â€œBut where does it end?â€ Asked the child patiently. He was a young boy — somewhere between 6 and 7 years old and still full of wonder and curiosity.
â€œWhat if I told you it went on and on for ever?â€ I said.
â€œWell — nothing can go on and on foreverâ€¦ It has to have an end somewhere.â€
â€œWhat about space?â€ I asked, â€œIf you go in a spaceship away from the sun, will you eventually get to the edge of something?â€
The boy rolled his eyes, â€œBut thatâ€™s differentâ€¦ This is just a tunnelâ€.
â€œWell, itâ€™s a long tunnel but if you must know Derek, it ends about 3 kilometers from here in another chamber Â much like this one.â€ The room we were standing in now was quite large — maybe 40 to 50 feet tall and a little wider. From where we stood, it basically looked as long as it was wide. One side of the room was an iron gate through which we had just entered, and the other side of the room tapered down into a vestibule and a long corridor shot off straight north of our present location. It was this passage that Derek was staring down now. And it was a bit strange. The dimensions were perfect. From where we stood, with our flashlights in hand, it was a perfectly straight line down the tunnel. The light only carried so far and limited how far we could see, but the effect of the perfectly square cut walls of the channel resulted in an effect that seemed too real to be real. I guessed it was because I was used to thinking of underground tunnels like this in terms of sewers or ancient catacombs — functionalÂ structures and ones made with imperfect tools. But this was no sewer or catacomb. We were currently standing in a service entry to one of the most extensive bunker complexes in the world.
â€œHow long is a kilometer?â€ Derek piped in, interrupting my thoughts.
â€œWell, itâ€™s like a mile, but shorter.â€
â€œWell if itâ€™s like a mile, why not just say a mile?â€ asked the curious Derek.
â€œMainly because the rest of the world has got used to using kilometers and is asking us why we donâ€™t just use themâ€, I parried.
â€œWell, everyone knows how long a mile isâ€, he responded. â€œIf I walked to school, Iâ€™d have to walk one and a half miles. A mile is long but you can walk that far if you need to.â€
â€œThe main reason, actually, is because the units are hard to work with.â€ Derek just looked at me blankly. â€œThe units that we use for a mile are hard to convert to other units. Do you know how many feet make a mile?â€ I asked.
â€œA lot — over 5,000 I thinkâ€
â€œRight — itâ€™s actually 5,280 feet in each mile. And there are 12 inches in each foot.â€ Those are hard numbers to work with. With kilometers, they measure it to be exactly 1,000 meters. And 1 meter is exactly 100 centimeters, and each centimeter is exactly 10 millimeters. Itâ€™s easy because everything is divisible by tenâ€. I was starting to feel a little pedantic.
â€œBut why is it harder to remember 5,280 instead of 1,000? Theyâ€™re both just numbers and theyâ€™re both pretty big. Why is it easier just because everything has a ten in it?â€ asked Derek.
â€œI donâ€™t know — I guess our brains just can handle it more easily. So for example, itâ€™s harder to multiple 5,280 by 12 compared to multiplying 1,000 by 10.â€ I said, somewhat unsure I wanted to into detail of why multiplication by the radix of any numeral system was inherently easier. I wondered suddenly if the ancient Babylonians with their base 60 system or perhaps the Mayans with their base 20 system would feel uncomfortable trying to multiply 100 by 100. It sounded weird that they would. Stupid Babylonians. Itâ€™s there fault weâ€™re still stuck with 360 degrees in a circle and 60 minutes in an hour.
â€œI guess that makes sense.â€ Derek said, jolting me back to the present, â€œBut it doesnâ€™t really help me because I still donâ€™t really know what a kilometer isâ€ he said, somewhat sadly.
â€œYou and 300 million Americans.â€ I said, glumly.
Just to the left of the long corridor, on the concrete wall was a very large painted number indicating â€œ27â€. According to the map that I had been looking at all morning, that was good — service entrance 27 was what we were trying to find and it had actually been fairly easy to get this far.
I was a little surprised by the lack of any sort of security features. There were no visible locks, or mechanisms to restrict entry, no electronics visible of any kind. The iron gate to enter had been shut, but it was held simply by a latch to prevent it from swinging in the wind and probably to keep debris and larger animals from getting in and making a mess. Everywhere I looked, all I saw visible was expertly finished concrete walls.
â€œWell we better get going. You lead the way Derek.â€
Derek already had his flashlight at the ready and he eagerly moved forward toward the corridor. â€œLetâ€™s do some exploring!â€ he said with a big goofy smile.