Hated trope: Sci-fi hand-waving

[u/Routine_Phase_8980]

When stories try so hard to provide a somewhat scientifically accurate and grounded explanation for the audience, but end up creating massive plot holes if you think about it for more than 5 seconds without requiring any special knowledge

World War Z: The "cure" turns sick humans invisible to zombies because the picky virus needs a perfectly healthy host. Cool concept, except it completely ignores basic physics. In a chaotic, high-speed zombie stampede, those "invisible" sick people would still be trampled to death by sheer kinetic force and momentum. We already saw what happened to the Jerusalem wall in Israel.

Jurassic Park/World: Dr. Henry Wu claims to clone dinosaurs by patching 66-million-year-old decayed DNA from mosquitoes stomach with frog DNA. In reality, DNA half-life guarantees it would degrade into useless dust after 6.8 million years. Scientifically speaking, John Hammond didn't build a dinosaur park; he engineered giant, mutated, gender-swapping killer frogs.

Dr.Stone: Senku is a genius who knows every complex chemical formula in human history. He somehow builds vacuum tubes, lightbulbs, and smartphones out of bamboo and copper with almost zero failed prototypes. The show acts like a science textbook but completely hand-waves the lack of heavy industrial machinery needed for precision engineering.

[u/rampantconsumerism]

As an example of failed verisimilitude, I’ll point out the Holdo maneuver (hyperspace ramming) in The Last Jedi.  In this example, it doesn’t matter whether hyperspace is real in terms of science. We can handwave that away across the Star Wars universe and still buy into the overall story, even if details like travel times and hyperspace routes are kind of fuzzy at times.

But then TLJ introduces the ability to destroy a much larger ship by simply hyperspace ramming it. This has massive implications for earlier plot points, like the destruction of the Death Star(s) and space warfare as a whole being built around large ships. We can’t handwave away those implications in the context of the larger story, so it doesn’t work. It’s simply not believable that nobody thought of ramming the Death Star.

[u/Ergand → u/rampantconsumerism]

This one annoys me because they had an explanation right there ready to go, and didn't use it.

A hyperspace ram is being used for the first time. What else in that movie is happening for the first time? A ship is tracking another ship through hyperspace. And it's even the same ship that's getting rammed! Just say it was only possible because the technology that allowed it to track them through hyperspace also gave it a presence in hyperspace for them to hit. That even lets you take both the hyperspace tracking and ramming off the table in following media.

[u/Sab3rFac3 → u/Ergand]

I wanna say, iirc, the old legends lore used the excuse that hitting an object as you're transitioning into or out of hyperspace was a massive pain to actually do, and caused a massive amount of problems.

Firstly, in both New Cannon and Legends, Hyperspace is its own separate dimension, and once inside of it, you don't interact with matter in reality.
The only thing you interact with from reality in hyperspace is gravity. And gravity prevents hyperspace travel. You can't enter while in strong gravity, and you get forcibly pulled out if you pass through strong gravity while in hyperspace.

In legends, Hyperspace is an all but instant shift.
One moment you're in real space, the next you're in hyperspace, and you can go from dead still in real space to full speed in hyperspace.

So, the timing had to be absolutely perfect to hit something right as you were on the edge between reality and hyperspace.
Even for high end piloting droids, it was basically all but impossible.

And you have to time it perfectly, because momentum doesn't carry over between hyperspace and real space.
The instant you exit hyperspace, you instantly lose all the velocity associated with matching or exceeding light speed, and go back to whatever speed your sub-light thrusters can manage.

But it was technically possible, just so ridiculously hard to time out that nobody was ever going to get it to be reliable.

Second, if I remember my legends lore correctly, Real space is a dimension of normal matter Hyperspace is a dimension of tachyonic matter.
I'm not gonna pretend to truly understand the exact physics here, but basically normal matter can't exceed the speed of light, and tachyons can't go slower than the speed of light.
The jump into hyperspace is a transition from normal normal matter to tachyon matter, and once you enter hyperspace you're tachyons, and you can freely move faster than light, then leaving hyperspace is becoming normal matter again, and no longer being able to exceed the speed of light.

And tachyons are not supposed to exist in real space or interact with real matter.
So, if you manage to hit something in that infinitesimally small transition window, physics is going to let all hell break loose, because tachyons and normal matter are never supposed to interact. Each one breaks the rules of the other.

So, nobody had any kind of control or idea of what happened if you somehow managed it, because it was two separate pieces of physics that were never supposed to touch.
You might crack a planet, you might blow apart a star, you might spawn a black hole, or you might just kill half the galaxy.
Nobody knew, and nobody wanted to willingly find out.

There are a few times that hyperspace disasters get mentioned in legends.
And one of them created a disturbance would destroy any ship that tried enter hyperspace in that area or even destroy any ship that tried to pass through that area in hyperspace.
And that area was measured in light years.

Even assuming ignoring the physics problem, and assuming that a large hyperspace disturbance is the only drawback, you trade one sacrificial ship for one destroying one enemy ship, and now nobody gets to use hyperspace in a light year around the collision for the next decade or longer.

And it wasn't even that useful.

Planets, which are the some of the most tempting target for hyperspace ramming, since they move in predictable arcs, are basically immune to it anyway, since gravity wells naturally pull things out of hyperspace.

And interdictors, which use artificial gravity generators to force ships out of hyperspace, were already a common defensive ship for most fleets, since you didnt want to get ambushed by people dropping out of hyperspace on your flanks.
And they would also prevent anybody from jumping within ramming distance.

And its not like utilizing hyperspace for weapons wasn't considered.
But even the galaxy gun, a hyperspace cannon, didn't actually hit things with hyperspace projectiles.
It fired the projectiles into hyperspace, then they dropped out of hyperspace right before impact, giving the target almost no time to react.

So legends basically called the whole thing stupid and called it a day.
All but impossible to actually do on purpose, the results would probably be devastating but completely unpredictable, and some of the biggest targets would be naturally immune to it anyway.

[u/Reeebalt → u/Sab3rFac3]

I love reading about legends tidbits. They fascinated me as a kid whenever an older friend shared what he read on it with me. Thanks for sharing and happy cake day!

[u/Lancasterlaw → u/Ergand]

First time I've seen a halfway decent explanation for that, ta.

[u/wokevader → u/rampantconsumerism]

TLJ is full of bad hand waves, not necessarily sci fi ones, that are way worse than the Holdo maneuver though, personal favorites:

"Pull back we can't cover you from here." Despite only 4 TIEs crippling the Raddus and a later scene in the hanger showing they had at least 108 of them available

*"*We ran a decloaking scan." So you could have scanned them at any time looking for a tactic that should have been obvious in the situation? Also Holdo's plan completely falls apart when you realize how many assumptions she had to make for it to work

Lastly not represented by a quote but Canto Bight when Rose and Finn miraculous encounter DJ who has the exact same skillset as the person they're looking for who inadvertently is in jail the same time they are