Impossible? Perhaps not!

Lord Kelvin

Throughout the history of science there have been proofs that something is impossible. These proofs are usually true in mathematics, such as that it is impossible to generate the number π with a ruler and compass. Despite which, many amateurs continue to assert that they have made it. I myself have had to face one of these “proofs”.

Another similar case is the proof, this time related to physical science, that it is impossible to build machines with perpetual motion, because they oppose the first or the second principle of thermodynamics. Also, in this case many amateurs insist that they have made it. In these cases, one should not waste time looking for the error, which is known to exist.

The symbol of death

Azrael, the angel of death
Evelyn De Morgan (1855-1919)

For an educated classical Greek, the number 8 represented death. Why? Let’s see what this funeral assignment was based on.

1. Multiply by 8 the first 8 natural numbers.
2. Add the digits for each result.
3. If the total obtained has more than one digit, we add those digits again.

Multiply	Add digits	2nd addition
1×8=8	8	8
2×8=16	1+6=7	7
3×8=24	2+4=6	6
4×8=32	3+2=5	5
5×8=40	4+0=4	4
6×8=48	4+8=12	1+2=3
7×8=56	5+6=11	1+1=2
8×8=64	6+4=10	1+0=1

Observe that we obtain the sequence 8,7,6,5,4,3,2,1. For the Greeks, this succession starts at 8 and descends to die at 1. That is why number 8 represented death.