Fresco,
You've misinterpreted the diagram. The backward arrow refers to the positive charge of the positron which is equal in mass to the electron and when combined with the electron annihilatesit and produces two gamma ray photons.
positron particle
Yes, a code by which they talk to themselves and to others. Social agreement or a culture of physics ?
Talk 700
From google:
... These are diagrams that explain the structure of matter by showing how particles (electrons) travelling forward in time may be thought of as anti-particles (positrons) traveling backwards in time.....
If this were not the case there would be no significance in using arrow heads and the left->right rule. What Feynman is saying is that experimentally there is no distinction between "an electron travelling forwards in time" and "a positron travelling backwards in time".
JLN,
No distinction - just areas of focus.
A version of "relativity"? When X moves relative to Y, Y is moving relative to Y. A difference that makes no difference.
fresco
In the second diagram, the electron and positron meet and annihilate, or disappear. For a short time there is only a single virtual photon present, which then disappears to produce a new electron and positron pair, traveling apart in different directions from the initial pair.
It was just theorizing and diagrams anyway.
Now "the mathematical formalism of field theory suggests that [the world lines of the positron-photon scattering on the right] can be interpreted in two ways; either as positrons moving forward in time, or as electrons moving backwards in time!" (Ibid., p. 183; this is why antiparticles can be conceived of as particles moving backward in time.)
The moving backward in time is just a theoretical equivalence of positron.
Link
Talk,
Within the "code" I think you will find that "direction" is defined "in time" as on a distance time graph where the vertical axis in this case is a condensation of the three normal space co-ordinates. They may have been "just diagrams and theorizing" but they were the basis of Feyman's Nobel prize.
It is like debt a negative dollar. Nobody can produce a negative dollar note.
Yes we crossed in the post !
Nice to see you are quoting Capra (one of my good guys) who in his later works has much more to say on epistemology.
....are you sure nobody can "produce" a "positron" ? ....I've not looked it up yet.
What I am saying is that the equivalence of a positron is an electron going back in time as Capra says. You cannot go back in time.
Time is like cooking. You have food. You prepare the food for cooking. Nothing really happens until you apply heat. Depending on the level of heat, time passes. Try cooking a chicken forever. It will disintegrate!
Time is relative to the moment, and the person perceiving the moment.
The nature of time changes with where you are physically located in the universe. Since we are here, and it is now, we are experiencing time. We are also experiencing some level of heat.
Some places in the universe, in theory, have no experience of the passing of time.
Journey
When I was little, my grandmother would roast a chicken (it smelled sooo good), it would take forever to cook.
So there goes that theory.
I want to know how much of "now" is in the past and how much is in the future. Is each instant made of a tiny chunk of "past" and a tiny chunk of "future". Is there a theoretical limit to the "shutter speed" by which each instant can be measured?
The present is the passing of the non-existent (because it is "not yet") future into the non-existent past (because it is "no longer"). This past is, therefore, empty yet the locus of everything we experience. Go figure.
Is it though JL ?
If you wanted to you, could see now as having a length, rather than a single point, the length being determined by the practical situation,.... when studying electrons, very short...when my wife is ready to leave the house "Yes, I'm coming now", quite a bit longer.
I meant to ssay "This PRESENT is, therefore empty...."
Sorry.
