Technologies

If The Universe Is A Hologram, We May Soon Gaze Into A Black Hole

A mind-bending theory called holographic duality could lead us into the universe’s deepest, darkest voids.

If you fell into a black hole, your journey might look something like this.

First, you’d stare into the rich, red event horizon of the abyss. Beyond this barrier, light cannot escape. As you get closer, your body would stretch out like chewing gum until it spaghettifies into the void. If you’re still conscious at this point, you’d peer out the entrance and watch a warped universe grow smaller by the second. That wouldn’t be your universe anymore. The black hole would be.

In all probability, though, you’d quickly be ripped to shreds.

Because of this absolutely horrifying disaster, we’ll likely never receive firsthand evidence of what lies within these cosmic mysteries. But in a paper published this month in the journal PRX Quantum, scientists are working toward the next best thing. They developed computing algorithms to help solve a mind-bending theory in physics called «holographic duality.»

In a nutshell, holographic duality suggests that the three-dimensional universe, like space inside black holes, is mathematically strung to the two-dimensional universe, like particle planes and magnetic fields. It basically presents the fabric of spacetime as a 3D hologram «projected» by 2D webs.

I know what you’re thinking. No, this wouldn’t be like the Star Trek holodeck. Unlike classic sci-fi holograms projected by light from a screen, holographic duality is bound by pure mathematics.

«It has not been proven formally, under the point of view of rigorous mathematics, but we know many examples where this duality actually works,» says lead author Enrico Rinaldi, a research scientist at the University of Michigan, based in Tokyo and hosted by the Riken Center for Quantum Computing and the Theoretical Quantum Physics Laboratory.

If holographic duality truly dictates the universe, scientists wouldn’t have to go inside a black hole to take a picture of it. Instead, they could study easy-to-handle 2D space around the beast, then extrapolate the 3D architecture lurking inside. «It is often the case that things difficult to compute on one side are easy to compute on the other side,» Rinaldi says. «That is why this duality is very important and useful.»

He compares the idea to having a dictionary where you can look up a word on one page and find its meaning on another. We just need some sort of index to bridge the 2D space-words with their 3D space-definitions — aka, the mathematical connection. And that’s precisely what Rinaldi’s algorithms are poised to do.

However, before we can use them to unlock the inside of a black hole, there are several, pretty trippy, steps to take. «The duality, as it is right now, applies to a specific spacetime, which is different from the spacetime of our universe,» Rinaldi says.

In other words, holographic duality is confined to a sort of alternate, theoretical world that scientists use as a sandbox.

A spacetime playground

1916 was a big year for physics. Albert Einstein had published the first of many papers that would forever alter the field: a holy grail chronicle of general relativity. Since then, the theory has earned a reputation for being unbreakable. I could go on forever about its spectacular consequences, but here’s the important part for holographic duality.

Suppose you have a trampoline and drop a soccer ball into it. The flat surface will morph inward, depending on where the ball settles. Now, add a tiny marble to the scene. It’ll fall along the trampoline’s curve and nestle next to the soccer ball.

In this analogy, the marble is you, the soccer ball is Earth and the trampoline is the intangible fabric of space and time — spacetime. According to general relativity, gravity is this «curve» we fall along until we’re planted on the ground.

In our universe — which, per experts, is known as the «de Sitter» universe — spacetime’s curvature is positive. That’s a problem. A positive model isn’t great for math equations, Rinaldi explains, especially when it comes to ultra high-dimensional ones. But there’s an easy fix. Scientists simply calculate stuff in a theoretical universe with negative curvature: the anti de Sitter universe. Then they translate their results back to our realm.

Fast-forward to the late 1960s. String theory is born.

Allowing for simplification, string theory says if you break down atoms, the building blocks of our universe, into elementary particles, then pulverize those into even smaller specks, and so on, you’ll eventually get to infinitesimal vibrating «strings.»

Presumably, these strings make up all we know: particles, fields, spacetime. If string theory is true, even you and I are made up of the wiggling bits. That’s why this concept is such a big deal. It might well be the closest we’ve gotten to a theory of everything. On the flip side, however, some physicists consider string theory a dead end because we still haven’t found concrete evidence for its premises.

But regardless, string theory requires unfathomable 11-dimension equations — as you might’ve guessed, that means it’s rooted in the anti de Sitter universe. And per Rinaldi, holographic duality relies on string theory. Thus, it’s also rooted in the anti de Sitter universe.

«Black holes we can investigate right now, with this duality, are not the same black holes that we imagine being out there,» Rinaldi says. «These black holes are a sort of mathematical playground that we can use to formulate this duality and test it.»

Simply put: In this mathematically ideal universe, Rinaldi is observing theoretical black holes to understand holographic duality. It’s like playing a game in tutorial mode before the real level starts. Our universe.

Getting to that level, though, is the crux of this whole procedure. «If we can do it for anti de Sitter,» Rinaldi says, «then we should be doing it for de Sitter.»

«The final goal is still to be able to describe gravity and black holes in our universe.»

The road into a black hole

OK, here’s where it all comes together.

First, a quick recap: Holographic duality can show us what’s inside a black hole because it suggests the 2D universe is connected to the 3D universe via mathematics. We just have to construct an index to bridge the two dimensions. But holographic duality is based on string theory. So, first, we have to make the index’s blueprints in our sandbox universe — the theoretical, anti de Sitter universe.

How do we make the blueprints? Well, Rinaldi says, start with the easier side. That’s the 2D half. But even though this side hurts less to think about, it isn’t that simple; we still need strong numerical methods to analyze it. «That’s what we’re doing,» Rinaldi says. «The numerical part.»

Think of the universe as a blanket knitted by strings that have a bunch of points. Rinaldi’s algorithms use quantum computing and deep learning to help calculate where these points are on the blanket and how they’re attached to each other. The goal is to sort of draw out the «strings» of string theory, then put them all together, like cosmic connect-the-dots.

However, the researchers are still in the proof-of-principle stage. They solved a few prototype points with their method, but these points don’t really represent anything. In the future, though, Rinaldi says the method can scale up to study complex points really present on anti de Sitter strings, including those relevant to anti de Sitter black holes.

Then, we’ll be on our way to making the anti de Sitter 2D-to-3D index that’ll reveal the insides of these theoretical black holes.

Then, if the index is precise enough, it can be translated to our true-to-the-bone, observable universe.

Then… we can use the final index to learn about the threatening insides of real, de Sitter black holes from the comfort of our homes and tucked away from terror.

A new theory of everything?

When you think about the steps Rinaldi and tons of other researchers are taking to realize the insides of a black hole — study prototype theoretical universe strings, scale up to learn about the full theoretical universe’s geometry, zero in on theoretical black holes, take all of that and filter the real universe through it, and probably more we can’t even comprehend — a jarring question might be… why?

Why does this all matter?

«We think we are very close to explaining the information paradox of black holes,» Rinaldi says. «If information goes inside a black hole, general relativity says, OK, whatever goes in is gone forever.»

But quantum mechanics, the other founding principle of our universe, says you cannot lose information. It says information is always maintained. Perhaps it can change, transform or adapt, but it cannot go away. So what’s happening to the information plunging into these massive space-borne voids?

«Stephen Hawking came up with this idea of the evaporation of a black hole and said ‘Look, actually there is stuff coming out of a black hole, it’s just slowly coming out’,» Rinaldi says.

But even those bits coming out don’t look like what went in. Stuff still seems lost in the process. «This is a very, very big problem in physics,» Rinaldi says. «And people are using the duality to understand that paradox.» If we can understand what’s inside, then maybe we can prove so-called lost information is actually, well, inside.

«Maybe it’s not lost, it’s just in a different configuration. It’s not particles anymore; it’s not spacetime anymore; it’s something else.»

Technologies

An AWS Outage Broke the Internet While You Were Sleeping, and the Trouble Continues

Reddit, Roblox and Ring are just a tiny fraction of the 1,000-plus sites and services that were affected when Amazon Web Services went down, causing a major internet blackout.

The internet kicked off the week the way that many of us often feel like doing: by refusing to go to work. An outage at Amazon Web Services rendered huge portions of the internet unavailable on Monday morning. Sites and services including Snapchat, Fortnite, Venmo, the PlayStation Network and, predictably, Amazon, were unavailable off and on through the start of the day.

The outage began shortly after midnight PT, and took Amazon around 3.5 hours to fully resolve. Social networks and streaming services were among the 1,000-plus companies affected, and critical services such as online banking were also taken down.

The issues seemed to have been largely resolved as the US East Coast was coming online, but spiked again dramatically after 8 a.m. PT as work began on the West Coast.

AWS, a cloud services provider owned by Amazon, props up huge portions of the internet. So when it went down, it took many of the services we know and love with it. As with the Fastly and Crowdstrike outages over the past few years, the AWS outage shows just how much of the internet relies on the same infrastructure — and how quickly our access to the sites and services we rely on can be revoked when something goes wrong.

The reliance on a small number of big companies to underpin the web is akin to putting all of our eggs in a tiny handful of baskets. When it works, it’s great, but only one small thing needs to go wrong for the internet to come to its knees in a matter of minutes.

How widespread was the AWS outage?

Just after midnight PT on Oct. 20, AWS first registered an issue on its service status page, saying it was «investigating increased error rates and latencies for multiple AWS services in the US-East-1 Region.» Around 2 a.m. PT, it said it had identified a potential root cause of the issue. Within half an hour, it had started applying mitigations that were resulting in significant signs of recovery.

«The underlying DNS issue has been fully mitigated, and most AWS Service operations are succeeding normally now,» AWS said at 3.35 a.m. PT. The company didn’t respond to request for further comment beyond pointing us back to the AWS health dashboard.

But as of 8:43 a.m. PT, many services were still impacted, and the AWS status page showed the severity as «degraded.» In a post at that time, AWS noted: «We are throttling requests for new EC2 instance launches to aid recovery and actively working on mitigations.»

Around the time that AWS says it first began noticing error rates, Downdetector saw reports begin to spike across many online services, including banks, airlines and phone carriers. As AWS resolved the issue, some of these reports saw a drop off, whereas others have yet to return to normal. (Disclosure: Downdetector is owned by the same parent company as CNET, Ziff Davis.)

Around 4 a.m. PT, Reddit was still down, while services including Ring, Verizon and YouTube were still seeing a significant number of reported issues. Reddit finally came back online around 4.30 a.m. PT, according to its status page, which was then verified by us.

In total, Downdetector saw over 6.5 million reports, with 1.4 million coming from the US, 800,000 from the UK and the rest largely spread across Australia, Japan, the Netherlands, Germany and France. Over 1,000 companies in total have been affected, Downdetector added.

«This kind of outage, where a foundational internet service brings down a large swath of online services, only happens a handful of times in a year,» Daniel Ramirez, Downdetector by Ookla’s director of product told CNET. «They probably are becoming slightly more frequent as companies are encouraged to completely rely on cloud services and their data architectures are designed to make the most out of a particular cloud platform.»

What caused the AWS outage?

AWS didn’t immediately share full details about what caused the internet to fall off a cliff this morning. Then at 8:43 a.m. PT, it offered this brief description: «The root cause is an underlying internal subsystem responsible for monitoring the health of our network load balancers.»

Earlier in the day it had attributed the outage to a «DNS issue.» DNS stands for the Domain Name System and refers to the service that translates human-readable internet addresses (for example, CNET.com) into machine-readable IP addresses that connect browsers with websites.

When a DNS error occurs, the translation process cannot take place, interrupting the connection. DNS errors are common internet roadblocks, but usually happen on small scale, affecting individual sites or services. But because the use of AWS is so widespread, a DNS error can have equally widespread results.

According to Amazon, the issue is geographically rooted in its US-East-1 region, which refers to an area of North Virginia where many of its data centers are based. It’s a significant location for Amazon, as well as many other internet companies, and it props up services spanning the US and Europe.

«The lesson here is resilience,» said Luke Kehoe, industry analyst at Ookla. «Many organizations still concentrate critical workloads in a single cloud region. Distributing critical apps and data across multiple regions and availability zones can materially reduce the blast radius of future incidents.»

Was the AWS outage caused by a cyberattack?

DNS issues can be caused by malicious actors, but there’s no evidence at this stage to say that this is the case for the AWS outage.

Technical faults can, however, pave the way for hackers to look for and exploit vulnerabilities when companies’ backs are turned and defenses are down, according to Marijus Briedis, CTO at NordVPN. «This is a cybersecurity issue as much as a technical one,» he said in a statement. «True online security isn’t only about keeping hackers out, it’s also about ensuring you can stay connected and protected when systems fail.»

In the hours ahead, people should look out for scammers hoping to take advantage of people’s awareness of the outage, added Briedis. You should be extra wary of phishing attacks and emails telling you to change your password to protect your account.

Technologies

Apple Watch Series 11 Deals: How to Save Up to $335 on Apple’s Latest Wearable

Technologies

Take Your Apple Watch Experience to the Next Level With These 8 Tips and Tricks

Get the most out of your Apple Watch with these expert-approved tips.

Apple’s smartwatch lineup is getting better year after year. This year is no exception with the new Apple Watch series 11, Apple Watch SE 3 and the Apple Watch Ultra 3. Whether you’ve got a brand new model to get acquainted with or you’re trying out the new features in WatchOS 26, there are options to keep you productive, become more active and take control of your life. These are the features I love the most.

Don’t miss any of our unbiased tech content and lab-based reviews. Add CNET as a preferred Google source.

Swipe between watch faces (again)

Until WatchOS 10.0, you could swipe from the left or right edge of the screen to switch active watch faces, a great way to quickly go from an elegant workday face to an exercise-focused one, for example. Apple removed that feature, likely because people were accidentally switching faces by brushing the edges of the screen.

However, the regular method involves more steps (touch and hold the face, swipe to change, tap to confirm), and people realized that the occasional surprise watch face change wasn’t really so bad. Therefore, as of version 10.2, including the current WatchOS 26, you can turn the feature on by toggling a setting: Go to Settings > Clock and turn on Swipe to Switch Watch Face.

Stay on top of your heart health with Vitals

Wearing your Apple Watch while sleeping offers a trove of information — and not just about how you slept last night. If you don the timepiece overnight, it tracks a number of health metrics. The Vitals app gathers that data and reports on the previous night’s heart rate, respiration, body temperature (on supported models) and sleep duration. The Vitals app can also show data collected during the previous seven days — tap the small calendar icon in the top-left corner.

If you own a watch model sold before Jan. 29, 2024, you’ll also see a blood oxygen reading. On newer watches in the US, that feature works differently because of an intellectual property fight: The watch’s sensors take a reading, and then send the data to the Health app on your iPhone. You can check it there, but it doesn’t show up in the Vitals app.

How is this helpful? The software builds a baseline of what’s normal for you. When the values stray outside normal ranges, such as irregular heart or respiratory rates, the Vitals app reports them as atypical to alert you. It’s not a medical diagnosis, but it can prompt you to get checked out and catch any troubles early.

Make the Wrist Flick gesture second nature

WatchOS 26 adds a new gesture that has quickly become a favorite. On the Apple Watch Series 9 and later, and the Apple Watch Ultra 2 and Ultra 3, Wrist Flick is a quick motion to dismiss incoming calls, notifications or really anything that pops up on the screen. Wrist Flick joins Double Tap as a way to interact with a watch even if you’re not in a position to tap the screen.

But what I like most about the gesture is that it’s also a shortcut for jumping back to the watch face. For example, when a Live Activity is automatically showing up in the Smart Stack, a quick flick of the wrist hides the stack. Or let’s say you’re configuring a feature in the Settings app that’s buried a few levels deep. You don’t need to repeatedly tap the back (<) button — just flick your wrist.

Make the Smart Stack work for you

The Smart Stack is a place to access quick information that might not fit into what Apple calls a «complication» (the things on the watch face other than the time itself, such as your Activity rings or the current outside temperature). When viewing the clock face, turn the digital crown clockwise or swipe from the bottom of the screen to view a series of tiles that show information such as the weather or suggested photo memories. This turns out to be a great spot for accessing features when you’re using a minimal watch face that has no complications.

Choose which Live Activities appear automatically

The Smart Stack is also where Live Activities appear: If you order a food delivery, for example, the status of the order appears as a tile in the Smart Stack (and on the iPhone lock screen). And because it’s a timely activity, the Smart Stack becomes the main view instead of the watch face.

Some people find that too intrusive. To disable it, on your watch open the Settings app, go to Smart Stack > Live Activities and turn off the Auto-Launch Live Activities option. You can also turn off Allow Live Activities in the same screen if you don’t want them disrupting your watch experience.

Apple’s apps that use Live Activities are listed there if you want to configure the setting per app, such as making active timers appear but not media apps such as Music. For third-party apps, open the Watch app on your iPhone, tap Smart Stack and find the settings there.

Add and pin favorite widgets in the Smart Stack

When the Smart Stack first appeared, its usefulness seemed hit or miss. Since then, Apple seems to have improved the algorithms that determine which widgets appear — instead of it being an annoyance, I find it does a good job of showing me information in context. But you can also pin widgets that will show up every time you open the stack.

For example, I use 10-minute timers for a range of things. Instead of opening the Timers app (via the App list or a complication), I added a single 10-minute timer to the Smart Stack. Here’s how:

View the Smart Stack by turning the Digital Crown or swiping from the bottom of the screen.
Tap the Edit button at the bottom of the stack. (In WatchOS 11, touch and hold the screen to enter the edit mode.)
Tap the + button and scroll to the app you want to include (Timers, in this example).
Tap a tile to add it to the stack; for Timers, there’s a Set Timer 10 minutes option.
If you want it to appear higher or lower in the stack order, drag it up or down.
Tap the checkmark button to accept the change.

The widget appears in the stack but it may get pushed down in favor of other widgets the watch thinks should have priority. In that case, you can pin it to the top of the list: While editing, tap the yellow Pin button. That moves it up but Live Activities can still take precedence.

Use the watch as a flashlight

You’ve probably used the flashlight feature of your phone dozens of times but did you know the Apple Watch can also be a flashlight? Instead of a dedicated LED (which phones also use as a camera flash), the watch’s full screen becomes the light emitter. It’s not as bright as the iPhone’s, nor can you adjust the beam width, but it’s perfectly adequate for moving around in the dark when you don’t want to disturb someone sleeping.

To activate the flashlight, press the side button to view Control Center and then tap the Flashlight button. That makes the entire screen white — turn the Digital Crown to adjust the brightness. It even starts dimmed for a couple of seconds to give you a chance to direct the light away so it doesn’t fry your eyes.

The flashlight also has two other modes: Swipe left to make the white screen flash on a regular cadence or swipe again to make the screen bright red. The flashing version can be especially helpful when you’re walking or running at night to make yourself more visible to vehicles.

Press the Digital Crown to turn off the Flashlight and return to the clock face.

Pause your Exercise rings if you’re traveling or ill

Closing your exercise, movement and standing rings can be great motivation for being more active. Sometimes, though, your body has other plans. Until WatchOS 11, if you became ill or needed to be on a long-haul trip, any streak of closing those rings that you built up would be dashed.

Now, the watch is more forgiving (and practical), letting you pause your rings without disrupting the streak. Open the Activity app and tap the Weekly Summary button in the top-left corner. Scroll all the way to the bottom (take a moment to admire your progress) and tap the Pause Rings button. Or, if you don’t need that extra validation, tap the middle of the rings and then tap Pause Rings. You can choose to pause them for today, until next week or month, or set a custom number of days.

When you’re ready to get back into your activities, go to the same location and tap Resume Rings.

Bypass the countdown to start a workout

Many workouts start with a three-second countdown to prep you to be ready to go. That’s fine and all, but usually when I’m doing an Outdoor Walk workout, for example, my feet are already on the move.

Instead of losing those steps, tap the countdown once to bypass it and get right to the calorie burn.

How to force-quit an app (and why you’d want to)

Don’t forget, the Apple Watch is a small computer on your wrist and every computer will have glitches. Every once in a while, for instance, an app may freeze or behave erratically.

On a Mac or iPhone, it’s easy to force a recalcitrant app to quit and restart, but it’s not as apparent on the Apple Watch. Here’s how:

Double-press the Digital Crown to bring up the list of recent apps.
Scroll to the one you want to quit by turning the crown or dragging with your finger.
Swipe left on the app until you see a large red X button.
Tap the X button to force-quit the app.

Keep in mind this is only for times when an app has actually crashed — as on the iPhone, there’s no benefit to manually quitting apps.

These are some of my favorite Apple Watch tips, but there’s a lot more to the popular smartwatch. Be sure to also check out why the Apple Watch SE 3 could be the sleeper hit of this year’s lineup, and Vanessa Hand Orellana’s visit to the labs where Apple tests how the watches communicate.