Jump to content

Longest Running Thread EVER


Recommended Posts

  • Replies 34.1k
  • Created
  • Last Reply

Top Posters In This Topic

  • Cancer

    6869

  • L. Marcus

    6410

  • Bazza

    4002

  • AliceTheOwl

    1718

Top Posters In This Topic

Popular Posts

We've been looking madly for a new apartment (amazing how a deadline will motivate you!), and we found a place we really like. It's a large (1600 square foot) side of a duplex with three bedrooms on a

Re: Longest Running Thread EVER   Edit: Okay, I managed to fill every line, but goodness knows I'm open to suggestions for improvement!     Welcome to the Forum NGD   Welcome to the Forum NG

Long preamble here.   The administrative unit in which I have the Associate Director title got moved out of one building last spring (that one was subsequently demolished and the spot is bei

Posted Images

  • 2 weeks later...
  • 2 weeks later...
  • 3 weeks later...
On 10/10/2017 at 10:36 PM, Cancer said:

Putting this here for Lucius, since it's prose follow-up to something in the haiku thread.

 

There seem to be three flavor eigenstates, or just flavors, of neutrinos: each neutrino is associated with a lepton. Electron neutrinos go with electrons (and anti-electrons, a/k/a positrons). Muon neutrinos go with muons and their antiparticle. Tau neutrinos go with tau leptons. These flavors matter for reactions with other particles. As an example, an isolated neutron is unstable and it will decay into a proton, an electron, and a neutrino. That neutrino is *always* an electron neutrino. There are other reactions that will produce particles including a muon and a neutrino. In such a reaction, that neutrino is *always* a muon neutrino.

 

If messed with, though, one flavor of neutrino can turn into a different flavor. That is, once an electron neutrino is made, somewhere later in its travel if you try catching it, it may no longer be an electron neutrino; it may be a muon neutrino.

 

This can only happen if the neutrinos have a nonzero mass (in the original concept, and for decades thereafter, it was assumed they were massless) and if the masses are modestly different and the actual "real masses" of the neutrinos are not exactly the same as the average masses of the three neutrino flavors. In that case, a neutrino in one of these "mass eigenstates" will be a mixture of more than one of the flavors, and the probability of finding a particular neutrino as a particular flavor varies as the neutrino travels. It oscillates among the flavors. ...

 

Following up on this a bit more, since there was something among my news feeds bearing on this this morning.

 

The lightest neutrino mass is no larger than 0.086 eV/c2.  In other words, it is at least 6 million times "lighter" than the electron (the electron mass is about half a mega-electron-volt; the lightest neutrino mass is no larger than 86 milli-electron-volts).  This comes out of a simultaneous fit to particle physics data and cosmology data (the neutrino mass does have observable effects in the distribution of galaxies in the Universe).

Link to post
Share on other sites
  • 4 weeks later...
On August 23, 2019 at 9:56 AM, Cancer said:

 

Following up on this a bit more, since there was something among my news feeds bearing on this this morning.

 

The lightest neutrino mass is no larger than 0.086 eV/c2.  In other words, it is at least 6 million times "lighter" than the electron (the electron mass is about half a mega-electron-volt; the lightest neutrino mass is no larger than 86 milli-electron-volts).  This comes out of a simultaneous fit to particle physics data and cosmology data (the neutrino mass does have observable effects in the distribution of galaxies in the Universe).

 

New direct measurement in a lab in Germany puts the upper limit at 1.1 eV.

Link to post
Share on other sites

Long preamble here.

 

The administrative unit in which I have the Associate Director title got moved out of one building last spring (that one was subsequently demolished and the spot is being built on now), and into another one.  The current location is a building that is older than the building that was demolished.

 

In this older building/new location, the only men's restroom is on the third floor (the only women's restroom is on the second floor).  Yes, classes are held in this building (which has three floors), and things get pretty congested during passing periods.

 

So ... unless it is pouring down rain, when my morning coffee demands liberation, rather than go upstairs, it is more convenient for me to duck outside and walk into another building right across the way, where there is a less-used men's room right near the entry on that entry level.  That other building houses the Business School.

 

I realized today that what I am doing is ... using the Business School as my outhouse.

 

After some consideration ... as a member of the College of Science & Engineering, I am oddly OK with that.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...