Tag Archives: Physics

The idea of creating a new universe in the lab is no joke

By Zeeya Merali – There’s an established principle in quantum theory that pairs of particles can spontaneously, momentarily pop out of empty space. Alex Vilenkin took this notion a step further, arguing that quantum rules could also enable a minuscule bubble of space itself to burst into being from nothing, with the impetus to then inflate to astronomical scales.

Our cosmos could thus have been burped into being by the laws of physics alone. Many cosmologists have made peace with the notion of a universe without a prime mover, divine or otherwise.

.. flipping the problem around, I started to wonder: what are the implications of humans even considering the possibility of one day making a universe that could become inhabited by intelligent life? As I discuss in my book A Big Bang in a Little Room (2017), current theory suggests that, once we have created a new universe, we would have little ability to control its evolution or the potential suffering of any of its residents. Wouldn’t that make us irresponsible and reckless deities?

We will not be creating baby universes anytime soon, but scientists in all areas of research must feel able to freely articulate the implications of their work without concern for causing offence. Cosmogenesis is an extreme example that tests the principle.

Parallel ethical issues are at stake in the more near-term prospects of creating artificial intelligence or developing new kinds of weapons, for instance.

As Anders Sandberg put it, although it is understandable that scientists shy away from philosophy, afraid of being thought weird for veering beyond their comfort zone, the unwanted result is that many of them keep quiet on things that really matter. more> https://goo.gl/GjCJpd

Updates from Georgia Tech

Decades of Data on World’s Oceans Reveal a Troubling Oxygen Decline
By Takamitsu Ito, Shoshiro Minobe, Matthew C. Long and Curtis Deutsch – A new analysis of decades of data on oceans across the globe has revealed that the amount of dissolved oxygen contained in the water – an important measure of ocean health – has been declining for more than 20 years.

The majority of the oxygen in the ocean is absorbed from the atmosphere at the surface or created by photosynthesizing phytoplankton. Ocean currents then mix that more highly oxygenated water with subsurface water. But rising ocean water temperatures near the surface have made it more buoyant and harder for the warmer surface waters to mix downward with the cooler subsurface waters. Melting polar ice has added more freshwater to the ocean surface – another factor that hampers the natural mixing and leads to increased ocean more> stratification.

Falling oxygen levels in water have the potential to impact the habitat of marine organisms worldwide and in recent years led to more frequent “hypoxic events” that killed or displaced populations of fish, crabs and many other organisms. more> https://goo.gl/3F17TB


X-rays from Copper Source Set New Gold Standard for Measuring Industrial Materials

By Alison Gillespie – Researchers at the National Institute of Standards and Technology (NIST) have produced and precisely measured a spectrum of X-rays using a new, state-of-the-art machine. The instrument they used to measure the X-rays took 20 years to develop, and will help scientists working at the agency make some of the world’s most accurate measurements of materials for use in everything from bridges to pharmaceuticals.

The process of building the instrument for making the new measurements was painstaking. “This new specialized precision instrument required both a tremendous amount of mechanical innovation and theoretical modeling,” said James Cline, project leader of the NIST team that built the machine.

“That we were able to dedicate so many years and such high-level scientific expertise to this project is reflective of NIST’s role in the world of science.” more> https://goo.gl/e0zrET

Updates from Georgia Tech

Surprising twist in confined liquid crystals: A simple route to developing new sensors
By Karthik Nayani, Jinxin Fu, Rui Chang, Jung Ok Park, and Mohan Srinivasarao – To answer some fundamental questions pertaining to the material’s phase behavior, the researchers used the microscopes to observe the molecules’ textures when they were confined to droplets known as tactoids.

“Surprisingly, we found a configuration that hasn’t been seen before in the 70 years that people have been studying liquid crystals,” said Mohan Srinivasarao, a professor in the Georgia Tech School of Materials Science and Engineering. “Historically, liquid crystals in tactoids conform to what is known as a bipolar and a bipolar configuration with a twist. At lower concentrations, we found that these liquid crystals arrange in a concentric fashion, but one that appears to be free of a singular defect.”

The researchers then used a simple model of the aggregation behavior of these molecules to explain these surprising results. Further, spectroscopic experiments using polarized Raman microscopy were performed to confirm their findings.

These new findings add to the growing understanding of how chromonic liquid crystals could be used in sensing applications, Srinivasarao said. more> https://goo.gl/YVq0TE


The Spiritual, Reductionist Consciousness of Christof Koch

By Steve Paulson – Consciousness is a buzzing business in neuroscience labs and brain institutes. But it wasn’t always this way. Just a few decades ago, consciousness barely registered as a credible subject for science.

Why were humans able to create civilizations that have transformed the planet?

We don’t have a precise answer. We have big brains and are, by some measure, the most intelligent species, at least in the short term. We’ll see whether we’ll actually survive in the long term, given our propensity for mass violence. And we’ve manipulated the planet to such an extent that we are now talking about entering a new geological age, the Anthropocene.

But it’s unclear why whales or dolphins—some of which have bigger brains and more neurons in their cortex than we do—why they are not called smarter or more successful. Maybe because they have flippers and live in the ocean, which is a relatively static environment. With flippers, you’re unable to build sophisticated tools.

Of course, human civilization is all about tools, whether it’s a little stone, an arrow, a bomb, or a computer. more> https://goo.gl/bmNgK6


Turning Back Time: Watching Rust Transform into Iron

By W. Zhu, J.P. Winterstein, W.D. Yang, L. Yuan, R. Sharma and G. Zhou – Using a state-of-the-art microscopy technique, experimenters at the National Institute of Standards and Technology (NIST) and their colleagues have witnessed a slow-motion, atomic-scale transformation of rust—iron oxide—back to pure iron metal, in all of its chemical steps.

In a new effort to study the microscopic details of metal oxide reduction, researchers used a specially adapted transmission electron microscope (TEM) at NIST’s NanoLab facility to document the step-by-step transformation of nanocrystals of the iron oxide hematite (Fe2O3) to the iron oxide magnetite (Fe3O4), and finally to iron metal.

By lowering the temperature of the reaction and decreasing the pressure of the hydrogen gas that acted as the reducing agent, the scientists slowed down the reduction process so that it could be captured with an environmental TEM—a specially configured TEM that can study both solids and gas. The instrument enables researchers to perform atomic-resolution imaging of a sample under real-life conditions—in this case the gaseous environment necessary for iron oxides to undergo reduction–rather than under the vacuum needed in ordinary TEMs. more> https://goo.gl/8lJIAH

A Brief History of the Grand Unified Theory of Physics

By Lawrence M. Krauss – Each time we peel back one layer of reality, other layers beckon. So each important new development in science generally leaves us with more questions than answers. But it also usually leaves us with at least the outline of a road map to help us begin to seek answers to those questions.

The successful discovery of the Higgs particle, and with it the validation of the existence of an invisible background Higgs field throughout space (in the quantum world, every particle like the Higgs is associated with a field), was a profound validation of the bold scientific developments of the 20th century.

As elegant as this idea might be, it is essentially an ad hoc addition to the Standard Model of physics—which explains three of the four known forces of nature, and how these forces interact with matter. It is added to the theory to do what is required to accurately model the world of our experience. But it is not required by the theory. The universe could have happily existed with massless particles and a long-range weak force (which, along with the strong force, gravity, and electromagnetism, make up the four known forces). We would just not be here to ask about them. Moreover, the detailed physics of the Higgs is undetermined within the Standard Model alone. The Higgs could have been 20 times heavier, or 100 times lighter.

Why, then, does the Higgs exist at all? And why does it have the mass it does? (Recognizing that whenever scientists ask “Why?” we really mean “How?”) If the Higgs did not exist, the world we see would not exist, but surely that is not an explanation. Or is it? Ultimately to understand the underlying physics behind the Higgs is to understand how we came to exist. When we ask, “Why are we here?,” at a fundamental level we may as well be asking, “Why is the Higgs here?” more> https://goo.gl/UCn3w8


Updates from Georgia Tech

Four-Stroke Engine Cycle Produces Hydrogen from Methane and Captures CO<sub2
By John Toon – When is an internal combustion engine not an internal combustion engine? When it’s been transformed into a modular reforming reactor that could make hydrogen available to power fuel cells wherever there’s a natural gas supply available.

By adding a catalyst, a hydrogen separating membrane and carbon dioxide sorbent to the century-old four-stroke engine cycle, researchers have demonstrated a laboratory-scale hydrogen reforming system that produces the green fuel at relatively low temperature in a process that can be scaled up or down to meet specific needs. The process could provide hydrogen at the point of use for residential fuel cells or neighborhood power plants, electricity and power production in natural-gas powered vehicles, fueling of municipal buses or other hydrogen-based vehicles, and supplementing intermittent renewable energy sources such as photovoltaics.

Known as the CO2/H2 Active Membrane Piston (CHAMP) reactor, the device operates at temperatures much lower than conventional steam reforming processes, consumes substantially less water and could also operate on other fuels such as methanol or bio-derived feedstock. It also captures and concentrates carbon dioxide emissions, a by-product that now lacks a secondary use – though that could change in the future.

Unlike conventional engines that run at thousands of revolutions per minute, the reactor operates at only a few cycles per minute – or more slowly – depending on the reactor scale and required rate of hydrogen production. And there are no spark plugs because there’s no fuel combusted. more> https://goo.gl/h4K7fV


How to play mathematics


The Pearly Gates of Cyberspace, Author: Margaret Wertheim.
Physics on the Fringe, Author: Margaret Wertheim.
African Fractals: Modern Computing and Indigenous Design, Author: Ron Eglash.

(glasbergen.com)By Margaret Wertheim – The world is full of mundane, meek, unconscious things materially embodying fiendishly complex pieces of mathematics. How can we make sense of this? I’d like to propose that sea slugs and electrons, and many other modest natural systems, are engaged in what we might call the performance of mathematics.

Rather than thinking about maths, they are doing it.

In the fibers of their beings and the ongoing continuity of their growth and existence they enact mathematical relationships and become mathematicians-by-practice. By looking at nature this way, we are led into a consideration of mathematics itself not through the lens of its representational power but instead as a kind of transaction.

Rather than being a remote abstraction, mathematics can be conceived of as something more like music or dancing; an activity that takes place not so much in the writing down as in the playing out.

Since at least the time of Pythagoras and Plato, there’s been a great deal of discussion in Western philosophy about how we can understand the fact that many physical systems have mathematical representations: the segmented arrangements in sunflowers, pine cones and pineapples (Fibonacci numbers); the curve of nautilus shells, elephant tusks and rams horns (logarithmic spiral); music (harmonic ratios and Fourier transforms); atoms, stars and galaxies, which all now have powerful mathematical descriptors; even the cosmos as a whole, now represented by the equations of general relativity.

The physicist Eugene Wigner has termed this startling fact ‘the unreasonable effectiveness of mathematics’.

Why does the real world actualize maths at all? And so much of it?

Even arcane parts of mathematics, such as abstract algebras and obscure bits of topology often turn out to be manifest somewhere in nature. more> https://goo.gl/ifKV2Z

Updates from Georgia Tech

Pioneer of Modern Electronics
By Michael Baxter – The smartphone you peer into, the LED bulb in your desk lamp, the Blu-Ray player that serves up your favorite film – all are here largely because of Russell Dupuis, a professor in electrical and computer engineering at Georgia Tech.

That’s because an essential component of their manufacturing traces back to a process that Dupuis developed in the late 1970s, a process that ushered in a new breed of mass-produced compound semiconductors. These electronic components – particularly those forged of elements from columns III and V in the periodic table — can operate at extremely high frequencies or emit light with extraordinary efficiency. Today, they’re the working essence of everything from handheld laser pointers to stadium Jumbotrons.

The process is known as metalorganic chemical vapor deposition, or MOCVD, and until Dupuis, no one had figured out how to use it to grow high-quality semiconductors using those III-V elements. Essentially, MOCVD works by combining the atomic elements with molecules of organic gas and flowing the mixture over a hot semiconductor wafer. When repeated, the process grows layer after layer of crystals that can have any number of electrical properties, depending on the elements used. more> https://goo.gl/eG2G8e