Think Humanity in Space, somewhere around 1000 Years from now. My main character wants to 'call' somebody in the vicinity. I would like to use a telephone, if that wouldnt be entirely ridicolous. Therefore I am asking for you opinion and ideas. What will everyday communication (devices and use) in the far future be like?

I have the following criteria:

  • No lengthy explanation needed, easily understandable to the reader.
  • Possibility of Encryption and Interception.
  • Mainly about communication in space, atmospheric effects can be dealt with, but it's no requirement.
  • No FTL-communication (important for the plot).

As always, thanks for the help!

  • $\begingroup$ "Possibility of Encryption and Interception." Any signal that is transmitted is going to have to be encoded, or more accurately modulated, according to some specific scheme. This is where 802.11, QAM, AFSK, NFM, PSK, ... all come into the picture. Encryption normally just means that you modulate using some slightly different baseband signal. As an example, take HTTPS over IP over Ethernet: IP doesn't care that you're using HTTPS rather than HTTP, and Ethernet doesn't care about what IP doesn't care about. To the next lower level, one bit is as good as any other. $\endgroup$
    – user
    Commented Apr 23, 2015 at 13:38
  • $\begingroup$ Also, it's quite easy to design an encryption scheme in such a way that it can be decrypted; it's actually more difficult to come up with a practical encryption scheme that cannot relatively easily be broken. The hard part is somehow coming up with a scheme that can be broken by "the good guys" but not by "the bad guys", because the math doesn't care about good or bad. $\endgroup$
    – user
    Commented Apr 23, 2015 at 13:38
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    $\begingroup$ I saw in a different comment that you do have FTL travel and maybe you already have a solution for this, just thought I'd mention: What's stopping me to communicate with a drone right next to jumpgate, that will then jump through and communicate the message on the other side of the jumpgate? Effectively enabling FTL communication. $\endgroup$
    – HSquirrel
    Commented Apr 23, 2015 at 13:53
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    $\begingroup$ @MichaelKjörling For a public system, where you can call anyone else on the same system, everyone will use the same physical layer. For any public communication network, encryption would take place on a much higher level. If you changed your physical layer (modulation, baseband, etc) you'd only be disconnecting yourself from the network. $\endgroup$
    – Samuel
    Commented Apr 23, 2015 at 16:37
  • $\begingroup$ @HSquirrel Exactly! That's what is happening. But then you have a chance to be faster than the courier ship. $\endgroup$
    – user6415
    Commented Apr 23, 2015 at 17:16

10 Answers 10


Thought-activated implant. You decide to call, they decide to take the call, and presto! Talk away.

Mild extrapolations from current encryption technology can provide security against eavesdropping. Heck, it can be done today between people who met in person before, if they bothered sharing a secret key.

  • $\begingroup$ A thought-activated implant sounds quite expensive: i cannot imagine a way to create a thought sensor that would be at least as cheap as a simple microphone. Therefor i doubt it would be the most plausible everyday device for common people. $\endgroup$
    – Burki
    Commented Apr 23, 2015 at 8:53
  • $\begingroup$ I think in 1000 years from now our knowledge of the human brain will have significantly advanced. It's not unreasonable to assume that will we be able to make an accurate sensor of the neurological activity, especially taking nanotechnology into account. I doubt that if we're also space faring, we would really struggle to get the necessary rare metals or intellect. I think this is a strong possibility for an everyday device. $\endgroup$
    – sydan
    Commented Apr 23, 2015 at 9:01
  • $\begingroup$ To be honest I think in 1000 years time this conversation would not occur out-loud. The characters would entirely use thought speak as the tech then should be able to turn the thoughts in our brains into words. We can already do this, just not accurately. Further more they would probably find themselves sharing live feeds of each others visual environment and maybe even be placed in some sort of virtual call room. $\endgroup$
    – sydan
    Commented Apr 23, 2015 at 9:04
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    $\begingroup$ @Burki: I cannot imagine a way to create a thought sensor that would be at least as cheap as a simple microphone. Therefore I doubt it would be the most plausible everyday device for common people. Can you imagine someone in the late 1990s saying, "I cannot imagine a way to create a DVD that would be at least as cheap as a simple VHS cassette. Therefore I doubt it would be the most plausible everyday device for common people"? Better technology sometimes wins, not by being cheaper, but by being obviously so much better that it makes the old tech obsolete. $\endgroup$ Commented Apr 23, 2015 at 15:31
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    $\begingroup$ @Burki The implant (or array of implants) would be fabricated in its entirety on a silicon wafer with thousands of copies. It would actually be cheaper to fabricate than a microphone of today (an irrelevant comparison, what are you going to connect your microphone to?). $\endgroup$
    – Samuel
    Commented Apr 23, 2015 at 16:47

It's 3015 and you're in space. Where do you keep your technology? Well, everywhere! Right now, every living human in space is no more than a meter or so from some pretty sophisticated tech. So why not assume that there's technology literally everywhere that your characters go, and they therefore don't need to carry anything around with them. Perhaps they have a digital personal assistant that follows them through the architecture behind the walls and is always running locally, or perhaps everyone interfaces with a single program that serves everyone. Note that I'm not assuming AI, just a more advanced form of our current, non-sentient programs, which I imagine most readers will be familiar with.

So to make a call, I'd just call out into the air and my assistant would place the call for me. Of course this implies speakers and microphones placed everywhere, but by then they'd be so small and cheap that that's entirely acceptable. Similarly, there could be cameras and screens (or holo-projectors, direct-to-eye lasers, or whatever kind of display tech you like) if you want video calls.

Of course all this brings up questions about privacy, but that could play into your criteria about encryption and interception. As for the technology that sends the signals across space, unless it's a plot point then if you want to avoid explanation to the readers, just don't mention how it works at all. I imagine there'd be some kind of networking systems similar to our current ones for transferring data, but there's no need to go into details if you don't want to!

  • $\begingroup$ Spot on - implies that the answer really depends on putting together some kind of model of the overall state of the technological environment. $\endgroup$
    – Keith
    Commented Apr 24, 2015 at 3:05


A very small detector is placed on or in the user's throat. When you "think" words and say them out loud in your head, the muscles in your throat will move as if you were saying them, but with no air it doesn't create any actual sound. The detector looks for these movements and translates them into speech/commands, without you talking out loud and bothering people around you.

Small speakers in your ears (either like hearing aids or as implants) deliver sound to you. Adding in glasses would give you two-way video (they'd have super tiny cameras), plus a HUD overlay of your surroundings.

Since we're a 1,000 years in the future, I suspect even those tiny devices would be capable of their own "cellular" connection (I use that term very loosely because at that point I'm sure they'd use something far different).

This is, basically, a super-advanced phone. The primary benefit is that since you don't need to say anything out loud, you can talk without air. This lets you talk without bothering others, or in space. You would, of course, need other scientific advances to make that survivable, and therefore useful.


I would go for a StarTrek-style communicator.

A simple wearable device, voice controlled, and maybe touch activated. It is easy to understand, easy to handle, and seems fairly failsafe.
It also seems to fulfill your other requirements.

If necessary, you could add a headset like nowadays bluetooth bits, maybe in-ear with a skull microphone, if you like.


Technology becomes obsolete. Replacing an implant every 2-3 years sounds painful.

You would use existing infrastructure. Since we are already surrounded by sensors I imagine in the future you would ask your personal assistant in the cloud - a la siri only way smarter - to call so-and-so. Sensors in the ship or station or home register your voice and that you said you pa's name and it will make the call.

  • $\begingroup$ You are assuming a firmly fixed, non-modular implant. Replacing it would possibly be as painful or as difficult as replacing a PCI card in a PC. Keep relatively stable brain interface and a modular core which can be trivially removed and replaced. $\endgroup$
    – SF.
    Commented Apr 23, 2015 at 14:05

I would suggest an implant that registers inside the brain when the person intends to talk. Thought's aren't usually organized into coherent speech patterns, so someone essentially listening to your thoughts would send an incoherent message that is all over the place.

You can speak a password ("Call Mom") and that selects the person you're trying to contact, with the message encrypted with a private key, that only the person's communication implant on the receiving end can decrypt (officially, though I'm sure there are people out there that can hack it).

And speaking it out loud isn't even necessary, just as long as the person is whispering or mouthing the words, the speech patterns will be recognized within the brain and be translated into regular speech to the recipient. So someone hiding in a cupboard from bad guys will be able to have a full on conversation without making a sound.

Hearing the receiving message works in the same way, you listen to it straight into your brain, rather than the ears needing to register it.

As for no FTL, trying to have a conversation with someone a significant distance away will be essentially like leaving messages, and when it reaches the person they have the option of listening to it as soon as gthey receive it, or can store it on their comms device for whenever they want to listen to it ("not now Cortana, I'm in the middle of a gunfight!")

Then for two way communication, it's similar to receiving a phone call now, with your communication implant asking if you want to receive the call in real time.


Final outcome of the technology is in the last section of the post

Currently, the cell phone seems to be becoming the "do-everything" tool that the public uses for all its mobile personal needs when it comes to needing or storing information. (Assumably you call someone because you want to send or receive information?)

When they first came out, they were large and could only place calls. Since then, they have gotten smaller and smaller. They had more and more functionality put into them so they became the only electronic device you need when you are on the go, as well as became a personal storage device (Don't see people with briefcases as often, except where paper copies are required).

Then, they started getting bigger again. Why?

  • Touch interface is easy to intuitively grasp, but requires adequate screen-space.

  • Having a larger screen is more visually attractive as clarity and definition increases.

  • It doesn't make the phones any less mobile.

It seems clear that having an easy-to-see visual screen is of some importance to the mobile electronic helper, as well as having a simple and easy to use interface, otherwise it would have continued to get as small as possible while being able to fit major functions.

To expand that to your situation - you have a person in space, probably in a suit of some kind? He at least requires some way to breathe. This suit or headpiece, or whatever the largest object you have that is personally owned and has to go everywhere with you, is probably the do-it-all device which is also capable of providing a mic of some kind near the mouth, and speakers somewhere in the vicinity of the head.

Imagine what this person will typically be doing while placing a call. If his hands or eyes cannot be distracted, he probably has to use his voice or some other way without having to look and push a button, though a button or physically interaction would probably still be available.

Then consider the screen aspect - how can they view images with their device. Holograms could be projected. If they wear a helmet, it could be a screen overlay on the interior in front of the face. It could be a touch-screen built on top of their fore-arm.

Depending on the technologies you want available, the solution you choose may heavily depend on a person's daily routine. If you drive to work everyday in your space jumpsuit, its likely going to be built into the jumpsuit. If you just walk down the hall, it may be an object that automatically follows you around.

My ultimate solution

If just about any technology is available without adverse side-affects, I would think the perfect solution is something that is able to always be with me, but not directly implanted. It could continuously scan my brain for commands and do them just by me thinking them - with sophisticated enough technology in that area it would literally know exactly what I'm thinking. It would for the most part require no charging or plugging in on my behalf. It could easily provide audio for only me to hear, and can easily provide clear visuals. The smaller it could be, while being able to provide the above, the better.

I am thinking something the size of a coin, which is typically carried in a simple slot on a belt or in a pocket, and has the capability to automatically follow you by some type of floating or propulsion technology. It is linked to my brainwaves to know when I give it a command. If I want to place a call, It comes up to my ear to provide audio and I can either talk normally or provide brain-commands. When receiving a call, it will notify me in my preferred method. Could be an audible noise, a slight visual, or vibrating. It can project an image in front of my eyes, either a translucent one or a completely opaque and super-ultra-HD one. When I get in my spaceship, there is a spot for it near my head. If I put on a helmet, it goes into the helmet first, automatically by brain command. If I am a big-shot CEO or something, maybe I have many working in conjunction - simultaneously calling people with messages, driving me to work, and grabbing my coffee for when I get there, while I use another to read the morning paper.

It would seem like an extension of yourself, without actually being one - meaning you could assign it simple tasks and not have to worry about the little details of getting the task done. You can easily get it replaced if it malfunctions, send it physically to other places if needed, and store highly sensitive or personal information only on it.


Vernor Vinge in Fast Times at Ridgemont High and Rainbow's End describes contact lenses that provide augmented reality, and computing and sensor ability in clothing that lets them issue commands in subtle, eventually subconscious, ways.

In the far future, people still living as corporeal self-contained entities (those that like exploring real-universe, for example) would just talk and use body language like they would if the person they are communicating with is in the same room to get his attention. The technology would project an image or just voice, as needed.


Think what our current tech would look like to anyone living 1009 years ago. Shocking, magical, omniscient, and powerful.

Future comms tech will be limited only by social mores of the time. AI will be real. There will be total convergence between phone, computer, tv, personal coach, doctor, multi-tool, personal security guard. These devices will be available as either a sentient companion, intelligent fashion accessory, tattoo, or implant. Perhaps people will be assigned a robot companion and mentor at birth. It sounds creepy but so is the internet and facebook today.

Perhaps it will be handy to have a credit card sized gizmo that unfolds like paper to a screen the size of an iPad. Calls could be a tactile 3d version of Skype or voice-only depending on the choice of the users.

The infrastructure might use quantum entanglement for instantaneous communication over a short distance, or some other exotic particles like tachyons or neutrinos that travel at relativistic speeds.


"I have the following criteria:

No lengthy explanation needed, easily understandable to the reader. Possibility of Encryption and Interception. Mainly about communication in space, atmospheric effects can be dealt with, but it's no requirement. No FTL-communication (important for the plot)."

Then you won't be building a science based universe as quantum entanglement should provide instant (ftl) and un-intercept-able communications for pretty much everyone by that time period, given they have already achieved it at short ranges now.

It may be however that this requires relatively large equipment e.t.c. but at the very least, quantum entanglement would be used much like a telephone hub, the first 'hop' to the hub may not be via quantum entanglement, but the middle part of the journey will be. Must like current telephone systems use copper cable from the phone to the exchange, the signal leaves the exchange via fibre-optic cable to another exchange.

In this case a purely local call would be still via radio, either a star-trek style voice activated job, or a true thought controlled device (via implant or a piece of jewellery).

As for the entanglement, you could impose a range limit (say 0.5au) which would require repeater stations, if they were damaged, it couldn't be used, however its very unlikely there would be a man-sized communicator capable of throwing transmissions over distances where there would be a noticeable time-delay, even 1000 years from now. The power required for that by anything but quantum entanglement is absolutely massive.

  • $\begingroup$ Well, not that i care for a strict 'sciene-based universe' as I already have FTL via jumpholes and interdimesional stuff in it :) The populated systems are thousands of lightyears apart, so with range limits, the non-ftl-restriction would kinda still apply. $\endgroup$
    – user6415
    Commented Apr 23, 2015 at 10:54
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    $\begingroup$ I've looked some stuff up. It seems like you cannot use quantum entaglement to transfer information. $\endgroup$
    – user6415
    Commented Apr 23, 2015 at 11:46
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    $\begingroup$ Quantum entanglement does not enable FTL communication: en.wikipedia.org/wiki/Faster-than-light#Quantum_mechanics $\endgroup$ Commented Apr 23, 2015 at 12:10
  • $\begingroup$ No, because like warp drive, its not really FTL. True FTL communication is not possible, like true FTL travel as it would require infinite energy. However pseudo-FTL is possible as proven by the expansion of the universe, either via wormholes, Quantum Tunneling or warp. $\endgroup$
    – Drenzul
    Commented May 8, 2015 at 15:54

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