Book review 1) The Particle at the End of the Universe

I saw already lot of people to do book review, like Joseph from Rationalising the Universe or Abyssbrain from Mathemagical site. I have already used a lot of parts from this book in posts about dark matter, dark energy, particle accelerators and so on.

It is book: The Particle at the End of the Universe by Sean Carroll. It is about particle physics and the Higgs boson.

This book has 13 chapters and three extra three parts explaining some stuff around.
Author starts the book with short introduction to history of particle physics, what people thought that was making up everything. He mentions elements, atoms and so on, then he introduces higgs boson and his role in standard model of physics. He explains why he thinks that it is important to study it and what part LHC plays in this.

In second chapter Sean explains why Higgs is also called “god particle” and the relationship of physicists with god. There is also review of properties of Higgs and some things about fields.

In third chapter author introduces whole standard model and how higgs boson changes it. There are parts about all particles and all four interactions.

Fourth chapter is about the story of accelerators and how they work. This continues to next chapter where there is description of all the work that had to be done to build LHC with credit to all people. Author describes how are particles detected and how they decay.

Whole chapter is just about fields and gravitational waves continuing about symmetries and how they are broken. This is also probably the most complex part of the book which I had to read more times to really get to know what is it all about.

He continues with deep look into finding of Higgs boson with stories about all the people around, and the excitement about it.

There are stories about destroying the world with LHC creating black holes and author perfectly talks about the way news are used in magazines and how physicists were trying their best to not let spread a wrong news about Higgs.

In 11th chapter Sean is talking about Nobel awards for particle physics that led towards Higgs.

The book ends with text about the new things that are now opened for scientists to discover when they know that the particle really exists.

In three extra parts author adds some more context to spin, standard model and Feynman diagrams.


This book is really well written and I give it 10/10. I really recommend it to anybody who wants some introduction to particle physics because with all those analogies you will never be lost. I like how Sean also describes all those people around the great work and how all of this makes the whole picture and story behind “The Particle at the End of the Universe.”


Picture of Czech book
Picture of English book

The book review of: The Organized Mind
The book review of: On the Origin of Species

Higgs boson for dummies!

finally here it comes, here it goes, post about Higgs boson is coming. Lets look what the “god’s particle” is how physicists found it and what it means.


God’s particle

Lets see how Higgs boson was named the god’s particle.

One of the best particle physicists Leon Lederman who found out that there are more types of neutrinos and so on and on. He wrote a book named the “God’s particle”. The book was partially named like this because the publisher did not want it to be named “Damned particle”.

He did this and now all physicists can agree on one thing, they hate this phrase because Higgs boson has nothing to do with God.

While all journalists can agree that “God’s particle” is amazing phrase.

So if you want some physicist to be angry on you, just mention the God particle and he will never forget.

Higgs boson was found 4.7.2012 in Large Hadron Collider.

Higgs field

What is actually more important than Higgs boson, the particle, is the field from which it came, this is the Higgs field. I already talked in last post about fields and how specific vibrations can form particles. Higgs field can do this too and it makes the higgs boson which decay almost immediately and is really hard to detect.

Higgs field is a very different from other fields because other fields can get to 0 energy while Higgs field can not. What is more accurate to say is that non zero value of Higgs field is less energetic than zero so Higgs field does not want to fall on the value of 0.

What does it do?

Well you may have heard about Higgs field giving mass to matter. This is partially true since when particle interacts with Higgs field they are kind of slowed so they do not travel at the speed of light. Some particles interact more than others like some people interact with group of people more than others because they are well known [1].

At one post I wrote about symmetries, check it out if you did not already. There is symmetry in particles. They are all the same.
What? Now this symmetry is broken, this means that there are differences between particles, thanks Higgs field! This is the most important effect of the field with the effect that while it would not change much the mass of protons and neutrons, it would change the mass of electron rapidly if it would not exist. Now the space occupied by particles as electrons is set and such a light particles need to have a lot of space around them. If you would turn off Higgs field completely, things would probably gone exploding a lot since the size of atom would increase as the space around electron needed would get bigger.


[1] This does not mean that all the mass is from Higgs field, most mass of neutron and proton is made up of energy m=E/c^2.





Various fields for dummies!

fields? Well yes, this is probably the last post before I will write about Higgs boson. Today you will learn that everything is made up of fields and that particle is just a special vibration.

Take for example magnet, it is something totally special if you think about it. Not that it sticks to stuff but that you can feel how it wants to stick without actually touching anything, just through EMPTY SPACE!

Magnet has his magnetic field all around, that is why we can feel it from some distance and the strength decreases with distance increasing.

On the picture above you can see lines of force around magnet.
This is electromagnetism and now we know that there is electromagnetic field around all the stuff that have charge. We know that we can magnetize needle using electric current.

This field is not only around magnets but also around all things that have mass, this is called gravitational field and even that it does not sound very exciting to us, in Newtonian age it was very cool when Newton found out that there is similarity between apple falling on his head and Moon orbiting Earth!

What happens when you start to rapidly move with source of electromagnetic field? Well you create waves. If you do it well enough such waves will create light! This light then comes to you in quantum! If you do it more rapidly you will get gamma rays and if you do it less rapidly you will get radio waves. This is just a vibration of field.

Or when you take radioactive decay. There is neutron which somehow changes itself into proton, electron and antineutrino. This is just a change of vibration in various fields.

Now there are 4 fields if I do not count Higgs field. What physicists want to achieve is the prove that all those fields are just one field and everything is just a various vibration of it, creating the effect of gravity, electromagnetism and so on. This would be the Theory of Everything.


Symmetry for dummies!

as I said, I will continue with the explanation of what I mentioned in some earlier posts. Today I will try my best to learn you what physicists mean when they say something about “symmetry”.

First of all, when you say symmetry you probably mean that it is the same on both sides.

On the next picture you have some shapes with the right and left “lines of symmetry”.
This means that you can flip them around this line and they will be exactly the same pictures.

Square has more than one line of symmetry, there are four of them [1].

This is what we think as symmetry but physicists use it in more kind of complicated way.

When somebody makes experiment with coca-cola and candy [2] it will explode. And it will explode in New York, Prague, under water, upside down if you do it properly and even in space. This is symmetry, it does not matter where you do the experiment. But it does matter what you do it with, if you would have used water instead of coca-cola, or chocolate bar you would see that there is no symmetry [2.5]! Because it is not going to work!

When we talk about particles we can say that there is a symmetry in them, for example you can have 3 quarks, labeled as Paul, Rick and Nick. It does not matter which one you will use, because all of them have the same properties! This is symmetry all quarks are same, all electrons are same and so on.

There is a symmetry in fundamental forces. For example in strong nuclear force there is symmetry in quarks and their colors [3]. It does not matter how you label one of three quarks, it can be red, green or blue.

Also charged particles are created in pairs. This means that you have to conserve the charge so if you create electron you must create positron or something else with positive charge.

Only weak nuclear interaction of all fundamental forces has special kind of symmetry. Weak force is the only force which makes difference between particles which are right and left handed.

Such a particles  are in pairs:

  • quark u ←→ quark d
  • quark c ←→ quark s
  • quark t ←→ quark b
  • electron ←→ electron neutrino
  • mion ←→ mion neutrino
  • tauon ←→ tauon neutrino

This is also called the breaking of parity.

So weak interaction breaks symmetry and behaves differently with right and left handed particles while other forces do not do this, take for example gravity, everything is attracted by it and it does not matter if it is quark u or quark d.

Of course those particles are diametrically different their mass varies a lot, but this is only because of what is called: Higgs field, and I am going to talk about it another time.



[1] Star has 5 lines of symmetry, triangle has 3 and arrow only 1.
[2] I do not know if it is in English mentos.
[2.5] This is also called “broken symmetry” if it would not be broken, in this analogy anything would work as the mentos candy and there would be no difference between coca-cola and oil.
[3] Quarks have colors as I mentioned in last post and also in post about strong nuclear force.
[4] Maybe you remember from chemistry how you were filling the orbitals with pairs of electrons: ↑↓. Those arrows mean that one electron has negative and second positive spin (but still the same value: 1/2  .. -1/2)

The Standard Model for dummies!

last time I talked about some stuff like dark matter (1 & 2), dark energy and I did not explain a lot of things which I mentioned and this time I will talk about Standard Model.

Standard model or Standard model of particles and interaction is the model of all observed and proved particles.

The next picture shows how it looks like, you could say that it is the “modern” periodic table or some kind of holy grail of physics.

So in this standard model you have particles that make up everything we know [1].

There are four main groups which are sorted by the forces they interact with.

All of those particles interact with gravity. Quarks also interact through strong nuclear force while leptons do not interact that way, also all of them have whole numbers for charge.

The red part has inside particles which are what is called “force carriers” they carry the fundamental forces with graviton excluded because he is not proven yet.

The most mysterious is the yellow part with only Higgs boson inside, I will make sure to make a whole chapter only about it.


Already months and months ago I made post about quarks. Here I will cut it short so, quarks are particles that made everything there is except just a little part which is made from electrons. Quarks normally group together into hadrons – protons, neutrons, pions. Quarks have charge of either +2/3 or -1/3. They also have a property called color which is not color at all and they must group together so their colors cancel into white (white) [2].


There are three main particles called: electrons, muons and tauons. Only electrons are actually somewhere while we can create other in the particle accelerator.

All of those have -1 charge but there are other particles called neutrinos. Electrons, muons and tauons all have their neutrino.

I already wrote about neutrinos but they are actually extremely light particles sometimes called “ghost” particles because they can easily go through whole planet Earth without touching anything. They are also electrically neutral.

Force carriers

Gluons are particles that are mass less and they carry the strong nuclear force.
Photons are also mass less and they carry electromagnetism.
Gauge bosons (W+- and Z) carry weak nuclear force.

Most of those particles have mass and that is because of Higgs boson, but that is whole new story which I will have to start with symmetries and fields, stay tuned.

Also main difference between force carriers and everything else is that they do not need any space to exist, there can be millions of them at one spot while only one lepton or quark.



[1] I do not talk about dark matter which I mentioned in earlier posts. WIMPs are not here since they do not belong into standard model, those are particles beyond the model even if they exist.

[2] Quarks have 3 basic colors: Red, Green and Blue but there are of course anti quarks which have just opposite colors: Antired, Antigreen and antiblue.

The riddle of DARK MATTER! (Part 2)

about three days ago I was asked by the writer of “Oopsmymistake” to update about dark matter, so today I decided to write something more about it, here you go.

Last time I talked about dark matter as stuff that fills about 25% of all matter in whole Universe but we can not feel it and the only way to observe it is by its gravitational effect, for example it is extremely important in whole galaxies.

Now there are some things that I did not mention because actually there are more things that we can deduce from its behavior.

As I said, it is assumed that dark matter is composed of new kind of particle/s beyond standard model.

Lets assume that this is right, now this particle does not react much as we know, it has to be electrically neutral, otherwise it would react through electromagnetism and we would be able to observe the photons which would come out of the interaction.

Also dark matter still exists which means that it has to have half life at least the age of Universe (top and bottom quarks for example do not form anything because simply they are not here, they have too small half life).

We know that it does not interact much, otherwise it would concentrate in the middle of galaxies and not all around. So dark matter can not interact via strong nuclear force.

Now this kind of hypothetical particle is called WIMPWeekly Interacting Massive Particle.

It is assumed that the mass of such WIMP is about 10-1,000 GeV which is roughly around Higgs boson and other bosons like W and Z.

The amount of WIMPs with such a energy almost perfectly corresponds to the real amount of dark matter. Also model of super-symmetry predicts such particle with the properties we know now. It is definitely more complicated but it is called the WIMP miracle, while it could be just coincidence.

Scientists think that with this model WIMPs should interact with Higgs boson which would create something we call: “The Higgs portal” because Higgs boson would be the particle through which we would be able to observe whole dark universe (the portal between standard model and dark matter).

Of course particle physicists designed special detectors to detect WIMPs. There are two main way to do that, first is cryogenic, which is the detection of heat made by WIMP interacting with some super cooled element and the second one is to measure flash of light during interaction of WIMP and liquid xenon or argon. Such detectors are buried deep under Earth so that normal radiation does not disturb it.

Approximately in the volume of cup of coffee is always one WIMP and it is assumed that they travel at the speed of hundreds of kilometers per second, which means billions of them whizzing through you every second. Also about 10 interactions of WIMPs happen every year with atoms in your body (this is kind of similar to neutrinos).


PS: if you did not understand some terms I will mention them in next posts: Standard Model, Higgs boson and so on..



Superconducting Super Collider

so yesterday I was in Prague, the capital city of Czech Republic, because of some serious business. When I was waiting on the train station I went to bookstore there and bought really cool book, it is called The Particle at the End of the Universe, by Sean Carroll (By this particle author means Higgs boson). So, I already read 80 pages and now I want to make post about Superconducting Super Collider or SSC.

This book is about Higgs boson, which is particle I will write about some other time. Anyway it was discovered in Large Hadron Collider but there is whole history of other particle accelerators before this one.
Today lets see why SSC was never build.

Ssc mdl.JPGThe most important thing about particle accelerators is their power they can create. LHC which is the strongest on the Earth right now is able to create force of 13 TeV (tera electron volts.) At the same time this may sound powerful and weak.

1 TeV is around the energy of flying mosquito. Well that does not sound like it is much but the other thing is that LHC is able to make 13 TeV and at the same time give this energy to only one proton. When LHC is active, there may be billions of protons flying with this energy, when you add it up it may be as much as the energy of whole locomotive.

But SSC was planned to be even stronger so that it would be able to reveal even more energetic things. It was planned to be about 40 TeV strong which is quite mind blowing.

In the year of 1987 president Reagan accepted the construction of SSC. Then the place to build it had to be found.
Such a place must be geologically inactive, there must be no floods and so on. Of course all most of the states (43) wanted to have it in their city. Finally place called Waxahachie in Texas was accepted as the most safe one (it is located bit south from Dallas).

It was planned to be 87 kilometers long and activated in the year of 1996. First it was thought that it would cost 4.4 billions of dollars, but soon afterward the price rose to 12 billions of dollars. At the same time huge project needed money: ISS (50 billions of dollars, later it rose to over 100 billions of dollars).

When there were 2 billions already invested, it was decided that it was not worth it. Reasons for this were that it was poorly leaded, with prices that were underestimated all the time and so on.

This had some serious causes, like lots of particle physicists were without work. The area was then sold to guy who wanted to create super protected area for computer data, but he fell on the ice and died. Luckily USA decided that they will donate some money to LHC (particle accelerator in CERN) which was activated in the year of 2008.


1st picture