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Archive for the ‘physics’ category: Page 202

May 12, 2020

NASA releases design for a warp drive ship

Posted by in categories: physics, space travel

Star Trek fans get hyped as scientists at NASA’s Johnson Space Center have just unveiled a design for a warp drive ship. NASA scientist and Advanced Propulsion Team Lead Harold White revealed that he was investigating if a warp drive ship could travel faster than light and if so, how can we build one.

enterpriseship1[Image Source: Mark Rademaker]

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May 11, 2020

Physicists Think They’ve Found a New Way to Stabilise And Control Fusion Reactors

Posted by in categories: nuclear energy, physics

A team of research physicists at Princeton University may have found a new way to control fusion reactions inside doughnut-shaped tokamak reactors — an incremental step towards making fusion energy, the ‘holy grail of energy production’, a reality.

Many fusion reactors today use light elements in the form of plasma as fuel. The problem is that this elemental plasma is extremely hot — practically as hot as the Sun — and extremely unpredictable and difficult to control.

But there may be a way to force the plasma into doing what we want more predictably and efficiently, as detailed in a new theoretical paper published in the journal Physics of Plasmas.

May 8, 2020

Pulse-driven robot: Motion via solitary waves

Posted by in categories: bioengineering, biological, physics, robotics/AI

Scientists have recently explored the unique properties of nonlinear waves to facilitate a wide range of applications including impact mitigation, asymmetric transmission, switching and focusing. In a new study now published on Science Advances, Bolei Deng and a team of research scientists at Harvard, CNRS and the Wyss Institute for Biologically Inspired Engineering in the U.S. and France harnessed the propagation of nonlinear waves to make flexible structures crawl. They combined bioinspired experimental and theoretical methods to show how such pulse-driven locomotion could reach a maximum efficiency when the initiated pulses were solitons (solitary wave). The simple machine developed in the work could move across a wide range of surfaces and steer onward. The study expanded the variety of possible applications with nonlinear waves to offer a new platform for flexible machines.

Flexible structures that are capable of large deformation are attracting interest in bioengineering due to their intriguing static response and their ability to support elastic waves of large amplitude. By carefully controlling their geometry, the elastic energy landscape of highly deformable systems can be engineered to propagate a variety of nonlinear waves including vector solitons, transition waves and rarefaction pulses. The dynamic behavior of such structures demonstrate a very rich physics, while offering new opportunities to manipulate the propagation of mechanical signals. Such mechanisms can allow unidirectional propagation, wave guiding, mechanical logic and mitigation, among other applications.

In this work, Deng et al. were inspired by the biological retrograde peristaltic wave motion in earthworms and the ability of linear elastic waves to generate motion in ultrasonic motors. The team showed the propagation of nonlinear elastic waves in flexible structures to provide opportunities for locomotion. As proof of concept, they focused on a Slinky – and used it to create a pulse-driven robot capable of propelling itself. They built the simple machine by connecting the Slinky to a pneumatic actuator. The team used an electromagnet and a plate embedded between the loops to initiate nonlinear pulses to propagate along the device from the front to the back, allowing the pulse directionality to dictate the simple robot to move forward. The results indicated the efficiency of such pulse-driven locomotion to be optimal with solitons – large amplitude nonlinear pulses with a constant velocity and stable shape along propagation.

May 8, 2020

Physicists Discover New Trick to Stabilize Fusion Reactors

Posted by in categories: nuclear energy, physics

Also could do a magnonic fusion reactor.


Magnetic Islands

But there may be a way to force the plasma into doing what we want more predictably and efficiently, as detailed in a new theoretical paper published in the journal Physics of Plasmas.

Continue reading “Physicists Discover New Trick to Stabilize Fusion Reactors” »

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.