The Physics of Time: Why does it flow?
Richard Muller, Prof. Physics UC Berkeley emeritus, author: Now—the Physics of Time.
Abstract: We know much about time, about its variability with velocity and gravity. Einstein took time to be the fourth dimension. But time is different. We can stand still in space (given any coordinate system) but not in time. Why? What is the meaning of “now”—that ephemeral concept whose meaning changes every moment? I don’t know where you are, but I do know something about you: you are reading the word “now” right now! I will present a new theory for the flow of time, one that links it to the creation of new space through the expansion of the Universe. The old postulated connection between entropy and the arrow of time will be discredited as an untestable theory—or, more precisely, as a theory that has failed multiple tests. Remarkably, the new theory I will present is testable. Events that create new space, such as the collision of two black holes that led to the observation of gravitational waves, create new space at the site of the collision, and according to the theory, they should create a potentially observable level of new time.
Richard Muller is a retired (emeritus) Professor of Physics at UC Berkeley, with well-over 100 peer-reviewed publications. His “Physics for Future Presidents” was voted by students to be the best course at UC Berkeley. He is a prolific author, with 10 books including "Energy for Future Presidents" and the best-selling "Physics for Future Presidents." He is a frequent contributor of Op Eds to the Wall St. Journal and the New York Times on issues involving energy and environment. Prior to specializing in advanced energy, his research was in geophysics and astrophysics His proudest work include the discovery of the cosine anisotropy of the cosmic background and the invention of the now most-used method for measuring radiocarbon. He founded two astrophysics projects that went on to win Nobel Prizes in Physics for the scientists he hired to take them over. He has many awards, including a MacArthur "genius" Prize, the Texas Instruments Founders' Prize, election to fellow of the American Academy of Arts and Sciences. Largely because of his work on energy and environment, Foreign Policy cited him as one of the top 100 global thinkers in the world; Atlantic listed him as one of 21 "brave thinkers" in 2011; Time Magazine listed him as one of the top 100 "people who matter".
Subsequent to his academic retirement in 2010, Muller cofounded Berkeley Earth, a non-profit that studies global warming and air pollution. This work has been reported in peer-reviewed as well as in popular journals; he is particularly well known for his NYTimes OpEd “The Conversion of a Climate Change Skeptic.” In 2015 he cofounded Deep Isolation, a company offering a private approach to the storage and disposal of nuclear waste. The CEO is his daughter Elizabeth Muller, with a strong background in business and stakeholder engagement; he is CTO.
His most recent book “Now—the Physics of Time” (and an associated academic paper) address the issue of time; why does it move? He presents strong evidence that the widely accepted connection between the arrow of time and entropy is false, and argues that the “motion” of time is a result of the expansion of time as well as space in a 4-dimensional Big Bang.
Towards Integrated Optical Time Standards and Frequency Synthesizers
Kerry Vahala (Ted and Ginger Jenkins Professor of Information Science and Technology and Professor of Applied Physics, CalTech)
Abstract: Communication systems leverage the respective strengths of optics and electronics to convey high-bandwidth signals over great distances. These systems were enabled by a revolution in low-optical-loss dielectric fiber, complex integrated circuits as well as devices that link together the optical and electrical worlds. Today, another revolution is leveraging the advantages of optics and electronics in new ways. At its center is the laser frequency comb which provides a coherent link between these two worlds. Significantly, because the link is also bidirectional, performance attributes previously unique to electronics and optics can be shared. The end result has been transformative for time keeping, frequency metrology, precision spectroscopy, microwave-generation, ranging and other technologies. Even more recently, low-optical-loss dielectrics, now in the form of high-Q optical resonators, are enabling the miniaturization of frequency combs. These new `microcombs’ can be integrated with electronics and other optical components to potentially create systems on-a-chip. I will briefly overview the history and elements of frequency combs as well as the physics of the new microcombs. Efforts underway to develop integrated optical clocks and integrated optical frequency synthesizers using the microcomb element are also described.
Professor Vahala studies the physics and applications of high-Q optical microcavities. His research group has pioneered resonators that hold the record for highest optical Q on a semiconductor chip and has also launched many of the research topics in the field of optical microcavities. Applications currently under study include micro-gyros with Earth-rotation-rate sensitivity and soliton micro-combs. Vahala was involved in the early effort to develop quantum-well lasers for optical communications and he received the IEEE Sarnoff Medal for his research on quantum-well laser dynamics. He has also received an Alexander von Humboldt Award for work on ultra-high-Q optical microcavities and is a fellow of the IEEE, the IEEE Photonics Society and the Optical Society of America. Vahala is the Jenkins Professor of Information Science and Technology and Professor of Applied Physics and received his B.S., M.S., and Ph.D. degrees from Caltech. He currently serves as the Executive Officer of the Department of Applied Physics and Materials Science and holds over 30 patents in photonics.
Encapsulated MEMS: What’s Good for the Resonator is Good for the Sensor
Tom Kenny (Associate Dean, Professor of Mechanical Engineering, Stanford University)
Abstract: Since the demonstration of the Resonant Gate Transistor by Harvey Nathason and his team more than 50 years ago, we’ve all been interested in the potential application of MicroElectroMechanical Systems (MEMS) for timing applications. Of course, there were obstacles, with the biggest associated with the frequency stability of MEMS resonators. After significant effort, we found that stability in MEMS resonators could be improved by ultra-clean high-temperature encapsulation processes. Today, oscillators based on MEMS resonators are providing stability competitive with the best quartz-based oscillators, with improved size, power, weight, reliability, and cost.
Since the earliest demonstration of MEMS inertial sensors for automotive applications more than 30 years ago, we’ve all be interested in the potential application of these devices for inertial navigation applications. Of course, there were obstacles, with the biggest associated with the stability of MEMS sensors. There has been extensive effort on development of materials, operational schemes and other approaches to overcome stability issues. Our group has been exploring one central question : can we build inertial sensors in an encapsulation process similar to that used for the highest-stability MEMS resonators, and is this a path towards ultra-stable inertial MEMS sensors?
Thomas W. Kenny received the B.S. degree in physics from the University of Minnesota, Minneapolis, in 1983, and the M.S. and Ph.D. degrees in physics from the University of California, Berkeley, in 1987 and 1989, respectively. From 1989 to 1993, he was with the Jet Propulsion Laboratory, National Aeronautics and Space Administration, Pasadena, CA, where his research focused on the development of electron-tunneling high-resolution microsensors. In 1994, he joined the Department of Mechanical Engineering, Stanford University, Stanford, CA, where he directs Microsensor-based research in a variety of areas, including resonators, wafer-scale packaging, cantilever beam force sensors, microfluidics, and novel fabrication techniques for micromechanical structures. He was Founder and CTO of Cooligy (now a division of Emerson), a microfluidics chip cooling component manufacturer, and was Founder and Board Member of SiTime Corporation (now a division of MegaChips), a developer of timing references using MEMS resonators. He is founder and Board Member of Applaud Medical, developing non-invasive therapies for kidney stones. He is currently the Richard Weiland Professor of Mechanical Engineering and the Senior Associate Dean of Engineering for Student Affairs. He was the General Chairman of the 2006 Hilton Head Solid State Sensor, Actuator, and Microsystems Workshop, and the General Chair of the Transducers 2015 meeting in Anchorage. From October 2006 through September 2010, he was on leave to serve as Program Manager in the Microsystems Technology Office at the Defense Advanced Research Projects Agency, starting and managing programs in thermal management, nanomanufacturing, manipulation of Casimir forces, and the Young Faculty Award. He has authored or coauthored over 250 scientific papers and is a holder of 50 issued patents, and has been advisor to more than 60 graduated PhD students from Stanford.