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Archive for the ‘physics’ category: Page 210

May 7, 2020

You Could Travel Through a Wormhole, But It’s Slower Than Space, Say Scientists

Posted by in categories: cosmology, physics, space travel

Circa 2019


Special Relativity. It’s been the bane of space explorers, futurists and science fiction authors since Albert Einstein first proposed it in 1905. For those of us who dream of humans one-day becoming an interstellar species, this scientific fact is like a wet blanket.

Continue reading “You Could Travel Through a Wormhole, But It’s Slower Than Space, Say Scientists” »

May 6, 2020

Physicists Criticize Stephen Wolfram’s ‘Theory of Everything’

Posted by in category: physics

The iconoclastic researcher and entrepreneur wants more attention for his big ideas. But so far researchers are less than receptive.

May 6, 2020

A new law for metamaterials

Posted by in categories: engineering, law, mapping, physics

Metamaterials, which are engineered to have properties not found in nature, have long been developed and studied because of their unique features and exciting applications. However, the physics behind their thermal emission properties have remained unclear to researchers—until now.

In a paper published in Physical Review Letters, Sheng Shen, an associate professor in Carnegie Mellon’s department of mechanical engineering, and his student Jiayu Li, a Ph.D. candidate, have created a new scale law to describe the thermal emission from metasurfaces and metamaterials.

“With this new scale law uncovering the underlying physics behind the collective thermal emission behavior of metamaterials, researchers could easily utilize existing design and optimization tools to achieve desired thermal emission properties from metamaterials, instead of blindly searching for the best solution through mapping the entire design space,” Li said.

May 5, 2020

EcoFreeze: Passive Freezer in Essex, VT

Posted by in category: physics

In the summer of 2010, I had the opportunity to be part of the team that designed and built the first passive freezer that we’d ever heard of. The idea was simple, we create a well-insulated room and stack several thousand 2-liter bottles full of salt water along the walls. In the winter, we open hatches in the ceiling and everything freezes. At the end of the winter, we close the hatches and it stays at about 25°F for the whole year.

The team of students, led by physics teacher Tom Tailer ran some calculations to make sure the physics added up and calculated that we needed about 3000 bottles and about 18 inches of foam insulation on the walls and ceiling for good performance. We built the structure and insulated it using waste styrofoam, ground-up using a modified leaf shredder.

May 5, 2020

This Is How Physics, Not Math, Finally Resolves Zeno’s Famous Paradox

Posted by in categories: mathematics, physics

Zeno’s paradox stumped philosophers, mathematicians, and intellectuals for millennia. It took physics to finally solve it.

May 2, 2020

Gravitational Wave Generator Apparatus

Posted by in category: physics

O,.o circa 2012.


An apparatus or structure is proposed for generating high-frequency gravitational waves (HFGWs) between pairs of force–producing elements by means of the simultaneous production of a third time derivative of mass motion of the pair of force–producing elements. The elements are configured as a cylindrical array in the proposed structure and are activated by a radiation wavefront moving along the axis of symmetry of the array. The force-producing elements can be micro-electromechanical systems or MEMS resonators such as film-bulk acoustic resonators or FBARs. A preferred cylindrical array is in the form of a double helix and the activating radiation can be electromagnetic as generated by microwave transmitters such as Magnetrons. As the activating radiation wavefront moves along the axis of the structure it simultaneously activates force elements on opposite sides of the structure and thereby generates a gravitational wave between the pair of force elements. It is also indicated that the Earth is completely transparent to the HFGWs. Thus a sensitive HFGW detector, such as the Li-Baker under development by the Chinese, can sense the generated HFGW at an Earth-diameter distance and could, in theory, be a means for implementing transglobal HFGW communications.

Apr 30, 2020

A Second Look at the Second Gas Effect

Posted by in categories: information science, physics

The Newtonian laws of physics explain the behavior of objects in the everyday physical world, such as an apple falling from a tree. For hundreds of years Newton provided a complete answer until the work of Einstein introduced the concept of relativity. The discovery of relativity did not suddenly prove Newton wrong, relativistic corrections are only required at speeds above about 67 million mph. Instead, improving technology allowed both more detailed observations and techniques for analysis that then required explanation. While most of the consequences of a Newtonian model are intuitive, much of relativity is not and is only approachable though complex equations, modeling, and highly simplified examples.

In this issue, Korman et al.1 provide data from a model of the second gas effect on arterial partial pressures of volatile anesthetic agents. Most readers might wonder what this information adds, some will struggle to remember what the second gas effect is, and others will query the value of modeling rather than “real data.” This editorial attempts to address these questions.

The second gas effect2 is a consequence of the concentration effect3 where a “first gas” that is soluble in plasma, such as nitrous oxide, moves rapidly from the lungs to plasma. This increases the alveolar concentration and hence rate of uptake into plasma of the “second gas.” The second gas is typically a volatile anesthetic, but oxygen also behaves as a second gas.4 Although we frequently talk of inhalational kinetics as a single process, there are multiple steps between dialing up a concentration and the consequent change in effect. The key steps are transfer from the breathing circuit to alveolar gas, from the alveoli to plasma, and then from plasma to the “effect-site.” Separating the two steps between breathing circuit and plasma helps us understand both the second gas effect and the message underlying the paper by Korman et al.1

Apr 28, 2020

Scientists explore the power of radio waves to help control fusion reactions

Posted by in categories: nuclear energy, physics

A key challenge to capturing and controlling fusion energy on Earth is maintaining the stability of plasma—the electrically charged gas that fuels fusion reactions—and keeping it millions of degrees hot to launch and maintain fusion reactions. This challenge requires controlling magnetic islands, bubble-like structures that form in the plasma in doughnut-shaped tokamak fusion facilities. These islands can grow, cool the plasma and trigger disruptions—the sudden release of energy stored in the plasma—that can halt fusion reactions and seriously damage the fusion facilities that house them.

Improved island control

Research by scientists at Princeton University and at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) points toward improved control of the troublesome magnetic islands in ITER, the international tokamak under construction in France, and other future facilities that cannot allow large disruptions. “This research could open the door to improved control schemes previously deemed unobtainable,” said Eduardo Rodriguez, a graduate student in the Princeton Program in Plasma Physics and first author of a paper in Physics of Plasmas that reports the findings.

Apr 28, 2020

World’s first 3D simulations of superluminous supernovae

Posted by in categories: cosmology, physics, supercomputing

For most of the 20th century, astronomers have scoured the skies for supernovae—the explosive deaths of massive stars—and their remnants in search of clues about the progenitor, the mechanisms that caused it to explode, and the heavy elements created in the process. In fact, these events create most of the cosmic elements that go on to form new stars, galaxies, and life.

Because no one can actually see a supernova up close, researchers rely on to give them insights into the physics that ignites and drives the event. Now for the first time ever, an international team of astrophysicists simulated the three-dimensional (3D) physics of superluminous supernovae—which are about a hundred times more luminous than typical supernovae. They achieved this milestone using Lawrence Berkeley National Laboratory’s (Berkeley Lab’s) CASTRO code and supercomputers at the National Energy Research Scientific Computing Center (NERSC). A paper describing their work was published in Astrophysical Journal.

Astronomers have found that these superluminous events occur when a magnetar—the rapidly spinning corpse of a massive star whose magnetic field is trillions of times stronger than Earth’s—is in the center of a young supernova. Radiation released by the magnetar is what amplifies the supernova’s luminosity. But to understand how this happens, researchers need multidimensional simulations.

Apr 28, 2020

Scientists think we’ll finally solve nuclear fusion thanks to cutting-edge AI

Posted by in categories: nuclear energy, physics, robotics/AI

Scientists believe the world will see it’s first working thermonuclear fusion reactor by the year 2025. That’s a tall order in short form, especially when you consider that fusion has been “almost here” for nearly a century.

Fusion reactors – not to be confused with common fission reactors – are the holiest of Grails when it comes to physics achievements. According to most experts, a successful fusion reactor would function as a near-unlimited source of energy.

In other words, if there’s a working demonstration of an actual fusion reactor by 2025, we could see an end to the global energy crisis within a few decades.