There might be a way to build traversable wormholes without needing negative mass.

Take a gander: https://phys.org/news/2019-04-wormholes.html

Now, these wormholes have a big limitation, they can't be used for shortcuts, as they're longer than going straight to the destination.

Still they sound neat, however, I lack the knowledge (and time) to look into how the poor worldbuilder could use these wormholes.

I'm wondering if there are any features of these wormholes that could be exploited on the macro scale, and if yes, what?

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    $\begingroup$ Extra storage space. Get a trillion of those rubbermaid tubs, and store all your junk in an extradimensional void. $\endgroup$
    – John O
    Jan 28, 2020 at 17:19
  • $\begingroup$ There's a follow-up article at newscientist.com/article/… $\endgroup$ Jan 29, 2020 at 8:14
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    $\begingroup$ @John O : Or, in other words, our universe may not have Hyperspace, but it just might be that it has Hammerspace! :) $\endgroup$ Jan 29, 2020 at 10:53
  • $\begingroup$ @Renan I've just seen your post at worldbuilding.stackexchange.com/a/103973/61035 - do you know if this type of wormhole would have the same problem of excessive mass? I can't tell from the paper if these wormholes really do bypass the need for negative energy, or if they would have a similarly prohibitive mass for some other reason. $\endgroup$ Feb 12, 2020 at 19:09

4 Answers 4


I wanted to follow up on @John O's comment, there are a couple of obvious uses

Extra storage

The extra space can be used to store things you didn't have enough room for without wormholes.


A base inside one of these wormholes will have fewer entry points than one out in open space. A bank inside this wormhole has fewer directions to be attacked from. A prison would be virtually inescapable.


Because of the previous point, observing what's happening inside this wormhole, from the outside, is easier to prevent. You just cover up the entry points with heavy shielding and no one can see the experimental weaponry you're building on the inside.

Safe passage

Because of the limited number of entry points, you have an easier time controlling what is inside the passage. This can mean a reduced amount of debris endangering fast moving vessels, but it can also ensure the safety of very important cargo passing through. Sure, the traveled distance is longer, but that can be worth it if you can ensure the safe travel of, for example, the president between the capitol and their home planet.

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    $\begingroup$ Since there presumably won't be any drag inside a wormhole, your last point also nicely connects with long-distance travel on planet surface - traveling in near vacuum is way faster, to the point one idea for the Hyperloop was building extremely low pressure tunnels. $\endgroup$
    – jaskij
    Jan 28, 2020 at 20:55

If the ends of the wormhole can be moved, then maybe terraforming

Let's imagine your explorers have travelled to a new solar system. It's got a type G sun, pretty much identical to our Sun. There may or may not be aliens living on an Earth-like planet in the habitable zone, in fact you aren't sure if there is such a planet there. Out in the distance, at a radius we might call "trans Neptunian"... you've got:

  • ice giants

  • A Pluto-like planet

  • A mostly rocky/metallic planet that's actually very like Earth, but doesn't get enough heat from the Sun at that distance to be habitable.


  • You open a large wormhole very near the sun, with it's other end about eight light-minutes away from that rocky planet. Sure, it'll take the light a bit longer to get through the wormhole to Planet Rock than it would if it were going directly, but that's only a short initial delay of less than a day. After that, the planet is getting as much sunlight (& so heat, UV etc.) from the sun as if it were at an Earth-like distance to it. Continuously.

    (You've just beaten the inverse-square law! Well done.)

But there are still problems.

  1. The gravitational effect of the Sun is also coming through that wormhole. Or at least, I think it is - people with more knowledge of physics, please comment! It'll change the planet's movements, and you don't want to destabilise the orbits of the other planets in the system. So you maybe open another wormhole first, with something very dense but emitting very little radiation, at the other end. By moving that wormhole, you use the mass of that larger body to tow the transneptunian rocky planet to a safer distance. Then you open the wormhole to the Sun.

    You'll still probably need to make occasional course corrections, nudging the existing planets a bit to keep them in orbit. I think. My knowledge of physics doesn't go far enough. Remember, if there are aliens living in a habitable zone planet, you don't want them to find their planet hurtling out of orbit. Possibly these small adjustments are viable with your future technology, but the wormhole towing trick is the only way you can move a planet over large distances.

  2. You need to get oceans established. How long a timescale do you have? You could open another such wormhole, with an opening very close to the ice giant. The Sun's heat then evaporates the gas and begins to melt the icy core. Then you open another wormhole, through which the now liquid water pours - and comes out the other end on Planet Rock.

    If you're in a hurry, and you have a Pluto-like planet, you might be able to melt away the nitrogen ice crust and get at a useful liquid water mantle faster.

  3. You don't want a planet that's effectively tidally locked. No problem! You just get that end of the wormhole moving so that it orbits the rocky planet. You probably make it take 24 hours to complete its orbit.

Critique and discussion welcome, especially because I am using this idea in my story.


Make beacons. Yes, new wormholes make the trip longer, but stretched in the right way and kept open make a permanent highway from beacon to beacon (as long as they are powered). To create a new beacon it needs to be carried and installed there in normal space, and takes some time to stretch, but once set, it can be used for FTL travel.


Long distance communication on planet surface

While your source does not state (or at least I didn't find it) how much longer this travel takes, it would presumably be shorter than a round-trip on the surface or bouncing off of satellites. Or at least require less infrastructure (depending on the energy required).

A large-scale connection could, say, half the lags and greatly increase the bandwidth between continents (especially east Asia or Australia and the rest of the world).

While doing back-of-envelope calculations, remember that signal propagation in copper is (AFAIK) roughly 2/3 of the speed of light. Or at least that's the approximation we use when designing electronics.


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