The Plausibility of 10 Sci-Fi Concepts

[wcw43921]

The Article At Livescience

 

Interesting that they didn't have an entry for artificial gravity--that's a concept found in many, many science fiction movies and TV series, so much so that it's almost a surprise to me when it doesn't appear.

[zslane]

They left out time travel, but I'm pretty sure that's because the impossibility of it precludes it from appearing in any article with the word "Plausibility" in its title.

[Surrealone]

The planet-busting super weapons entry needs to be done away with.  Why?  Because if you have faster-than-light travel inside of a warp bubble, then all you need to do is release something the size of a marble (with the density of a marble) from the warp bubble on a trajectory toward a planet or star ... while the warp bubble is moving faster than light ... and then stop/slow the warp bubble (while the marble-like object you released outside the bubble keeps right on going). Key to this is that something moving faster than light (and outside of the warp bubble) will have infinite mass per Einsteinian physics ... and be traveling on a vector toward a target at which you aimed it using your trajectory ... most likely turning said target into Alderaan-sized particulate matter upon impact ... since the infinitely-massive marble will have more mass than the finite-mass planet or star at which you aimed it.  (And wow is it going to impart some energy upon impact!)

 

i.e. If you have FTL and you also have the ability to release something on a vector while at FTL speeds ... and then stop short of a target, yourself ... you automatically have a planet-busting super weapon.

[Sundog]

Don't need FTL. Near light speed is more than good enough. 

[zslane]

Not if your destination is many light years away. If it takes four years to receive a distress call from the nearest non-local star in your empire, and then five years for the help you send to arrive there, the crisis will be long over before your characters can participate meaningfully. Your science fiction story ceases to feel like science fiction and more like ancient pre-history.

[mrinku]

Artificial gravity doesn't break physics, strictly speaking. It's mostly just a matter of working out the mechanics of applying acceleration to stuff. It can already be done simply by spin or thrust. Making a field in which everything is accelerated in one direction (possibly requiring a counter field to mirror it) is just something we haven't worked out yet, and might not be possible.

 

"Anti-gravity", to make flying cars and such,  is mostly just a matter of directed thrust. That's how a helicopter or VTOL fighter works. Modifying the buoyancy of a thing will also make it float (i.e. airships). If a means can be found to artificially reduce the density of an object, you'd get something close to SF antigravity, at least in an atmosphere. Note that this does not have to mean mass manipulation... if you could generate a field that contained a partial vacuum but was still anchored to a vehicle, it might work like a gasbag and provide enough buoyancy. Actual thrust could be employed to maneuver, as with airships.

 

Or, as in classical SF, maybe a better understanding of quantum physics and gravity would allow direct manipulation of the gravity field, as we already can do with other intrinsic fields such as magnetic ones. But that's well outside the scope of the article, which is not dealing with "unknown unknowns".

[Lawnmower Boy]

On 11/13/2017 at 1:29 PM, zslane said:

They left out time travel, but I'm pretty sure that's because the impossibility of it precludes it from appearing in any article with the word "Plausibility" in its title.

 

Wellactually, the article used to have time travel, but it degenerated into a flame war, so the author travelled back in time and edited it out.