That is a slick gauge, but you weren't told why it was named Fibonacci gauge.
Leonardo Fibonacci was an Italian mathematician born in 1175 AD. In a book he published in the early 13th century, he defined the Fibonacci number sequence. The sequence is formed by adding together the previous two numbers in the sequence to obtain the next number. 0 1 1 2 3 5 8 13 21 34 55 89 144 etc.
How does the relate to the Greek 'golden ratio'? As it turns out, if you take any number in the Fibonacci sequence and divide it by the number previous to it, you will get an approximation of the 'golden ratio'. The larger the selected number the closer the division comes to the 'golden ratio'.
In the above sequence, if you divide 3 by 2, you get 1.5, but if you divide 21 by 13 you get 1.615. Going further up the sequence, 144/89 = 1.6179. Since the sequence is infinite, we can assume that the golden ratio is also infinitely long. As it turns out, the golden ratio is defined as (1+ sqrt(5))/2. The sqrt of 5 is a number that is also infinitely long, hence the golden ratio is also infinitely long.
Things like this lead to think that the Great Architect of the Universe is a mathematician.