The speed of light is NOT constant

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All muons decay to three particles. An electron and two neutrinos.

An electron is a type of lepton, so are neutrinos an antielectrons.

A Tau is the only lepton that can decay into hadrons.

A "Lepton" is used to describe multiple items. You need to define which item your talking about specifically.
 
A lepton is what's there before a muon decays, too.

As far as is known, leptons are truly fundamental in the sense that they are not made of anything 'smaller' and have no internal structure. This of course refers to the bare lepton; any charged lepton will be surrounded by a sea of virtual particles just like any other.

BTW is there a problem with science education in Canada?
 
A muon is a lepton. Lepton has a very specific definition, though perhaps not in comic books. There are charged and neutral leptons. A muon is a charged lepton, just like an electron or a tau. Neutrinos (three types) are neutral leptons. So there are six flavors of leptons, all of which have in common a single property: no strong interaction.

edit: x-post with DF96, sorry. And he asks a very pertinent question.
 
I can't answer DF96's question about our friends to the north, but here, yes. We have schools that are the best of the best, and schools that are below third world standards. I would say there is something wrong!

My understanding, again at the mercy of Chem 102 circa 1974, is that an electron can not decay into smaller particles, but is a manifestation of energy. I was not aware the Tau could decay. Wiki time.

Lunch is over, back to modding the Hafler.
 
If your interested, you can show protons/neutrons are composite particles by looking at scattering experiments. R. Hofstadter won a nobel prize for discovering it. You look at the scattering energies/angles and deduce they are made up of "partons" or "quarks", both mean basically the same thing. The same methods can show that leptons are not composite particles, in other words, are not made up of anything else.

take a look at this chart: http://imglib.lbl.gov/ImgLib/COLLEC...SICS/images/1992Spring_pg33_chart.lowres.jpeg

A decay process does not mean that the particle was a composite particle. Third generation matter (third family in this table - tau electrons, tau neutrinos) decays very quickly because it is most massive. Generally matter decays back down to the more stable first generation matter (the top line in the table - things like electrons and neutrinos) but not always. Then second generation matter is the in middle obviously with muon electron, and muon neutrino. The weak force accounts for much of these decay processes. For example, a neutron can decay into a proton where a down quark decays into an up quark. And the muon decays to an electron, an electron-antineutrino, and a muon-neutrino all at once (that's just one decay option). It has no relevance to whether the particle is composite or not.

Interestingly, once you get down to the level of quarks and leptons, it makes little sense to use the words "fundamental" and "particle". Because there is no such fundamental aspect about it. We can only observe Quarks in PAIRS, (called mesons), if you try and break them apart (by applying energy to it) you have to keep supplying more energy until the Pair of quarks (meson) splits into TWO mesons. It's hard to get your head around it, but there is nothing fundamental about it, the "building blocks of matter" model works fine at larger scales, but i'm afraid it makes no physical sense when your in this quantum world of tiny things.
 
Who mines the best copper?

Chile! Really. They have the best concentration in the ore and produce the most. The US is a distant second. China is well behind.

Of course the standard for copper is 99.9% pure. So the common impurities including silver and gold probably alter the characteristics a bit. (Back of envelope calculation says -80 db distortion when the cable impedance is about the same as the source + load.)
 
GloBug said:
I don't know what they teach you down there but, all muons decay into three particles: an electron and two neutrinos.
It is undisputed that this is the normal decay mode, so what are you trying to say by repeating this? It certainly does not mean that the three particles were somehow inside the muon before it decayed. BTW one of the neutrinos is actually an antineutrino, so lepton number conservation is OK.

simon7000 said:
Back of envelope calculation says -80 db distortion when the cable impedance is about the same as the source + load.
Could you share that calculation with us?
 
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I'm getting bored of people repeating things, how about something different. There are theories where the electron and proton Can decay ;) and they are very interesting. As the age of the universe tends towards infinity or an unimaginable long time, all matter decays into photons. Thus time ceases to exist in any meaningful way. This can look like a pre-big bang period or lead to a big bang itself... that gets your mind churning! A decay process is defined by an average lifetime, so you have to be cautious and admit that there may be decay processes we haven't seen yet because the universe is only so old. Theory only tries to match or predict what we see in nature, in the end we are at natures mercy. Speculating new things is half the fun guys!
 
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