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This is the episode for anyone who has wondered about the fundamental structure of the universe and its extremely distant future — a time which is so distant that for all practical purposes, it’s almost synonymous with eternity. Black Holes, Fundamental Physics, and the meaning behind the cosmological catchphrase — Turtles All the Way Down. Please listen.


What happens when all the stars in our cosmos’ galaxies burn out; with little or no hydrogen gas left to fuel star formation; and everything pretty much turns to toast? It will presage an age of black holes where extremely low temperatures and fundamental particle decay will alleviate life as we know it. This universal endgame in an almost infinite far future may actually be a Dark Age where little or nothing can happen. And if it does, only on the longest timescales. Yale University astrophysicist Gregory Laughlin and I discuss these and other issues in this cosmological “turtles all the way down” episode of the podcast.

Spintronic devices are attractive alternatives to conventional computer chips, providing digital information storage that is highly energy efficient and also relatively easy to manufacture on a large scale. However, these devices, which rely on magnetic memory, are still hindered by their relatively slow speeds, compared to conventional electronic chips.

In a paper published in the journal Nature Electronics, an international team of researchers has reported a new technique for magnetization switching—the process used to “write” information into magnetic memory—that is nearly 100 times faster than state-of-the-art spintronic devices. The advance could lead to the development of ultrafast magnetic memory for computer chips that would retain data even when there is no power.

In the study, the researchers report using extremely short, 6-picosecond to switch the magnetization of a thin film in a magnetic device with great energy efficiency. A picosecond is one-trillionth of a second.

Circa 2018


The world’s first-ever hiking boots to use graphene have been unveiled by The University of Manchester and British brand inov-8.

Building on the international success of their pioneering use of graphene in trail running and fitness shoes last summer, the brand is now bringing the to a market recently starved of innovation.

Just one atom thick and stronger than steel, graphene has been infused into the rubber of inov-8’s new ROCLITE hiking boots, with the outsoles scientifically proven to be 50% stronger, 50% more elastic and 50% harder wearing.

Crews working on the largest U.S. experiment designed to directly detect dark matter completed a major milestone last month, and are now turning their sights toward startup after experiencing some delays due to global pandemic precautions.

U.S. Department of Energy officials on Sept. 21 formally signed off on project completion for LUX-ZEPLIN, or LZ: an ultrasensitive experiment that will use 10 metric tons of liquid xenon to hunt for signals of interactions with theorized dark matter particles called WIMPs, or weakly interacting massive particles. DOE’s project completion milestone is called Critical Decision 4, or CD-4.

Dark matter makes up an estimated 85 percent of all matter in the universe. We know it’s there because of its observed gravitational effects on normal matter, but we don’t yet know what it is. LZ is designed to detect the two flashes of light that occur if a WIMP interacts with the nucleus of a xenon atom.

Patrick Windpassinger and his team demonstrate how light stored in a cloud of ultra-cold atoms can be transported by means of an optical conveyor belt.

A team of physicists led by Professor Patrick Windpassinger at Johannes Gutenberg University Mainz (JGU) has successfully transported light stored in a quantum memory over a distance of 1.2 millimeters. They have demonstrated that the controlled transport process and its dynamics has only little impact on the properties of the stored light. The researchers used ultra-cold rubidium-87 atoms as a storage medium for the light as to achieve a high level of storage efficiency and a long lifetime.

“We stored the light by putting it in a suitcase so to speak, only that in our case the suitcase was made of a cloud of cold atoms. We moved this suitcase over a short distance and then took the light out again. This is very interesting not only for physics in general, but also for quantum communication, because light is not very easy to ‘capture’, and if you want to transport it elsewhere in a controlled manner, it usually ends up being lost,” said Professor Patrick Windpassinger, explaining the complicated process.

We stored the light by putting it in a suitcase so to speak, only that in our case the suitcase was made of a cloud of cold atoms,” says physicist Patrick Windpassinger from Mainz University in Germany. “We moved this suitcase over a short distance and then took the light out again.


The storage and transfer of information is a fundamental part of any computing system, and quantum computing systems are no different – if we’re going to benefit from the speed and security of quantum computers and a quantum internet, then we need to figure out how to shift quantum data around.

One of the ways scientists are approaching this is through optical quantum memory, or using light to store data as maps of particle states, and a new study reports on what researchers are calling a milestone in the field: the successful storage and transfer of light using quantum memory.

The researchers weren’t able to transfer the light very far – just 1.2 millimetres or 0.05 inches – but the process outlined here could form the foundation of the quantum-powered computers and communication systems of the future.

“Whenever we have developed better clocks, we’ve learned something new about the world,” said Alexander Smith, an assistant professor of physics at Saint Anselm College and adjunct assistant professor at Dartmouth College, who led the research as a junior fellow in Dartmouth’s Society of Fellows. “Quantum time dilation is a consequence of both quantum mechanics and Einstein’s relativity, and thus offers a new possibility to test fundamental physics at their intersection.”


A phenomenon of quantum mechanics known as superposition can impact timekeeping in high-precision clocks, according to a theoretical study from Dartmouth College, Saint Anselm College and Santa Clara University.

Research describing the effect shows that superposition — the ability of an atom to exist in more than one state at the same time — leads to a correction in atomic clocks known as “quantum time dilation.”

The research, published today (October 23, 2020) in the journal Nature Communications, takes into account quantum effects beyond Albert Einstein’s theory of relativity to make a new prediction about the nature of time.