Physics keeps life going-物理 依据 生命


Πράγματι, όπως εκτίμησε και ίδιος ο Feynman στον πρόλογο του από τις διαλέξεις φυσικής, όταν διαπίστωσε ότι ο αριθμός των φοιτητών του μειωνόταν, ενώ αυξανόταν ο αριθμός των πτυχιούχων φυσικών.
‘ Δεν υπάρχει άλλη λύση στο ζήτημα της εκπαίδευσης παρά να συνειδητοποιήσουμε πως η καλύτερη διδασκαλία επιτυγχάνεται μόνο όταν υπάρχει άμεση προσωπική σχέση μεταξύ του φοιτητή και ενός καλού καθηγητή – όπου ο φοιτητής θα σχολιάζει τις ιδέες, θα σκέφτεται και θα συζητά τα διάφορα ζητήματα. Είναι αδύνατον να μάθει κανείς αρκετά απλώς και μόνο παρακολουθώντας μια διάλεξη ή ακόμα λύνοντας τα προβλήματα που του ανατίθενται. Στη σημερινή εποχή, όμως, έχουμε να διδάξουμε τοσο πολλούς φοιτητές ώστε πρέπει να προσπαθούμε να βρούμε κάποιο υποκατάστατο του ιδανικού.’( Φέυνμαν,1963) 

Why this van has this designs on it?

Feynman was so proud of his diagrams that he had them painted on his van (which also had “Qantum” on the license plate). Once someone--not recognizing the scientist--asked him in a perplexed voice why he had Feynman diagrams all over his van. "Because I'm Richard Feynman!" came the quick response

A student can play and learn with this link: Interactive Feynman diagrams.

Feynman diagram is like a pair of compass, which help us to find the way in the jungle of the elementary particles!!

Interesting educational Method for Teaching Feynman Diagrams

or you can see the video in the youtube 

Interesting technological  prosedure for teaching Feynman Diagrams is the following program as you  can see in the video:    

interaction e-e

 the interaction of two photons,
known as pair production γ +γ ➝ e- + e+. (One of
those photons is normally part of a strong static field
that interacts with a high energy passing photon.)                   

the procedure can be seen in the following video:

What feynman said about Poynting Theory.

 general relativity and uncertainty principle

interesting videos with Feynman

Generalized we can explain relativistic collisions with feynman diagrams.

Tachyons the  exchanged objecst appear only during relativistic collisions, never on their own. They are called virtual objects, to distinguish them from the usual, real objects, which we observe everyday.
In the following diagram the first object ( left line) has changed its momentum
before the second one.That would mean that there is a short interval when momentum
and energy are not conserved! The only way to make sense of the situation is to assume that there is an exchange of a third object, drawn with a dotted line (virtual particle).

Tachyon is always a virtual object and its mass is an imaginary number!
On top of that, we also see directly from the  graph that the exchanged object
moves faster than light. It is a tachyon, from the Greek ταχύς ‘rapid’. In other words,
collisions involve motion that is faster than light! That collisions are indeed
the only processes where tachyons play a role in nature.

More details you can read at Christoph Schiller's  Motion Mountain

Writing on the board