Science of Godzilla: Armored Hide and Regeneration

I've decided to start a series of threads that each one will look at aspects of the Gojira/Godzilla design to see how would it be like realistically, and how to actually make it plausible.

In this first topic, it's the tough armored hide and/or regeneration that Gojiras will typically have to withstand human weaponry. Let's look at that first bit, the tough hide.

In the 2014 Godzilla film, for example, Godzilla was shown to survive an Atomic Bomb without much damage, if any... and he was practically right next to that bomb when it went off! Well, browsing around online I found http://glasstone.blogspot.com/2006/04/ten-largest-nuclear-tests.html website that has a lot of declassified nuclear testings during the 50s. What caught my eye was this bit near the bottom...

"In the 15.2 Kiloton REDWING-INCA nuclear test on June 26, 1956, 30 cm diameter carbon-coated steel balls were placed 9 meters from the bomb by researcher Lew Allen, and were undamaged with only a loss of 0.1 mm of surface graphite."

Okay, so a 15.2 Kiloton Nuclear Bomb couldn't really hurt this 11.8" diameter carbon-coated steel ball, that's impressive by itself. Remeber, Kiloton Nukes, though weaker than the Megaton variety, are used frequently in mondern times. This is due to the fact that the Megaton bombs are huge in missile size and extremely heavy. You'd have to fly a plane over the target zone/city because of this weight... and for that you could launch a kiloton nuclear missile at a safer distance.

Stealth Bombers carry nuclear missiles, the warhead at max being 340 Kilotons! So let's do some math here to see how thick a hide Gojira would need to survive the modern nuclear bomb, using "G" as our unknown number for the thickness of Gojira's hide. For simplicity, let's  say that steel ball in the experiment was right at the blast point and not 9 meters away.

11.8" = 15.2 kilotons

G inches = 340 Kilotons

We cross-multiply to solve for 'G' so that G = 264.2 inches, or if we rounded to an even 264 inches we would get 22 feet! For a land creature, having 22' thick scales/skin would mean very thick limbs... thus your ability to move around (if at all) is very limited.

Solution: The above is naturaly using a scale that's the same as that carbon-coated steel design from that experiment. To have Gojira as a land creature yet able to actually move, he'd need a brand new material that's just as strong but in a lighter and thinner package.

====Regeneration====

Some Gojira movies depict him with a super-faster regeneration instead of a tough armored hide. Unfortunately, regeneration at high speeds isn't realistic. The faster the regeneration, the higher the metabolism is. Meaning, to have a regeneration at such speeds that tank fire damage is healed in 2 seconds or so would mean Godzilla would have to be eating a LOT! For the amount of military fire he takes in many Toho films, he'd have to constantly eat just to keep up with the high metabolism demands.

Of course there's another solution, use the nuclear radiation as the 'food' for the high metabolism. However, that would mean the nuclear reserves for the Atomic Breath would greatly shrink over a prolonged military attack.

The Solution: Instead of fast regeneration, why not a better regenerative ability? Planarian worms (aka flatworms) are very tiny worms with a cool regenerative ability. They can repair any damaged or aged cell in their bodies. If cut in half, each piece will grow what's missing... thus you'd have two flatworms! According to one science video, it takes 2 weeks for the two halves to grow into full flatworms. They can even be cut into 279 pieces and each piece will regenerate into a new flatworm! Can you imagine a Gojira having this style concept? You could blow Gojira into many of pieces (including 6 sizable pieces), and in say 60  years (if bombed in 1954) you'd have 6 Gojiras running about!