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

Thomas 'PointedEars' Lahn <[email protected]> writes:

> 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.
>
>> 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.
>
> 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 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.

This reminds me of a conversation I had with someone I didn't know at a
cigar lounge. He posed a question, I'm assuming, expecting to remain
unchallenged by his assumptions.

He laid out a hypothetical: "We" figure out how to compress space such
that the ten feet ahead of a space ship is compressed down to one
nanometer. And with this discovery, "we" could travel at some easy
velocity like 100m/s and cross light years in hours.

I let him talk for a few minutes with the other dudes. Some seemed
convinced it could work. I spent a few minutes to considering the
concept. Honestly I've talked about star trek warps before. But this was
a diffrerent approach (for me). I'm not sure how much of this has been
explored by real physicist, but this is a cigar lounge. He was talking
about compressing space/time, so continuously altering the geometry of
a frame. 

The guys kept looking over, expecting me to jump in. I gave one of
them a smirk. It took a few minutes to come up with a good question that
would have him thinking. It was obvious he lacked education. His cocky
demeanor bugged me though.

I finally asked him "how do 'we' prevent a causal horizon from
inadvertently forming?" He didn't expect to hear that. I got silence
while the look of perplexity replaced his cocky expression.

I followed up "you somehow prevent the formation of a causal horizon, so
how do you propose 100m/s would suffice to escape Earth's gravity? Our
sun's gravity? Let's set aside all reality for a moment and consider
brass tacks. How does 100m/s allow you to traverse light years in mere
hours? I mean, Captain Picard would love to know while he's running from
the Borg." 

The boys knew to change the topic. The conversation went on a natural
progression to sports. yeah, not relevant. But, cigar lounges aren't
really the forum for such topics. I don't think they've seen his return.

Daniel
sysop  | air & wave bbs
finger | [email protected]