Electronics, Engineering, Experiments, Milestones, Notes on everyday life, Physics, Trips

Supersymmetry: Why do we need the Future Circular Collider?

This is the text of the mini-lecture on Supersymmetry that nuclear physicist Filip Moortgat kindly gave us during our visit to CERN and the Large Hadron Collider last week.

Filip Moortgat: Supersymmetry stands out among all the other Beyond Standard Model theories (like extra dimensions and so on). It’s particularly interesting because it answers multiple things at the same time. I would say that most other extensions of the Standard Model solve one problem but not five like supersymmetry.

The first problem: because it connects the internal property of a particle to spacetime, it actually opens a way of gravity entering the Standard Model. As you know, the main problem with the Standard Model is that gravity is not in there. So one of the major forces that we know exists is not in there. Nobody has succeeded to make gravity part of it in a way that is consistent. People hope that supersymmetry can do it, although we’re not there yet.

The second problem is called the hierarchy problem. What that means is that you have a base  mass for a particle and then you have corrections to it from all the other particles. What happens is that if you don’t have any other particles beyond the Standard Model particles you get corrections that become gigantic. What you need to do is tune the base mass and these corrections so that you get the mass that we measured for the Higgs Boson or for the w and z bosons. It’s like 10^31 minus 10^31 is a 100 type of tuning, and we find it unnatural. It’s ugly mathematics. In supersymmetry, you get automatic cancelation of these big corrections: You get a big one and then you get minus the big one (the same correction but with a minus in front of it), it cancels out and it’s pretty, it’s beautiful.

The third thing is dark matter, a big problem. 85 procent of the matter in the universe is dark matter (if you also include the energy in the universe, you get different numbers). And the lightest stable supersymmetry particle is actually a perfect candidate for dark matter, in the sense that it has all the properties and if you compute how much you expect it’s exactly what you observe in the universe. It works great. It doesn’t mean that it’s true, it would work great if you could find it.

And then there’re more technical arguments that make things  connect together in nicer ways than before. Normally, the electric symmetry is broken in the way that everything becomes zero. All the masses would be zero, the universe would just be floating particles that wouldn’t connect to each other, it would be very boring. But that’s not what happened. To show what actually happened you need to drive one mass squared term negative, which is kind of weird but that is what supersymmetry does automatically! Because the top quark mass is so heavy. Heavier than all the other quarks. For me it’s the most beautiful extension of the Standard Model that gives you a lot of solutions to problems in one go.

The problem is that we haven’t seen anything, yet! We have been looking for it for a long time and we have absolutely zero evidence. We now have reasons to believe that it’s not as light as we have originally thought, that it’s a little bit heavier. Which is not a problem. The LHC has a certain mass range, for supersymmetry it’s typically up to a couple of TeV. But it could be 10 TeV and then we couldn’t get there, we can only get up to 2 or 3 TeV. It could be factor 10 heavier than we think!

This why we are starting to discuss the planning of the Future Collider that will be able to go up the spectre of 10 TeV in mass, for supersymmetry and other theories. There’re several proposals, some of them are linear colliders, but my favourite one is a 100 km circular collider which will connect to the LHC, so that we have one more ring. That ring will actually go under the lake and that would be quite challenging, but in my opinion – although we don’t have any guarantee – we will then have a very good shot, at least in terms of supersymmetry. At the LHC we also have a good shot but don’t have enough reach that we need to really explore the supersymmetry. 

When we use conservation of energy and momentum at the collision point, what we do is we measure everybody, we sum it all up and what we need is we need to get the initial state. If something is lacking, then we know there’s something invisible going on. It could be neutrinos, or neutralinos, or it could be something else. So we have to look at the properties and the distributions to figure out exactly what we’re seeing. It’s not a direct detection but it’s a direct derivation if you want, from not seeing something, from lacking something, that we can still say it is consistent with neutralinos. 

How do you know if it’s neutrinos or neutralinos?

Neutrinos we know well by now so we know what to expect with neutrinos. Otherwise it could be neutralios but it could be something else. And then to actually prove that it’s neutralinos we have a long program of work. 

And is that mainly math?

No, it’s everything. It needs all the communities to work together, because we need to measure certain properties, distributions with the detector and we will need the theoretical ideas on how to connect these measurements to the properties of the particle. So we will need both the mathematical part and the experimental part. Translating the mathematics into the particle predictions, we will need all of that.   

Group, In the Media, Milestones, Murderous Maths, Notes on everyday life, Set the beautiful mind free

The Netherlands Chase Away Extreme Talent

This summer, aged 9, Simon @simontigerh was named a World Science Scholar and joined a two-year program for the world’s most exceptional young math talents, as the youngest among the 75 students selected in 2018 and 2019. See the official press release for more info: https://www.businesswire.com/news/home/20190905005166/en/World-Science-Festival-Announces-Newest-Class-%E2%80%9CWorld

Simon’s passion for science and his unique way to see the world have blossomed again once we have pulled him out of school, where he was becoming increasingly unhappy and was considered a problem student. The only way to set his mind free and allow him to follow the path that suits him best, the path of self-directed learning, was to leave Simon’s native Amsterdam and The Netherlands, where school attendance is compulsory.


I am sharing this at the time when educational freedom and parental rights in The Netherlands are in serious danger to become limited even further. It is bittersweet to celebrate Simon’s beautiful journey and at the same time see how The Netherlands are chasing away extreme talent as we are aware of more stories similar to that of Simon’s.

art, Crafty, Geometry Joys, Math and Computer Science Everywhere, Math Riddles, Murderous Maths, Notes on everyday life, Simon makes gamez, Simon teaching, Simon's sketch book, Together with sis

Math puzzles: Is it Possible?

Simon has been fascinated by these possible-impossible puzzles (that he picked up from the MajorPrep channel) for a couple of days. He prepared many paper visuals so that Dad and I could try solving them. This morning he produced this beautiful piece of design:

Simon showing one of the puzzles to another parent while waiting for Neva during her hockey training
Simon’s original drawing of the doors puzzle. The solution of the puzzle is based on graph theory and the Eulerian trail rule that the number of nodes with an odd degree should be either 0 or 2 to be able to draw a shape without lifting your pencil. The number of rooms with an odd number of doors in the puzzle is 4 (including the space surrounding the rectangle), that’s why it’s impossible to close all the doors by walking though each of them only once.
Simon explaining odd degree nodes
Computer Science, Electronics, Engineering, Good Reads, Notes on everyday life, Uncategorized

The Digital Computer Electronics book

Simon has been mesmerised by this book for a couple of days by now, the Digital Computer Electronics eBook (third edition). He has downloaded it online and has been reading about the so called “simple as possible” processors or the sap’s (he loves the name) one of which is like the 8-bit computer he is currently trying to build from scratch.

Simon reading the book in the playroom. I hearbhim laughing and reading aloud.
a screenshot of the book
Taking notes on SAP-2 instructions (and listening to a quiz show on YouTube at the same time) – his way of learning
Computer Science, Electronics, Geometry Joys, Logic, Math and Computer Science Everywhere, Murderous Maths, Notes on everyday life, Simon's sketch book, Trips

Doing math and computer science everywhere

One more blog post with impressions from our vacation at the Cote d’Azur in France. Don’t even think of bringing Simon to the beach or the swimming pool without a sketchbook to do some math or computer science!

This is something Simon experimented with extensively last time we were in France. Also called the block-stacking or the book-stacking problem.
Simon wrote this from memory to teach another boy at the pool about ASCII binary. The boy actually seemed to find it interesting. A couple days later two older boys approached him at the local beach and told him that they knew who he was, that he was Simon who only talked about math. Then the boys ran away and Simon ran after them saying “Sorry!” We have explained to him that he doesn’t have to say sorry for loving math and for being the way he is.
Drinking a cocktail at the beach always comes with a little lecture. This time, the truth tables.
Exercise, Notes on everyday life, Together with sis

Vacation Milestones

A couple more milestones passed! Going on a Ferris wheel after having been afraid of heights for years. “Mom, do you know how many rays there are? I’ll tell you: it’s the only time that exponentiation is commutative!”

Diving deep into the water (after being afraid to put his head underneath the water for years), swimming to the platform in the sea and diving from the platform, using a diving mask.

the platform Simon has been diving from is seen in the background
history, Logic, Milestones, Murderous Maths, Notes on everyday life, Philosophy

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.

Milestones, Murderous Maths, Notes on everyday life, Simon teaching, Together with sis

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)

The picture is taken on August 16 when Simon turned 10
Simon’s age in binary
Good Reads, history, Milestones, Notes on everyday life, Philosophy

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.