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

Today’s NYT Strands Hints, Answers and Help for May 25, #448

Here are hints and answers for the NYT Strands puzzle No. 448 for May 25.

Looking for the most recent Strands answer? Click here for our daily Strands hints, as well as our daily answers and hints for The New York Times Mini Crossword, Wordle, Connections and Connections: Sports Edition puzzles.

Today’s NYT Strands puzzle plays on something many people do this time of year. Not me — though I probably should. If you need hints and answers, read on.

I go into depth about the rules for Strands in this story.

If you’re looking for today’s Wordle, Connections and Mini Crossword answers, you can visit CNET’s NYT puzzle hints page.

Read more: NYT Connections Turns 1: These Are the 5 Toughest Puzzles So Far

Hint for today’s Strands puzzle

Today’s Strands theme is: Get out the dust buster!

If that doesn’t help you, here’s a clue: Sweep out the corners.

Clue words to unlock in-game hints

Your goal is to find hidden words that fit the puzzle’s theme. If you’re stuck, find any words you can. Every time you find three words of four letters or more, Strands will reveal one of the theme words. These are the words I used to get those hints, but any words of four or more letters that you find will work:

PORT, RUNT, BEAD, GALE, LAID, DIAL, DALE, LINE, TUNE, TUNES, RUNG, TREE.

Answers for today’s Strands puzzle

These are the answers that tie into the theme. The goal of the puzzle is to find them all, including the spangram, a theme word that reaches from one side of the puzzle to the other. When you’ve got all of them (I originally thought there were always eight but learned that the number can vary), every letter on the board will be used. Here are the nonspangram answers:

SELL, LABEL, DONATE, DECLUTTER, REORGANIZE

Today’s Strands spangram

Today’s Strands spangram is SPRINGCLEANING. To find it, start with the S that’s four letters down on the first row on the left, and wind up and back.

Technologies

Today’s Wordle Hints, Answer and Help for May 25, #1436

Here are hints and the answer for today’s Wordle No. 1,436 for May 25.

Looking for the most recent Wordle answer? Click here for today’s Wordle hints, as well as our daily answers and hints for The New York Times Mini Crossword, Connections, Connections: Sports Edition and Strands puzzles.

Today’s Wordle puzzle includes a fairly rare letter in its fourth spot, so maybe guess a starter word that you don’t usually think to try. If you need a new starter word, check out our list of which letters show up the most in English words. If you need hints and the answer, read on.

Today’s Wordle hints

Before we show you today’s Wordle answer, we’ll give you some hints. If you don’t want a spoiler, look away now.

Wordle hint No. 1: Repeats

Today’s Wordle answer has no repeated letters.

Wordle hint No. 2: Vowels

There is one vowel in today’s Wordle answer.

Wordle hint No. 3: First letter

Today’s Wordle answer begins with the letter G.

Wordle hint No. 4: Lawbreaker

Today’s Wordle answer relates to crime.

Wordle hint No. 5: Meaning

Today’s Wordle answer can refer to a petty swindle.

TODAY’S WORDLE ANSWER

Today’s Wordle answer is GRIFT.

Yesterday’s Wordle answer

Yesterday’s Wordle answer, May 24, No. 1435 was SUEDE.

Recent Wordle answers

May 20, No. 1431: BORNE

May 21, No. 1432: ALARM

May 22, No. 1433: FOLIO

May 23, No. 1434: SHUCK

Technologies

I Won’t Travel Without Apple AirTags, and a 4-Pack Is Down to $75 for Memorial Day

I trust Apple’s trackers to keep all my luggage safe, and this Memorial Day deal at Amazon and Best Buy gives me the perfect excuse to buy more.

I knew something was amiss as I stood at the baggage carousel after my return flight from Paris and my fellow passengers collected their bags one by one. My trusty rolling suitcase was nowhere to be seen. But I knew there was no reason to panic. Before handing over my suitcase at check-in at the Charles de Gaulle airport, I had tucked a sophisticated little tracking device into it. So, with just a few taps on my iPhone, I could see that my bag had apparently never left Paris. (Merde!)

Over the years, I’ve come to depend on Apple’s AirTags to keep track of just about all my easy-to-lose valuables. They’re not only good for luggage, I also use them to track wallets, bikes, keys and even my car. I tell everyone who will listen that you can never have too many of these handy devices. That’s why it’s worth taking advantage of the Memorial Day sales at both Amazon and Best Buy that slash the price of a four-pack of AirTags down to $75.

Here’s how the Apple AirTag that was in my suitcase on that fateful trip works. It uses an ingenious method of tracking itself, detecting its location from nearby iPhones and using them to anonymously piggyback the coordinates to a secure server where I could look it up on my iPhone. Until just a few years ago, this would have seemed like a scene straight out of a spy movie.

Hey, did you know? CNET Deals texts are free, easy and save you money.

Instead of wondering if my belongings were stuck on an abandoned luggage cart or strewn across the tarmac, I could see in almost real time that my suitcase was still chilling at Charles de Gaulle airport in Paris. I was able to calmly tell the airline my bag didn’t make the flight, and it made arrangements to have it delivered to me a few days later.

Apple AirTags are all about peace of mind

By itself, an AirTag isn’t much. A 1.26-inch smooth round puck that looks like a glossy white breath mint, it sinks to the bottom of a bag or dangles from a key chain (with a compatible key ring, sold separately). It’s meant to disappear.

Activating the AirTag was a simple process of pairing with my iPhone. And then, because it obviously doesn’t really do anything out of the box, I forgot about it.

But the next time I couldn’t find my keys? Sorcery. My iPhone didn’t just tell me they were somewhere nearby — it walked me directly to them, thanks to the AirTag’s built-in Ultra Wideband chip. Suddenly, all that time I’d spent retracing my steps and overturning couch cushions in the past felt like ancient history.

Now I have AirTags in or attached to every significant item I’d want to keep track of: My everyday laptop bag, my camera backpack, the suitcase I use most when traveling, my key chain, my car and a smaller sling bag I take on walks. I can pull up the Find My app on any of my Apple devices (or sign in to iCloud on any web browser) and see where my items are and the last time the AirTags registered their locations.

AirTags aren’t just for my everyday items. People I know in the movie business tell me that AirTags are tossed into nearly every bag and Pelican crate, not solely to ensure that the valuable equipment inside doesn’t walk away but to quickly differentiate equipment amid similar looking containers. Some of my friends also attach AirTags to their pets’ collars (though experts say there are better ways to track pets).

AirTags are also useful for things that you want to keep close by

Being able to detect my luggage a continent away provided a sense of relief, to be sure. But at the local level, my AirTags will also trigger an alert when I get too far away from them. For example, if I accidentally forget my camera bag in the car when I stop somewhere for lunch, a Find My notification appears telling me I’ve left it behind. It works the same for newer AirPods models as well.

Impulse Buys Under $25 That Make Surprisingly Great Gifts

+17 More

See all photos

Sharing is now a big part of AirTag tracking

My family has two cars, and I wanted to be able to track them both. But it used to be inconvenient to pair the AirTag in the car my wife drives to her iPhone (and the one in my car to my iPhone).

To guard against unwanted tracking, an AirTag will notify nearby iPhones of its existence, so whenever I drove my wife’s car without her in it, I got a notification that an AirTag was traveling with me. (If the owner is near the AirTag, the alert does not appear.)

However, ever since the release of iOS 17, AirTags are shareable, which solves this problem. I shared my AirTag with my wife, and she with me, so regardless of which car I’m driving, I can find it more easily in a crowded parking lot without getting constant, unnecessary alerts.

A new feature to AirTags that arrived with iOS 18.2 is the ability to temporarily share an AirTag’s location with someone I trust. In my luggage example above, if the suitcase was in the airport with me, but the airport’s staff hadn’t yet been able to locate it (not uncommon during peak travel times), I could share its location with an attendant who could quickly retrieve it from areas inaccessible to the public.

Apple AirTag specs

Diameter: 1.26 inches (31.9 mm)
Height: 0.31 inches (8 mm)
Weight: 0.39 ounces (11 g)
Splash, water and dust resistance: Rated IP67 (maximum depth of 1 meter up to 30 minutes)
Connectivity: Bluetooth 5.0
Battery: Replaceable CR2032 coin cell battery

The only minor annoyance about AirTags

An AirTag includes Bluetooth, the U1 Ultra Wideband chip and an NFC chip to share basic details when it’s in Lost Mode. That’s all powered by a CR2032 coin cell battery, which in my experience lasts roughly a year before I need to replace it.

I get notified when a battery is starting to get low, although there’s no gauge to see how much is left until it goes into the red. And it’s easy to change batteries. But my small fleet of AirTags means I need to swap multiple ones each year. I buy them in packs of 20 that I slowly work through.

AirTags also make great gifts

Apple AirTags consistently appear in our gift guides throughout the year because you can always find another use for one. They’re often reduced in price when sold in packs of four. And there’s an ever-growing ecosystem of ways to mount them, from sturdy vaults that adhere to a car to discrete fabric holders that will keep your favorite classic bomber jacket from flying away. Whenever I show someone how I use AirTags on a bag or keychain, I kind of wish I had a pocket of AirTags to hand out because once someone sees how it works, they’re sold.

Looking to save on more things that’ll make your life easier? Check out our roundup of all the best early Memorial Day deals going on now.

When will this deal expire?

We don’t know how long this deal will last, but it’s a limited-time offer so it could expire at any time. We expect the discount will probably continue through Memorial Day, but there’s no guarantee. We recommend placing your order sooner rather than later if you want to purchase the AirTags at this low price.