Aurora 4x

Aurora => Aurora Chat => Topic started by: vorpal+5 on November 25, 2017, 01:21:26 AM

Title: [Science Question] Speed limit reasoning in a series of books
Post by: vorpal+5 on November 25, 2017, 01:21:26 AM
Hey,

In the rather nice series of books from Joshua Dazelle, 'Expansion Wars', there is several time a kind of justification that I don't get. Here it is.

Ships have a maximum speed they can reach, much much below the speed of light (so I'm not talking about the increase in mass by nearing C), past which the thrust of the engines is compensated by ... I don't know what! friction, gravity?

That said, the author seems rather knowledgeable of many physical processes, so I don't get why. If I'm not mistaken, if you apply constant acceleration to a starship/rocket/shuttle you can reach ultimately a speed very close to C. Even at 99% the speed of light, the increase of mass is relatively low.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: TheDeadlyShoe on November 25, 2017, 03:34:03 AM
most books that have magical widgets that let their spaceships do cool stuff do put limits on their magical widgets to keep things sane
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: 83athom on December 04, 2017, 07:22:36 AM
I also have read those books (and the ones from the series before it), and the speed limit is somewhat justified. The speed "limit" is a per-system basis because of the various gravitational bodies effecting lines of travel coupled with the fact that with Newtonian physics any additional force one direction needs to be compensated with force in the other direction to slow down (meaning that they would hit their destination to fast or need a longer time to slow down).
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: Barkhorn on December 04, 2017, 06:37:45 PM
Space isn't totally empty.  There's approximately 1-3 hydrogen atoms per cubic meter.  At relativistic speeds, this is non-negligible, so the ship will experience drag much like an aircraft.

Plus, any microscopic dust particle you hit will hit about as hard as an artillery shell.

This isn't the excuse for speed limits Aurora uses.  Aurora's excuse is some extra-dimensional handwavey nonsense that's just meant to make space ships move like oceangoing ships.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: TheDeadlyShoe on December 04, 2017, 07:21:59 PM
Aurora is explicitly 'trans newtonian'. Inertia canceling. Normal drag doesn't apply to it.

Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: vorpal+5 on December 05, 2017, 09:41:06 AM
Space isn't totally empty.  There's approximately 1-3 hydrogen atoms per cubic meter.  At relativistic speeds, this is non-negligible, so the ship will experience drag much like an aircraft.

Plus, any microscopic dust particle you hit will hit about as hard as an artillery shell.

This isn't the excuse for speed limits Aurora uses.  Aurora's excuse is some extra-dimensional handwavey nonsense that's just meant to make space ships move like oceangoing ships.

Seems logical (the part about Joshua Dazelle books), thanks.

By the way, I know of very few military science fiction books that bother take into account the "any microscopic dust particle you hit will hit about as hard as an artillery shell" part, and this is indeed a huge problem...
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: MarcAFK on December 06, 2017, 06:08:53 AM
Star trek handwaves it by saying (deflector emitters). Though the ships do suppsoedly have bussard ramscoops which would collect that hydrogen as fuel .... How you could possibly get more energy burning those atoms in a fusion reactor than it would take to give them the same velocity as the ship and prevent any kind of damage is beyond my knowledge.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: Hazard on December 06, 2017, 07:20:21 AM
Star trek handwaves it by saying (deflector emitters). Though the ships do suppsoedly have bussard ramscoops which would collect that hydrogen as fuel .... How you could possibly get more energy burning those atoms in a fusion reactor than it would take to give them the same velocity as the ship and prevent any kind of damage is beyond my knowledge.

Dilithium.

Seriously, dilitihium in high energy plasma works as a subspace energy siphon in Star Trek, which lets them effectively gain a lot more energy than what their power systems would normally generate to operate their FTL system.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: TheDeadlyShoe on December 06, 2017, 10:38:50 AM
all this mis use of handwave irritates me1

the deflector in star trek is not handwavium; it's directly addressing the problem!
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: MarcAFK on December 07, 2017, 08:06:42 AM
That's still handwaved though. It Emits deflectors? Wtf is a deflector and how do you emit them?
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: Hazard on December 07, 2017, 08:23:21 AM
It doesn't emit deflectors.

It emits a powerful and deliberately poorly defined forcefield that protects the ship while traveling from stuff happening in space that's not massive impacts and weapons fire by deflecting them away from the ship.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: MarcAFK on December 08, 2017, 06:04:29 AM
Totally sensible. No Handwaving there at all.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: TheDeadlyShoe on December 08, 2017, 10:51:00 AM
'handwaving' is essentially saying eh, dont worry about it.  The way shields work in star trek is handwaved.  Interstellar debris impacts are not; the problem is specifically addressed.  The ships even have Bussard collectors for free hydrogen. 

Similarly, Aurora does not handwave it, because it relies on inertia canceling which implicitly solves the problem.

I honestly cant remember what the expansion wars books say about it, though i have read them...
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: Barkhorn on December 08, 2017, 11:55:02 AM
I think what people are getting at though, is that their explanation is just kicking the can.    It's like you're saying "Oh they don't handwave that problem away, they use handwavium."
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: TheDeadlyShoe on December 09, 2017, 03:19:31 AM
I think that doing that is pushing the term to stretch it far beyond what is useful, though.

Sorry I came off as aggressive in this thread; I had just come off an argument about hard vs soft scifi and the definitions thereof, so i am/was sensitive to relatively minor distinctions, and brought that into my posting :(

Handwaving is a pejorative term and it implies that an explanation is being slapdash, inconsistent, or possibly just nonexistent.  I think its sufficient to establish generally consistent rules and that ships and technology in a setting are generally capable of X but not Y., especially in the television or movie formats; info-dump space is strictly limited both as a practical and acting-practices matter.

Like, what if you turn it around? What would *not* qualify as handwavium for a science fiction setting under a wide standard?  If everything is handwavium, than the term is useless, because it's not actually making any useful distinctions between things.





Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: Barkhorn on December 09, 2017, 12:31:43 PM
I don't think there is any sci-fi, no matter how hard, that can completely avoid handwaving anything.  Take the book/TV show The Expanse.  That work is mostly really great about getting the physics of space travel right.  But even they have a magic engine that gets ludicrous delta-V, and they don't even try to explain how it works.  When you get right down to it, we handwave things in real life even.  Nobody knows why bicycles are so stable, but that doesn't stop us from using them.

I think things which are both vital to the plot, but get no explanation are handwavium.  How people walk around inside ships in Star Wars is handwaved.  Why there is sound in space in Star Wars is not.  For something to be handwavium, to me, it needs to be both important AND unexplained, not just unexplained.
Title: Re: [Science Question] Speed limit reasoning in a series of books
Post by: Tor Cha on March 21, 2018, 10:18:34 PM
People Many years ago I read the Star Trek tech Book in there it stated that the Main Deflector Emitted two fields One a Cone with the Point of the cone away from the ship, and the base of the cone was the size of the ship ( roughly ), the field was weak at the point, somewhat stronger the closer it got to the base of the cone ( the weak force moving Micro to small Mass objects out of the way of the ship. Other objects would be seen and Maneuvered around . The second part was a field that acted like a close in shield, With many secondary Emitters all over the ship. Now it was over 20+ years ago so i may have Miss stated it. and sadly i no longer have it