You are viewing a single comment's thread from:

RE: 100 years of discoveries in particle physics - building the Standard Model brick by brick

in StemSocial8 months ago

Thanks a lot for this very interesting post 👍

Is a photographic plate used for the same type of experiment as a Wilson cloud chamber or are they totally different experiments? If different (what I think because if I remember, a Wilson cloud chamber does not allow to see any collisions but only the trail of the particles), the 2 are complementary or for totally different research fields?

If mass is not an intrinsic value but an acquired value, what other property or knowledge would we need to be able to know that these 12 entities are in fact an aggregation of other elements?

Sort:  
 8 months ago (edited)

Thanks a lot for these questions, which I will try to answer below.

Is a photographic plate used for the same type of experiment as a Wilson cloud chamber or are they totally different experiments? If different (what I think because if I remember, a Wilson cloud chamber does not allow to see any collisions but only the trail of the particles), the 2 are complementary or for totally different research fields?

Photographic plates, cloud chambers, bubble chambers. They are different devices that do the same thing: recording the tracks of charged particles passing through them. The collision that has given rise to the tracks does not necessarily need to happen on the plate (but could).

The disadvantage of the plate... is that you needed to develop them. The advantage is that they were cheap, compact and easy to carry on. Their modern versions are used today in various detector (for instance those of the neutrino experiments).

If mass is not an intrinsic value but an acquired value, what other property or knowledge would we need to be able to know that these 12 entities are in fact an aggregation of other elements?

There are analyses trying to unravel the substructure of what we consider as elementary particles today. However, they have not found anything so far. Also, quantum mechanical properties (the uncertainty relations) make it a bit hard to conceive. Let me explain this last point which I find particularly striking.

Whereas quarks and leptons are elementary particles, we in fact only have an upper bound on their size. For the electron, it is less than 10-18 m (the proton is 1000 times this). The momentum uncertainty (in the quantum mechanical sense, that is close to the statistical sense) of a constituent of the electron would then be about 400,000 times larger than the electron mass (50,000 times for a quark of the same size). Here is the problem: how could light quarks or leptons be made of smaller entities that would have an enormous energy arising from their momenta, this energy being much larger than the mass of the composite system?

Thanks for your comment!

Hahaha you killed me, next time I will wait for the French post (not sure it will change something LOL!). The paracetamol company thanks you, I just ordered a few boxes from them.

Thank you for these clarifications on the different devices and this very interesting last paragraph of your answer. I believe that science still has wonderful and exciting discoveries to make!

As for quantum mechanics, I think that as human, it's really difficult to conceive because on the one hand our senses (sight, hearing, smell, touch) have conditioned our brain to have a distorted representation and on the other the knowledge taught is sometimes not in conformity with the reality because of the lack of technology. For me it took years of deconditioning before I could finally visualize our solar system not as a sun stationary with the planets revolving around it as learned with a 2D plan on a book but as the sun evolving in the universe with the planets following it in a spiral around it.

Noooooooo!!!! I didn't want to kill you, really. ^^

As a funny coincidence, a fresh bachelor student asked me and colleagues earlier today what quantum mechanics was. It is very hard to explain but the impact are easier to grasp. It explains why matter is coherent and not falling apart. It also explains while although any stuff (object or being) is mainly made of vacuum, it has a solid envelope somehow. And it is damned counter-intuitive in its first approach.

If you are interested, I wrote a bachelor's level primer book on quantum mechanics (in French). Otherwise, I am afraid that I do not know what to answer without having the question more specific.

Don't worry, my job has made me used to big headaches.

One thing that helps me put things in perspective is to remember that when I sit down, my ass never touches the atoms of the chair Hahaha

Yes, I am interested :)

Where have you heard that sentence? We used it yesterday too :)

Would there be a quantum entanglement between France and Thailand? 🤔 Hahaha... I probably heard it on Youtube, video of scientific popularization or replay of a conference (Alain Aspect, Julien Bobroff, Roland Lehoucq, Marc Lachièze-Rey, Étienne Klein...)

Hehe I see. I however don't see for quantum entanglement with human beings ;)