You can find here an utility to calculate the probabilities of random sequences of symbols.

It tries to answer questions like this: “a random process generating sequences of length L from an alphabet of S symbols in T trials of t seconds each, involving c chemical reactions, does exceed the resources of the universe (age, max number of chemical reactions, universal probability bound)?”.

The user interface is meant to be self-explanatory. The “Demo” button has the function to preset an example of input values. After the “Demo” you can eventually change some or all inputs and click the “Calculate” button to obtain your new output results. Otherwise if you want to start from entirely different inputs you may click the “Reset” button that zeroes inputs and outputs.

Disclaimer: this is a mathematical tool dealing with processes considered purely random. It doesn’t pretend to simulate the physical, chemical, biological, functional constraints specific of the processes. For example, about proteins and biopolymers, it doesn’t include the deterministic effect of amino acids forcing other amino acids to come with them, which could make the sequence more probable. Besides it doesn’t deal with all the specialized cases where functional issues somehow dominate the sequence structure. However the tool may give an idea of the orders of magnitude of the numbers involved in scenarios as origin of life, production of biopolymers, binary and character text generation, and so on.

Note about notation: almost all numbers are in “exponential E” notation, which is used in informatics as equivalent to the “scientific 10^” notation. Example: 4.4E+17 = 4.4×10^17 (scientific notation) = 440,000,000,000,000,000 (integer notation). The decimal dot moves rightward as many places as the exponent/power of ten (in this case 17).