While in Southern France, Simon really enjoyed solving this puzzle (he originally saw in a Brilliant.org vid). He was so happy with his solution he kept drawing it out on paper and in digital apps, and later shared the puzzle on Twitter. This sparked quite a few reactions from fellow math lovers, encouraged Brilliant to tweet new puzzles and now Brilliant follows Simon on Twitter, how cool is that!

# Simon on: Will we ever live in a pure mathematical world?

In reaction to Yuval Noah Harari’s book *Homo Deus* (the part about humans evolving to break out of the organic realm and possibly breaking out of planet Earth):

When you cross the street there’s always a risk that an accident will happen that has a non-zero probability. If you live infinitely long, anything that has a non-zero probability can happen infinitely many times in your life. For example, if the event we are talking about is an accident, the first time it will happen in your life, you’re already dead. So when you cross the street and want to live infinitely long there’s a risk that an accident will happen and you die. So we come to the conclusion, that if you want to live infinitely long it’s not worth crossing the street. But there’s always a risk that you die, so if you live infinitely long, it’s not actually worth living. So we’ve got a little bit of a problem here. Unless you come to the more extreme idea of detaching yourself from the physical world all together. And I’m not talking about the sort of thing that you don’t have a body, but somehow still exist in the physical world. I mean literally that you live in a pure mathematical world. Because in mathematics, you can have things that have zero probability of happening. You can have something definitely happening and you can also have something that is definitely not happening.

However, there’s another thing. How does mathematics actually work? There are these things called axioms and it’s sort of built up from that. What if we even do away from those axioms? Then we can actually do anything in that mathematical world. And what I mean by anything is really anything that you can from any set of axioms that you can come up with. There’s a little bit of a problem with that, you can come to contradictions, it’s a little bit risky. We are really talking about the ultimate multiverse, we’re talking about quite controversial stuff here. The only way anyone can come up with this is by pushing to the extremes.

# My little pure connections to Simon, now 10 years old

What do I love most about Simon’s learning style and being around him are the precious moments he pulls me out of my regular existence, sits me down next to him and shares a piece of his sharp vision with me. I often take notes to make sure I haven’t missed out on the details. Reading back the notes I am often surprised at the hidden layers in his razor-sharp logic that hadn’t revealed themselves to me at first or had even seemed irrelevant to my journalist mind eager to cramp everything to the size of a cocktail bite. Sometimes, Simon takes over and types the rest of the blog entry himself. Like this time.

Dad says he saw someone by the swimming pool reading the book *A Mathematician’s Apology*. We google it and find out it’s a 1940 essay by British mathematician G. H. Hardy about the beauty of pure mathematics. Knowing how much Simon is drawn towards pure mathematics and that he, too, prefers pure mathematics to applied mathematics, I tell him about our discovery. Simon replies that it’s a silly question to ask him whether he knows Hardy: Yes, Hardy was actually the one who invited Ramanujan!

Simon pauses his breadboard tutorial, comes to the balcony with the view across the Cote D’Azur, sits down against the wall of bright purple flowers and patiently tells me an interesting fact about Hardy. It’s just a fleeting tiny conversation, but the beauty of Simon’s precise memory, the connection I feel to Simon and the setting is so striking I would rather grab my video camera but I don’t dare move as not to lose momentum. I later ask Simon to repeat the facts he told me so spontaneously.

“Hardy came up with the total number of chess games. Well, Shannon estimated it to be 10^120, however Hardy estimated it to be 10^…, 10^50.

Clarification: the former is:

1 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000

(1 with 120 zeros)

And the latter is:

1 with 100 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 zeros

(1 with, a 1 with 50 zeros, zeros)

# Simon on collective intelligence

In reaction to Yuval Noah Harari’s book *Homo Deus* (the paragraph about the a-mortals anxious about dying in an accident):

With individual intelligences, you can have the car that’s driving down the street not knowing that you are going to be crossing the street at that point in time and then poof! You got yourself an accident. With collective intelligence though, that doesn’t happen. Because the whole definition of knowing something or not knowing something breaks down. The members of collective intelligence don’t have the notion of knowing something. It’s only the “central intelligence” that the members are hooked up to that has the notion of knowing something. Which means that you can have the central intelligence deciding that a car driving down the street does not create an accident with the person crossing the street.

# Another evening tea

Simon was showing Dad a graph of how technology is developing exponentially, y = a^x. Dad asked for a specific value of a, and Simon said: “All exponentials are stretched out or squished versions of the same thing.” He then quickly came up with the proof (“a few lines of relatively simple algebra”). “If all exponentials are pretty much the same, that means that all exponentials have proportionately the same derivative.”

# In case you’re wondering what our evening tea looks like

# Some more London

# On top of The Shard, the tallest building in the EU

A real victory for Simon, who has had a bit of a fear of heights for years. But what he found most impressive were the noticeable changes in gravity while going up and down with the elevator. When descending from the 72nd floor he could feel the decreased G!

# The Camera Obscura at the Royal Observatory in Greenwich

# We’ve found the real 0° meridian!

And it turned out to be a that little path next to the Royal Observatory in Greenwich, not the Prime Meridian line. The 0° meridian is what the GPS uses for global navigation, the discrepancy results from the fact that the Prime Meridian was originally measured without taking it into consideration that the Earth isn’t a perfect smooth ball (if the measurements are made inside the UK, as it it was originally done, this does’t lead to as much discrepancy as when vaster areas are included).