The Science of Godzilla

Obviously Godzilla is a figment of our imagination but if the history of Earth had been slightly different, could creatures like he and the MUTOs have actually evolved?

1. Food

The first thing I tell the kids when they're wondering if some type of monster could really exist either in the deep sea or in some remote jungle is to answer a simple question: what does it eat?

Godzilla in the latest reboot is described as 350 feet tall and 90,000 tons (for perspective a super aircraft carrier weighs only 65,000 tons). From this we can calculate the bare minimum amount of calories he'd need everyday just to sustain his weight without considering movement costs:

E = 70M^3/4

So if one pound is .453592 kg, and one ton is 2000 pounds, and Godzilla weighs 90000 tons we get:

E = 70(.453592 * 2000 * 90000)^3/4

E = 70(81646560)^3/4

E = 60,124,497.341691341071069635490924 calories

Having established that, to figure out how much he'd need to eat in a day, we need to calculate how many calories are in a pound of meat. This of course varies depending on the specific animal and even more from species to species.

There is no firm agreement on even the number of calories in a pound of ground beef but generally estimates range from 700 to 1200 calories per pound of cow meat. Let's split the difference and say 1000.

Using this as our baseline we can conclude that just to survive each day, Godzilla would need to eat 60124 pounds of cow or 30 tons of meat.

By itself this isn't necessarily impossible. A blue whale, the heaviest known animal to ever live on Earth averages 180 tons. So Godzilla would need to eat a blue whale every six days. This isn't feasible today but in earlier geological eras like the Jurassic or the Permian period when the ecosystem was far more energetic and large animals more common, this might have been reasonable.

Of course this calculation is bare minimal for the animal's survival and does not consider caloric expenditures in hunting, fighting, or moving. For perspective putting my own weight into this same calculation we get:

E = 70(.453592 * 185)^3/4

E = 70(83.91452)^3/4

E = 1940 calories

So to just maintain my weight I need to eat at least 1940 calories a day. This assumes I do nothing but lay there and eat. If I take an hour bike ride I'll burn roughly 779 calories and this goes up as size and weight increases.

If Godzilla who weighs 90,000 tons took a swim he'd be burning millions of calories an hour.

Godzilla is obviously not just sitting in a McDonald's munching on Big Macs all day (although frankly I'd love to see that) so he must require drastically more calories than we've calculated.

At no time in the history of our planet has any creature that needed to eat the equivalent of a blue whale every day been viable.

The recent movie actually provides a hand wave explanation for this. The movie claims that creatures like Godzilla and the MUTOs eat radiation rather than food. Is such a thing a possible?

Well if you talk about something eating radiation you are essentially describing a tree. Trees eat light (a form of EM radiation) to produce simple sugars. It's a viable life strategy but because this produces so few calories if Godzilla wanted to try the same technique he would have to be completely immobile. Even then it's extremely doubtful he could absorb enough fuel to supply his vast weight.

We all know plants can absorb light but are there plants that absorb real nuclear radiation?

Surprisingly yes. Near Chernobyl have been discovered a type of mushroom called Radiotrophic fungi which consume hard gamma rays from the sealed reactor to produce food.

This of course is only slightly better than eating normal light. It does not produce enough calories for an animal, certainly not an active one.

To support the existence of a creature the size and weight of Godzilla we'd need a radically different approach to its metabolism. While the MUTOs are described as feeding off radiation, we actually see them ingesting nuclear fuel. While feeding off radiation is not viable for active animals, there has been xeno-biological speculation at MIT that somewhere in the universe animals might have evolved metabolisms very different from ours.

For example, while it never happened on Earth (except for some types of bacteria) it is conceivable that an animal could have evolved to eat crude oil if it was plentiful enough. Oil is actually very similar to most types of carbohydrates. It has a long hydrogen chain that burns and releases energy.

Humans (and all other known animals)eat chemicals. These chemicals release energy which we use for fuel. We evolved to eat sugar and carbohydrates (also a type of sugar) which release a small amount of energy when digested. If oil had been plentiful enough and available enough in the distant past, our ancestors might have evolved the ability to consume this instead of sugars.

Humans of course never evolved to eat oil, despite it's similarities with carbohydrates. Our bodies would choke on it and even if we could digest it our cells can't handle that much heat and energy all at once.

The reason I point this out is oil produces FAR more energy per pound than sugar, which is why we use oil to drive our cars. If animals were eating oil and other powerful chemicals rather than sugar, a creature the size of Godzilla becomes feasible.

However considering an animal which consumes nuclear material rather than chemical material is very challenging. There is no known animal that behaves this way. If we wanted to design an animal that consumed oil, we'd just need to modify it's biology slightly. All know Earth organisms already have means for digesting chemical energy and using it. We'd just be changing specifics of it's cellular structure to support a different chemical.

When describing an animal that consumes nuclear fuel we need to essentially throw away most of what we know about biology and start from the ground up.

First and foremost the current record for a nuclear reactor in production is 200 GWd per ton of Uranium supplied. This is equivalent to "digesting" about 20% of the fuel ingested. If biology permitted Godzilla to metabolize higher percentages, the amount of energy he gained would go up drastically. While the correlation between Watts and calories is not exact, this is roughly equals 47,769,179.325 calories or about

23,884.589 calories per pound of Uranium consumed. Compare the number of calories per pound of Uranium versus the calories we described in a pound of meat (1000 calories).

Update: I've since come across a better calculation. A pound of uranium contains

154,808,000,000,000 calories according to http://www.ocean.washington.edu/courses/envir215/energynumbers.pdf.

Assuming a 20% burnup rate a pound of uranium has 30,961,600,000 kilocalories

We previously described Godzilla as requiring about 60 million calories a day just to survive or less than the calories contained in 1 pound of Uranium.

Let me emphasize that. One pound would sustain a 90,000 ton creature for 516 days.

Granted swimming, hunting, and fighting would force it to eat more but with 30 billion calories per pound of fuel this does not seem unreasonable any more.

If Godzilla can consume nuclear fuel, how would this be accomplished?

Well normal animals consume chemical energy using molecules called ADP and ATP. These molecules do a lot but in simplest terms they absorb energy from food we eat and store it until they come to a cell that needs the energy.

Then they supply it to the cell.

Can we do something similar with nuclear energy?

Well yes and no.

Uranium is the major element used in current nuclear engineering. However other elements also have potential uses. A fairly common element called Thorium for example is not naturally radioactive. However it is attracting interest for its ability to absorb nuclear activity and release it, somewhat similar to ADP and ATP. Godzilla and others could have special cells circulating in their blood streams that use Thorium to absorb nuclear energy from the nuclear reaction in their bellies and transfer it to other cells.

However Thorium after releasing its energy can often not absorb it again as it has undergone nuclear synthesis. This means that the process of absorbing nuclear energy can change Thorium into another element. For Godzilla to have a sustainable metabolism it would need to cyclically have Thorium absorb energy (which will transform it into a new element or isotope) and then deplete it back to normal Thorium again. There is no know nuclear technique that would accomplish this but one would theoretically exist. More likely Godzilla would have to replenish its Thorium supply periodically the same way as animals create new red blood cells.

If Godzilla can use thorium and uranium as it's key fuel source, it would be able to supply it's massive appetite. More to the point with sufficient fuel sources all manner of amazing biological adaptations become possible.

2. No Bones about it

At one point or another many of my more scientifically minded cousins have asked me, "Why aren't our bones made of metal? Surely evolution would have come up with that improvement by now, unbreakable bones would be a good investment."

Before analyzing this question we need to first stop and consider what bones are and how they're made. Bones are made of what is called osseous tissue. This is a combination of calcium and protein which our bodies weave into a solid structure much like coral. Bones are made (like everything else in our bodies) from the food we eat. So could our bones be made of metal?

Certainly. We could have a solid gold skeleton. We eat gold. We eat it in very small amounts but it is always there. We eat small amounts in our food and in the water we drink. Our bodies could in theory very very slowly use gold as the main ingredient of our bones and construct our skeletons over many many years.

The reason why we don't do this should be obvious. Pure gold is about as hard as clay and would make a terrible skeleton. Also absorbing enough gold to build ourselves a golden skeleton would probably take centuries. Evolution is not going to gamble on anything living that long, let alone gestating that long.

On top of which our bones are actually stronger than most crude metals, or at least it absorbs shock better than most.

How would a creature the size and weight of Godzilla support it's weight?

Well human bones are able to support about 150 Mega Pascals. That's how much force it would take before snapping.

Estimating how much force Godzilla's bones would need to be able to take on given step is complex because we have no idea how big his feet are.

Ignoring that issue for the moment the stress endured by bones can be described using the Square-Cube Law. This basically means that as an organism's size increases, it's surface area increases by that factor squared and its mass increases by that factor cubed. This essentially means that an elephant is not built like an incredibly big mouse. It has much much thicker bones just to support it's own weight. This rule tends to put a hard limit on how big mega fauna can be.

Our bodies perform chemical operations to spin calcium and protein into bones. However nuclear operations are capable of vastly more powerful transformations.

For example, one type of nuclear reaction turns Thorium into Uranium, then into Protactinium. Sometimes into Radium, Bismuth, and Thallium. These are transformations our bodies are not capable of.

I mention this just to postulate that Godzilla's bones really could be made of metal or even diamond. His biology could perform these transforms the same way as our bodies work with calcium.

It is even possible that his biology could produce elements currently unknown to us (The Island of Stability is a theory that at a certain point materials made by nuclear reactions become stable and no longer radioactive. A discussion of this theory is beyond the scope of this article).

3. The Heart of the Matter

The bigger an animal is the harder its heart must work to ensure that every cell receives its regular refueling. This is often a criticism of kaiju. However before analyzing this point let us take a moment and consider why we have hearts in the first place and why they must beat.

Normal animals can be considered in terms of chemical reactions. Everything our bodies do is form of chemistry. When the chemical reactions stop, we call that death.

One of the major reasons why our hearts need to beat is to make sure every cell gets oxygen. The chemical reactions our bodies depend on require oxygen or they stop immediately.

You might think of it as a fire burning. Take away the oxygen and the fire stops instantly.

However this ignores that Godzilla's metabolism is based on nuclear energy. Taking away the oxygen does not stop a nuclear reaction or a heavy metal fire. These reactions are incredibly difficult to stop which leads one to question if Godzilla would need to breathe at all. Oxygen would offer him very little.

Also because nuclear reactions and heavy metal fires burn for so long, Godzilla's heart might not have to beat very often. A cell having been given a supply of nuclear fuel might not require refueling for hours, days, or even longer. Conversely if the reaction only occurs in his belly the Thorium would still be transferring a massive supply of heat, possibly enough to sustain the cell for a very long time.

An interesting thought is that monsters based on nuclear biology would be very very hard to kill. Because the loss of most central organs are not immediately fatal it becomes possible for these monsters to become comatose and even regenerate some organs. As long as the individual cells can continue their own metabolism without these organs for a sufficient period of time there is no reason the animal would not have evolved to be able to regenerate these organs.

This could explain how creatures like Kaiju and Lovecraftian monsters are able to go into dormancy for so long and regenerate from such incredible trauma to their bodies

4. Dragons breathe fire

You want to figure out how a monster breathes fire? How long do I have to answer these questions?

Well that's complicated because we're never really told what Godzilla is actually breathing. The term "atomic breath" doesn't have a lot of scientific meaning.

If we assume that he's just blasting superheated steam mixed with radioactive particles then the process becomes easy. Godzilla could have evolved a way to increase or decrease the force of the nuclear reactions inside of him at will. He almost certainly would have had to evolve some controls over the reaction, maybe something as simple as using muscles to gather or separate the radioactive materials inside of him.

As the reaction increases (assuming he could contain the mounting energy) all he'd have to do is open his mouth and let the pent up heat and steam blast out.

If he's breathing plasma as some have claimed the matter gets slightly more complicated. Plasma is difficult to generate without immense heat and tight pressure. Plasma has very low density and unless it's concentrated it will expand and cool. Godzilla would need to have a special gland containing some chemical under pressure that he could heat up and transform into plasma before spitting it out.