as well, with their solar sail probe example) or even just to keep them at more favorable operating temperatures. This could simplify their design & result in a net cost savings, and possibly extend their operational lifetimes.

  • $\begingroup$ Hmm.. I had thought of the possibility of using portals to avoid using as much fiber optic cable but hadn't considered how valuable a small time advantage could be. $\endgroup$ Commented Dec 21, 2015 at 19:33
  • $\begingroup$ @VakusDrake: At least until trading commissions get sick & tired of flash crashes, and legislate minimum time lengths and/or delays for trade execution :P $\endgroup$
    – Wingman4l7
    Commented Dec 21, 2015 at 19:44
  • $\begingroup$ Well given how fast current trading already is, i'm not sure that this would be enough to legislate anything new. $\endgroup$ Commented Dec 21, 2015 at 19:46
  • 2
    $\begingroup$ "half a million for a wormhole and some fiber-optic repeaters is still a lot cheaper than laying undersea cable ($28,000-$90,000 / km), and a lot easier & cheaper to repair & upgrade." - plus it has a much lower latency. In the order of tens of milliseconds, even. $\endgroup$ Commented Dec 22, 2015 at 10:41

Medical scanning.

If your wormholes are one-way, then the ultimate x-ray machine costs a million dollars. If they bi-directional, cut that cost in half.

What you do is have two identically shaped 'holes placed very close to each other - this is your scanner. Shine a light into one, it comes out of its paired end, goes straight into the other 'hole and out the final exit.

How is this the ultimate x-ray machine?

Well, push a person through this thing and you get an image of the tiny sliver that's between the two 'holes.

  • $\begingroup$ How exactly is this cheaper? You still need a source of X-rays to penetrate the body, and a X ray detector, so how is adding portals making it better? $\endgroup$ Commented Dec 21, 2015 at 23:51
  • $\begingroup$ You don't actually use an x-ray. Just a torch, so you have full colour images of any part of the body. It would give you FAR more detail than an x-ray or an MRI. $\endgroup$
    – user6511
    Commented Dec 22, 2015 at 0:34
  • 3
    $\begingroup$ This is an awesome application! The first provides a light-source inside the body while the second provides a camera inside the body. Love it! $\endgroup$
    – jhabbott
    Commented Dec 22, 2015 at 3:55
  • 1
    $\begingroup$ Oh I get it you have a person walk partway through the portal so you can see inside them. Given the price of FMRI's using a portal would actually be cheaper as well. $\endgroup$ Commented Dec 22, 2015 at 4:10
  • $\begingroup$ I bet that would look really weird, having a millimeter (or less?) slice of lit up tissue across your whole body. Scanning the part with the eyes would be a little rough, since closing them wouldn't help any. $\endgroup$
    – AndyD273
    Commented Dec 22, 2015 at 18:01

Well certainly different ways of generating energy could be used. opening windows closer to the sun and sending the receiving end to a solar array of some kind.

Since it only allows photons (not explicitly stated in the question) I have to modify this answer.

We would use it for entertainment, education and spying. We would be able to send a ship to orbit any of the other bodies orbiting the sun and 'see' much more closely, for far longer periods of time what is going on, like a cctv camera. I could see them being put into orbit around the Earth by governments to act as spy satellites and they would be cheaper too.

Then people might use them for entertainment, people watch 'reality' tv now, well, maybe having one looking out at Time Square, or Tienanmen square high quality 'video' of real life places that interest people.

AND another idea! for entertainment, put a 'dune' buggy on Mars or the Moon, have one end as a 'windshield' on Earth, and allow people to 'drive' the dune buggy around mars, since the buggy could take commands via light through the window (need a satellite in between a window in space and the buggy for communication, not as fast as instantaneous, but a pretty small lag) and the person driving would have visual feedback. "Let's go drive up mount Olympus!" That would be awesome!

One more idea! You could use it to push solar sails on ships across space to other stars, it could be used for propulsion as well as an energy source for the ship in transit.

  • $\begingroup$ It only lets photons through. $\endgroup$
    – AndyD273
    Commented Dec 21, 2015 at 18:46
  • $\begingroup$ Apparently I missed that, I'll reread the question. $\endgroup$
    – bowlturner
    Commented Dec 21, 2015 at 18:46
  • $\begingroup$ Another thought... since the portals apparently ignore any non photos and gravity, you could send them through planets. You could find out exactly what's at Jupiter's core, and if there is anything surprising. The only limit is the energy threshold, so you couldn't send one through the sun for instance. $\endgroup$
    – AndyD273
    Commented Dec 21, 2015 at 18:57
  • 1
    $\begingroup$ Sure. Visible, infrared, radio, x-ray. The whole spectrum is photons at different wavelengths. And he doesn't specify that it's limited in any way. Yet. The spectrum of whatever gets returned would tell us a lot, like composition, temperature, etc. $\endgroup$
    – AndyD273
    Commented Dec 21, 2015 at 19:07
  • 2
    $\begingroup$ Easy limitation to get around though. Put a satellite in orbit alongside the portal. Transmit video from the dune buggy via radio up to the satellite network, and then through the portal with either radio or visible spectrum back to earth. Commands go back through the same channel. Total lag will be pretty small. The army controls drones through satellite after all. $\endgroup$
    – AndyD273
    Commented Dec 21, 2015 at 20:32

There are of course all the weird and wonderful applications, but I get the impression you're trying to figure out what the more practical everyday applications would be in such a world, so here are some ideas:

  • Non-destructive scanning/searching: Similar to the X-ray machine idea, you could send a portal (or pair of portals if you need one to provide a photon source) through solid objects. For example: a volcano (or the planet) to map its internal structure; a seam of minerals to know where to mine; an avalanche or rubble from destroyed buildings to find trapped people; selected areas of land with archaeological interest; enemy intelligence HQs for spying purposes; broken/damaged things such as a car engine or an old bridge, for diagnosis of problems or structural integrity.

  • Mapping: Google would send one up every day, looking down and moving upwards slowly. They would film the output portal and send it to Google maps for real-time mapping at all heights, then sell access to anyone and everyone.

  • Instantaneous communications: This has already been covered amply in other answers.

  • Entertainment: Huge 'screens' for popular events like sports games, music concerts, royal weddings, the Oscars, etc. - fill the live venue, plus a few others in other locations to increase profits.

  • Monitoring: Security for high-value locations - the portal can't be interacted with physically like traditional cameras that could be disabled. Remote or dangerous locations could be monitored that don't have power or communications access.

  • Decoration / effects: The super-rich, expensive hotels, and similar could have fantastic views of any location from their city-centre buildings. Theme parks could launch thrilled roller-coaster riders past (or even through) scenes that would be impractical to build safely on-site. City councils could make small parks look much more open and hide huge eye-sores such as waste-land, construction, etc.

  • Cloaking device: Portals on either side could be used to cloak small or large objects.

  • $\begingroup$ I'm not sure the "multiple huge screens" idea will work ... as I understand, the starting portal has to eat the light which will come out of the other one, so you can't have many portals showing the same image. $\endgroup$ Commented Dec 22, 2015 at 17:18
  • $\begingroup$ @PaŭloEbermann think of a music concert - organisers would set up multiple portals hovering above the live crowd and sell access to the other end, like a private box, or to theatres elsewhere in the world. The visual experience for viewers would be like looking through a window as the light coming in from all angles would give a full parallax effect as they moved/turned their head in relation to the window. However, audio would have to be transmitted via a digitally encoded light pulse or radio waves also coming through the portal and played through speakers at the receiving end. $\endgroup$
    – jhabbott
    Commented Dec 31, 2015 at 17:07

With respect to the energy levels given, 1 ton of TNT is roughly equal to 4 gigawatt-seconds, actually a bit more.

This is much more energy than anywhere in earth receives from the sun. According to this website on solar insolation, the amount maxes out at ~7.5 KW/m2/day.

If we assume a window size of 1m^2, use 4GWs as the amount of energy in 1 ton of TNT, and set a day at exactly 24 hours, we get an insolation of 345TW/m2/day. The Wikipedia article on Watts has some interesting information on this level of power.

A window of this size, putting out the equivalent of 1 ton of TNT a second is a death ray. At lower energy levels, you could easily use these as heat sources for power plants.

If I have time later, I'll look at larger windows, but I guess you could you a km^2 windows for providing earth-like solar conditions to sections of other planets.

  • $\begingroup$ The energy limit of 1 ton pers second holds true whether the portal is a millimeter or 2600 meters. This means that a larger portal won't actually be able to create more effective death rays. Since the portal collapses if more than a kiloton of energy attempts to pass through it larger portals collapse easier since there's more space for light to hit. $\endgroup$ Commented Dec 21, 2015 at 22:34
  • $\begingroup$ You can obviously just create multiple portals to get more energy, however it's important to remember that for a single portal the energy output maximum is always the same regardless of size. $\endgroup$ Commented Dec 21, 2015 at 22:36
  • $\begingroup$ Gigawatts per second? I guess you mean gigawatt seconds, or gigajoules for short. GW/s would definitely not be an energy. $\endgroup$
    – celtschk
    Commented Dec 22, 2015 at 10:29
  • $\begingroup$ @celtschk - You are correct. I thought that Watts would be more familiar than joules but I messed up the units. $\endgroup$ Commented Dec 22, 2015 at 14:17

After thinking about it for a bit you can use mainly in space travel.

One portal is near the sun and the other attached to the spacecraft.

You can do the following:

  • Grow food in the spaceship(veg and what not).
  • Provide energy for the spacecraft.(maybe not directly for movement but still...)
  • Also has health benefits, vitamin D and helps people keep their sanity while in space.

I think you will need to address the theory of relativity in your world in regards to two portals emitting light while one is near a gravitational body like the sun.

  • $\begingroup$ It's important to keep in mind portals will continue moving with the relative velocities it had when created, so if you want to keep the portal near the ship you need to plan the ships course very carefully. $\endgroup$ Commented Dec 21, 2015 at 19:36
  • $\begingroup$ It is stated that if the portal is still linked to the machine then it moves with the machine. If I were to put that machine in space on the ship then the portal would move with the ship. Or would the portal disintegrate if I move too fast? $\endgroup$
    – Jonathan
    Commented Dec 22, 2015 at 8:53
  • $\begingroup$ Yes you could keep the portal linked that way, however the machinery required would be extremely large as stated in my question. If you were to make a spaceship that housed the machinery it would need to be massive essentially as large or larger than those used to get people to the moon. $\endgroup$ Commented Dec 22, 2015 at 17:01
  • $\begingroup$ If used for deep space exploration then it already would have to include a greenhouse, gravity generator, water recycler, living accommodations, warehouse and a whole lot of other facilities. Its definitely going to be a larger ship then the one used to get people to the moon. $\endgroup$
    – Jonathan
    Commented Dec 23, 2015 at 8:23
  • $\begingroup$ Yeah well if you're talking about a ship the size of a city then yeah. If you're making a ship like that with current tech, it would only be possible if you used nuclear weapons for propulsion. $\endgroup$ Commented Dec 23, 2015 at 17:14

Half mill is a heck of a lot cheaper than transcontinental cables. Lagless internet over any distance(there would still be some local bottlenecks but transcontinental lag would be a thing of the past). The portals would probably not be used directly as windows but instead attached to some sort of apparatus to transcribe data as light signals and return it to a central hub.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .