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---------------------- 1868 - What do Neutron lifetimes have to do with it?
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- A Neutron is a proton and an electron combined to become a neutral charge. Normally protons are in the nucleus and electrons in orbital rings around the nucleus. Protons are positive charge and electrons an equal and opposite negative charge. The Neutron in the nucleus is a combined proton and electron that unstable over time. But how much time?
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- How long does the Neutron live before radioactive decay and it separates into its two components again? Decaying back to its fundamental particles is a question known as the “ Neutron Lifetime Puzzle”.
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- Science knows the decay process involves the nuclear “weak force” interactions. The “strong nuclear force” is what holds the protons together, like positive charges, in the nucleus. If science knew the Neutron Lifetime they could calculate the abundance of the other elements and support or refute current theories that are addressing this puzzle.
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- The physics of nuclear decay is well understood ( we think?). In “ beta decay” a Neutron breaks down into a proton, and electron, and an anti-neutrino. The resulting particles carry the difference in mass in the form of kinetic energy ( the energy of motion).
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- The timing of this decay is a “random quantum phenomenon”. Science gets an average lifetime by studying the decay of many, many Neutrons. But, any single decay is random. Statistics is the math that comes up with the answer using large numbers.
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- Neutrons easily pass through the walls of any container making them difficult to count. The trick is to tarp extremely cold Neutrons that have very low kinetic energy. The kinetic motion must be reduced to speeds of a few meters per second. Neutrons are normally traveling at 10,000,000 meters per second.
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- Statistical error arises because any experiment can only measure a finite sample size of neutrons.
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- Having 2 different methods of measurement help to reduce these measurement uncertainties. Another experiment uses the “ beam method” sending a stream of cold Neutrons through a magnetic field. A ring of high voltage electrodes trap positively charged particles. If a neutron decays within the trap the protons are counted as the decays occur over time.
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-------------------- The beam experiment got a lifetime of 887.7 seconds + or - 0.3 seconds statistically and + or - 1.9 seconds systematically. So, a 2.2 second uncertainty.
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------------------- The bottle experiments measured a lifetime of 878.5 seconds + or - 0.7 and + or - 0.3 seconds. A + or - 0.8 second uncertainty.
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- What we have left is 9 seconds of disagreement. This is not good enough. We need more accurate knowledge of Neutron decay in order to understand the Weak Nuclear Force responsible.
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- Determining the “ exact” rate of decay should help us understand Big Bang Theory and the early evolution of the Cosmos. In the first seconds the universe temperature was 10 billion degrees, which is too hot for nuclei to even form. After 3 minutes the expansion and cooling allowed protons and neutrons to form. Deuterium, a heavy hydrogen isotope, first formed. Deuterium atoms combined to form helium, and some lithium.
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- Neutron decay rate versus cooling rate is critical to understanding the ratios of hydrogen and helium in the early Universe. All the heavier elements in the Periodic Table were formed in the cores of stars composed of just these first, lightest, two elements, hydrogen and helium.
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- In order for science to mathematically predict the ratios we observe we need to know the precise value of Neutron lifetimes. If predictions disagree our theory might indicate we are missing other exotic particles yet to be discovered. Maybe Dark Matter particles?
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- Deeper knowledge may explain why matter out-numbers anti-matter. Our theories tell us equal amounts of each had to come form “ nothing” in the Big Bang. If an asymmetry did not happen we would have an empty, cold Universe instead of the one we live in?
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- Discovering the matter-anti-matter imbalance is the search for “ new physics”, rare decays of Bottom Quarks, Charm Quarks, and Tau Leptons. This stuff really gets complex. It can only be studied in very high energy particle accelerators or in the stars. In effect science is trying to recreate the first seconds of the Universe.
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- This new physics is not just theoretical stuff you are not interested in. Spin models of atoms may lead to new digital computers, new neural networks, even understanding proteins and social networks.
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- Even the design of the smallest engines, a single electrically - charged calcium atom. The single atom is both the fuel and power plant with equivalent thermodynamic efficiency of an automobile engine.
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- The atom power plant is heated by electrical noise and cooled by a laser beam. This could lead to tiny motors, single-ion refrigerators, heat pumps. Who knows/ new science leads to new innovations. These innovations you should be interested in. Stay tuned, an announcement will be made shortly.
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- Request these Reviews to learn more Particle Physics:
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- #1848 - Particle physics a history lesson. Biographies of the famous physicists.
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- #1799 - Primer on particle physics.
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- #1693 - How can a Quark and an anti-Quark decay into an Electron?
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- #1512 - Getting familiar with the Standard Model.
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- #1573 - The math is beautiful. The challenge of physics is to discover evidence that it represents reality.
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- #1511 - Sterile Neutrinos in particle physics.
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- #1217 - How to find the Higgs Boson.
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- #1136 - Our whole world in only 6 particles.
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- #1097 - Nature’s constants and particles.
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- #1046 - Particles of everything. 18 fundamental particles?
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- #977 - Fermions and Bosons
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- #973 - Physics in a nutshell.
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- #960 - Phonons, Plasmons, and Magnons
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- #811 - Large Hadron Collider.
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- #632 - The force carriers, gluons , bosons, and photons.
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- #631 - Mass , momentum, and inertia.
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--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
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----- 707-536-3272 ---------------- Monday, May 9, 2016 -----
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