Why is Physics so sexy?

As you may have understood, those following few words aim to do two things: show how our fascination for Physics is natural, and how to raise that interest. However, let's first focus on our dear Hendrik

Kuldar Leement - Never Quiet

By a dark day of winter, Hendrik went back home and stepping into the darkness of his room, switched the light on. Miracle: and there was light! He reiterated the experiment successfully so many times that he gave up the idea of any divine intervention. He thought to himself: "that is only science!"

Nope! This wonder obviously comes from some very advanced technology, but is far from being science. Where technology  implement our knowledge for our everyday life, science is only concerned by that pure knowledge. For instance, Physics is not going to explain how to make the switch but it will explain how it is working and why the laws of nature make it so that it can be turned on. Enlightened, Hendrik said with passion: "so, it was divine".

Is Science a religion?

Here again the border between what is natural and what is a miracle gets thiner and thiner. Some would even say that Physics and its laws have almost completely erased their religious beliefs leaving room for a rational formalism closer to intuition. However those would have done nothing more than create another God, more logical, more palpable, more human… A 2.0 version of a God.

But the foundation of all demonstration and calculations always lies in primary axiomes and postulates. 

Science is not a religion.

The question is not whether or not to believe in the Big Bang. The aim is not to reach what is called real nor to say what it substantially is but simply to describe what we see. That big boom (we’re naming the Big Bang) Fred Hoyle was referring to, with sarcasm, is nothing more than a cosmological  model aiming to describe the origin and the evolution of the Universe. Yes, a model. One among others. That one working better than others: it is consistent with most of our current observations. The Big Bang is more of a geek equation than a creation at the origine of space-time. At the end of the day, the main goal in Physics would be to find the phenomena that can not be explained by the current model and would lead to a better one. (For sure the dude that finds that would get a Nobel prize.)...And so on and so forth. 

From that moment on, when Hendrik understood the ephemeral nature of our reflexion's base, he couldn't help thinking: "what is our science really worth?"

Physics is beautiful. That's indeed what makes it so sexy.

Let's take an example: rainbows. No one can claim to be insensitive to the beauty of the colors of the light spectrum (not even Hendrik). From the child to the old man, we all are mesmerized by its beauty.

Of course the physicist doesn't always think: "well, a rainbow is a phenomenon of optics that displays a spectrum of light due to the sun shining on droplets of moisture in the atmosphere." He just doesn't. However, be certain that his scholarly contemplation expands by a thousands times his imagination's horizon.

That way, free from any spiritual or metaphysical thoughts, let's curiosity be the fuel to unwrap the mysteries of the Universe and its phenomena; the link between that knowledge and beauty would come naturally. In the end, what matters is our ability to wonder, our ability to keep looking at the world the way we used to do as a child discovering the world around him…

NB: The man on the cover could not in any case be mistaken with our dear Hendrik…



Sophie incognito

Particles, myth or reality?

   If I ask you « How do you know trees exist? » you may answer « Well....because I can see them, I can touch them, I can hear the wind blowing in their leaves. My senses are telling me that this thing we call tree exist». Ok, the truth is that you're more likely to look at me and be like...shut up, you wierdo, do I ask you how you know your mother exist ?! Anyway...

My point is that you experience the world around you thanks to your senses.

Now how do you know particles exist ? I mean not you, you. I know you have other stuff to do in your life than looking for particles, and yes, some people called physicists get paid to do that.

So how do physicists know fundamental particles exist ?

And no, they are no superheros that can use ultraviolet vision to do exciting stuff!

That'd be awesome...the League of Superhero physicists version...

                                                   well, superheros or superheroïnes....

   First of all we may wonder how small those particles are. I mean if those were big enough we could answer by saying that we can see/hear/touch...them...But unfortunately, God, the mystery of the universe or whaterver is bigger, decided that those particles should be small. Like super small, like below 10^(-18) meter which is 0. 00000000000....01 meter (zero dot followed by 17 zeros and a 1).

A nucleus (which is already small) is 10 thousand times bigger than the biggest elementary particle ! It's like the size of a basketball compared to the size of a basketball field !

                                                                         an atom

So we would need some super microscopes to see them.

   The best microscopes nowdays are electrons microscopes and the smallest object they can see must be at leat 10^(-12) m (remember zero dot followed by 11 zeros and a 1). I'm so sorry to come up with the bad news. I hate doing that. Well, it's still a hundred thousand times the size of an electron. So even if you were planing on trading one of your eye and replace it by an electron microscope (I know...who would even think about doing that...), it would still not be good enough to see particles. 

                                        Nice try dude, but u'll have to work on it a bit more                                            

   So basically we are not able to see them. Moreover some particles (not electrons) usually have a very short life time. Not like when you think that you wanna make it 'til 250 years old 'cause seriously that's not even that long...I mean I also do wanna meet my grandgrandgrand children...maybe those ones will finally save the familly honour.

No, here I'm talking about fraction of fraction of second.

For example the tau t's life time is only 2.8 10^(-13) s

Like you don't even have time to begin wanting to think that it's already dead. It's like one day compared to the life time of the universe !

                                                 The tau is like a very massive electron

   And I am not even talking about the mass of those particles. Since they are super small, they are also very very light. The electron is 10^(-31) kg ! The ratio between an electron and a rabbit is similar than that of a mosquito and Jupiter !

   Too much numbers everywhere... All of it is too small for me to wrap my mind around it ! I know.

I mean seriously I am happy drinking my coffee in the morning and meeting my bed at the end of the day...(and knowing about the mysteries of the universe, sometimes..okay, let's keep on...)

   Hopefully all particles are not so shy and snobs. Some of them like to electrify us. I name electrically charged particles...i.e. particles carrying an electric charge. You know it's like when you meet someone who's super magnetic, like he attracts everyone. Here it's the same. There are two charges : + and -, same charges repulse each other and different charges attract each other. Like « opposite attract each other » quote thingy. Well those particles are pretty cool 'cause they bend, and leave traces when the right environment is created. Just like in a cloud chamber !!!!

Yes....I hear you...what is a cloud chamber, is it like the smoking room in a club ?..... Wo wo wo . We're still doing physics folks !

   In 1911 Charles Thomson Rees Wilson a Scottish dude invented the first cloud chamber! Basically it's a box filled with vapor of water or alcohol. When a charged particle crosses the mixture, ions are gonna be formed through its path and leave a trace, just like in the GIF below.

                                       cloud chamber: all the little traces are particles' path

                                            (in the beginning some gaz is being introduced)

HOW COOOOL !

                                                                 #feelingexcited

   That was just the very beginning of particles detectors history.

In 1952 Donald A. Glaser invented the Bubble chamber that kinda work the same with liquide instead of vapor, and in 1968 French physicist (feeling proud!) Georges Charpak built the first wire chamber that kinda doesn't work the same at all....

                                                 particles trajectories in a bubble chamber

And some years after the biggest particle physics facility as we know it today: The CERN!

Sophie incognito

Yes, even Particles have their own history !

   In 1909 two physicists, Hans Geiger and Ernest Mardsen under the direction of Ernest Rutherford made the following experiment : they sent alpha particles on a thin metal foil made of gold atoms and checked how alpha particles would bounce back. I know, who on Earth would wake up and be like, I'm gonna send alpha particles on a sheet of gold... 

                                                               Rutherford experience

Well those guys did and made a breakingthrough discovery : atoms are made of a nucleus positively charged and electrons graviting around this nucleus. You may think, how great...everybody knows that. How else could an atom be. 

  Well untill that time most physicists thought that atoms were like a pudding where negative and positive charges would happily swim around. Too bad for those physicists to realize that positive and negative charges are like cats and dogs. Now, your cat may like your dog, but you got the point right...They don't share the same room. When electrons race around the nucleus (pretty far away) in their own clouds, positive charges are happier cuddling in the nucleus. 

                               illustration of positive charges cuddling....(that dude looks creepy though)

So now, you may ask me... so there's a cloud full of electrons, a nucleus where positive charges cuddle (orgie...lol), so... What's in bewteen ?

Well Ladies and Gentlemen, be ready for the greatest answer ever.... There's nothing. Not like when you open your fridge coming back from holiday and have to make the following sad statement : « there's nothing in my f***** fridge », not that kind of nothing. I'm sure, there's a beer left, a rotten tomato, some left over of chinese food.

                                               Hum....what am I gonna have for dinner?!      

 When I tell you there's nothing bewteen the electronic cloud and the nucleus I mean the void, total void, not even the smallest, slightess particle. NOTHING.

That was something to admitt for those guys. Matter is made of molecules. Molecules are made of atoms. Atomes are made of an electronic cloud, and a nucleus with Nothing in between !

                                                              atome: electronic clouds 

Now we know that matter is made of electrons and a nucleus.

Cool, but let's take a look closer.

What is the nucleus (but an orgie, yes yes, we talked about it before...) or should I ask, what's in the nucleus ? Rutherford -yes that same dude who discovered the structure of atom, some have it all- realized that the nucleus was made of protons and neutrons. Protons carry a positive charge and neutrons are electronically neutral. So here it is. We know a lot about atoms. And we're not done ! We can zoom more ! How exciting, how far are we gonna go. Well, sorry guys, this is gonna be the last zoom for now. So we know that electrons are fundamental particles, which mean that they cannot be decomposed into smaller pieces. However protons and neutrons are not ! They are made of smaller particles called quarks. Those guys however are fundamental particles. Fiou....we're done zooming !

A proton is made of two up quarks and one down quark and a neutron is made of two down quarks and one up quark .

So now we have three elementary particles :

the electron and the up and down quarks.

And this is just a very small piece of the puzzle.

During the 20^th century physicists putting their brains together established the existence of no less than 16 fundamental particles !!!! Plus the Higgs Boson that was discovered three years ago.

Basically there are two kinds of particles :

-Leptons which are particles of matter. like you can touch them. I mean if you were really, like really small.

-Bosons which are particles of forces. They carry forces. Okay, now you're like...wait, what are you talking about 0.0 So imagine you're on a boat. One of your friend is on another boat. (I'm talking about small boat, not yatch and stuff). You throw a ball to your friend. Let's also say you know how to throw and your friend knows how to catch a ball. So, you throw this ball, and your friend catches it. What is likely to happend is that your friend's boat may move away a little bit. You see, your ball was carrying some energy, some force and carried it to your friend's boat. Bosons kinda work the same.

So here is the standard model of particle physics.

                                                   Standard model of particle physics

There are 6 quarks, 6 leptons and 4+1 bosons, each boson correspond to a fundamental force.
g: Strong force (the one that keeps quarks together)
W and Z: Weak force
γ (also called photon) : electromagnetic force

So now you can try to put them together the same way you used to do with your lego when you were a kid...(Well there are some rules...but same with lego right...)

                                          Haha...We're so happy swimming in legos!!!! x_x

After a century of intensive reseach, gigantic installation like the CERN, the puzzle is finally completed!

Sophie in cognito