- 3960 - PHYSICS - Standard Model of Physics - With few exceptions, it has stood up to this scrutiny, passing experimental test after experimental test with flying colors. But this wildly successful model has conceptual gaps that suggest there is a bit more to be learned about how the universe works.
------------ 3960 - PHYSICS - Standard Model of Physics
- If you ask
a physicist to explain how the world works, the answer might be: "It
follows the Standard Model." The
Standard Model explains the fundamental physics of how the universe works. It
has endured over 50 trips around the sun despite experimental physicists
constantly probing for cracks in the model's foundations.
-
- Neutrinos
represent three of the 17 fundamental particles in the Standard Model. They zip
through every person on Earth at all times of day. In 2021, physicists around the world ran a
number of experiments that probed the Standard Model. Teams measured basic
parameters of the model more precisely than ever before.
-
- Scientists
have built more powerful technologies designed to push the model to its limits
and potentially discover new particles and fields. If these efforts pan out,
they could lead to a more complete theory of the universe in the future.
-
- The
Standard Model of physics allows scientists to make incredibly accurate
predictions about how the world works, but it doesn’t explain everything.
-
- In 1897,
J.J. Thomson discovered the first fundamental particle, the electron, using
nothing more than glass vacuum tubes and wires. More than 100 years later,
physicists are still discovering new pieces of the Standard Model.
-
- The
Standard Model is a predictive framework that does two things. First, it
explains what the basic particles of matter are. These are things like
electrons and the quarks that make up protons and neutrons.
-
- Second, it
predicts how these matter particles interact with each other using
"messenger particles". These are called bosons, photons and the
famous Higgs boson, and they communicate the basic forces of nature. The Higgs
boson wasn't discovered until 2012 after decades of work at CERN, the huge
particle collider in Europe.
-
- The
Standard Model is incredibly good at predicting many aspects of how the world
works, but it does have some holes. It
does not include any description of gravity. While Einstein's theory of General
Relativity describes how gravity works, physicists have not yet discovered a
particle that conveys the force of gravity.
-
- A proper
"Theory of Everything" would do everything the Standard Model can,
but also include the messenger particles that communicate how “gravity”
interacts with other particles.
-
- Another
thing the Standard Model can't do is explain why any particle has a certain
mass. Physicists must measure the mass
of particles directly using experiments. Only after experiments give physicists
these exact masses can they be used for predictions. The better the
measurements, the better the predictions that can be made.
-
- Recently,
physicists at CERN measured how strongly the Higgs boson feels itself. They measured the Higgs boson's mass more
precisely than ever before. And finally, there was also progress on measuring
the mass of neutrinos. Physicists know
neutrinos have more than zero mass but less than the amount currently
detectable.
-
- In April
2021, members of the “Muon g-2” experiment at Fermilab announced their first
measurement of the magnetic moment of the muon. The muon is one of the
fundamental particles in the Standard Model, and this measurement of one of its
properties is the most accurate to date.
-
- The reason
this experiment was important was because the measurement didn't perfectly
match the Standard Model prediction of the magnetic moment. Basically, muons
don't behave as they should. This finding could point to undiscovered particles
that interact with muons.
-
- In April
2021, physicist showed how they used a mathematical method called “Lattice QCD”
to precisely calculated the muon's magnetic moment. Their theoretical
prediction is different from old predictions, still works within the Standard
Model and, importantly, matches experimental measurements of the muon.
-
- The
disagreement between the previously accepted predictions, this new result and
the new prediction must be reconciled before physicists will know if the
experimental result is truly beyond the Standard Model.
-
- The world's
largest particle accelerator, the “Large Hadron Collider” at CERN, was shut
down and underwent some substantial upgrades. Physicists just restarted the
facility in October, 2021, and they plan
to begin the next data collection run in May 2022.
-
- The
upgrades have boosted the power of the collider so that it can produce
collisions at 14 TeV, up from the previous limit of 13 TeV. This means the
batches of tiny protons that travel in beams around the circular accelerator
together carry the same amount of energy as an 800,000-pound passenger train traveling at 100 mph. At
these incredible energies, physicists may discover new particles that were too
heavy to see at lower energies.
-
- Some other
technological advancements were made to help the search for dark matter. Many
astrophysicists believe that dark matter particles, which don't currently fit
into the Standard Model, could answer some outstanding questions regarding the
way gravity bends around stars, called “gravitational lensing”, as well as the
speed at which stars rotate in spiral galaxies.
-
- In 2021
highlighted some of the ways the Standard Model fails to explain every mystery
of the universe. But new measurements and new technology are helping physicists
move forward in the search for the “Theory of Everything”
-
April 16, 2023 PHYSICS -
Standard Model of Physics 3960
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to
whomever is interested. ---
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for
copies or Index of all reviews
--- to:
------
jamesdetrick@comcast.net
------ “Jim Detrick” -----------
---------------------
--- Sunday, April 16, 2023 ---------------------------
-
No comments:
Post a Comment