Re: The fantasy of starships is no more realistic than magic

On Sun, 29 Mar 2026 18:35:38 +0200, Thomas 'PointedEars' Lahn
<[email protected]> wrote:

>Steve Silverwood [KB6OJS] wrote:
>> On Tue, 10 Feb 2026 18:44:24 +1100, Whisper <[email protected]>
>> wrote:
>>> As a wise man once said, a man's gotta know his limitations.  Not 
>>> everything you can think up in sci fi fantasy can actually happen.  We 
>>> will never get close to reaching another star system.
>> 
>> Quoting Clint Eastwood in this topic...?  Interesting.
>> 
>> The universe is a surprising thing.  Lots of things are possible if
>> one has the dream.
>
>Imagination is helpful, but not sufficient for progress.  There has to be
>some connection to the real world.

No argument here, I agree.  Nobody could fly until we did it.  Nobody
could explore space until we did it.  If that's not a connection with
the real world, I'd like to know what I'm missing.

>> They're already experimenting with "transporters" (a la Star Trek),
>
>"They" are not; that is a common misconception (because of the term used).
>Quantum teleportation -- which is probably what you are alluding to -- is a
>far cry from /Star Trek/'s transporters in many ways, including:
>
>  1. only single elementary particles have been "teleported";
>
>  2. a particle is *duplicated only* with regarding to one its properties
>     because a particle that already existed at the destination is
>     given that property;
>
>  3. this has only been done with photons (AFAIK), not with stable particles
>     with non-zero mass (out of which matter consists);
>
>  4. the problem of not being able to determine certain properties of
>     a particle simultaneously exactly ([Heisenberg] uncertainty principle)
>     remains (in /Star Trek/, the Heisenberg compensators take care of that
>     }8-)).
>
><https://en.wikipedia.org/w/index.php?title=Quantum_teleportation&oldid=1345660195>
>
>> and it's entirely possible in my mind that eventually we'll "conquer
>> physics" and come up with a practical way to make interplanetary space
>> travel happen (beyond Earth, obviously, and hopefully beyond the Solar
>> System).
>
>One does not have to "conquer physics" for that, i.e. no new physics is
>required, and no exotic possibilities of currently known physics (like warp
>drive, or wormholes kept open by matter with negative energy) have to be
>realized.

Understood.

>As for interstellar travel:
>
>Andy Weir gives a pretty convincing example in his novel "Project Hail
>Mary", of which a film adaptation of the same name (co-produced by and
>starring Ryan Gosling, with Andy Weir advising) was recently released, of
>how it could work.  (I have not read the novel yet, but I watched the movie;
>certainly the latter is highly recommended if you are interested in science.)

I read the novel a couple of months ago.  After "The Martian" I HAD to
read "Hail Mary" and will be digging into Weir's other work as I find
it and add it to my Kindle library.

>I have calculated (you can even do that with a scientific desktop calculator
>if you know the physics/maths and a mathematical trick) that, considering
>special relativity, it would suffice for a spacecraft to accelerate from
>relative rest with 9.8 m/s^2 (=~ 1 g_0; would provide artificial
>gravitation, too) for ca. 91 standard days to achieve the speed 0.25 c.
>Cruising at that speed to Proxima Centauri, ca. 4.25 light-years away (for a
>pass-by, otherwise you have to decelerate for ca. 91 days, too) would take
>only ca. 17 (Julian) years in the terrestrial rest frame (ca. 16.5 years for
>the astronauts; so the "time dilation" at that speed is relatively benign,
>and people will still remember the astronauts should they return the same way).
>
>The main problem for using conventional propulsion is the propulsion system
>(no spoilers here on how they solve it in the novel/movie; suffice it to say
>that they still travel at subluminal speeds ;-)).  Radiation shielding
>(light towards the front is blueshifted; ionizing radiation is
>harmful/deadly), and deflection/evasion of interstellar dust (at large
>relative speeds, even a relatively small object like a speck of dust has the
>same kinetic energy as a hand grenade produces; this problem already exists
>with space debris in orbit, and asteroid impacts) are other problems that
>need to be solved.

Thanks for the information.  I'm retired so I'm reading purely for
pleasure these days.  I keep up on the "broad brush" stuff but I don't
have the proper education in physics to dig into the nuts and bolts of
it all.  At 68 and with memory issues creeping cm by cm into my life,
I doubt I ever will, but it's fun to read about what's going on even
though I will never =fully= understand any of it.

-- 
//Steve//