MovieChat Forums > Robot & Frank (2012) Discussion > Brute force would not work

Brute force would not work

posted 12 years ago by sth128
52 replies | jump to latest

So the robot says that it takes between 4 seconds and 1 hour 43 minutes to crack a 3-number combination safe. That is complete rubbish. The 4 seconds is likely the estimate for opening the safe on the first try, this means it takes the robot 4 seconds to rotate the dial 3 times. 1 hour 43 minutes equals 6,180 seconds, divided by 4 gives 1,545 trials.

A combination lock dial usually scales between 1 and 100 (search "combination lock dial" on Google and you'll see). 3 number combination means at least 100 x 99 x 99 permutations (I'm assuming you can't have 3 identical numbers). That is 980,100 possible combinations, 634 times more combinations than the trials the robot can perform in the given time.

Ignoring that "little" problem and say the robot does brute force its way through the lock, another problem with spinning the dial so many times in such a short duration is heat generation. If every 3 trials span one single revolution (that is, the equivalent of rotating the dial exactly 360 degrees), that means 326,700 revolutions over the 103 minutes, which is over 3000 RPM. Imagine spinning the lock dial at that speed for over an hour. That thing will be so frigging hot the gears would probably expand and lock the entire assembly.

Even if the safe was using a high school combination lock (ie. 30 numbers), there will still be 25,230 possible permutations, 16 times more than the 1545 trials the robot can perform in the given time.

That robot might be able to cook and garden, but it sure as *beep* can't do basic math.

[–] Eponymous-too 12 years ago

If you want to get realistic about the movie Frank left a bunch of DNA evidence when he was robbing the house. Presumably in the future they will be even better at finding it at robbery sites and matching it to someone, especially if they have a prior criminal record. (The same can be said about the stealing of the book, but Frank goes to the library a lot, so he could argue that's where his DNA came from. He had never officially been in the house he robbed, though.)

In addition, the police show no warrants whatsoever when they enter Frank's home multiple times. (Finding a few soaps does not constitute "probable cause"; all it means is Frank had a few soaps. And the "probable cause" is what they need to get the warrant, not to enter the home illegally.)

Also, the presence of the man who was robbed would not be allowed at Frank's house.

"My name is Paikea Apirana, and I come from a long line of chiefs stretching all the way back to the Whale Rider."

[–] Otkon 12 years ago

Here is the glaring problem with your theory:

The 4 seconds is likely the estimate for opening the safe on the first try, this means it takes the robot 4 seconds to rotate the dial 3 times.

This is a deplorable supposition on your part. It is not a scientifically-verifiable speed restriction of the robot's ergonomic dexterity. It is you arbitrarily making a bone-headed assumption based on the robot's temporal estimation. We do not know how fast the robot can manually spin anything. We do not know the robot's statistical algorithm nor its computational margin of error when calculating the chronological range of a job completion. The robot can not spin the dial at a constant speed because of the bidirectionality of motion involved.

So unless you have some time trial averages on this particular automaton doing this particular task, then you are simply bloviating for your own edification.

Also, you are postulating your "heat" theory on known mechanical design. This film is set in the (near) future - one with obvious technological advances beyond current application. The safe dial innards could be a hitherto unpatented component with a frictionless internal construction. Again, if you don't have any peer-reviewable data to back up your statements, your only evidence is your limited understanding of high school mathematics.

P.S. The movie is also fiction and not the real world - you know that stuff presently outside the one little window in your mom's basement.

[–] shanayneigh 12 years ago

Game, set, and match.

Working in the movie business since -92

[–] MovieVVhore 12 years ago

What s/he said. This thread is hilarious!

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[–] joshuayeary 12 years ago

I didn't do the math, but I could tell the moment he said how long it would take him that it couldn't be correct. But don't let people here get you all riled up, that's the nature of the message board; somebody is going to call you stupid no matter how legitimate your post is. And the reason it didn't take him forever to open the safe isn't the same reason that a moon can be square in a movie, because he almost assuredly would have opened it in real life in less time than the maximum time figured (not figuring in your very-plausible gear melting theory), unless the odds were heavily stacked against him, and the correct combination was the very last one he tried.

But all said and done, you are absolutely correct, and it seems like that would have been caught early on in the script writing process.

[–] Otkon 12 years ago

He is not absolutely correct. This is a work of fiction with a futuristic setting whose unknown technology he is criticizing with contemporary conventions based on seriously flawed suppositions.

Science fantasy - no matter how slight - needn't conform to modern science fact.

[–] omoxus 12 years ago

Here's what I want to know. How come no one has mentioned Robot's "disguise"? That black cape was hilarious and cute.

Im the Alpha and the Omoxus. The Omoxus and the Omega

[–] chicago85 12 years ago

The cape was a sweater draped over him but looked like a cape. I think they were trying to cover up all that whiteness so he wouldn't be so visible at night time.

It was funny.

[–] sagat4 12 years ago

Learn to loosen up a little as this is only fiction i.e. not meant to be real. If you take things too seriously you might end up been single forever!

My Voting history is secret;)

[–] brucegxbg 12 years ago

the calculation is ridiculous and retarded cuz normal people dont post a thread like this

[–] JrnlofEddieDeezenStudies 12 years ago

Now try telling us what your post has to do with the film.

http://www.rateyourmusic.com/~JrnlofEddieDeezenStudies

[–] android_movie 12 years ago

Interesting point.

My friend was a locksmith. I remember he told me once that not all combinations were possible, depending on the type of lock. Only certain combinations were possible. For example, you wouldn't be able to have a combination that's like X - X - Y and there are other ranges....

Show me the holes!