Hollywood has no time for science! It's too slow/too fast, too dangerous/too benign, and mostly too complicated to be bothered with on the big screen. Disaster movies are the worst offenders of them all.If you have your fave bad-science moments in any disaster film at all, add it! I want more! MORE!
A Tsunami Can Come Towards a Disrupting Fault
Look out! Here comes a tsunami! A gajillion feet high and all frothy and cresty and majestic as it sweeps towards the Golden Gate bridge in San Andreas!
Hold the phones. Two things. One, the earthquake was on the San Andreas fault -- since that's kind of the whole point and name of the movie. This particular fault is a slip strike fault. It cannot cause the uplift or down-drop required to cause a tsunami even if the fault was out past the coast (and indeed, the San Andreas DOES run out past land by the Golden Gate bridge - but it still couldn't cause that massive wave).Two, No way come "hell or high water" (haha) can a tsunami be that ginormous right off the continental shelf. It could only be as high as the bay is deep. AND, it wouldn't be in some showy surfer wave... it would be a giant increase in the water level --- imagine a monstrous swelling, not something you can imagine the Point Break dudes surfing. Plus, there would be a large displacement of the water in the bay, sucking it all out towards the incoming, rising swell.
Suspension Bridges Ignore Physics
Ha ha... sorry, this is a total science-nerd one. But seriously.
Look at the image here. See the tower on the bridge after the magic microwaves "break through" the Earth's magnetic field (pssst...microwaves can already pass through the magnetic field)? The middle of the Golden Gate Bridge is destroyed and the suspension towers, for some reason, are bending inwards as if the cables in the middle were pushing the two towers apart.Fun game for at home: get a rope and two friends. Each of you stand on either side of the rope and pull like you are playing tug-of-war. This is how a suspension bridge works. Now, get another friend to cut the middle of the rope. Do you fall forward when that happens? Or backward?
Ha ha, you fell down.
You Can Miss An Approaching Asteroid the Size of Texas
Ceres is a real asteroid... well, I guess it's technically a dwarf planetoid. It's also the largest asteroid in our asteroid belt. It's big enough that you can actually see it with your naked eye if you know where to look and there's not too much ambient light where you're standing. Ceres is 900km across and this new, never-before-seen asteroid in Armageddon is supposedly the size of Texas. That's 1600km. in case you don't carry that kind of info around with you.
So. The movie says that it's about 18 days away, which puts it closer to Earth than Ceres is in real life. It's both closer and bigger than the asteroid we can already see without a telescope. The math says that it would be 3-4,000 times brighter than Ceres. The MOVIE, on the other hand, says that only 15 telescopes in the world could have spotted something that anyone who wasn't completely blind and not wearing a neck brace could have seen for themselves.Right there. Up in the sky. Any time someone looked up.
You Can Survive the Blast of a SuperVolcano
Now, let's sit back together, steeple our fingers thoughtfully and remember how John Cusack stood there with his kid and watched as the Caldera in 2012 blew. Not only did the force of the blast not completely liquify the pair of them, but they weren't even deafened. Or blinded.
Fun fact: RVs can outrun the blast radius of an Extinction Level Event like this. I bet your grandpa feels much more justified in his retirement purchase now.