Ask Hentzau: Scrat Continental Crack Up.


Yes, I have a name asks

How scientifically accurate is this? [link to the above video]

Well, Yes, I have now subjected the video to my merciless Science Sight several times, and I think it’s best to break it down stage-by-stage.

Scrat is attempting to plant his nut in an icy landscape of some kind. He very, very gingerly places it down…

…and the entire mountain splits open beneath him in two neat halves. This might be possible if the mountain had no faults in its structure whatsoever aside from a really big one down the middle, but I don’t know why it suddenly stops mid-split the way it does. Perhaps it is on hinges?

The more pressing concern is how Scrat managed to do this by tapping it with a nut. Clearly the nut must be made of something incredibly dense to transfer that amount of kinetic energy to the mountain, and so Scrat must be commensurately strong.

Scrat begins falling towards the centre of the Earth. He attempts to break his fall by bracing his hands against the sides of the tunnel he’s falling down, but his hands quickly start to glow red hot and he is forced to snatch them away before they catch on fire. From this we can conclude that Scrat has a skin that is both very, very tough – it has to be for his little arms not to be worn down to nubs way before they get to the red hot point – and which has a very high specific heat capacity.

Scrat then turns into a whooshing fireball similar to a spacecraft making a re-entry maneuver. If you’re a skydiver, this doesn’t happen to you because the atmosphere through which you are falling is thick enough that it creates a significant amount of drag. Eventually the drag force upwards will equal the force of gravity pulling you downwards, and you reach a steady terminal velocity.

Now, if you’re a spacecraft you’re messing around in parts of the atmosphere which are very thin. This permits much higher velocities to be obtained (indeed, they are required for spacecraft to stay in orbit) on the order of several kilometres per second, but since the spacecraft is moving so fast it’s still striking a lot of atmospheric gas molecules very, very quickly. This heats it up, creating the characteristic re-entry fireball. It’s why all spacecraft have at least one side which is covered with a heat-resistant shield: to prevent the spacecraft from burning up on re-entry.

Scrat doesn’t have a heat shield, but that’s okay because we’ve already established that he has a tough, heat-resistant skin that amounts to much the same thing. More interesting is the fact that while he must be falling through some sort of gas in order to create the fireball, the concentration of that gas must be very, very low to allow him to reach fireball velocity. Therefore Scrat does not need to breathe. If he did, he’d be dead.

The action switches to an internal schematic of the Earth showing Scrat’s descent through the various layers – crust, mantle and core. This is actually mostly genuinely accurate, although I really don’t know what the animators were smoking when they say the inner core is often drawn in textbooks to resemble a giant floating pinball. I’ve certainly never seen one that drew it like that.

Scrat then lands on the inner core of the Earth, which is… uh, floating in space like a giant pinball. I don’t really have a problem with the floating because if it’s dead centre it’s going to be evenly surrounded by the rest of the Earth’s mass pulling in all directions, which could conceivably cause it to float. The problem here is that the inner core is a) not hot, b) not rotating and c) very small, only being a few dozen times the size of Scrat. The camera zooms out into space, showing the Earth as it was “a really, really long time ago” with the land mass all clustered together into one supercontinent, Pangaea. Awesomely it really does resemble our closest estimate of what Pangaea looked like, so a point to the film makers there.

Scrat picks himself up and returns to his immediate objective of retrieving his acorn. But, disaster! As he moves towards it, the Earth’s core begins to rotate underneath him! Scrat must be very strong in order to pick up and carry his super-heavy acorn, but this is the first indication we’ve been given that Scrat himself is dense/heavy enough to be able to physically move the core of the Earth.

As Scrat runs on the core, bad things start happening up above. The Pangaean continent begins to split and separate, with his increasingly desperate efforts creating the present-day continents one after another. This, sadly, is the most scientifically implausible part of the whole film, since I really don’t see any way running on the core could even begin to affect the land masses floating around on the mantle like this. Giraffes are created when the land they’re grazing on splits and separates underneath them forcing their necks to stretch to compensate, which is actually a fairly neat shorthand for what actually happened.

There’s some hijinks with Scrat creating various landmarks and monuments in his image that I’m not going to go into because I’m not an architect, but finally Scrat loses his footing and gets bounced around the core before ending up wrapped around it like spaghetti. This is important, because we now know that Scrat is made of something that is incredibly ductile and elastic which suffers almost no plastic deformation. He then unwinds from the core and is flung back up through the hole he fell through all the way out into space – but since Scrat has a very tough skin and does not need to breathe, vacuum is no problem for him.

The film ends with Scrat landing on top of a piece of ice floating on the ocean which – incredibly – is not pulverised instantly beneath his vast weight, but instead merely fractures in two, separating Scrat from his beloved acorn. We’ve learned many, many important things about Scrat from our three minutes in his company, and I’ll sum them up here.

  • Scrat is inhumanly strong.
  • Scrat is made of something very tough.
  • Scrat is made of something that resists heat very well.
  • Scrat is made of something incredibly dense.
  • Scrat does not need to breathe.
  • Scrat can stretch and deform at will and still resume his original shape.

Normally I’d say that there’s no one material that can fulfil all of these criteria and dismiss the whole thing as scientifically inaccurate, but if you think hard enough it turns out there is something that can do the job. If Scrat is composed of mimetic polyalloy he could alter his internal composition at will so that he possessed all of these qualities. What I am saying here is that, yes, Scrat is the T-1000.

Don’t fuck with him.

PS — This was fun, but don’t expect me to deconstruct a cartoon every week.

Tagged , , , ,

6 thoughts on “Ask Hentzau: Scrat Continental Crack Up.

  1. Smurf says:

    This was everything I hoped for and more! :D

  2. Masked Dave says:

    Haha, awesome.

  3. innokenti says:

    I love Scrat.

    I also love your treatment of Scrat.

  4. Goosaba says:

    Randomly came across your post today. I sent it out to everyone at Blue Sky. Nice work. But now that the secret of Scrat’s identity is out……. he’s coming for you. Get your liquid nitrogen ready. And good luck.

Leave a Reply to innokenti Cancel reply