Adafruit has officially launched the Kee Boar 2040, a Raspberry Pi RP2040-based keyboard driver for custom builds, which mimics the Arduino Pro Micro pinout — making it an easy drop-in replacement.
First teased by the company seven months ago the Kee Boar 2040, or KB2040, the new board is designed to offer a more powerful alternative to the traditional microcontroller development boards that find their way into custom keyboard projects.
The new Kee Board 2040 (KB2040) is designed to put an RP2040 at the heart of your next custom keyboard build. (📷: Adafruit)
“We mixed together what we liked most about the SparkFun Pro Micro RP2040 (Qwiic/STEMMA QT I2C port on the end, so good!) and Elite-C (castellated pads & pins for D+ and D-) and our existing RP2040 boards (boot button can be used for user, 8MB QSPI flash, onboard NeoPixel, jumper for skipping the diode/fuse for high power RGB LEDs or USB hosting),” the company explains. “We even got it to all fit on a 2-layer PCB with 7/7 routing – just needed to make the smallest caps and resistors 0402.”
The resulting board shares the size and form factor as a SparkFun Pro Micro, though has fewer analog pins available, and includes 18 general-purpose input/output (GPIO) pins plus a further two on the STEMMA QT port — enough, Adafruit explains, for a 100-switch keyboard matrix. A USB Type-C port provides connectivity for data and power, and like the RP2040-based Raspberry Pi Pico the board’s pin headers are castellated for optional surface mounting.
The board breaks out 18 GPIOs, plus a further two on the STEMMA QT port at the end. (📷: Adafruit)
The RP2040 at its heart, meanwhile, offers two 32-bit Arm Cortex-M0+ processors and 264kB of RAM, to which Adafruit has added 8MB of SPI flash. It also includes CircuitPython compatibility: “We’re seeing lots of people use CircuitPython for keebs,” the company claims, “which is awesome!”
The new board has been listed on the Adafruit store at $8.95, though at the time of writing was showing as out of stock.
Headphone designers have to balance scientific limitations with human preferences.
What you like to listen to is also important for choosing the right pair.
Between music, podcasts, gaming, and the unlimited supply of online content, most people spend hours a week wearing headphones. Perhaps you are considering a new pair for the holidays, but with so many options on the market, it can be hard to know what to choose.
I am a professional musician and a professor of music technology who studies acoustics. My work investigates the intersection between the scientific, artistic and subjective human elements of sound. Choosing the right headphones involves considering all three of those aspects, so what makes for a truly good pair?
Sound is simply a series of low pressure and high pressure areas where air molecules, represented by the small dots, compress or spread apart. Credit: Pluke/WikimediaCommons
What is sound really?
In physics, sound is made of air vibrations consisting of a series of high and low pressure zones. These are the cycles of a sound wave.
Counting the number of cycles that occur per second determines the frequency, or pitch, of the sound. Higher frequencies mean higher pitches. Scientists describe frequencies in hertz, so a 500 Hz sound goes through 500 complete cycles of low pressure and high pressure per second.
The loudness, or amplitude, of a sound is determined by the maximum pressure of a wave. The higher the pressure, the louder the sound.
To create sound, headphones turn an electrical audio signal into these cycles of high and low pressure that our ears interpret as sound.
The human ear is a complex system that turns vibrations in the air into electrical signals that go to the brain. Credit: Iain/WikimediaCommons, CC BY-SA
The human ear
Human ears are incredible sensors. The average person can hear a huge range of pitches and different levels of loudness. So how does the ear work?
When sound enters your ear, your eardrum translates the air vibrations into mechanical vibrations of the tiny middle ear bones. These mechanical vibrations become fluid vibrations in your inner ear. Sensitive nerves then turn those vibrations into electrical signals that your brain interprets as sound.
Most people don’t know that hearing sensitivity varies and, frankly, would never need to consider this phenomenon – it is simply how people hear. But headphone engineers definitely need to consider how human perception differs from pure physics.
Speakers are fundamentally made of four components, a magnet (1), a coiled wire (2), a spring or suspension (3) and a diaphragm (4). Credit: Svjo/WkimediaCommons, CC BY-SA
How do headphones work?
Headphones – both bigger varieties that sit over your ears as well as small earbuds – are just small speakers. Simply put, speakers do the opposite of your ear: They convert the electrical signals from your phone, record player or computer into vibrations in air.
Most speakers are made of four components: a stationary magnet, a wire coil that moves back and forth around that magnet, a diaphragm that pushes air and a suspension that holds the diaphragm.
Electromagnetism states that when a wire is wrapped around a magnet and the current within the wire changes, the magnetic field around the wire changes proportionally. When the electrical signal of a song or podcast pulses through the wires in a set of headphones, it changes the current and moves the magnet. The magnet then moves the diaphragm in and out – kind of like a plunger – pushing and compressing air, creating pulses of high pressure and low pressure. This is the music that you hear.
Ideally, a speaker would convert the electrical signals of the input perfectly into sound representations. However, the real physical world has limitations. Things like the size and material of the magnet and diaphragm all prevent a speaker from perfectly matching its output to its input. This leads to distortion and some frequencies being louder or softer than the original.
While no headphone can perfectly recreate the signal, there are infinite different ways to choose to distort that signal. The reason two equally expensive headphones can sound or feel different is that they distort things in different ways. When engineers build new headphones, they have to not only consider how human hearing distorts sound, but also the physical limitations of any speaker.
What you like to listen to and how you like your headphones to sound play a huge role in determining what makes for a ‘good’ pair of headphones.
For example, some people prefer bass-heavy headphones for hip-hop music, while classical music listeners may want less frequency distortion. But music or recreational listening aren’t the only things to consider. Headphones for the hearing impaired may highlight frequencies from approximately 1,000 Hz to 5,000 Hz, as this helps to make speech more understandable.
You could certainly play a hip-hop song through headphones designed for the hearing impaired, but most people would agree that the results aren’t going to sound very good. Making sure the headphones you choose match how you are going to use them goes a long way in determining what will sound good.
Ultimately, the science of headphone design, the artistry of the content creators and the human experience all intersect to form the perception of “good” headphones. Despite all these moving pieces, there is one foolproof way to know when headphones are good: choose a good song and put a pair on! Because when all the attributes align, a good pair of headphones can give you the opportunity to be transformed by sound.
Written by Timothy Hsu, Assistant Professor of Music and Arts Technology, IUPUI.
Image by superpeet / iStockNovember 30, 2021 — 12:02 PMShare on:
We’ve discussed a wealth of sleep hacks here at mbg. From magnesium-rich bedtime snacks to lighting tricks to tried-and-true sleep rituals—we are certainly no strangers to sleep hygiene around here, and we’re pretty much game for anything. So trust us when we say: We have never heard a sleep tip like Thatcher Wine’s before. Sure, the author, entrepreneur, and cancer survivor leans on a few traditional techniques—he avoids late-night heavy meals, keeps his room pitch dark, and leans on sleep-supporting supplements*—but his go-to hack for high-quality sleep has left us floored.
“I’m a grown adult, and I love my pillow fort,” he says on the mindbodygreen podcast.
Wine didn’t mention this exactly, but we’d assume he relies on this pillow fort to help him sleep on his back—this sleep position allows the spine to be aligned and supported, which is the optimal posture for deep, uninterrupted sleep. “A strong sleep posture allows these natural curves to be maintained throughout the night: no crunching at your neck, no sagging of your lower back, no torquing of your middle back,” board-certified sleep specialist Michael J. Breus, Ph.D., once told us about the sleep position. “For these curves to fall naturally during sleep, the whole body must be supported,” he adds. Like, say, with a fortress of pillows.
That said, you can achieve spinal alignment sleeping on your side—you just may need an adequately supportive pillow that can adjust to the shape of your head, neck, and shoulder. In addition to a pillow under your head, experts recommend placing one between your knees to ensure your lower spine isn’t twisted and one next to you to rest your top arm on—so your shoulders aren’t twisting or crouching in a way that could leave you with a neck kink. Regardless, you might not want to sleep on your stomach if you can help it, as your head is likely cranked to one side, which puts stress on the ligaments of the neck. ADVERTISEMENT
The takeaway.
Whether you’re partial to the fetal position or lying on your back, your pillows can play a significant role in spinal alignment—which will not only make you feel better during the day (i.e., less sore and creaky) but help you achieve more restful sleep at night. Sure, it’s not exactly like the pillow fort you might have built as a kid—but doesn’t it make the sleep tip sound a bit more fun?
If you’re someone who can’t sleep at night, or worse, you suffer from insomnia, which Healthline defines as some who “finds it difficult to fall asleep, stay asleep, or both,” then you may be inclined to reach for some sleeping pills.
But, there may be something else you can try that is just as, if not more effective and doesn’t require you to put drugs into your body. Benzodiazepines – a common drug prescribed to those who suffer from insomnia – were found to be the “most common substance found in male overdose deaths in the past 20 years in Australia.”
As CNN Healthreports, a new study, published Wednesday, November 24 in the JAMA Psychiatry journal, has found that “undergoing cognitive behavioural sleep training may help prevent depression in older adults with insomnia.”
Cognitive behavioural sleep training can be likened to therapy, since it teaches you, and gives you the tools to help break any bad habits you might have in order for your mind and body to get into a state where good sleep is made possible.
The study’s author, Dr Michael Irwin, says “some 30% to 50% of older adults complain of insomnia,” a condition that has been proven time and time again can be a major contributor towards suffering from depression.
In order to obtain his findings, Dr Irwin took 291 adult participants all over the age of 60 and all of whom had insomnia. Importantly, all of the participants “had no major depression or major health events in past year.”
The group was then split into two, with one group undergoing CBT-I (cognitive behavioural therapy for insomnia) while the other was given SET (sleep education therapy).
SET taught participants about sleep hygiene, characteristics of healthy sleep, sleep biology and how stress can impact sleep. CBT-I, meanwhile, is more in-depth and comprises five components: “cognitive therapy, stimulus control, sleep restriction, sleep hygiene, and relaxation.”
Sleep Foundation says CBT-I “focuses on exploring the connection between the way we think, the things we do, and how we sleep.” It theorises that insomnia can be a vicious cycle. Sleep Foundation gives an example of this, saying “prior experiences of insomnia may lead to worry about falling asleep. This worry may lead to spending excessive time in bed to try to force sleep.”
“Both worry and excessive time in bed can make falling and staying asleep more challenging. This can become a frustrating, nightly cycle that can be difficult to break.”
A woman trying to sleep. Image: Head Topics
CBT-I works to break these habits. Stimulus control, for example, involves “getting people to get out of bed when they’re not able to sleep. Most people stay in bed, fretting about not falling asleep, which then turns the bed into a negative space,” Dr Irwin told CNN Health.
“Instead, people are taught to get up after 10 minutes of tossing and turning, do quiet, non-stimulating activities and not come back to bed until they are sleepy.”
The key difference in how the two therapy programs were delivered, is that the CBT-I group received in-person training with a trained therapist for the eight-week duration. The SET group simply had to take the information they were given and, according to Dr Irwin, “figure out how to use it without our help.”
With the CBT-I group, for example, a therapist worked with them to disrupt their “dysfunctional thoughts and beliefs about sleep.”
CNN Health cites Wendy Troxel, a senior behavioural scientist at RAND Corporation, but who was not involved in the study, as saying: “The benefit of this treatment approach is that it used the most evidence-based behavioural treatment for insomnia, CBT-I, which has been proven to be as effective, longer-lasting, and (have) fewer side effects than sleep medications – which can be particularly problematic in older adults.”
Following the eight week treatment period, participants were then monitored for a further three years (only 81 from the CBT-I group and 77 of the SET group agreed to the full 36 months of follow-up) and were asked every month about symptoms of depression.
The study concluded, “Those in the CBT-I group with sustained remission of insomnia disorder had an 82.6% decreased likelihood of depression compared with those in the SET group without sustained remission of insomnia disorder.”
As for the SET group, the study found “modest effects in improving and treating insomnia but they were not durable. They didn’t last.”
Wendy Troxel also added, “What is exciting about these findings is that they are among the first to demonstrate that treating insomnia with a behavioural strategy, not a pill, can prevent the development of depression in older adults.”
Another strategy people have found useful (separate from this study) for getting a better night’s sleep, is to sleep in the same room, but in a different bed to their partner. Watch health hacker Dave Asprey explain this technique below.https://cdn.jwplayer.com/players/h4MViRCh-KKjjplFe.html
It should be worth noting this study was conducted on adults over 60-years-old. Dr Irwin deliberately chose this demographic because: “Older adults with insomnia have a high risk of incident and recurrent depression. Depression prevention is urgently needed, and such efforts have been neglected for older adults.”
This means the results can’t necessarily deliver the same for adults under 60, although the study certainly does show that CBT-I can be an incredibly effective form of treatment for insomnia.
Google Cloud AppSheet is a no-code, intent-driven app development platform. Its web-based design environment runs in the Google Cloud, and it generates apps for web, iOS, and Android. Even though it is billed as no-code, AppSheet supports spreadsheet formulas, filter expressions, and bots defined with expressions and diagrams, giving it much of the functionality of low-code app builders.
Google Cloud AppSheet allows you to automate business processes such as order approvals and user notifications, and automatically build actions and views based on user intent with Google Cloud AI and ML. You can use AppSheet to build one app for use on desktop, mobile, and tablet. And you can connect to a variety of data sources, as well as add data such as GPS locations, pictures, drawings, barcode scanning, and character recognition from end-user devices.
Google doesn’t pretend that “citizen developers” can build apps in a vacuum. Instead, they say that IT and citizen developers can efficiently collaborate with governance and corporate policy capabilities. They also tout the integration between AppSheet and Google Workspace tools as time-saving. As is true of most no-code and low-code app builders, citizen developers use AppSheet because it is easy, and professional developers use it because they can create apps quickly.
Much of the design work for AppSheet comes at the data design stage. Of course, it helps to know what you’re trying to accomplish and why. AppSheet’s process of inferring intent from your data structure is quite good. I wasn’t surprised when AppSheet turned Google’s own example spreadsheet into a good prototype app and included a map view (because Google Maps, duh). I was more impressed when AppSheet turned Microsoft’s example spreadsheet (from its Power Apps demo) into a good prototype app, one that was functionally the same as what Power Apps created.
AppSheet supports many data and service integrations, including some non-traditional data sources such as a Google Drive folder treated as a table. Power Apps, which is more mature,
In part one, we discussed what E-Modes are and how applying first principles has ultimately ended a 25-year argumentative phase as to the variations to the Move Over laws. That serves as the primary reason why E-Modes are being donated to Elon Musk for Tesla. If you haven’t read part one, you can do so here.
James Law explained:
“I get a lot of flack because I’m donating E-Modes to Elon. You have to understand that the data collected is based on hundreds of men and women who have died in the line of duty. First-principles [thinking] gave me the tool to simplify all this information into simple truths. Ending the [argumentative] phase translates to all those who have lost their lives will have not died in vain.
In part deux, this article, we look at Tesla’s positive effect on traffic behavior — present and future — as well as the Cybertruck’s future role in protecting lives and possibly saving the government millions, maybe even billions of dollars.
The new phase that we are in is leading to James Garcia’s effort for unification and standardization of the Move Over laws (which require, in various terms, that drivers Slow Down, Then Move Over And Be Prepared To Stop for emergency vehicles and tow trucks stopped on the road or side of the road). Garcia said:
“The government is aware of the magnitude of this problem. Every roadway-responding federal agency has taken an active but independent interest in struck-by injuries: the Federal Highway Administration (FHWA), the National Highway Traffic Safety Administration (NHTSA), the Department of Transportation (DOT), the Federal Emergency Management Agency (FEMA), the Federal Interagency Committee on EMS (FICEMS). Even the National Aeronautics and Space Administration (NASA) has sponsored employee safety training to address struck-by awareness. You will be hard-pressed to find any government agency that hasn’t expressed interest in protecting its workers while in the roadway.”
James Law’s effort is to actively change vehicle behavior through Tesla’s AI and Full Self-Driving (FSD) advanced driver-assistance system (ADAS). However, changing traffic behavior is not new for Tesla.
“If you look at the roadways as a circulatory system, it’s just flowing. With the constant rise in accidents, it is clear we have a serious health problem. The only notable change is Tesla’s intelligent features. Without change, there’s no change. To change traffic behavior, you have to set the right example and others will follow. It’s literally the cure, and it has already begun.”
AWS today announced a new machine learning service, Amazon SageMaker Canvas. Unlike its existing machine learning services, the target audience here isn’t highly technical data scientists and engineers but any engineer or business user inside a company. The promise of SageMaker Canvas is that it will allow anybody to build machine learning prediction models, using a point-and-click interface.
If that sounds familiar, it may be because Azure and others offer similar tools, though AWS may have the advantage that a lot of companies already store all of their data in AWS anyway.
“SageMaker Canvas leverages the same technology as Amazon SageMaker to automatically clean and combine your data, create hundreds of models under the hood, select the best performing one, and generate new individual or batch predictions,” writes AWS’ Alex Casalboni in today’s announcement. “It supports multiple problem types such as binary classification, multi-class classification, numerical regression, and time series forecasting. These problem types let you address business-critical use cases, such as fraud detection, churn reduction, and inventory optimization, without writing a single line of code.”
Unsurprisingly, the service is backed by SageMaker, AWS’s fully managed machine learning service.
The general idea here is that users can use any dataset, down to a basic CSV file, and then decide which of the columns in this dataset Canvas should predict. There’s no need to worry about how to train this model. Yet while this is a far easier user experience that using traditional ML tools, we’re still not quite talking drag-and-drop either. This is AWS, after all. The overall experience is more akin to working in the AWS console than a modern no-code application.
Pin ItGetty Images/Karina MansfieldShare on facebookShare on twitterShare on pinterestShare on emailAsk any morning person, and they’ll likely be thrilled to rattle off the benefits of their particular morning routine: They may say it improves their mood, or sets them up well for being productive, or maybe it just gives them some much-needed time alone before the emails and pings begin to mount. But what they might not know is that embracing a morning ritual can have just as much of an impact on sleep quality the following night as it does on the day ahead. That’s because, when done well and routinely, certain elements of a healthy morning routine can actually facilitate better sleep.
Generally, good-quality sleep comes when our behaviors align well with our circadian rhythm, or the 24-hour body clock that causes us to feel sleepy at nightfall and alert during the day. And several components of a morning routine—that is, light, temperature, food, schedule, and social interaction—can directly influence and help regulate that rhythm, says neurologist W. Chris Winter, MD, advisor for Sleep.com and author of The Sleep Solution: Why Your Sleep Is Broken and How To Fix It. “Practices involving these cues tell our bodies to feel awake and also orient us as to where we are within that 24-hour cycle, which, over time, can help with falling asleep at night,” he says.
“Cues that tell our bodies to feel awake and also orient us as to where we are within the 24-hour cycle can, over time, help with falling asleep at night.” —neurologist W. Chris Winter, MD
Since the whole shebang operates on a timetable, though, your first step to regulating your circadian rhythm (and, in turn, clocking higher-quality sleep) will always be following a sleep schedule. Keeping a consistent wakeup time every day, even on weekends, will eventually make waking up feel easier and easier, says sleep specialist Angela Holliday-Bell, MD. And that alone means you’ll be in a better position to go to bed easily at your usual time the next night, too.RELATED STORIESNot an Early Bird or Night Owl? Science Suggests There May Be…How To Make Waking Up in the Dark Suck Less, According to…
Beyond timing, adjusting your wake-up routine to jibe well with your circadian rhythm comes down to a few key practices. Read on for the four essential parts of a morning routine that can help promote better sleep that night—and every night to follow.
Here’s what to do each morning in order to sleep more soundly at night, according to sleep doctors
1. See the light
Of all sleep-affecting elements, light exposure is perhaps the most powerful force driving your circadian rhythm. “Light suppresses the release of sleepiness hormone melatonin while promoting the release of the alertness hormone cortisol,” says Dr. Holliday-Bell. And in a nutshell, that’s why it’s so hard to feel fully awake in the morning when it’s still dark outside (aka almost all winter long): The lack of light essentially prevents the alertness hormone from flooding your system in the same way it would in the brighter, lighter summer months.
Season aside, getting exposure to light when you wake up—whether by flinging open the blinds or windows (assuming it’s not frigid), stepping outside, or turning on a bright light—is a sure way to switch your brain to wakefulness mode. Doing so also anchors your circadian rhythm, “so your brain stays on track with when to make you sleepy and when to make you awake,” says sleep-medicine specialist Jade Wu, PhD, DBSM, advisor for Sleep.com. And the more awake, energized, and active you feel in the morning and throughout the day, the more sleep drive you’ll build up before it’s time for bed—making you more likely to fall asleep easily when you do rest your head, says Dr. Wu.https://09da148e3f22158629fc24990db62e2b.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html
Not to mention, the big contrast between the darkness of your bedroom while you’re asleep and the burst of brightness in the morning can help mitigate the detrimental effects of light exposure later at night, Dr. Wu adds: “In other words, the brighter your days, the less your evening screen time will interfere with your sleep.”
2. Take a walk (or run) outside
Stepping outside shortly after you get up doesn’t just have the benefit of potentially increasing your light exposure. “Exercise can release those natural endorphins that make you feel good and even more awake, while also leading to increased deep wave sleep at night,” says Dr. Holliday-Bell. And again, the extra activity built into your day helps increase sleep drive, so you’re naturally more tired and ready to fall asleep when bedtime rolls around.https://09da148e3f22158629fc24990db62e2b.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html
3. Check in with a friend or loved one
Social interaction can have a similar effect as taking a walk in terms of boosting your mood through the release of feel-good neurotransmitters dopamine and serotonin, says Dr. Winter: “This can help not only with positivity and motivation, but also with wakefulness.” (Better yet? Meet up with a friend for a walk in a sunny place, and achieve all of the above in one fell swoop.)
4. Eat a breakfast that you’ll look forward to
Having breakfast in the morning shortly after you wake up helps signal to the body that it’s time to get to work—particularly when you keep that mealtime regular. “It gets your metabolism going and is another factor helping to keep your circadian rhythm on track,” says Dr. Wu.
While any protein-rich breakfast can provide you with the fuel you’ll need to be active throughout the day (and again, accumulate that trusty sleep drive, as a result), eating a breakfast that you’re legitimately excited about can also lift your mood in a way that promotes alertness. “And planning it in advance just makes it easier to get out of bed on schedule,” says Dr. Holliday-Bell, which just goes back to the most important part of any morning routine for better sleep: the routine part.
The Google Sycamore chip used in the creation of a time crystal. Credit: Google Quantum AI
There is a huge global effort to engineer a computer capable of harnessing the power of quantum physics to carry out computations of unprecedented complexity. While formidable technological obstacles still stand in the way of creating such a quantum computer, today’s early prototypes are still capable of remarkable feats.
For example, the creation of a new phase of matter called a “time crystal.” Just as a crystal’s structure repeats in space, a time crystal repeats in time and, importantly, does so infinitely and without any further input of energy—like a clock that runs forever without any batteries. The quest to realize this phase of matter has been a longstanding challenge in theory and experiment—one that has now finally come to fruition.
In research published Nov. 30 in Nature, a team of scientists from Stanford University, Google Quantum AI, the Max Planck Institute for Physics of Complex Systems and Oxford University detail their creation of a time crystal using Google’s Sycamore quantum computing hardware.
“The big picture is that we are taking the devices that are meant to be the quantum computers of the future and thinking of them as complex quantum systems in their own right,” said Matteo Ippoliti, a postdoctoral scholar at Stanford and co-lead author of the work. “Instead of computation, we’re putting the computer to work as a new experimental platform to realize and detect new phases of matter.”
For the team, the excitement of their achievement lies not only in creating a new phase of matter but in opening up opportunities to explore new regimes in their field of condensed matter physics, which studies the novel phenomena and properties brought about by the collective interactions of many objects in a system. (Such interactions can be far richer than the properties of the individual objects.)
“Time-crystals are a striking example of a new type of non-equilibrium quantum phase of matter,” said Vedika Khemani, assistant professor of physics at Stanford and a senior author of the paper. “While much of our understanding of condensed matter physics is based on equilibrium systems, these new quantum devices are providing us a fascinating window into new non-equilibrium regimes in many-body physics.”
During her graduate school years, Khemani, her doctoral advisor Shivaji Sondhi, then at Princeton University, and Achilleas Lazarides and Roderich Moessner at the Max Planck Institute for Physics of Complex Systems stumbled upon this recipe for making time crystals unintentionally. They were studying non-equilibrium many-body localized systems—systems where the particles get “stuck” in the state in which they started and can never relax to an equilibrium state. They were interested in exploring phases that might develop in such systems when they are periodically “kicked” by a laser. Not only did they manage to find stable non-equilibrium phases, they found one where the spins of the particles flipped between patterns that repeat in time forever, at a period twice that of the driving period of the laser, thus making a time crystal.
The periodic kick of the laser establishes a specific rhythm to the dynamics. Normally the “dance” of the spins should sync up with this rhythm, but in a time crystal it doesn’t. Instead, the spins flip between two states, completing a cycle only after being kicked by the laser twice. This means that the system’s “time translation symmetry” is broken. Symmetries play a fundamental role in physics, and they are often broken—explaining the origins of regular crystals, magnets and many other phenomena; however, time translation symmetry stands out because unlike other symmetries, it can’t be broken in equilibrium. The periodic kick is a loophole that makes time crystals possible.
The doubling of the oscillation period is unusual, but not unprecedented. And long-lived oscillations are also very common in the quantum dynamics of few-particle systems. What makes a time crystal unique is that it’s a system of millions of things that are showing this kind of concerted behavior without any energy coming in or leaking out.
“It’s a completely robust phase of matter, where you’re not fine-tuning parameters or states but your system is still quantum,” said Sondhi, professor of physics at Oxford and co-author of the paper. “There’s no feed of energy, there’s no drain of energy, and it keeps going forever and it involves many strongly interacting particles.”
While this may sound suspiciously close to a “perpetual motion machine,” a closer look reveals that time crystals don’t break any laws of physics. Entropy—a measure of disorder in the system—remains stationary over time, marginally satisfying the second law of thermodynamics by not decreasing.
Between the development of this plan for a time crystal and the quantum computer experiment that brought it to reality, many experiments by many different teams of researchers achieved various almost-time-crystal milestones. However, providing all the ingredients in the recipe for “many-body localization” (the phenomenon that enables an infinitely stable time crystal) had remained an outstanding challenge.
For Khemani and her collaborators, the final step to time crystal success was working with a team at Google Quantum AI. Together, this group used Google’s Sycamore quantum computing hardware to program 20 “spins” using the quantum version of a classical computer’s bits of information, known as qubits.
Revealing just how intense the interest in time crystals currently is, another time crystal was published in Science this month. That crystal was created using qubits within a diamond by researchers at Delft University of Technology in the Netherlands.
Quantum opportunities
The researchers were able to confirm their claim of a true time crystal thanks to special capabilities of the quantum computer. Although the finite size and coherence time of the (imperfect) quantum device meant that their experiment was limited in size and duration—so that the time crystal oscillations could only be observed for a few hundred cycles rather than indefinitely—the researchers devised various protocols for assessing the stability of their creation. These included running the simulation forward and backward in time and scaling its size.
“We managed to use the versatility of the quantum computer to help us analyze its own limitations,” said Moessner, co-author of the paper and director at the Max Planck Institute for Physics of Complex Systems. “It essentially told us how to correct for its own errors, so that the fingerprint of ideal time-crystalline behavior could be ascertained from finite time observations.”
A key signature of an ideal time crystal is that it shows indefinite oscillations from all states. Verifying this robustness to choice of states was a key experimental challenge, and the researchers devised a protocol to probe over a million states of their time crystal in just a single run of the machine, requiring mere milliseconds of runtime. This is like viewing a physical crystal from many angles to verify its repetitive structure.
“A unique feature of our quantum processor is its ability to create highly complex quantum states,” said Xiao Mi, a researcher at Google and co-lead author of the paper. “These states allow the phase structures of matter to be effectively verified without needing to investigate the entire computational space—an otherwise intractable task.”
Creating a new phase of matter is unquestionably exciting on a fundamental level. In addition, the fact that these researchers were able to do so points to the increasing usefulness of quantum computers for applications other than computing. “I am optimistic that with more and better qubits, our approach can become a main method in studying non-equilibrium dynamics,” said Pedram Roushan, researcher at Google and senior author of the paper.
“We think that the most exciting use for quantum computers right now is as platforms for fundamental quantum physics,” said Ippoliti. “With the unique capabilities of these systems, there’s hope that you might discover some new phenomenon that you hadn’t predicted.”
Bruce's Blog 
