## Introduction[]

The File Island is one of the first places in the Digital World explored in Digimon Adventure and had already been presented in the V-Pets and in console games such as Digimon World for PS1. In the appearances in the games and toys, File Island has a more cartoonish appearance exaggerating specific details of certain regions, such as a stylized map.

In Digimon Adventure the game map was used as a basis to create the more realistic map of the TV series, but maintaining the original map as an "observable version" of the real form, as seen from the flashbacks involving Oikawa and his friend, where the design original of the File Island and the Digimon in sprites could be observed.

## File Island Size[]

### Taichi’s Height[]

Well, we have a big problem here because we don't exactly have an exact measurement of the Season 1 characters in the franchise. In one of the linearts it is described that Etemon is 165 centimeters high, if we use this as a base, scaling it to Taichi’s height that’s in the same image we’ll get

Etemon’s Height = 165 cm = 190 px

Taichi’s Height = (165/190) * 145 = 125.92 cm…

This is very small, Taichi is 11 years old, the average height of a male child at that age is 145.7 cm and in this height chart from 02 the new protagonists are around 150 cm tall, at minimum, and they are around younger Taichi’s age and height. So, we of course can’t use the first chart, at least the value that they use as Etemon height.

Well, in the Digimon Adventure Novel we have the following description of Etemon:

“ | With a cheerful clearing of his throat,
the real Etemon, about two meters tall, appeared in front of them. He pulled off the flying V guitar from his shoulder and struck out a single high note as he sang in a random tune. |
„ |

~ Digimon Adventure novel |

Novel puts Etemon's height at around 2 meters ... Let's use that value

Etemon’s Height = 200 cm = 190 px

Taichi’s Height = (200/190) * 145 = 152.631579

This is slightly above the standard height and is close to the limit of the standard variance of height of children at that age. It’s not only very possible that Taichi’s height is around 152 cm, but this is coherent with 02 chart that puts the characters around the 150 cm tall. Thanks novel for helping us to find our ruler. Taichi’s height is of about 152.63 cm

### Infinite Mountain and File Island[]

Using this lineart we can scale Taichi’s height to Leomon’s height.

Taichi’s Height = 152.63 cm = 278 px

Leomon’s Height = (152.63/278) * 536 = 294.279424 cm

In this scene we can compare Leomon’s height to one of the pillars inside Devimon’s temple

Pillar’s diameter = (294.279424/107) * 123.35 = 339.24642

We can then use this size to compare the pillar to the whole temple and then the temple to the Mountain’s peak

Temple Height = (339.24642/20) * 192 = 3256.76563 cm

Mountain’s peak diameter = (3256.76563/81.41) * 333.12 = 13326.2961 cm

Finaly, we can find Infinite Mountain height and then File Island diameter

Infinite Mountain height = (13326.2961/5) * 404 = 1076764.72 cm

“Infinite Mountain base” diameter = (13326.2961/5) * 666 = 1775062.64 cm = 17750.6264 m = 17.7506264 km

Infinite Mountain has an height of 10767.6472 meters, a bit higher than 10 km, this is bigger than Mount Everest

And simply a small part of File Island that serve as the base for the Infinite Mountain has diameter of nearly 18 km, this is just a small section of the whole island that was destroyed by Devimon’s Black Gears.

Unfortunately, this is where we stop having too much precision in the images. Other images, like the ones I put in the introduction, give an aerial view of the whole island and because of perspective distortion, it is difficult to scale the Infinite Mountain with the rest of the island precisely, since its height is distorted by the field of view.

This means that "height" is too distorted for very tall bodies, such as the Infinite Mountain. So I calculated the diameter of the base where the Infinite Mountain was, as this base is only part of the surface of the island, we are working with bodies that are at the same "depth" as the rest, and therefore the lengths will not be distorted as would be the case if we use the Infinite Mountain.

The fragment of the island where the Infinite Mountain was located contained some of the surrounding forest, so I will consider the size to the limit of the "white" region that is around the mountain in this image.

Infinite Mountain base = 17750.6264 m = 275 pixels

File Island diameter = (17750.6264/275) * 772 = 49830.8494 meters = 49.8308494 km

## File Island Destroyed[]

### Mass[]

During episode 8 of Digimon Adventure, "Messenger of Darkness, Devimon!", Devimon uses his Black Gears to fragment File Island into several pieces. The image below is an idea of how fragmented was File Island

As you can see the fragmented part of the Island where the Infinite Mountain is located is composed almost exclusively by the Infinite Mountain and a small amount of forest around it, that was the part that I calculated as the size of the Mountain and that section of the island. Let’s find the volume and then the mass of File Island first.

Island Coast Height = (294.279424 cm/16) * 279 = 5131.49746 cm = 51.3149746 meters

Assuming File Island is a circle/cylinder (The format is close to one, but not exactly the same)

Volume = pi * (49830.8494/2)^2 * 51.3149746 = 1.00076148e11 m³

However, the center of the island, where Infinite Mountain is located, has not moved, so we will have to discard that part of the island Volume = pi * 51.3149746 * ((49830.8494/2)^2 - (17750.6264/2)^2)) = 8.73773863e10 m^3

Taking into account the unregulated shape of the island, I will remove 20% of the total volume to make up for the lack of area in some regions.

Actual Volume = 8.73773863e10 m^3 * 0.8 = 69901909040 m^3

Rock density in Japanese islands are around 2.7*10³ kg/m³

Mass = Volume * Density = (69901909040 m^3) * (2.7*10^3 kg/m^3) = 1.88735154e14 kg

### Speed[]

I’ll use this site to set the exect frames of the movements.

The scene starts at the frame 1434 and ends at the frame 1484], the video is at 25 fps

Time = (1484 - 1434)/25 = 2 seconds

These are the exact moments and the overlapped image of the two, I’ll use the “Infinite Mountain base” diameter of 17.7506264 km as our ruler.

Distance between the fragments = (17.7506264/190) * 61.5224 = 5.7476902 km

Speed = 5.7476902 km/2 seconds = 2873.8451 m/s

The fragments appear to be moving at similar speeds, so I will assume that this value is valid for the island as a whole.

### Kinetic energy[]

Even after this scene, the fragments continue to distance themselves from the Infinite Mountain. After it was discovered that there were Black Gears in the fragments, when they were attacked and started to turn in reverse, the island stopped moving and then moved back towards Infinite Mountain. Therefore, we know that the Black Gears are responsible for the movement of the fragments, so we can scale their kinetic energy to the Black Gears.

KE = 0.5 * m * v^2 = 0.5 * 1.88735154e14 kg * (2873.8451 m/s)^2 = 7.79380465e20 joules, Large Island level

## Meramon dries a mountain[]

A small village of Yokomon on File Island draws its water from Miharashi Mountain. Here we can see the beginning of the lake on Miharashi Mountain, and after Meramon is infected with a Black Gear, it "explodes". The direct result of this was that the entire lake was vaporized, and the entire system of underground water currents began to catch fire.

So we know that the feat is that Meramon vaporized a lake on a mountain that flowed into a village. Miharashi Mountain is large, it is basically one of the only regions on File Island that is visible in the aerial views we have. As you can see in the images of File Island that I put in the introduction, the only things that we can see from a distance are Miharashi Mountain, Infinite Mountain and the Seadramon Lake. None of the buildings, factories, cities or other villages are really seen from this distance, so we know it is huge.

The problem we have is that due to distortion in the image, we cannot easily calculate the height of the mountain in those images. What we can do is calculate the diameter of the base of the mountain, since it would be at the same depth as the rest of the surface of the island, and then use a complete view of the mountain to calculate its height.

For this I will use the already used image of the fragments of the File Island, since we have a direct view of the base of the Infinite Mountain and the fragment of the Miharashi Mountain.

Miharashi Mountain base diameter = (17750.6264/190) * 32 = 2989.57918 = 2.98957918 kilometers

This is nearly 1.5 km of radius

(1/3) * pi * h * (R1^2 + R1*R2 + R2^2) where R1 is equal to the lower radius and R2 is equal to the upper radius

We can divide the Miharashi Mountain in 6 sections, but as seen where Meramon was located, the first section has no water, only starting at the surface of the second section, so I’ll start with the second section.

Miharashi Mountain base diameter = 2.98957918 km

Second section upper radius = ((2.98957918/690) * 123)/2 = 266.462492 m

Second Section lower radius = ((2.98957918/690) * 239)/2 = 517.760452 meters

Second Section height = ((2.98957918/690) * 34) = 147.312597 meters Second Section volume = (1/3) * pi * 147.312597 * (517.760452^2 + 517.760452*266.462492 + 266.462492^2) = 73591052.9 m^3

Third Section lower radius = ((2.98957918/690) * 361)/2 = 782.056583 meters

Third Section height = ((2.98957918/690) * 39) = 168.976215 meters

Third Section volume = (1/3) * pi * 168.976215 * (517.760452^2 + 517.760452*782.056583 + 782.056583^2) = 227312994 m^3

Fourth Section lower radius = ((2.98957918/690) * 532)/2 = 1152.50444 meters

Fourth Section height = ((2.98957918/690) * 58) = 251.29796 meters

Fourth Section volume = (1/3) * pi * 251.29796 * (1152.50444^2 + 1152.50444*782.056583 + 782.056583^2) = 747686940 m^3

Fifth Section lower radius = ((2.98957918/690) * 656)/2 = 1421.13329 meters

Fifth Section height = ((2.98957918/690) * 44) = 190.639832 meters

Fifth Section volume = (1/3) * pi * 190.639832 * (1152.50444^2 + 1152.50444*1421.13329 + 1421.13329^2) = 995342739 m^3

With the sixth and final section, unfortunately, we don't have a full picture of how it ends, so I'll just assume it's a cylinder.

Sixth Section height = ((2.98957918/690) * 69) = 298.957918 meters

Sixth Section volume (Cylinder) = pi * 298.957918 * 1494.78959^2 = 2.09855358e9 m^3

Total Volume = 2.09855358e9 m^3 + 995342739 m^3 + 747686940 m^3 + 227312994 m^3 + 73591052.9 m^3 = 4.14248731e9 m^3

Water density is equal to 997 kg/m³

Water mass = 4.14248731e9 * 997 kg/m³ = 4130059848070 kg

Lake temperature isn’t constant, I’ll simply use an average value from that source, 13.4833333 ºC

Water specific heat is 4181.3 J/(kg * K)

Heat (Change of Temperature) = 4130059848070 kg * 4181.3 J/(kg * K) * (100 - 13.4833333) = 1.49405798e18 joules

Water latent heat of vaporization is equal to 2264.7 kJ/kg, or 2264700 J/kg

Heat (Change of physical state) = 4130059848070 kg * 2264700 J/kg = 9.35334654e18 joules

Total heat = 1.49405798e18 joules + 9.35334654e18 joules = 1.08474045e19 joules, Large Mountain

## Final[]

- Devimon destroys File Island = 7.79380465e20 joules, Large Island level
- Meramon vaporizes an Lake = 1.08474045e19 joules, Large Mountain