Physics keeps life going-物理 依据 生命

Κυριακή, 25 Αυγούστου 2013

Only physics can explain it: Conservation o f Energy

Many transformations of energy can see someone in the following video.
Students in France enjoy their summer,  feeling the amazing  alternations of kinetic and potential energy.

 As the kid goes through its twists, turns, rolls, and loops, it gains and loses its initial potential energy. Energy changes from potential into kinetic energy and back into potential energy.

How are you enjoy your summer?

Σάββατο, 17 Αυγούστου 2013


 The Venus of Laussel is a 1.5 foot high figurine cut in limestone, between 25,000 to 30,000 years in age. Image courtesy of Joseph (2002).

Thus, we should not be surprised that the rock art in Lascaux (French Dordogne) depict what may be the oldest drawings of the constellations (Antequera, 1994; Rappenglueck, 1999), created more than 16,000 years ago, with the ubiquitous Pleiades −the most international asterism of the firmament − already riding on the back of the great celestial bull .
..more details

Κυριακή, 11 Αυγούστου 2013

Relativistic collisions-interactions and 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

Παρασκευή, 9 Αυγούστου 2013


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:

more detail click here