Showing posts with label time. Show all posts
Showing posts with label time. Show all posts

Wednesday, July 22, 2026

Acid Test


Reading this is like tripping on acid.

Crystals of space and time: A structural phenomenon that may collapse into tiny black holes
May 2026, phys.org

Space and time can form a kind of "crystal" that may turn into a black hole. ... When spacetime organizes itself into a regular, crystal-like structure during a process known as critical collapse. Black holes usually form in spectacular events, such as the death of a massive star. But in theory, arbitrarily small black holes are also possible: tiny microscopic objects that can emerge from special critical states after the slightest addition of energy.

Wait

"This spacetime crystal is a very peculiar and fascinating object," says Grumiller. "It is a kind of intermediate state, an unstable point that can evolve in two different directions. It may simply dissolve again, leaving behind ordinary spacetime filled with freely moving particles. But if a tiny amount of energy is added, the evolution takes a completely different path: the inconspicuous spacetime crystal turns into a black hole."

Not done yet

"Our universe has four dimensions—three dimensions of space and one dimension of time," explains Christian Ecker. "But in principle, nothing prevents us from writing down physical equations for a larger number of dimensions—five dimensions, forty-two dimensions, or even infinitely many."

via Vienna University of Technology: Christian Ecker et al, Analytic Discrete Self-Similar Solutions of Einstein-Klein-Gordon at Large D, Physical Review Letters (2026). DOI: 10.1103/qgl5-5l3t

Image credit: Christopher Payne - Making Dum Dums at Spangler Candy Bryon OH - 2020

Posted by at No comments:
Labels: , ,

Wednesday, June 24, 2026

Time Check


These days it's all about optical lattice clocks; they're redefining the way we measure time. Not that like that matters to the average person. 

The negative time thing, on the other hand...I'll never understand it, but it sure sounds like something you'd want to understand, so I feel obligated to include it. 


Entanglement-enhanced optical lattice clock achieves unprecedented precision
Nov 2025, phys.org

Optical lattice clocks are devices that measure the passing of time via the frequency of light that is absorbed or emitted by laser-cooled atoms trapped in a repeating pattern of light interference known as optical lattice. ... 30,000 strontium atoms trapped in a 2D laser light grid (i.e., an optical lattice); they spin-squeezed two groups of atoms in the lattice, entangling them in a way that boosts the clock's precision.

via JILA National Institute of Standards and Technology and University of Colorado: Y. A. Yang et al, Clock Precision beyond the Standard Quantum Limit at 10−18 Level, Physical Review Letters (2025). DOI: 10.1103/6v93-whwq. https://dx.doi.org/10.1103/6v93-whwq
On arXiv: DOI: 10.48550/arxiv.2505.04538

Image credit: found on the watchmaker website Esslinger


Optical clock sets new accuracy record, bringing us closer to a new definition of the second
Dec 2025, phys.org

The official definition of the second is set to be updated for the first time in decades. The change will be based on new optical clocks, which are far more precise than today's standards.

Now, researchers at VTT MIKES have demonstrated a strontium single-ion optical clock with an exceptionally low systematic uncertainty of 7.9×10⁻¹⁹, among the lowest ever reported. Over 10 months, the clock's frequency was measured against International Atomic Time (TAI) with an impressive 84% uptime. The record-setting total uncertainty of this measurement was just 9.8×10⁻¹⁷, limited by the cesium clocks that realize the current definition of the second and calibrate TAI. The study is published in Physical Review Applied.

via Technical Research Centre of Finland: T. Lindvall et al, 88Sr+ optical clock with 7.9 ×10-19 systematic uncertainty and measurement of its absolute frequency with 9.8 ×10-17 uncertainty, Physical Review Applied (2025). DOI: 10.1103/czlf-bfvp


Strontium optical clock accurate to within 1 second over 30 billion years
Mar 2026, phys.org

Stability and uncertainty are both surpassing the 10⁻¹⁹ level, meaning the clock would lose or gain less than one second over roughly 30 billion years. Only a few leading institutions, such as the National Institute of Standards and Technology in the United States and Germany's Physikalisch-Technische Bundesanstalt, had approached this level of precision.

via University of Science and Technology of China: Zhi-Peng Jia et al, Improved systematic evaluation of a strontium optical clock with uncertainty below 1X10-18, Metrologia (2026). DOI: 10.1088/1681-7575/ae449e


Ytterbium atomic clock could open a new window on fundamental physics
Apr 2026, phys.org

We trapped ytterbium atoms in a three-dimensional optical lattice using a 'magic wavelength,' which eliminates the frequency shifts caused by the trapping light.

via Kyoto University: Taiki Ishiyama et al, Orders-of-magnitude improvement in precision spectroscopy of an inner-shell orbital clock transition in neutral ytterbium, Nature Photonics (2026). DOI: 10.1038/s41566-026-01857-8


Bringing quantum time into the lab—a single clock can run young and old at once
Apr 2026, phys.org

Rather than just cooling the atoms, they show that one can instead manipulate the vacuum itself, creating so-called squeezed states in which the position and velocity of the clock exhibit subtle quantum behavior.

The result is a new manifestation of relativistic time in the quantum regime, where superpositions and entanglement of time arise: a single clock can measure how it ticks both faster and slower simultaneously, and entangle with the squeezed motion. The team now aims to demonstrate the effects in the laboratory.

via Stevens Institute of Technology, Colorado State University and National Institute of Standards and Technology: Quantum signatures of proper time in optical ion clocks, Physical Review Letters (2026). doi.org/10.1103/qhj9-pc2b


Physicists have measured 'negative time' in the lab
May 2026, phys.org

Our experiment used photons and the against-the-odds journey they must undertake to pass straight through a cloud of rubidium atoms, which means they have a "resonance" with the photons, meaning the energy of the photon can be transferred temporarily to the atoms as an atomic excitation. This allows the photon to "dwell" in the atomic cloud for a time before being released.

If the photon does make it straight through, a strange thing happens. Based on the average time when the photon enters the cloud, one can calculate the expected average time it would arrive at the far side of the cloud, assuming it travels at the speed of light (as photons usually do). What one finds is that the photon actually arrives far earlier than that. In fact, it arrives so early it appears to have spent a negative amount of time inside the cloud - to exit, on average, before it enters.

This effect has been known for decades and was observed in a 1993 experiment. But physicists had mostly decided not to take this negative time seriously.

We fired a weak laser beam - unrelated to the single photon pulse - through the cloud of atoms, and measured small changes in the phase of the beam's light to probe whether the atoms were excited. Any single run of the experiment gives only a very rough indication of whether the photon dwelt in the atoms, but averaging millions of runs yields an accurate dwell time. Amazingly, the result of this weak measurement of dwell time, when the photon goes straight through the cloud, exactly equals the negative time suggested by the photons' average arrival time. Prior to our work, no-one suspected that these two times, measured in entirely different ways, would be equal.

via University of Toronto: Daniela Angulo et al, Experimental Observation of Negative Weak Values for the Time Atoms Spend in the Excited State as a Photon Is Transmitted, Physical Review Letters (2026). DOI: 10.1103/gjfq-k9dv

Posted by at No comments:
Labels: , ,

Wednesday, November 26, 2025

Time Crystals For Sale


Maybe I should stop posting about time crystals. 
(I will never understand time crystals)

Physicists investigate dynamic phenomena of a time crystal
Apr 2025, phys.org

The crystal, made of indium gallium arsenide, was continuously illuminated with a laser during the initial experiment. This interaction caused a nuclear spin polarization, which in turn spontaneously generated oscillations, embodying the essence of a time crystal through periodic behavior under constant excitation. Then they illuminated the semiconductor periodically instead of continuously, while also varying the frequency of the periodic drive. The observed behavior of the time crystal, its frequency response, ranged from perfect synchronization to chaotic dynamics.

Synchronization occurs only at specific fractions of the system's natural frequency. These fractions, in order of appearance with increasing drive frequency, correspond to the "Farey tree sequence," a well-known hierarchical structure implemented in a crystal for the first time.

If the driving frequency is varied further, the end of the synchronization range is reached. Here, each frequency component splits into at least two branches that are symmetrical to the synchronization frequency. These frequency branches connect the synchronization plateaus and together form a kind of staircase, known in the literature as "the devil's staircase," indicating a path either upwards or downwards.

Note: The Devil's Staircase is ... sorry, can't figure that out either. The internet is broken, sure, but this is one of those things that's referred to by everyone, but never actually described by anyone. So basically the people who need to know what it is, already know what it is. Something to do with phase transitions of different materials put together.

via TU Dortmund University: Alex Greilich et al, Exploring nonlinear dynamics in periodically driven time crystal from synchronization to chaotic motion, Nature Communications (2025). DOI: 10.1038/s41467-025-58400-6


Physicists create a new kind of time crystal that humans can actually see
Sep 2025, phys.org

via University of Colorado at Boulder Renewable and Sustainable Energy Institute, and WPI-SKCM2 International Institute for Sustainability with Knotted Chiral Meta Matter at Hiroshima University: Hanqing Zhao et al, Space-time crystals from particle-like topological solitons, Nature Materials (2025). DOI: 10.1038/s41563-025-02344-1


Quantum clocks deliver navigation accuracy far beyond current GPS systems in naval tests
Jul 2025, phys.org

"Outperforms GPS navigation systems by many orders of magnitude"

The clocks designed by the team rely on sealed cells containing a low-pressure gas of atoms (rubidium). These cells are then interrogated with lasers at specific colors, and the information extracted is used to steer the laser wavelength to the atom—providing stability.

Both clocks are optical atomic clocks, using sealed cells containing a low-pressure gas of the elements rubidium and ytterbium.

via University of Adelaide Institute of Photonics and Advanced Sensing, (Austrialian) Defense Science and Technology Group, Quantx Labs: A. P. Hilton et al, Demonstration of a mobile optical clock ensemble at sea, Nature Communications (2025). DOI: 10.1038/s41467-025-61140-2


New theory proposes time has three dimensions, with space as a secondary effect
Jun 2025, phys.org

This is not exactly related to the "Kletetschka's 3-D Time Theory"

If you could step onto that sideways path and remain in the same moment of "regular time," you might find that things could be slightly different—perhaps a different version of the same day. Moving along this perpendicular second path could let you explore different outcomes of that day without going backward or forward in time as we know it.

The existence of those different outcomes is the second dimension of time. The means to transition from one outcome to another is the third dimension.

Oh but wait, wow - we get a revised editor's note, something I do not see often while perusing phys.org (actually I've never seen this before)

Publishing in Reports in Advances of Physical Sciences (World Scientific Publishing), while a legitimate step, is not sufficient for a theory making such bold claims. This journal is relatively low-impact and niche, and its peer review does not match the rigorous scrutiny applied by top-tier journals like Physical Review Letters or Nature Physics. For a paradigm-shifting idea to gain acceptance, it must withstand critical evaluation by the wider physics community, be published in highly regarded journals, and provide reproducible predictions that align with existing evidence—standards this work has not yet met. (Andrew Zinn, editor at ScienceX which contains phys.org)

via University of Alaska Fairbanks Geophysical Institute: Gunther Kletetschka, Three-Dimensional Time: A Mathematical Framework for Fundamental Physics, Reports in Advances of Physical Sciences (2025). DOI: 10.1142/S2424942425500045


World's most precise clock achieves 19-decimal accuracy with aluminum ion technology
Jul 2025, phys.org

The most accurate clock ever. For now!

via National Institute of Standards and Technology: Mason C. Marshall et al, High-Stability Single-Ion Clock with 5.5×10−19 Systematic Uncertainty, Physical Review Letters (2025). DOI: 10.1103/hb3c-dk28

Posted by at No comments:
Labels: ,

Sunday, March 30, 2025

On Language the Universal Autoencoder

 
  
The 'Arrow of Time' effect: LLMs are better at predicting what comes next than what came before
Sep 2024, phys.org

Their performance at predicting the previous word is always a few percent worse than at predicting the next word. This phenomenon is universal across languages, and can be observed with any large language model."

"In theory, there should be no difference between the forward and backward directions, but LLMs appear to be somehow sensitive to the time direction in which they process text. Interestingly, this is related to a deep property of the structure of language that could only be discovered with the emergence of large language models in the last five years."

via EPFL Ecole Polytechnique Federale de Lausanne: Vassilis Papadopoulos et al, Arrows of Time for Large Language Models, arXiv (2024). DOI: 10.48550/arxiv.2401.17505



Ouch! Study investigates pain vocalizations and interjections across 131 languages
Nov 2024, phys.org

Each of the three emotions yielded consistent and distinct vowel signatures across cultures. Pain interjections also featured similar open vowels, such as "a," and wide falling diphthongs, such as "ai" in "Ayyy!" and "aw" in "Ouch!"

However, for disgusted and joyful emotions, in contrast to vocalizations, the interjections lacked regularities across cultures. The researchers expressed surprise at this latter finding.

Is this because disgust is cultural, or at least not entirely physical, and heavily mediated by culture, as compared to actual pain? This is commonly understood in the realm of olfactory perception, where some people think the smell of revolting, rotten fish is delicious (they're Norwegian). Or the smell of vomit (they're Italian, Parmesan to be specific), or the smell of the inside of the skin folds of a homeless person who hasn't been able to bathe in months (they're called New Yorkers, and they kind of long for the smell of the subway, which contains these volatiles). In fact, anything that's fermented is so close to rotten food, that unless you've been culturally conditioned to like it, you won't, at least not at first. Cilantro, I'm looking at you too. 

via CNRS et Université Lumière Lyon, School of Social Sciences at University of Western Australia, and Institute of Psychology at University of Wrocław: Vowel signatures in emotional interjections and nonlinguistic vocalizations expressing pain, disgust and joy across languages, Journal of the Acoustical Society of America (2024). DOI: 10.1121/10.0032454


Words activate hidden brain processes shaping emotions, decisions and behavior
Jan 2025, phys.org

Words have meaning, but they also have emotional meaning:

"There's no single brain region handling this activity, and it's not as simple as one chemical representing one emotion."

(These studies were done thanks to the participation of patients being treated for epilepsy.)

The researchers discovered emotionally charged words - whether positive, negative, or neutral - modulate neurotransmitter release. By measuring the sub-second dynamics of the releases, they identified distinct patterns tied to emotional tone, anatomical regions, and which hemisphere of the brain was involved.

"The surprising result came from the thalamus. This region hasn't been thought to have a role in processing language or emotional content, yet we saw neurotransmitter changes in response to emotional words. This suggests that even brain regions not typically associated with emotional or linguistic processing might still be privy to that information. For instance, parts of the brain responsible for mobilizing movement might benefit from having access to emotionally significant information to guide behavior."

Note: The words used in the study were drawn from the Affective Norms for English Words (ANEW) database, which rates words by positive, negative, or neutral emotional valence.

via Virginia Tech School of Neuroscience and Fralin Biomedical Research Institute: Seth R. Batten et al, Emotional words evoke region- and valence-specific patterns of concurrent neuromodulator release in human thalamus and cortex, Cell Reports (2025). DOI: 10.1016/j.celrep.2024.115162

Posted by at No comments:
Labels: , , , , , ,

Saturday, March 22, 2025

Automatic Updates to Your Spacetime Matrix


You would think something as universal as time would be less susceptible to major changes like revised definitions or refined measurements. But no, that's not how it works. 

Awareness without time? A deep look into timelessness in deep meditative states
Dec 2024, phys.org

Some good distinctions on "coherent conceptualization of deep meditative states, focusing in particular on phenomenal temporality during meditation", dubbed the Extended Now Interpretation.

On Duration - According to Extended Now Interpretation, deep meditation occurs over an interval that the person perceives as an extended present, with no awareness of change, succession, temporal order, beginning, or end. Thus, "timelessness" refers to a lack of temporal structure but not a lack of duration.

On Alertness - Since the option of staying alert or not presents itself anew for each passing moment, the meditator is aware of time passing, and thus aware of a period of time, Dr. Frischhut argues. This does not require the meditator to consciously keep track of a succession of moments, as maintaining alertness during meditation may be enough to give them an awareness of duration even without an awareness of succession.

On Memory - Meditators report having no access to memory during deep meditative states, which would present a problem to her argument. She proposes that the experience of being alert at any given moment has a particular phenomenological character that would be different had it not been preceded by an essentially identical experience of alertness - a second knock on a door wouldn't be experienced the same without the first knock. Thus, even without engaging memory, a meditator still experiences duration in the form of instances of momentary alertness that each flows seamlessly from a previous one.

via Akiko Frischhut at Sophia University in Japan: Akiko Frischhut, Awareness without time, The Philosophical Quarterly (2024). DOI: 10.1093/pq/pqae081



Study claims all observables in nature can be measured with a single constant: The second
Dec 2024, phys.org

The group argues that the number of fundamental constants depends on the type of space-time in which the theories are formulated; and that in a relativistic space-time, this number can be reduced to a single constant, which is used to define the standard of time.

Okun stated that three basic units—meter (length), kilogram (mass), and second (time)—were necessary to measure all physical quantities. In other words, he reaffirmed the so-called MKS system (M, for meter; K, for kilogram; S, for second), which was later incorporated into the International System of Units (SI). Veneziano, for his part, argued that in certain contexts two units would suffice: one for time and one for length. Duff was equivocal, stating that the number of constants could vary depending on the theory in question.

According to their criteria, the number of fundamental constants is related to the minimum number of independent standards needed to express all physical quantities. To repeat, in Galileo's space-time, all observables can be expressed in terms of units of time and space, which are usually the "second" and the "meter." In relativistic space-time, the unit of time—that is, the "second"—is sufficient to express any observable.

And the definition of "second" is currently based on a natural constant: the energy difference between two specific levels of the electronic layer of caesium-133. One second (1s) corresponds to the time of 9,192,631,770 oscillations of the radiation emitted when an electron passes between these two states of caesium-133.

via Institute of Theoretical Physics at São Paulo State University, Institute of Mathematics Statistics and Scientific Computing at the State University of Campinas, São Carlos Institute of Physics at the University of São Paulo: George E. A. Matsas et al, The number of fundamental constants from a spacetime-based perspective, Scientific Reports (2024). DOI: 10.1038/s41598-024-71907-0


Scientists observe 'negative time' in quantum experiments
Dec 2024, phys.org

Don't get too excited: The researchers emphasize that these perplexing results highlight a peculiar quirk of quantum mechanics rather than a radical shift in our understanding of time.

via University of Toronto: Daniela Angulo et al, Experimental evidence that a photon can spend a negative amount of time in an atom cloud, arXiv (2024). DOI: 10.48550/arxiv.2409.03680 , arxiv.org/abs/2409.03680

Posted by at No comments:
Labels: , , , , ,

Wednesday, February 5, 2025

To the Moon


The most dangerous place in the world for scientists to go is right in between fact and fiction, where the superstition meets the science, where the conspiracies become consensus. 

Granted, being that the purpose of science is to advance the perimeter of ignorance, all cutting edge science, all "new" science, exists in this liminal zone. Maybe this should be revised - it's not a scary place to be for the scientist, actually I'll bet it's pretty exciting. But it's a scary place for the person who has to explain said science to the general public, because it is confusing as hell. The truth is hard. Simple explanations for the fundamental rules of the universe are like military strategy - no plan survives first contact with the enemy. There are so many contingencies, that only the most deeply-steeped genius can tease them apart. And there's also the 'paradox of knowledge' to contend with, something about how the more you know about a thing the less able you are to talk about it in plain language, yet the less you know and the more you can talk about it easily, the lower the quality of your information. (I think nowadays we call that "low credibility information".)

And speaking of which, you've never had so much fun at a science lecture:
Sasquatch Distribution Modelling: Investigating patterns of Bigfoot sightings in North America
Annual Halloween lecture by Prof Joss Wright at the Oxford Internet Institute, Oct 31 2024

So here we are - the origin of the word "lunatic" comes from "lunar" - suggesting to us, from generations long before we were even calling "science" "philosophy", that the moon makes us crazy. Yet behavioral scientists, neurologists, biologists, etc., all say that's ridiculous. The truth is between the two, and as usual it's complicated.  

Gravitational action of sun and moon influences behavior of animals and plants
Jan 2022, phys.org

Gravitational cycles do not only affect the simplest organisms. Scientific studies have found that humans kept in the dark tend to establish a cyclical fluctuation lasting 24.4 - 24.8 hours, in harmony with the lunar cycle. This tendency has also been noted in people who spend long periods in caves. It conditions the alternation of sleep and wakefulness, meal times, and other metabolic functions.
via University of Campinas (UNICAMP) in the state of São Paulo, Brazil: Cristiano de Mello Gallep et al, Are cyclic plant and animal behaviours driven by gravimetric mechanical forces?, Journal of Experimental Botany (2021). DOI: 10.1093/jxb/erab462

Image credit: Who am I kidding, this has become futile.

As for the rest of this post, just moon things in general:
Moon cave discovered that could one day house humans
Jul 2024, BBC News

Scientists have for the first time discovered a cave on the Moon.

At least 100m deep, it could be an ideal place for humans to build a permanent base, they say. Countries are racing to establish a permanent human presence on the Moon, but they will need to protect astronauts from radiation, extreme temperatures, and space weather.

Humans could potentially be living in lunar pits in 20-30 years.

They found the cave by using radar to penetrate the opening of a pit on a rocky plain called the Mare Tranquillitatis. It is visible to the naked eye from Earth, and is also where Apollo 11 landed in 1969.

Moon landing live: US spacecraft Odysseus begins Moon landing descent
Feb 2024, BBC News

Odysseus successfully landed on the surface of the Moon, officially making Intuitive Machines the first commercial company to successfully land a spacecraft on the lunar surface.

Odysseus is also carrying 125 tiny sculptures made by US artist Jeff Koons, making them the first artworks land on the lunar surface.


Researchers figure out how to keep clocks on the Earth, Moon in sync
Aug 2024, Ars Technica

So, the International Astronomical Union has a resolution that calls for a "Lunar Celestial Reference System" and "Lunar Coordinate Time" to handle things there. On Monday, two researchers at the National institute of Standards and Technology, Neil Ashby and Bijunath Patla, did the math to show how this might work.

The Astronomical Journal, 2024. DOI: 10.3847/1538-3881/ad643a

Post Script:
1. We put reflectors on the moon, which you can still see from Earth.
2. The lunar calendar has 354 days, and the Egyptian calendar has 365. This averages to 360, which is coincidentally the number of degrees in a circle. (Is it really a coincidence?)
--via University of Glasgow: An Improved Calendar Ring Hole-Count for the Antikythera Mechanism. Graham Woan, Joseph Bayley. The Horological Journal, July 2024. bhi.co.uk; https://phys.org/news/2024-06-gravitational-antikythera-mechanism-mystery.html


Posted by at No comments:
Labels: , , , ,

Saturday, January 4, 2025

Measuring Things for Old Time's Sake


Starting with a stretch, this first one requires some concentration. We're talking about macro time vs micro time, and one where the time is measured by genetic changes. It's a new way to measure evolutionary time. Also it's scalar, which means fractals:

New research shows microevolution can be used to predict how evolution works on much longer timescales
May 2024, phys.org

By compiling and analyzing datasets from existing species and from fossils, researchers showed the evolvability responsible for microevolution (the evolution of a species over a few generations) of many different traits predicts the amount of change observed between populations and species separated by up to one million years (macroevolution).

"Darwin suggested that species gradually evolve, but what we found is that even though populations rapidly evolve over the short term, this (short-term) evolution doesn't accumulate over time. However, how divergent populations and species are, on average, over long periods of time still depends on their ability to evolve on the short term." 

via Norwegian University of Science and Technology Department of Biology: Agnes Holstad et al, Evolvability predicts macroevolution under fluctuating selection, Science (2024). DOI: 10.1126/science.adi8722

Further reading, from above: Traits with higher evolvability change rapidly because they are able to respond to environmental changes more quickly.

Highly evolvable traits can rapidly respond to these fluctuations in selection and will fluctuate over time with high amplitude. Traits with little evolvability will also fluctuate but more slowly and thus with lower amplitude.

"Populations or species that are geographically distant from each other are exposed to environments whose fluctuations are not synchronized. Consequently, these populations will have different trait values, and the size of this difference will depend on the amplitude of the trait's fluctuation, and therefore on the evolvability of the trait."

Note: "Evolvability" depends on the amount of heritable (genetic) variation in a species (which sounds like heterozygosity?).



Researchers more precisely calculate how much faster time passes on the moon
Jul 2024, phys.org

The team found that time on the moon ticks by at 0.0000575 seconds faster per day (57.50 µs/d) than it does on Earth. Based on that number, other calculations can be made - if a person were to live on the moon for 274 years, for example, they would be 5.76 seconds older than they would be had they lived on Earth all that time.

It doesn't seem like a big deal until you try to do something like dock with a space station.

via NASA's Jet Propulsion Laboratory at the California Institute of Technology: Slava G. Turyshev et al, Time transformation between the solar system barycenter and the surfaces of the Earth and Moon, arXiv (2024). DOI: 10.48550/arxiv.2406.16147


Why timekeeping is now on the verge of a giant leap forward in accuracy
Nov 2024, phys.org

Atomic clocks are about to be replaced by nuclear clocks that can use the Thorium atom instead of the Cesium or Strontium atom, because it has a faster electron transition, so with it we can measure time to the nineteenth decimal place, possibly redefining the second by 2030.

Some background:
  • Water clocks appeared around 2,000BC and measure time by regulating the flow of water into or out of a vessel.
  • The mechanical clock was established in the late 13th century.
  • Until 1967, a second was defined as 1/86,400 of a day.
  • The International System of Units then changed things: "The second… is defined by taking the… transition frequency of the cesium-133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s⁻¹."

Bonus: 
Scientists successfully create a time crystal made of giant atoms
Jul 2024, phys.org

via Vienna University of Technology Institute of Theoretical Physics and Tsinghua University: Xiaoling Wu et al, Dissipative time crystal in a strongly interacting Rydberg gas, Nature Physics (2024). DOI: 10.1038/s41567-024-02542-9.

Posted by at No comments:
Labels: , , , ,

Wednesday, July 24, 2024

Art Things


Banksy's 'Valentine's day mascara' mural freezer removed
Feb 2023, CNN Style

The mural shows a 1950s housewife with a swollen eye apparently pushing a man into an abandoned chest freezer, but the chest freezer was real, while the rest was painted on the wall. Then the freezer was stolen. So now the refrigerator is a work of art, in part, and art history is being re-written by the day. This was done for Valentine's Day, 2023.

Banksy: Artist confirms new London tree mural is his own work
Mar 2024, BBC News

Islington Council said its graffiti removal team is aware of the artwork and won't remove it.

I'm not even sure how to say this without it coming out wrong, but like you know your society is fucked up when the people are so wholeheartedly supporting illegal activity:

Crowds have gathered to see the mural, with one local saying they were "proud" their street had been chosen.

"It feels like a personal message to us residents, we just feel so proud," said Wanja Sellers, who lives along the street from the mural.

I am left wondering if there is no such thing as public art anymore? Public anything? What happens when there's no more public assets (public art, public music, public space, public parks, public restrooms, public water fountains, public benches, public transit, public public)? People start making their own, illegally, and the rest of the people start supporting it. Please rewind to the movie Death Wish, when hoodlums used a spraycan to terrorize, vandalize, rape and murder a middle class architect and his family living on the Upper West Side of New York City in 1974. Graffiti, and the spraycan specifically, was the ultimate symbol of societal dysfunction, collapse even. It was the mark of the beast, the trumpet of the apocalypse. Today, well things are much different. (Then again, Angela Davis's afro was scary as hell to a lot of Americans and now it's a Halloween costume.)

Post Script: 
The council believes the cherry tree in the foreground of the artwork is around 40-50 years old and is in declining health, with decay and fungi damage. It says it has been maintaining and pruning the tree for some time - both for safety, and to help prolong its lifespan - and will continue working to keep the tree alive. A resident says "It's spring now, and this tree should be bursting forth with leaves, but Banksy must have cycled past and thought how miserable it looks."


Examining why egg yolk was used in Old Masters' oil paints
Mar 2023, phys.org

The work involved creating two types of oil-based paints, both with yolk added. One mixture consisted of nothing but yolk and oil. The other had yolk, oil and pigments to add coloring. The team also created similar paints without using egg yolk. The group then used the paints to create paintings that could be used for testing purposes. Such tests included taking measurements of moisture amounts and movement, oxidation, time to dry and heat capacity.
  • stronger bonding between pigment particles for stiffer paint
  • reduced wrinkling of the paint to protect the paint against high humidity
  • antioxidants in the yolk prevent yellowing
  • more pigment to the oil to create more vivid images

via Institute for Mechanical Process Engineering and Mechanics at Karlsruhe Institute of Technology, Department of Chemistry and Industrial Chemistry and at University of Pisa, Institute of Chemistry of Organo Metallic Compoundsin Pisa, and Doerner Institut in Munich: Ophélie Ranquet et al, A holistic view on the role of egg yolk in Old Masters' oil paints, Nature Communications (2023). DOI: 10.1038/s41467-023-36859-5

Louise dancing on her 60th birthday - art by Jillian Edelstein  for Breast Cancer Now in Gallery of Hope at London's Saatchi Gallery - Apr 2024

AI photos show people with secondary breast cancer their lost future
Apr 2024, BBC News

I'm sure there's a history for this, but I'm not familiar with it. People have been aware of their own impending death for a long time, not just because of advances in cancer diagnoses (the guy with the "black spot" in Treasure Island anyone?). And artists have been making shit up forever, it's kind of what they do. All that being said, wow this is bonkers -

Using AI and photos taken by renowned photographer Jillian Edelstein, the images make up the Gallery of Hope at London's Saatchi Gallery.

Louise Hudson, from Caldicot, Monmouthshire, is one of those who took part.

Now 58, she was first diagnosed with breast cancer in July 2022 which then spread to her liver. In February an MRI scan showed lesions on her brain and she was told she had a life expectancy of about six months.

Louise's image at the exhibition shows her celebrating her 60th birthday by performing with her amateur dance company Chelsea Ballet, while her husband of 30 years Barry looks on with pride.
Michel-Marie Carquillat - Joseph-Marie Jacquard woven in silk on a Jacquard loom, 55 x 34 cm - 1839 

The Most Famous Image in the Early History of Computing : History of Information

Just in case this gets lost in the oncominig artificial info wars and subsequent death of the internet, I copy here:

In 1839 weaver Michel-Marie Carquillat, working for the firm of Didier, Petit et Cie, in Lyon, France wove in fine silk a Portrait of Joseph-Marie Jacquard. The image, including caption and Carquillat’s name, taking credit for the weaving, measures 55 x 34 cm.; the full piece of silk including blank margins measures 85 x 66 cm.

This image, of which perhaps only about 20 examples survived, was woven on a Jacquard loom using 24,000 Jacquard cards, each of which had over 1000 hole positions. The process of mis en carte, or converting the image details to punched cards for the Jacquard mechanism, for this exceptionally large and detailed image, would have taken several workers many months, as the woven image convincingly portrays superfine elements such as a translucent curtain over glass window panes.

The Jacquard loom did no computation, and for that reason it was not a digital device in the way we think of digital today. However the method by which Jacquard stored information in punched cards by either punching a hole in s standardized space in a card or not punching a whole in that space is analogous to a zero or one or an on and off switch.
  • The Jacquard method was used by Charles Babbage
  • It confirmed the potential of using punched cards for the input, programming, output and storage of information in the design and conception of the first general-purpose programmable computer the Analytical Engine.
  • It also challenged existing notions that machines were incapable of subtlety, and blurred the clear lines between industrial production and the arts. 
  • See Swade, The Cogwheel Brain. Charles Babbage and the Quest to Build the First Computer. 2000. 107-8.
  • More than once this woven image was mistaken for an engraved image.
  • In 2012 the only publically recorded examples were those in the Metropolitan Museum of Art, the Science Museum in London, The Art Institute of Chicago, and the Computer History Museum, Mountain View, California.
  • The image was the subject of the book by James Essinger entitled, Jacquard's Web. How a Hand Loom led to the Birth of the Information Age (2004).


Posted by at No comments:
Labels: , , , , , , , , ,

Tuesday, July 23, 2024

The Multisensory Multiplex Measures More Than You Think


This title means absolutely nothing, but it's unsettling to think "time" is as malleable as it is. 

Physicists develop highly robust time crystal
Feb 2024, phys.org

It's made of indium gallium arsenide, in which the nuclear spins act as a reservoir for the time crystal. The crystal is continuously illuminated so that a nuclear spin polarization forms through interaction with electron spins. And it is precisely this nuclear spin polarization that then spontaneously generates oscillations, equivalent to a time crystal.

A periodic time crystal was demonstrated in 2022 in a Bose-Einstein condensate but lived for just a few milliseconds. This one lasted for 40 minutes, or 10 million times longer. 

via TU Dortmund University: A. Greilich et al, Robust continuous time crystal in an electron–nuclear spin system, Nature Physics (2024). DOI: 10.1038/s41567-023-02351-6



The intricate dance of time and touch: Insights from the somatosensory cortex
Feb 2024, phys.org

The perception of time is intricately intertwined with touch, emerging within the tactile sensory representation.

Optogenetic intervention influenced perceived intensity in rats trained to assess vibration intensity while disregarding duration. Conversely, optogenetic intervention influenced perceived duration in animals trained to evaluate vibration duration while disregarding intensity.

"Since both percepts involve an overlapping set of neurons, we describe the two signals as 'multiplexed' in the somatosensory cortex.

via International School of Advanced Studies SISSA: Sebastian Reinartz et al, Direct contribution of the sensory cortex to the judgment of stimulus duration, Nature Communications (2024). DOI: 10.1038/s41467-024-45970-0


White House wants Moon to have its own time zone
Apr 2024, BBC News

The White House wants US space agency Nasa to develop a new time zone for the Moon - Coordinated Lunar Time (LTC).

Because of the different gravitational field strength on the Moon, time moves quicker there relative to Earth - 58.7 microseconds every day.

This might not seem like much, but it can have a significant impact when trying to synchronise spacecraft.

Time is currently measured on Earth by hundreds of atomic clocks stationed around our planet which measure the changing energy state of atoms to record time to the nanosecond. If they were placed on the Moon, over 50 years they would be running one second faster.


Image viewing experiments challenge theory of universal internal clock
Apr 2024, phys.org

The Universal Internal Clock (does not exist)

  • 170 volunteers participated
  • In the first two experiments, volunteers looked at photographs with varying degrees of size and clutter, and were asked how long they believed they had been looking at the images.
  • In the second two experiments, volunteers also estimated how memorable the photos were.
  • The took a memory test the following day.

  • Volunteers tended to overestimate the amount of time they viewed cluttered scenes, while underestimating the amount of time they viewed tidy areas.
  • Perception of time varied depending on the memorability of an image.
  • Volunteers were more accurate in their assessment of how much time had passed for the most memorable images
  • Experiments suggest that time perception is influenced by sensory perception.

via George Mason University: Alex C. Ma et al, Memorability shapes perceived time (and vice versa), Nature Human Behaviour (2024). DOI: 10.1038/s41562-024-01863-2


Posted by at No comments:
Labels: , , , ,

Monday, May 1, 2023

The Photonic Phreakout


Optical this and photon that, opto-genetics, opto-electronics, opto-dildonics. Optical quantum computers made of crystals and light, the fastest computers you can imagine, tuned lasers that can bleep your brain through your retina and treat depression, and optical tractor beams, that's right, aka quantum tweezers.

This is not to detract from the renewed interest in the fundamental nature of time, by way of "time crystals", and of something I will call time lasers, because where there's crystals there's lasers, but that idea hasn't been discovered yet. 


Laser attack blinds autonomous vehicles, deleting pedestrians and confusing cars
Oct 2022, phys.org

Expertly timed lasers shined at an approaching lidar system can create a blind spot in front of the vehicle large enough to completely hide moving pedestrians and other obstacles

via University of Florida, the University of Michigan and the University of Electro-Communications in Japan: Yulong Cao et al, You Can't See Me: Physical Removal Attacks on LiDAR-based Autonomous Vehicles Driving Frameworks, arXiv (2022). DOI: 10.48550/arxiv.2210.09482.

 
Researchers create an optical tractor beam that pulls macroscopic objects
Jan 2023, phys.org

Optical manipulation such as levitation and rotation: Optical tweezers, for example, are commonly used scientific instruments that use laser light to hold and manipulate tiny objects such as atoms or cells. We could also use laser light to create an optical tractor beam.

via QingDao University of Science and Technology in China: Lei Wang et al, Macroscopic laser pulling based on the Knudsen force in rarefied gas, Optics Express (2022). DOI: 10.1364/OE.480019


Deep learning-designed diffractive processor computes hundreds of transformations in parallel
Jan 2023, phys.org

Optical computers use light instead of electricity to perform computations, and now they can make massively parallel, wavelength-multiplexed diffractive processors.

via SPIE International Society for Optics and Photonics and UCLA: Jingxi Li et al, Massively parallel universal linear transformations using a wavelength-multiplexed diffractive optical network, Advanced Photonics (2023). DOI: 10.1117/1.AP.5.1.016003

AI Art - Cymatics - 2022

A new type of photonic time crystal gives light a boost
Apr 2023, phys.org

While some physicists were initially skeptical that time crystals could exist, recent experiments have succeeding in creating them.

"We found that reducing the dimensionality from a 3D to a 2D structure made the implementation significantly easier, ..."

via Aalto University, Karlsruhe Institute of Technology, and Stanford University: Xuchen Wang et al, Metasurface-Based Realization of Photonic Time Crystals, Science Advances (2023). DOI: 10.1126/sciadv.adg7541.


Optical switching at record speeds opens door for ultrafast, light-based electronics and computers
Mar 2023, phys.org

Imagine a home computer operating 1 million times faster than the most expensive hardware on the market. Light-based optical computing with optical transistors is a marked improvement from the semiconductor-based transistors that currently run the world.

Data transfer speeds exceeding a petahertz, measured at the attosecond time scale.

via University of Arizona: Dandan Hui et al, Ultrafast optical switching and data encoding on synthesized light fields, Science Advances (2023). DOI: 10.1126/sciadv.adf1015


Recreating the double-slit experiment that proved the wave nature of light in time, instead of space
Apr 2023, phys.org

Now, a team led by Imperial College London physicists has performed the experiment using "slits" in time rather than space. They achieved this by firing light through a material that changes its properties in femtoseconds (quadrillionths of a second), only allowing light to pass through at specific times in quick succession.

The team next want to explore the phenomenon in a "time crystal," which is analogous to an atomic crystal, but where the optical properties vary in time.

Co-author Professor Stefan Maier said, "The concept of time crystals has the potential to lead to ultrafast, parallelized optical switches."

via Imperial College London: Romain Tirole et al, Double-slit time diffraction at optical frequencies, Nature Physics (2023). DOI: 10.1038/s41567-023-01993-w. 

Light shaped into a twisted smoke ring - Y Shen and Z Zhu at SPIE King's College - 2023

Post Script:
Topology also plays a big part in the coming light hype cycle -- you might know topology as Gödel, Escher, Bach's Eternal Golden Braid, but it also has a strong link to the hyperbolic geometries of hallucinogenic hero doses. They make quantum computers work better, so we're trying to tie light into knots to make mega-sentient intelligentities, faster.

Photonic hopfions: Light shaped as a smoke ring that behaves like a particle
Jan 2023, phys.org

Topology, hyperbolic geometry, toroids, skyrmions, and now -- new, very unusual, structured-light family of 3D topological solitons, the photonic hopfions, where the topological textures and topological numbers can be freely and independently tuned. 

via SPIE International Society for Optics and Photonics, University of Southampton, and King's College London: Yijie Shen et al, Topological transformation and free-space transport of photonic hopfions, Advanced Photonics (2023). DOI: 10.1117/1.AP.5.1.015001


Posted by at No comments:
Labels: , , , , ,

Thursday, April 6, 2023

The Superluminal Observer


From the "rebel physicist" at University of Warsaw, and posted back in 2020, here's an attempt to explain what it's like to be the object that moves faster than light. 

Three time dimensions, one space dimension: Relativity of superluminal observers in 1+3 spacetime
Dec 2022, phys.org

The Superluminal World - Stretch your brain into this, the collapse of 3D space into 1D, or rather the flip from space to time dimensions.

I don't know why we had to wait for someone to say this, but why not? Why can't superluminal objects exist?

What happens when we assume—at least theoretically—that the world could be observable from superluminal frames of reference? There is a chance that this would allow the incorporation of the basic principles of quantum mechanics into the special theory of relativity. This revolutionary hypothesis of prof. Andrzej Dragan and prof. Artur Ekert from the University of Oxford presented for the first time in the article "Quantum principle of relativity" published two years ago in the New Journal of Physics. the latest conclusion is in the journal Classical and Quantum Gravity, titled "Relativity of superluminal observers in 1 + 3 spacetime", and is authored by a group of 5 physicists.

In their latest publication in the journal Classical and Quantum Gravity, titled "Relativity of superluminal observers in 1 + 3 spacetime", a group of 5 physicists goes a step further, presenting conclusions about the full four-dimensional spacetime.

via University of Warsaw and Center for Quantum Technologies of the National University of Singapore: Andrzej Dragan et al, Relativity of superluminal observers in 1+3 spacetime, Classical and Quantum Gravity (2022). DOI: 10.1088/1361-6382/acad60

Image credit: Neutron star merger - NASA's Goddard Space Flight Center, CI Lab - 2022


Post Script:
Time-synchronization is hard:
Network-crashing leap seconds to be abandoned by 2035, for at least a century
Nov 2022, Ars Technica

International Bureau of Weights and Measures (BIPM in its native French) just decided that Coordinated Universal Time, or UTC, would run without a leap second until 2135. 

Leap seconds in 2012 and 2017 caused multi-hour outages at companies including Reddit, Qantas, and Cloudflare. Many companies implemented a version of "leap smearing" to smooth out a leap second addition into micro-seconds spread across the globe throughout a day.


Posted by at No comments:
Labels: , , , ,

Tuesday, September 13, 2022

Attoclock My Blogspot


All these things have to do with time. We're getting better at seeing smaller time intervals. Back when femtosecond spectroscopy came out, someone used it to suggest a quantum nature of photosynthesis, as if the photons take all the routes possible through the leaf until they find the optimal route, and then all collapse onto that one (although this has since been revisited in 2020). 

Now we can see in attoseconds. 

We're getting better at coordinating on smaller time scales. Back before there were cross-continental railroads, we didn't need time zones. Now we need to periodically "smear" the clock at the micro-second scale just to keep all the world's computers in perfect synchrony. And big platforms are developing their own Time Cards to keep in sync with itself via radio wave oscillations from satellites. 

But then there's the far out stuff, the kind of phenomena that the average person, including myself, cannot understand. We're talking about time crystals and extra time dimensions. No idea what these really are, but they seem to be hanging around with the quantum computer news a lot.

Oh let's not forget that crazy but intuitive theory of Quantum Exoticism -- that we need to just get over it and accept that things move faster than the speed of light; the subluminal and the superluminal can co-exist [links and links].


A new window into the world of attosecond phenomena
May 2022, phys.org

X-Ray Free-Electron Lasers (XFEL) and chronoscopy.

via The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences: Wojciech Błachucki et al, Approaching the Attosecond Frontier of Dynamics in Matter with the Concept of X-ray Chronoscopy, Applied Sciences (2022). DOI: 10.3390/app12031721


Time crystals 'impossible' but obey quantum physics
Jun 2022, phys.org

Sounds like a challenge.

Scientists have created the first "time-crystal" two-body system in an experiment that seems to bend the laws of physics.

First theorized in 2012 by Nobel Laureate Frank Wilczek and identified in 2016, time crystals exhibit the bizarre property of being in constant, repeating motion in time despite no external input. Their atoms are constantly oscillating, spinning, or moving first in one direction, and then the other.

They cooled superfluid helium-3 to about one ten thousandth of a degree from absolute zero (0.0001 K or -273.15 C). The researchers created two time crystals inside the superfluid, and brought them to touch. The scientists then watched the two time crystals interacting as described by quantum physics.

Time crystals could be used to build quantum devices that work at room temperature.

via Lancaster University, Landau Institute, and Aalto University in Helsinki:  Nonlinear two-level dynamics of quantum time crystals, Nature Communications (2022). DOI: 10.1038/s41467-022-30783-w


Researchers observe continuous time crystal
Jun 2022, phys.org

In their experiment, the scientists used a Bose-Einstein condensate inside an optical high-finesse cavity. Using a time-independent pump, they observed a limit cycle phase which is characterized by emergent periodic oscillations of the intracavity photon number accompanied by the atomic density cycling through recurring patterns.

I'm just reading it for the words, and I see "time pump" in there. 

via University of Hamburg Institute of Laser Physics: Phatthamon Kongkhambut et al, Observation of a continuous time crystal, Science (2022). DOI: 10.1126/science.abo3382


As Earth spins faster, Meta joins fight against leap seconds
Jul 2022, Ars Technica

"Leap Smearing"

Facebook, like many large-scale tech companies, is tired of trying to time a global network of servers against leap seconds, which add between 0.1 and 0.9 seconds to Coordinated Universal Time (UTC) every so many years. There have been 27 leap seconds added since 1972. In a post on Meta’s engineering blog, Oleg Obleukhov and Ahmad Byagowi say 27 is quite enough for non-solar-scientist types—"enough for the next millennium."

International timekeeping bodies add leap seconds at unpredictable intervals because the things that cause them—the braking action of tides on rotation, moon position, the distribution of ice caps on mountaintops, mantle flow, earthquakes—are unpredictable. When the Earth’s speed varies too much from atomic time-keeping, a leap second is called for by the International Earth Rotation and Reference Systems Service (IERS).

At midnight on the designated day, clocks are set to tick from 23:59:59 to 23:59:60 to 00:00:00. That uncommon middle timestamp drives coordinated systems bonkers. A leap second in 2012 took down Reddit, Gawker, and Australian airline Qantas. Cloudflare took the hit on New Year’s 2017 (and detailed why). Since then, many technologies have prepped themselves for the next leap second with “leap smearing,” or using micro-second slowdowns over a long, global-server-friendly span leading up to midnight.

-"We encourage anyone smearing leap seconds to use a 24-hour linear smear from noon to noon UTC."
Google Developers, Public NTP, Aug 2022 

Image credit: Cold Atoms in an Optical Resonator Forming a Time Crystal, University of Hamburg, 2022


Posted by at No comments:
Labels: , , , , , , , ,
Subscribe to: Posts (Atom)