Last weekend I saw the movie: Seeking a Friend for the End of the World here’s my review sort of (spoilers to follow):
Forgetting everything else and jumping ahead to roughly where the movie turns from hilarious to depressing: Keira Knightley or “Penny” decides to see an ex-boyfriend, “Spec” who happens to have a well-equipped bunker and some tiny cars. Besides the obvious question about the wisdom of owning a “fleet” of tiny cars for the apocalypse with minimal off-road capabilities, he makes the claim that his bunker is lined with 12 inches of titanium.
Titanium is of course an incredible metal having a very good strength-to-weight ratio. The only problem with it is that is is very hard to work with and expensive. Generally it is used for things that need to be light but strong such as high-end bicycle or airplane parts. It is also quite expensive at around $10/pound not factoring in the expense of working with such an exotic metal.
So to be conservative, let’s assume that the bunker was 20 feet x 10 feet wide x 8 feet high on the inside (probably bigger). This would give 2 walls of 20 x 8, 2 walls of 20 x 12, and 2 walls of 12 x 10. Note that the dimensions factor in 12 inch thickness for the walls. Given this, the walls had a square footage of 1040 square feet. Each wall was 1 foot thick, which gives it a volume of 1040 cubic feet or 1,797,120 cubic inches of titanium wall space.
Multiplied by titanium’s density of .16 lb/in^3 and you have 287,539 pounds of titanium surrounding them. Quite impressive, but at around $10 per pound for this extoic metal you’ve got a structure that will cost you $2,875,000 dollars in unprocessed raw materials.
And that’s just for the unformed metal, add in the cost of forming and installing it, their massive gun collection, supplies, internal sewer system, and the fleet of nearly useless (on destroyed roads) tiny cars, and you’re talking about conservatively $4 million invested. The bunker really looked bigger than the space I listed, so let’s say they had $5 million dollars invested. Pretty impressive for a few guys in a fairly middle-class neighbourhood.
In my opinion “Spec” and his friends should have chosen a less expensive material like steel at around $.25/pound or 1/40th the price of building his bunker out of Ti. Simply using more dirt/cement would have been another good solution, even if it wouldn’t have sounded nearly as cool to Dodge or non-engineer audiences. Sure, those types of fortifications didn’t work for the French, but they wouldn’t have had to deal with the same threats as 1940s era European powers.
On another maybe more glaring note, I’m pretty sure his dad’s tiny prop-driven plane wouldn’t have made the nearly 3500 mile trip to England (A piper Meridian’s range, for example is about 1200 miles with a 45 minute reserve). Finally, the asteroid will arrive a week early? You’d think astronomers who calculated this based on the exact position in time of Earth’s orbit wouldn’t make that mistake since earth would be elsewhere…
Well anyway, I hope Spec and his friends survived. Actually, I don’t care. As for how the movie was itself, it went from quite funny at the beginning to very sad at the end. After all, it is indeed the end of the world. Overall I enjoyed it, but it wasn’t the best Steve Carell movie I’ve ever seen. If you’ve recently started dating someone and decide to take your significant other to this movie, just remember to keep your tech comments to yourself. Probably best to wait until at least a few months in until you reveal just how annoying Engineers can be to watch a movie with.