For the exhibition New Realism, Doina Kraal was linked to Nikhef, the national institute for subatomic physics and professor Marcel Merk, among others. Merk is the project coordinator of a FOM research program that studies why there is almost no antimatter present in our universe. With his group, he compares the decay of particles and antiparticles, for which they use the LHCb experiment at CERN in Geneva.

Matter - Antimatter

Just after the Big Bang, there was slightly more matter than antimatter. The matter and antimatter particles have cancelled each other out, but a very small part of the matter particles remained (about 1 in a billion antiparticles). In CERN, antimatter particles are made (antihydrogen particles) and matter and antimatter particles are also produced during proton collisions. The matter and antimatter particles should be each other's exact mirror image, but it seems that these particles do not always behave the same. In the LHCb project, they look at the differences between the behavior of the so-called beauty and anti-beauty particles and try to find out why they behave differently.

We live in a universe with a broken symmetry. When that symmetry was lost, the particles gained mass via the Higgs mechanism and the laws of nature were no longer symmetrical. The Standard Model describes forces based on a symmetry. If this symmetry were to apply exactly, all particles would be massless. After the symmetry breaking, we still have the force particles, but they have gained a mass. The younger the universe was, the more symmetrical.

Based on this research, Doina Kraal asks questions and searches for different visual and auditory forms to translate/imagine these questions.

Symmetry – Asymmetry

Left/right symmetry occurs in many places. Some phenomena appear to be perfectly symmetrical, but often things are only seemingly symmetrical. Does physics describe nature? Does physics describe both organic and inorganic phenomena? (Organic) nature as we know it has many symmetries, but it is never ‘truly’ symmetrical. Why is symmetry the fundamental principle on which we base all forces when so many things around us turn out to be asymmetrical? Can a comparison be made, or a metaphor be found for this supposed mirroring in nature? Wouldn’t a perfectly symmetrical world look very strange? Would a mirrored and inverted world look the same? What is beauty? What is health? What is (mathematical) elegance? What does a possible future Standard Model look like? And what happened to antimatter?

Particle Hunt

Particle Hunt is a treasure hunt and an audio tour that takes place at the Science Park in Amsterdam. The visitor is taken along various locations where objects can be seen and sometimes touched. Things that were already present in the Science Park are highlighted and things have been added by Kraal. Using a spoken story and pre-recorded sound, the visitor is invited to become acquainted with the search for (new) particles, the properties of particles and the questions that arise. It is an incredibly ambitious search for something that is almost invisible and yet it is everywhere.

On the website the audio tour can be listened to or the words spoken in the audio recording can be read. The images are all the sites and artworks visited when listening to the tour.

Introduction

You are listening to (reading) the audio tour ‘Particle Hunt’. My name is Doina, I am the person who made this multimedia tour. I would like to join you on a walk through the Science Park, where you will come across existing phenomena as well as objects placed here by me. All you have to do is follow the pink numbers on the map and hold your step every now and then. Please feel free to pause me anytime. Take a look at the map if you are lost or if my tempo is too fast or too slow. This audio tour takes about 30 minutes and is one continuous track.

Please go ahead and walk over to number 1. 

The past months I have tried to wrap my mind around elementary particles. I have gone to the particle accelerator at CERN in Geneva, where amongst others, protons are being brought into collision with one another. I have tried to understand some of the biggest questions physicists ask themselves today and of course I have my own questions, which I would like to share with you. 

Maybe you know a lot more about particles than I do… But I would like to pretend that you know as little as I did when I started this project. Forgive me for pointing out the obvious, but then again what is obvious? Certainly not the world of the smallest as I have come to find out.

We only know 4,5 per cent of all matter around us. We know solid matter, liquid matter, gas matter and plasma matter. Hmmm, different fields of science use the term matter in different and sometimes incompatible ways. Matter is anything that has mass and volume or… matter is made up of what molecules and atoms are made of, meaning anything composed of elementary fermions, namely quarks and leptons; the smallest building blocks of matter.

You will now be approaching – after having walked through a gate – my number 1 interference here at the Science Park – you may have to wait a little for the guard to let you in. Just behind the gate, on your left hand you will see the leftovers of a diagonally cut birch tree. 

1. A diagonally cut birch tree on the Amsterdam Science Park terrain (cut by Doina Kraal)

If I would zoom into this tree I could see cells. The cells are built up of molecules. Zooming into the molecules we find out that they are build up of atoms. In the centre of each atom we find a nucleus; a little gathering of neutrons and protons and around the atom circle electrons. If we now look closer at the neutrons and protons we find even smaller building blocks: the smallest building blocks; quarks. Both the neutron and the proton exist out of three quarks. A neutron has two ‘down quarks’, and one ‘up quark’ and is therefore negatively charged. A proton has two ‘up quarks’ and one ‘down quark’, which makes it positively charged and therefore it can be accelerated, which is what happens at CERN at the Large Hadron collider.

In his book ‘A short History of Nearly Everything’, Bill Bryson talks beautifully about atoms, their unimaginable size, the fact that they are everywhere and everything. Not just the food we eat and the chair we sit on is made of atoms, but also the air in between the things. 

“Atoms are fantastically small. Half a million of them lined up shoulder to shoulder could hide behind a human hair. Atoms are fantastically durable. Every atom you possess has almost certainly passed through several stars and been part of millions of organisms on its way to becoming you. We are made of such unimaginably large amounts of atoms that about a billion of each of our atoms probably once belonged to Shakespeare. A billion more, each came from Buddha and Genghis Khan and Beethoven, and any other historical figure you care to name. (The personages have to be historical, apparently, as it takes the atoms some decades to become thoroughly redistributed; however much you may wish it, you are not yet one with Elvis Presley.) We are all short-lived reincarnations. Atoms, however, go on practically forever. Nobody actually knows how long an atom can survive.” Bill Bryson 

Since you might now be trying to imagine the size of an atom, now just try to imagine that atoms aren’t even the smallest building blocks. The elementary particles, the quarks that make up the atoms are! 

I like looking into this tree trying to maybe discover a small universe in there: tiny planets orbiting in ellipses around their own point of origin. As long as I can remember I have tried to imagine what the edges of the universe look like. Could it be the bark of a birch tree? Will we ever ‘see’ or ‘experience’ the edges of the universe? 

Now to be able to see cells and molecules inside this tree, we would need a microscope. But atoms and particles… Can we actually see them? Could CERN be seen as a large microscope? Is there anything to be seen at all?

…

I would like to invite you to continue the walk towards number 2: the very Dutch version of CERN; you will walk to what is left of the Nikhef particle accelerator. This accelerator was closed down in 1998 and the last standing part of it will be demolished in the near future.

The Nikhef, is the Dutch National Institute for subatomic physics. Right here, below your feet, particles were colliding and the smartest of the smartest were figuring out how these particles behave when they bump into each other. 

By the way, did you notice the seashells cracking underneath your shoes? There are oyster shells amongst them and flint, in Dutch vuursteen: firestone.

2. Nikhef’s former particle accelerator, with a life-size photograph of a 100-meter-long corridor (made by Doina Kraal)

At number 2, you will be looking into a 100-meter-long corridor, which actually lies a couple of meters below the ground. It is what is left of a search for the invisible. I would have loved to walk into it together with you, as it is a somehow strangely magical place to visit, but this was impossible since the current function of this building is a data center and the security is very strict. The pink building on your map is the old accelerator and now data center, the shiny building on top of it, is the new data center. Inside this old structure are thousands of hard drives, computers and air conditioners zooming, keeping the temperatures stable.  

These 100 meters make up only 0,004% of the length of the accelerator at CERN, yet still it is a substantial length (the original machine was larger). 

Something as ungraspable as particles, made place for something equally ungraspable: the endless amount of data making up the Internet. All these drives, what are they storing? Is there a backup here of Wikipedia? Parts of the dark web?

Is it a coincidence that the world wide web was invented at CERN? “The web was originally developed to meet the demand for automatic information-sharing between scientists in universities and institutes around the world.” CERN may be the largest scientific project ever undertaken, bringing together a most colorful group of scientists who want to share their knowledge.

Marthe, the curator of this show, puts it beautifully: “Data streams structure society, like the subatomic world forms the environment. Invisible, yet constructing the visible itself. Incredible yet knowable through incredible ways.”

While I keep talking, please continue your walk towards number 3. I would like to share with you some dry and general facts about the research done at CERN:

- The LHC is approximately 27 km long. It is a circle. The hydrogen protons that are brought into collision with one another travel in little clouds that have a length of about 8 cm. One cloud contains about one thousand billion protons. At every 8 metres sits or travels another of these clouds. They go around the 27km tube 10.000 times per second. They travel almost at the speed of light. 40 million times per second, the packages of protons collide and 600 million times per second a proton hits another proton.

Now there are different research groups and I chose to learn more about the research coordinated by Marcel Merk – Marcel works at the Nikhef and is a professor at the VU University – but makes use of the LHCb experiment at CERN - his group researches matter-antimatter asymmetry. 

Before I continue to try and tell you a little more about this unbelievably complex research, I would like to point out to you number 3 on the map. 

3. Amolf – 'Space Piece', an artwork by Sema Bekirovic

Number 3 is Amolf: a research laboratory of the Foundation for Fundamental Research on Matter.

If today is a weekday, you can enter the building and take a look at the books you will find inside. If it is weekend, you ‘ll probably find yourself in a strangely desolate environment with more rabbits than humans around. You can still walk over to Amolf to take a look through the window to view Sema Bekirovics’ Space Piece. Bekirovic bought a piece of meteorite on Ebay and had it turned into glasses. Glasses are kind of silly objects, says Sema. But they are also the tool we, the half blind, use to observe the world. A meteorite is so to say ‘extraterrestrial’, but isn’t all matter we find on earth the same as the extraterrestrial matter? Aren’t we all made of Stardust? (And Shakespeare and Beethoven?) And can we ever succeed to formulate a comprehensive theory of the universe as we ourselves, looking through glasses made of the same thing, are part of that very universe. Are we looking at ourselves? 

Now if you continue your walk, you will see on your left hand side a brick building and you may have noticed a large outdoor print of one the experiments at CERN (this is not one of my pictures). This is the main Nikhef building. Again, on weekdays you can enter the building (number 4), on weekends, we’ll walk around it and pass by a sculpture I made together with Nikhef people. 

When entering the Nikhef, you should pause the tour and please walk into the main hall (after leaving your name with the receptionist) to look at the ‘Vonkenkamer’ or Sparkchamber and the ‘Nevelvat’ or Cloudchamber. Both are fascinating and beautiful examples of how particles can be visualized for us. The Sparkchamber shows the actual cosmic shower that constantly comes down upon us, containing most importantly muons, a particle that goes right through you, or the walls – by the millions. It made me wonder, what else travels through our bodies? 

Please continue the walk towards the second number 4. You will pass underneath a tunnel where people park their bicycles, in the distant you can see the cut tree again, but I would like to ask you to take a sharp right as you get out of the tunnel. Walk onto the mossy grass until you reach the second bay window. It is covered with a blue foil, which makes it harder to make out the sculpture I have placed there.  

4. Nikhef, basalt blocks (made by Doina Kraal)

I was granted the great privilege of working in one of the many impressive workshops that are being run inside this building. Behind this little room - which was built in the seventies to enable the women who were counting ones and zeros to take a break – you can find a cleanroom and an impressive precision machine. A new floor had to be constructed in order to not make the machine sink into the earth as the worktable is made of a massive block of granite. At the Nikhef they also work with 3D milling machines, which are for example being used to make ultra precise and very thin parts for the LHC. I wanted to know what it would be like to work with these machines, to work with these materials; mostly aluminium and brass. I found it striking that the weight of the one brass block is almost the same as the three aluminium ones. 

I was interested in using these machines to explore both perfectly symmetrical man-made shapes as well as seemingly symmetrical shapes that we find in nature.

I would like to tell you a little more about the matter-antimatter asymmetry research so please feel free to take a seat on one of the benches behind you.

At the beginning of the last century, theoretical physicist Paul Dirac combined the two theories, which we use to describe the world – the theory of quantum mechanics and the theory of special relativity – into one single theory. The consequences of quantum mechanics are only noticeable on small length scales and those of relativity only at extremely high velocities.

While doing this, he predicted that for every matter particle, an anti matter particle should exist. At first people were skeptical about this theory, but in 1932, the anti particle of the electron was discovered (using a Cloud chamber). And by now we know that for each particle there exists an antiparticle, a mirror particle, to which all the laws of physics are identical, except that they have opposite electric charge, the matter particle spins left and the anti-matter particle spins right (the matter particle is left-handed and the antimatter particle is right-handed). So are they *furthermore* fully identical?           

After the Big Bang, there was matter and antimatter. When matter and antimatter meet, the annihilate each other and become a photon. This is what must have happened, but a very small part of the matter particles remained, about one in a billion anti particles. At CERN they can make antimatter hydrogen particles and they are also detected during proton collisions. Now they should be the mirror image of the matter particle, but… they seem to behave a little different. (And another important question is; What happened to all the antimatter that should have existed?) 

We live in a universe with a broken symmetry. As the symmetry got lost, particles obtained mass through the Higgs mechanism and the laws of nature were less symmetrical. The Standard model describes how forces work based on a symmetry. If this symmetry would be exact, all particles would be without mass and matter would be equal to antimatter. Marcel Merk says: “The forces that particles (and we) experience, depend on the symmetries of nature and how these symmetries are distorted after the big-bang. The closer we look into the first moment of the big-bang the closer we come to discover natures ultimate symmetry.”

But my question is: is nature ultimately symmetrical? 

….

I would like to invite you to continue the walk. You will now walk all the way to the University of Amsterdam building towards number 5, which is the library of the University. You will pass the cut tree again and cross the street and just keep going straight. While doing so, I will talk a little more…

Left/right symmetry can be found anywhere in nature. Some phenomena are perfectly symmetrical, but often things are seemingly symmetrical. I was told to be cautious comparing the world of elementary particles with the world I observe around me, they may not be directly related to one another. But doesn’t the Standard Model intend to describe Nature? Doesn’t physics describe nature? Both organic and inorganic phenomena? 

Could it be that we grow asymmetrical just because of how we biologically develop? Are we ourselves fundamentally symmetrical? Maybe in time, the left and the right side of a biological structure experience slightly different things and thus become asymmetrical?

And I started to question do I actually like symmetry? Do I understand what mathematicians mean when they talk about mathematical elegance? And what if a Theory of Everything is found, the Standard model is completed and everything can be explained? 

Marcello Gleiser, a professor in natural philosophy and astronomy poses similar questions:

“We sometimes feel the need, we crave symmetry and sometimes we search chaos. 

From early on order was equated with safety, and symmetry with the predictable. In art and music what is considered modern is often asymmetric. 

Scientists only abandon symmetry with great reluctance. There are at least two very good reasons for this. The first is that symmetry has proven to be a phenomenally efficient tool to describe Nature. From cosmology to particle physics, much of what we have learned depends on different kinds of symmetries. The crystalline structure of many solids, from kitchen salt to diamonds, is absolutely critical to understanding different kinds of symmetries. Many structures in nature are symmetric. 

The problem starts when symmetry is taken too far and is enthroned as dogma. Symmetry is beautiful, but, beauty is not necessarily truth. Or for that matter, truth beauty. We have seen how our Universe seems to be the result of a random quantum fluctuation that burst out of the vacuum some 14 billion years ago. We have also seen how dark materials of an unknown nature surround us, and how dark materials are linked to both the birth of galaxies and the ultimate fate of the cosmos. We do not yet know what they are or why they appear in the quantities we measure. In fact, dark energy, the diffuse medium that permeates the cosmos, is downright mysterious. Whether we want it or not, this is our Universe. Different from what it was fifty years ago and different from what it will be fifty years from now. To be sure, there is plenty of beauty in it. But it’s another kind of beauty, a beauty of Becoming, not being; of change and transformation, not of equilibrium and stasis; of imperfection, not perfection. There is a need for a new kind of aesthetic in science, a new kind of beauty that leaves behind expectations of order and symmetry inspired by age-old monotheistic beliefs. This new aesthetic is founded on a single principle: the realization that Nature creates from imbalance.”

Says Gleiser.

…..

Depending on how fast you walk, you may by now have reached the University building. You may walk as far as the pillars and enter through the main entrance on the left. You will then climb the stairs on the right and at the top of the stairs you take a right towards the library. As you walk through this flashy building not everything is as new as it might seem. The palm trees for example – I learned – are mummies! Yes, they are! They are dead, but well conserved.

5.University of Amsterdam, faculty of science, library, Amsterdam Science Park. Mirror objects, photographs and book displays (made by Doina Kraal)

Here, in the library I have placed quite a few things. After walking past the first set of bookshelves you will find books from this library on bookstands and opposite that a variety of images. 

Please take a look around at the books, the images….

Some of the nature portrayed here is strangely symmetrical, not all of it is unprocessed, but just imagine how strange and maybe even scary a perfectly symmetrical world would be.

I’ll get back to these images after we have taken a look at the next section of the library, where you will find three mirror objects on your left. 

If you look straight into the V shaped mirror in the middle, you see yourself as other people see you. If you move your hand to your right eye, you will actually see it on the left side in the mirror. The differences between yourself and your mirror self are not trivial, they are actually very big. You probably have a very different idea of what you look like in reality. 

Now the other two mirror objects will allow you to see a perfectly symmetrical image of yourself. If you place your face at the long end of the mirror, letting the black metal circle cover your eye (and closing your eye on top of that helps) you can see in one object the mirrored version of the right side of your face and through the other object the mirrored version of the left side of your face. They will be entirely different. As different as the two halfs of your brain are. 

I’ll get back to the other images in the library; I am mystified with the question what is Nature, is it both organic and inorganic things? What is being described by physics? By the laws of nature? What are the differences between the organic and the inorganic? Is it carbon? Is it change? Is it about the balance – imbalance? 

Life chooses a very specific shape for the molecules to make up stuff. If you look at all the proteins in living things, they are always left-handed. If you take for example the atoms, which build caraway seeds (a spice used in rye bread – rogge brood in dutch) – take a mirror image of them and suddenly you get something which tastes of spearmint. Scientists all the time manufacture mirror molecules of all kinds of things (sometimes with disastrous consequences.) Isn’t this incredibly fascinating? Does this relate at all to the big matter – antimatter mystery?

Please continue your walk. Walk out of the library and turn right. You will go back past the mummy trees again into a long corridor with glass vitrines on the left. 

6. University of Amsterdam, faculty of science, display cabinets in the corridor (meteorite by Doina Kraal)

and

7. University of Amsterdam, faculty of science, display cabinets next to lab (photographic sculptures by Doina Kraal)

These vitrines show a permanent exhibition made by ‘Bijzondere Collecties’, the department Special Collections of the University. 

The exhibition continues for a longer walk all the way passing stairs on the left (down below which a large part of the New Realism show can be seen) into the next corridor where there are more vitrines on the right-hand side). Hidden amongst these objects are my numbers 6 and 7. I have placed several objects that question how we name things, how we categorise them. Once we named something we can never again see it the same way. Many of these objects could as well – especially nowadays – be found in a museum for contemporary art. They serve an educational purpose, but also a highly aesthetic one. They can be questioned, they can be used, they can be examined, the can be enjoyed.

I like it when the differences between categories fade. I like breaking the borders, where science is actually creating them. This is not an accusation against science, but it as a way to reflect upon and question some of the methodology of categorisation implicit in the scientific approach to understanding the world that surrounds us.

More incredible things may be discovered at CERN, at the Nikhef and I will follow those developments closely, I find it most exciting. But if the Standard Model will not be completed before I die, if no finite set of laws will be defined to describe the evolution of the universe, I won’t be all that sad.

As astrophysicist Adam Frank says: 

“If the becoming of the universe is partially beyond natural law, the issue is deeply important: The way the world becomes may be ever creative and open.”

8. Laboratory, Van der Waals-Zeeman Institute for experimental physics, low pedestals with tree trunks, gold (brass) and silver (aluminium) residue (by Doina Kraal)

We are about to reach the end of this audio tour. Almost at the end of the corridor, where the windows on the right side are no longer covered with foil, you can look into the laboratory on the left.

Again, I have placed some things in here. This time it will be easier to make out what. Is it art? I don’t know. It might be. The tree trunks, the gold and the silver are the residue of some of the pieces that I made for this audio tour. It is the material that was removed to shape an object. Can we ever remove something? Can anything disappear? When matter and anti-matter meet they make each other disappear, but they become a photon, which is again an elementary particle… Everything can become anything. Can waves become particles and particles waves? 

The research that takes place in this lab, the Van der Waals-Zeeman Institute for experimental physics, is equally complicated to understand as the matter-antimatter asymmetry problem, but they also work with symmetry. 

With one of the scientists who work here, Anne de Visser I also had a chat about symmetry. He works amongst other things with crystals and crystals are always symmetrical. He explained me how different materials and shapes can have different levels of symmetry. For example, water versus ice. Water has little symmetry and ice is more symmetrical, we all know what ice and snow crystals look like. In the ice, the molecules are caught in a grid. They can only move within the directions dictated by the grid. In water the molecules can move in any direction and the molecules have more possibilities and might actually end up being more symmetrical! Water is more creative. And isn’t it something that life itself needs water? It needs to be able to move in all possible directions. Wouldn’t it be so boring and moreover very cold if we would live in a frozen world, where our movements are dictated by a grid? Beautiful? Yes, very beautiful, those ice crystals and snowy mountains. We cannot live without them. We need order as much as we need chaos. We need scientists and we need artists, we need symmetry as much as we need asymmetry.