# Practical issues of space colonization: numbers and codes

When we are creating a new society in space, there are a lot of practical issue we have to deal with. Many authors of space colonization tend to ignore those issues, or believe someone else will deal with it. We are happy to be that “someone else”.

Everyday we are dealing with a multitude of numbers, and not only to express quantities. Most of these “numbers” are actually codes or even names, because they identify places, persons, thing etcetera. In this post we will discuss postal codes, telephone numbers and debit card numbers .

Postal codes

We believe, and with us many others, that the advancements in optical character recognition have made the entire idea of postal codes obsolete. Most countries introduced postal codes after the second world war, for a more efficient distribution by making sorting of post easier. Computers can nowadays read most handwritings, and therefore adding a postal code is superfluous.

Introducing postal codes in space settlements is a waste of time and money. Instead an address in a space settlement could be identified as follows: <street> <house number> <city/town> <space habitat><country>.

Given the large distances between space settlements, the most likely methods of communication within a space based society, are email and fax. Therefore the number of mail will be most likely to be very small, another reason against wasting resources for implementing postal codes.

Telephone numbers

Because of the distances in space and associated delay times, telephony is unlikely to become an important method of communication between space settlements. However, it will be important part of intra-settlement communication.

Currently most telephone numbers consist of a string of the decimal numbers, which means that a ten-digit phone number allows for 10 billion possible combination. However, the longer a string of apparently random numbers is, the more difficult it is to memorize it. Therefore we propose to use hexadecimal numbers (0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)  instead.

A 7-digit hexadecimal number allows for more than a quarter billion combinations, while a decimal phone number of the same length would have only ten million. Therefore hexadecimal phone number can be shorter, and hence easier to memorize.

Debit cards

In order to use a debit card at an ATM or in electric payments, the user need to enter a PIN code. These are often four-digit codes, this length is easy to memorize. But again technological advancements have made this technique obsolete.

Instead of a numerical identification method, we could use biometrics instead. Finger prints and iris patterns are unique. Biometrical data of the costumer can be stored at a debit card, and when (s)he wants to use the card, the iris or fingerprints are checked to those stored at the card. In order to increase security, multi-modal verification could be used (e.g. requiring both fingerprints and iris scans).

The benefits of this method are clear. One cannot, for instance, “forget” his iris or fingerprint. Further the uniqueness of these biometrics makes it virtually impossible to guess to right PIN code by strangers.