There are any number of clichéd plot points that we’ve seen over and over in movies and TV episodes. Maybe it’s the person who gets shot, sits up, and always rips open their shirt to show the viewer that they have a bullet-proof vest on – who does that in real life? Maybe it’s the criminal who takes One Last Job or the cop who is One Week from Retirement – either way we know it’s not going to turn out well. Maybe it’s the random object or person that shows up early on for no reason and then plays a critical role during the climax.
While all of these have been done to death, they are not wrong. (Note: by “wrong” I mean factually, not morally or ethically.) Bulletproof vests do stop some kinds of bullets. Sometimes big cases do come up just as a cop is going to retire. No, what I mean are plot points that have appeared tons of times, but every time they do they are flat out wrong, and it requires them to be wrong for the plot point to work.
I will count these down to the most common, most incorrect plot point. Here they are:
3. The prosecution is stuck because the only person who has the knowledge to get a criminal sent to prison is his wife and she can’t testify against him.
Many a gangster movie has the bad guy marrying the woman who knew he was bad because that then meant that the good guys could never get her testimony of what she knew. Or sometimes the wife doesn’t know her husband is a criminal until after the marriage, but even though she is horrified by what she learns, she can’t do anything to stop him because as his wife she can’t testify against him. Right?
What the law actually says is that a wife cannot be forced to testify against her husband (or a husband against his wife.) If she wants to testify, though, she is perfectly able to do so. There is nothing stopping her from going to the cops and being a witness against her husband at a trial.
This is only number three because it is not used as commonly now as it once was. This is probably because divorce is much easier to get, so writers figure if the wife was horrified by what her husband was doing she would just divorce him and then she could testify.
2. When you time travel, you arrive in the past (or future) at the exact same spot you were in the present.
Let’s just stipulate for the sake of this point that time travel and all its paradoxes are not problems and then let’s go forward from there. When a person time travels they are only moving through the dimension of Time, not any of the three dimensions they would normally move in. This means that they would end up exactly in the same house, on the same hillside, etc. as they were when they left the present. Right?
The concept that you would not move in any of the three dimensions is correct, but the concept that you would then end up in the same house, etc. is wrong. The problem is that the Earth is not stationary. It is both spinning on its axis and orbiting around the sun. And if you want to get geeky, the sun is in an arm of the Milky Way galaxy that is rotating, and the Milky Way galaxy is itself receding from the center of the universe.
What that means is that as you are reading this sentence you are simultaneously moving very swiftly in four different directions – five if you are reading this is a moving vehicle. (And if you are reading this in a moving vehicle I hope the hell you are not the one driving. If you are driving, pull over. The life you save may be mine.)
So if I were to travel back in time one month I would end up exactly where that point in the universe was one month ago. I would have a real big problem, though, because the Earth wouldn’t be there when I arrived. I’d be in the middle of space and I would die in a matter of seconds from explosive decompression.
So, if anyone wants to build a working time machine it’s also going to have to simultaneously be able to transport the traveler through the standard three dimensions to any point in the universe, otherwise, well, bye-bye.
1. When someone needs a life-saving blood transfusion they always have the rarest blood type there is.
I’ve seen this one so often it has to have been a cliché almost from the time blood transfusions were first shown in moving pictures. You know the drill: Important Person gets injured. They are losing blood. They need a transfusion almost immediately or they will die. The person who will do the transfusion cries out, “Oh no! Important Person has the blood type [say it all together folks] AB Negative! That’s the rarest blood type there is! Whatever will we do?” Then Random Person who has been in the movie or TV episode will raise their hand and say, “I have AB negative blood.” Cue rising score as we know Important Person will live to see another day.
Here’s the problem: if a person needing a transfusion has AB negative blood that is almost the best possible news. That means they can get a transfusion from most anyone. The reaction should be “Yes! They have AB negative blood!”
The four blood types – A, B, AB, and O – have different properties in regards to who can donate to whom and who can receive from whom. Type O is the most common and it is known as the “universal donor” type because anyone can receive Type O blood regardless of their own blood type. Type O can only receive Type O blood, however. Types A and B can accept both Type O as well as their own blood type.
is the least common blood type, but it
is known as the “universal recipient” since they can receive O, A, B, and AB blood. (Technically, AB positive is the universal recipient, but AB negative can receive
blood from any other blood type as long as the Rh factor is also negative. O negative
is the universal donor because anyone with a positive Rh factor can receive
blood regardless of whether the Rh of the donor is positive or negative, while
anyone with a negative can only receive negative.) Type AB
So those are the plot points I felt had been done to death and pretty much every time they appeared they perpetuated the wrongness that started who knows when. Do you have some others I didn’t mention?