I will have to apologize to Star Wars fans reading this.
Well, there are things I’ve really been aching to disprove watching the films. It’s also very itchy – my brain.
Star Wars is a great film: exhilarating, exciting, #Nerdgasmic, and all things wonderful. There’s a reason this is one of the most – if not THE most – successful film franchise in history.
But sadly, Hollywood has not been so precise when it comes to the real thing.
I have seen a few of these scenes getting busted on Myth Busters and most of these are found in the internet.
I looked for them but the explanations were just a taps on the surface. So, I researched further to explain why these don’t work in real life.
THIS IS QUITE A LONG READ. You’ve been warned.
BB8’s Skid-less Ride
There’s what we call skidding and in physics it’s the term used when a moving object deviates from its path due to loss in traction by friction. It’s something that BB8 should be good at as it is a smooth surfaced spherical droid but you know Hollywood.
Traction or tractive force is a type of force created by the motion between an object and a tangential surface by which it acts upon. It what keeps cars not skid when the ground is wet – thanks to rubber and cement working together. Hooray for friction!
On high friction solid ground, spherical objects will move if the mechanism inside has an opposite reactive force outside the sphere – following Newton’s Laws of Motion. In this case, it will move in a uniform line if all the forces’ vectors acts on a single direction (this is due to the texture of the ground, as well).
Think of it this way: when maneuvering your shopping cart on tiles versus very rough cement, it would be easier to control the cart’s direction when on cement than on the gleamed tiles. But this is just an analogy to explain how frictional force works.
So, assuming BB8 is a smooth metal sphere on flat sand (like that in the movie) and it follows the mechanics of holonomic motion and Sphero technology, it wouls not move at all. It would move, however, if the terrain was inclined downward but it would swerve relentlessly. When it reaches the bottom, it would have a hard time moving.
Here’s why: there are wheels inside the sphere that creates traction but only on the inside.
When it’s gravity’s turn to shift the potential energy inside to roll the ball (this includes very hard physics lexicon to explain but just imagine a man on rollerskates midway through an arc),
the frictional force between the sand and the ball is almost zero (again, to explain in layman’s term: just imagine that Gigantic Plastic Ball Rider in a lake where you try to move it forward but it doesn’t) so it will just spin in-place or it wouldn’t move at all.
I can write a whole post about why smooth surfaced BB8 can’t exactly move effectively on sand, but other scenes await.
Unscathed James Bond – BOOM!
We’ve seen this in many Hollywood films: actor casually walks away from an explosion behind him, unscathed.
Then, Hollywood came and said f*ck Thermodynamics and Gas Laws. Pfft!
We can’t help but be amazed with this scene as it portrays the resilience, strength, and awesomeness of the protagonist. Also, his very action movie appropriate outfit that makes girls scream out their pheromones.
Well, if we take Thermodynamics back into account, convection plays a very big part in energy transfer when something explodes.
Let’s take into account the amount of explosive energy from the sleeping whatever-stuff-that-explodes have.
In thermodynamics, heat requires a medium to transfer energy and this is through mostly infrared – the stuff that you feel from flames is your cells interacting with high-energy infrared and a few others from the spectrum.
Now if if an unlit candle contains 100KJ, it would emit the same or more energy if lit from start to finish. The temperature of the flame would not create too much heat as it “eat” its way down. This is not as catastrophic as the explosion since the it’s slowly releasing the energy.
But what happens when all the material’s potential energy of anything larger than a candlestick is suddenly transformed into kinetic energy almost instantly? Scorching temperatures reaching hundreds of degrees that would travel through the air by infrared and expanding shockwaves of air reaching speeds more than the speed of sound.
If it were a C4, and the actor is casually walking a few meters away from it as it explodes, it will roast him alive.
Bright Space Lasers
If you’ve been to a Laser Tag Game Facility, you will understand why Hollywood films with laser bullets fall into fallacy.
In order for light to be identified by our eyes, it needs to interact with matter, that’s why high powered lasers glow even in air. For the case of powerpoint laser pointers, you only see a dot on the screen since the low powered beam can only produce secondary electron emission on solid objects.
In order for EM Waves or ‘light’ to be seen by the eyes, it needs to interact with matter, specifically with the electrons. Excited electrons absorb the laser’s energy; jumps to a higher state (quantum state) but electrons also follow certain physical rules: it cannot stay in a higher quantum state since the entire system (the atom) needs to be stable. So, in order to achieve stability, it releases the absorbed energy and re-emits light at a certain wavelength (thus variance in colors).
Following me yet? HAHA!
In Sci-Fi movies by Hollywood, the laser beams would emit light while battle spaceships destroy one another. Which is wrong even if it was ultra super high powered because it would pass “empty” space.
It would only glow the moment it touches any matter. For this specific matter, that would be the spaceship it just destroyed.
Well, this was a tough article to make.
Anyway, I do not intend to bad mouth the movies (which were all entertaining) but when it comes to the natural side of things, Hollywood can be manipulative. But all is for entertainment, and it would be very boring if laser bullets/beams were invisible. If I had a laser gun, it would emit white beams because why not?