If the answer is &quot;there is such a program that reproduces the universe,&quot; then I have already found one such program that does it. Here it is: interleave the simulation of individual steps of every Turing machine in lexicographic order. That is, if the Turing machines are enumerated T_1, T_2, T_3, ... you do the following:<p><pre><code>    i = 1
    while True:
        j = 1
        while j &lt;= i:
           simulate step j of Turing machine T_i
           j += 1
        i += 1
</code></pre>
If there is some program, it will be in the list.<p>This is the pitfall you get into when you only care about finding extremely short programs and don&#x27;t think about efficiency. Similar pitfalls are in the philosophy of artificial intelligence. You get no useful information or theory or model if you ignore computational complexity.