Particles and the Universe (Physics in Our World)
Kyle Kirkland
Language: English
Pages: 158
ISBN: 0816061165
Format: PDF / Kindle (mobi) / ePub
Nuclear physics investigates the properties and behavior of the central portion, or nucleus, of the atom. This branch of physics had perhaps the biggest impact on the world in the 20th century because it evolved into the knowledge used to build the most destructive weapons people have ever known. The atomic bombs that ended World War II, and the weapons race that followed, changed the course of history. But applications of nuclear physics have also provided enormous energy for useful purposes, generating about 16 percent of the world's electricity. Particles and the Universe documents how modern physics formed and how it continues to evolve. Each chapter of this book delves into the observations, theories, and tests of a particular topic, including nuclear physics, quantum mechanics, particle physics, relativity, and cosmology.
From Eternity to Here: The Quest for the Ultimate Theory of Time
God and the Atom: From Democritus to the Higgs Boson: The Story of a Triumphant Idea
Schaum's Outline of Applied Physics (4th Edition) (Schaum's Outlines Series)
Arc welding control (Series in Welding and Other Joining Technologies)
Mathematical Physics: Applied Mathematics for Scientists and Engineers (Physics Textbook)
they may suffer from heat damage and allow radioactive material to escape. Allowing too many neutrons to wander around in the core will overheat the reactor, possibly resulting in melting the core itself. Temperatures can soar to thousands of degrees, high enough to melt anything. Nuclear reactors are shielded with radiation-blocking material such as thick slabs of lead, but in a catastrophic meltdown, radioactive nuclei may be released. Control rods are supposed to prevent overheating, but they
engines. A number of flights tested airborne reactors, although no nuclear-powered flights were ever made. In the end the plans were abandoned, mostly for safety reasons. The shielding required for the reactor was heavy, and fears arose over the potential radiation contamination should the airplane crash. Fears over nuclear propulsion were not unfounded. Soviet Union nuclear submarine K-19 suffered a tragic accident with its reactor in 1961. While at sea, 1,500 miles (2,400 km) away from port, a
as great an amount of matter and will not generate a black hole. A black hole forms only when there The giant star in this illustration would probably end up as a black hole. Underneath the star is a diagram of the solar system of the Sun. The radius of the giant star stretches well beyond Earth’s orbit. (NASA/JPL-Caltech) 112 Particles and the Universe is so much mass that its particles cannot withstand the resulting gravitational attraction. This may occur for stars with perhaps 10 times
chapter 2, as well as 130 Particles and the Universe the incompatibility of quantum mechanics and general relativity. There are several versions of string theory, each requiring complicated mathematics and objects or concepts that are difficult or impossible at present to test. Experimental support is lacking for string theory, so the theory remains an interesting but speculative (unproven) idea. The Fate of the Universe Describing all of physics with a single theory or equation would have a
expanding or it will not, and it might even one day begin to contract. Gravitational attraction is critical, and the forces exerted by gravitation depend on how much matter the universe contains. A sufficient amount of mass would generate enough gravitation to halt the universe’s expansion after a certain period of time and perhaps draw it back inward. Measuring the size of the universe and the amount of matter it contains is a difficult endeavor. In the process of gathering this information, a
