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