Wikipedia:Reference desk/Archives/Science/2017 October 16

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October 16

Holographic interactions

In several sci-fi tropes, like Blade Runner 2049 or Halo holograms of humans can interact with people both visually and audially, despite having any organs or sensors to receive and analyze visual and audio cues. How is that? Unlike modern virtual assistants, it seems holograms per se can't process any data due to their nature. 212.180.235.46 (talk) 07:58, 16 October 2017 (UTC)

You're talking about works of fiction. If the author doesn't give an explanation, you're free to make up your own. --69.159.60.147 (talk) 10:48, 16 October 2017 (UTC)

The image of a person on Skype has no actual eyes or ears and yet one can talk to the image as if it were the actual person. Dmcq (talk) 12:01, 16 October 2017 (UTC)

In the classic science fiction series Red Dwarf, the holograms could not interact with real matter: hologram Arnold Rimmer could not hold objects, could walk through walls, and (if memory serves), due to his nature, he was a complete and utter smeg-head. Of course, it would be wholly unfair to compare Red Dwarf to other science fiction, in terms of scientific accuracy, literary merit, and cultural impact; it’d be a no-contest win.

Nimur (talk) 15:24, 16 October 2017 (UTC)

I'm pretty sure that Arnold Judas Rimmer BSC was a total smeg-head before he ever became a hologram. Iapetus (talk) 16:22, 16 October 2017 (UTC)

There are already virtual CAD systems that even allow limited interaction with a hologram-like augmented and/or virtual, visual representation of objects. Developers also try to implement haptic/tactile feedback into these virtual systems! Everything is still in an early stage tho and you always need interactive bridge-devices like VR-googles, -pointers, -gloves and alike, to use these systems. Its highly doubtful that there will ever be a "holodesk" which will not need such "adapters" and on top these systems certainly will have allot more limitations then their imagination in sci-fi. So allot of sci-fi-"products" are actually branded wrong since they contain somuch clearly pure letsmakesometing up fantasy elements and mechanics. Warpdrives, Wormholes, artificial gravity, teleportation... never gona happen! --Kharon (talk) 16:38, 16 October 2017 (UTC)

Some of those seem doable:

1) Artificial gravity just requires spinning the ship, but it needs to be a large ship to avoid nausea induced by a noticeably variable (apparent) gravity field. Also spinning the ship introduces lots of new problems with docking, solar panels and communications arrays and telescopes tracking their targets, external maintenance, etc. Doable, but tricky. (One solution is a rotating part and a stationary part, but linking those parts together isn't easy.)

2) Teleportation seems possible, although again not in the way they show. It would require scanning an object down to the molecular level, transmitting that info, creating a copy in that exact configuration at the remote site, then destroying the original, if you want to avoid having a clone. See Think Like a Dinosaur for a realistic treatment of the problem. Certainly there could never be transporters with equipment at one side only.

3) The time it will take to get humans to other stars does seem to be a profoundly unsolvable problem. Even if you have a ship that can go close to light speed, it would still take around a year to get to that speed at 1 g and another year to slow down at the other end. So, add almost 2 years to the travel time for that, and then we have the nearest stars being over 4 years away at the speed of light (although little time would pass for them during this period). So now we're up to maybe 6 Earth years to get there, and another 6 to come back. Would people really want to sign up to not see their loved ones for 12 years, minimum, then being a decade younger than those loved ones when, and if, they came back ? I'd have to say robotic ships seems a lot more practical. They can accelerate faster, and not worry about coming back. Even in our own solar system we've sent robotic ships all over the place but never sent people further than the Moon. Maybe if we ever found a planet we could easily colonize then sending people might make sense, but I'm skeptical of that, too, considering how none of the planets, dwarf planets, and moons in our solar system seem particularly close to being able to support a self-sustaining colony. StuRat (talk) 20:06, 16 October 2017 (UTC)

The visual and audio interaction just requires cameras, microphones, and speakers. In Star Trek: Voyager, they had a "portable holographic emitter", and as long as it had those items, and the ability to display a hologram, that seems possible. However, actually manipulating objects in the real world is another matter ("photonic matter", to be specific). For that, you would need a robot, or at least a robotic arm. A more realistic version of the holographic doctor on that show might have had him do all the "bedside manner" human interactions (except touching), like asking patients about their symptoms, while robotic arms do all the physical operations, like surgical procedures.

As for Blade Runner, we could give them the benefit of a doubt and assume that the locations were all hooked up with microphones, cameras, speakers, and holographic emitters. StuRat (talk) 20:41, 16 October 2017 (UTC)

...never gona happen! --Kharon (talk) 01:41, 17 October 2017 (UTC)

We're already headed towards every public place being filled with microphones, cameras, and speakers. StuRat (talk) 02:02, 17 October 2017 (UTC)

I was going to link smart dust. That said, it seems conceivable to me that "holograms" (sensu lato) could have direct sensory capabilities by some more integrated means, since interfering lasers are inherently capable of measuring distances very precisely and have been used to detect very small vibrations (i.e. spying by bouncing off windows). But this depends on the specifics of how you make a seemingly 3D free floating hologram far from an emitter, which is the more difficult technical question. Wnt (talk) 19:55, 17 October 2017 (UTC)