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Breakthrough in creation of gamma ray lasers that use antimatter
Superpowerful lasers for next-generation technologies are closer to existence.
- A new study calculates how to create high-energy gamma rays.
- Physicist Allen Mills proposes using liquid helium to make bubbles of positronium, a mixture with antimatter.
- Gamma ray lasers can lead to new technologies in space propulsion, medical imaging and cancer treatment.
Scientists are closer to taming the most powerful light in the Universe. A physicist at the University of California has figured out how to make stable positronium atoms, which may lead to the creation of gamma ray lasers.
Gamma rays are the product of electromagnetic radiation that is caused by the radioactive decay of atomic nuclei. Harnessing these extremely bright (and usually very brief) lights, which have the highest photon energy, could lead to next-generation technologies. The highly penetrating gamma rays are shorter in wavelength than x-rays, and can be utilized for spacecraft propulsion, advanced medical imaging and treating cancers.
Creating a gamma ray laser requires manipulating positronium, a hydrogen-like atom that is a mixture of matter and antimatter — in particular, of electrons and their antiparticles known as positrons. The collision of a positron with an electron results in the production of gamma ray photons.
To make gamma-ray laser beams, the positronium atoms need to be in the same quantum state, called a Bose-Einstein condensate. The new study from professor Allen Mills of the UC Riverside Department of Physics and Astronomy, shows that hollow spherical bubbles filled with a positronium atom gas can be kept stable in liquid helium.
"My calculations show that a bubble in liquid helium containing a million atoms of positronium would have a number density six times that of ordinary air and would exist as a matter-antimatter Bose-Einstein condensate," said Mills.
Mills thinks helium would work as the stabilizing container because at extremely low temperatures, the gas would turn to liquid and actually repel positronium. This results from its negative affinity fo positronium and would cause bubbles to be created, which would be the source of the necessary Bose-Einstein condensates.
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Testing these ideas and actually configuring an antimatter beam to produce such bubbles in liquid helium is the next goal for the Positron laboratory at UC Riverside that Mills directs.
"Near term results of our experiments could be the observation of positronium tunneling through a graphene sheet, which is impervious to all ordinary matter atoms, including helium, as well as the formation of a positronium atom laser beam with possible quantum computing applications," explained the physicist.
Check out the new study in Physical Review A.
Professor Allen Mills of the UC Riverside Department of Physics and Astronomy.
Credit: I. Pittalwala, UC Riverside.
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Construction of the $500 billion dollar tech city-state of the future is moving ahead.
- The futuristic megacity Neom is being built in Saudi Arabia.
- The city will be fully automated, leading in health, education and quality of life.
- It will feature an artificial moon, cloud seeding, robotic gladiators and flying taxis.
The Red Sea area where Neom will be built:
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Frequent shopping for single items adds to our carbon footprint.
- A new study shows e-commerce sites like Amazon leave larger greenhouse gas footprints than retail stores.
- Ordering online from retail stores has an even smaller footprint than going to the store yourself.
- Greening efforts by major e-commerce sites won't curb wasteful consumer habits. Consolidating online orders can make a difference.
A pile of recycled cardboard sits on the ground at Recology's Recycle Central on January 4, 2018 in San Francisco, California.
Photo by Justin Sullivan/Getty Images<p>A large part of the reason is speed. In a competitive market, pure players use the equation, <em>speed + convenience</em>, to drive adoption. This is especially relevant to the "last mile" GHG footprint: the distance between the distribution center and the consumer.</p><p>Interestingly, the smallest GHG footprint occurs when you order directly from a physical store—even smaller than going there yourself. Pure players, such as Amazon, are the greatest offenders. Variables like geographic location matter; the team looked at shopping in the UK, the US, China, and the Netherlands. </p><p>Sadegh Shahmohammadi, a PhD student at the Netherlands' Radboud University and corresponding author of the paper, <a href="https://www.cnn.com/2020/02/26/tech/greenhouse-gas-emissions-retail/index.html" target="_blank">says</a> the above "pattern holds true in countries where people mostly drive. It really depends on the country and consumer behavior there."</p><p>The researchers write that this year-and-a-half long study pushes back on previous research that claims online shopping to be better in terms of GHG footprints.</p><p style="margin-left: 20px;">"They have, however, compared the GHG emissions per shopping event and did not consider the link between the retail channels and the basket size, which leads to a different conclusion than that of the current study."</p><p>Online retail is where convenience trumps environment: people tend to order one item at a time when shopping on pure player sites, whereas they stock up on multiple items when visiting a store. Consumers will sometimes order a number of separate items over the course of a week rather than making one trip to purchase everything they need. </p><p>While greening efforts by online retailers are important, until a shift in consumer attitude changes, the current carbon footprint will be a hard obstacle to overcome. Amazon is trying to have it both ways—carbon-free and convenience addicted—and the math isn't adding up. If you need to order things, do it online, but try to consolidate your purchases as much as possible.</p><p>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
Building a personal connection with students can counteract some negative side effects of remote learning.
- Not being able to engage with students in-person due to the pandemic has presented several new challenges for educators, both technical and social. Digital tools have changed the way we all think about learning, but George Couros argues that more needs to be done to make up for what has been lost during "emergency remote teaching."
- One interesting way he has seen to bridge that gap and strengthen teacher-student and student-student relationships is through an event called Identity Day. Giving students the opportunity to share something they are passionate about makes them feel more connected and gets them involved in their education.
- "My hope is that we take these skills and these abilities we're developing through this process and we actually become so much better for our kids when we get back to our face-to-face setting," Couros says. He adds that while no one can predict the future, we can all do our part to adapt to it.
Chronic irregular sleep in children was associated with psychotic experiences in adolescence, according to a recent study out of the University of Birmingham's School of Psychology.