Technologies

What Is Dark Matter? The Answer to Universe’s Greatest Mystery Could Be Axions

The saga of how an odd hypothetical particle became a star dark matter candidate.

Physics is permeated by conundrums, and in a sense, that’s what keeps the field going. These mind-bending puzzles foster a race toward truth. But of all the dilemmas, I’d say two of them unquestionably fall under priority A.

First off, when scientists look up at the sky, they consistently see stars and galaxies traveling farther from our planet, and from each other, in every direction. The universe kind of looks like a bubble blowing up, which is how we’ve come to know it’s expanding. But something doesn’t make sense.

Space doesn’t seem to have enough stuff floating around in it — stars, particles, planets and all else — for it to inflate so swiftly. In other words, the universe is expanding way faster than our physics says it can, and it’s even picking up speed as you read this. Which brings us to problem two.

Per experts’ best calculations, galaxies are spinning so incredibly quickly as everything zips around that we’d expect the spirals to behave like out-of-control merry-go-rounds flinging metal horses off the ride. There doesn’t seem to be enough stuff in the universe to anchor them together. Yet the Milky Way isn’t drifting apart.

So… what’s going on?

As blanket terms, physicists call «missing» stuff pushing the cosmos outward dark energy, and pieces holding galaxies together — presumably in a halo-like form — dark matter. Neither interacts with light or matter we can see, so they’re essentially invisible. Combined, dark matter and dark energy make up a whopping 95% of the universe.

Zeroing in on dark matter’s portion, the authors of a recent review, published in the journal Science Advances, write that «it may well consist of one or more types of fundamental particle … although part or all of it might consist of macroscopic lumps of some invisible form of matter, such as black holes.»

Black holes or not, dark matter is totally elusive. In an effort to decode its secrets, scientists have picked a handful of suspects out of the cosmic lineup, and one of the most wanted particles is an odd little speck called the axion.

The wide-eyed hypothesis of axions

You might’ve heard of the Standard Model, which is pretty much the holy grail, ever-strengthening handbook of particle physics. It outlines how every single particle in the universe works.

However, as the Science Advances review points out, some «particle physicists are restless and dissatisfied with the Standard Model because it has many theoretical shortcomings and leaves many pressing experimental questions unanswered.» More specifically for us, it leads right into a paradox regarding a well-established scientific concept dubbed CPT invariance. Aha, the physics puzzles continue.

Basically, CPT invariance states that the universe must be symmetrical when it comes to C (charge), P (parity) and T (time). For that reason, it’s also called CPT symmetry. If everything had the opposite charge, was left-handed instead of right-handed and traveled through time backward instead of forward, it states the universe should remain just the same.

For a long while, CPT symmetry seemed unbreakable. Then 1956 came around.

Long story short, scientists found something that violates the P part of CPT symmetry. It’s called the weak force, and it dictates things like neutrino collisions and element fusion in the sun. Everyone was shocked, confused and scared.

Nearly every foundational concept of physics relies on CPT symmetry.

About a decade later, researchers discovered the weak force violating C symmetry, too. Things were falling apart. Physicists could just hope and pray that even if P is violated… and CP is violated… maybe CPT still isn’t. Maybe weak forces just need the trio to uphold CPT symmetry. Thankfully, this theory seems correct. For some unknown reason, the weak force follows total CPT symmetry despite C and CP blips. Phew.

But here’s the issue. If weak forces violate CP symmetry, you’d expect strong forces to as well, right? Well, they don’t, and physicists don’t know why. This is called the strong CP problem — and precisely where things get interesting.

Neutrons — uncharged particles within atoms — abide by the strong force. Plus, allowing for simplification, their neutral charge means they violate T symmetry. And «if we find something that violates T symmetry, then it must also violate CP symmetry in such a way that the combination CPT is not violated,» the paper states. But… that’s weird. Neutrons don’t because of the strong CP problem.

And so the idea of the axion was born.

Years ago, physicists Roberto Peccei and Helen Quinn suggested adding a new dimension to the Standard Model. It involved a field of ultralight particles — axions — that explained the strong CP problem, thereby relaxing the conditions for neutrons. Axions appeared to fix everything so well that the duo’s idea became the «most popular solution to the strong CP problem,» the paper states. It was a miracle.

To be clear, axions are still hypothetical, but think about what just happened. Physicists added a new particle to the Standard Model, which outlines specks of the entire universe. What might that mean for everything else?

The key to dark matter?

Per the Peccei-Quinn theory, axions would be «cold,» or very slowly moving through space. And… the study researchers say «the existence of [dark matter] is inferred from its gravitational effects, and astrophysical observations suggest that it is ‘cold.'»

The paper also states, «there are experimental upper limits on how strongly [the axion] interacts with the visible matter.»

So, basically, axions that help explain the strong CP problem also seem to have theoretical properties that align with those of dark matter. Extremely well.

The European Council for Nuclear Research, better known as CERN, which runs the Large Hadron Collider and is leading the charge for antimatter studies, also underlines «one of the most suggestive properties of axions is that, in a natural way, they could be produced in huge numbers soon after the Big Bang. This population of axions would still be present today and could compose the dark matter of the universe.»

There you go. Axions are among the hottest topic in physics because they seem to explain so much. But once again, those sought-after bits are still hypothetical.

Will we ever find axions?

It’s been 40 years since scientists began hunting for axions.

Most of these searches are «mainly exploiting the action field interaction with the electromagnetic fields,» say the authors in that recent review published in Science Advances.

For instance, CERN developed the Axion Search Telescope, a machine built to find a hint of the particles produced in the sun’s core. Inside our star, there are strong electric fields that could potentially interact with axions — if they’re really there, that is.

But the quest has so far faced a few pretty big challenges. For one, «the particle mass is not theoretically predictable,» the authors write — that is, we have very little idea of what an axion might look like.

Right now, scientists are still searching for them while assuming a vastly wide range of masses. Recently, however, researchers offered evidence that the particle is likely between 40 and 180 microelectron volts. That’s unthinkably small, at about 1 billionth the mass of an electron.

«In addition,» the team writes, «the axion signal is expected to be very narrow … and extremely feeble due to very weak couplings to Standard Model particles and fields.» In essence, even if minuscule axions try their very best to signal their existence to us, we might miss them. Their cues could be so weak we’d barely notice.

Despite these hurdles, the axion search marches on. Most scientists argue that they must be out there somewhere but they seem too good to be true when it comes to fully explaining dark matter.

«Most experimental attempts assume that axions compose 100% of the dark matter halo,» the study authors emphasize, suggesting that perhaps there’s a way to «look into axion physics without relying on such an assumption.»

Though they may be the star of the show, what if axions are just one chapter of dark matter history?

Technologies

Today’s NYT Connections Hints, Answers and Help for Feb. 5, #970

Here are some hints and the answers for the NYT Connections puzzle for Feb. 5 #970.

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

Today’s NYT Connections puzzle is kind of tough. Read on for clues and today’s Connections answers.

The Times has a Connections Bot, like the one for Wordle. Go there after you play to receive a numeric score and to have the program analyze your answers. Players who are registered with the Times Games section can now nerd out by following their progress, including the number of puzzles completed, win rate, number of times they nabbed a perfect score and their win streak.

Read more: Hints, Tips and Strategies to Help You Win at NYT Connections Every Time

Hints for today’s Connections groups

Here are four hints for the groupings in today’s Connections puzzle, ranked from the easiest yellow group to the tough (and sometimes bizarre) purple group.

Yellow group hint: Star-spangled signs.

Green group hint: Smash into.

Blue group hint: Not green or red.

Purple group hint: Same surname.

Answers for today’s Connections groups

Yellow group: Cultural symbols of the US.

Green group: Collide with.

Blue group: Blue things.

Purple group: Lees of Hollywood.

Read more: Wordle Cheat Sheet: Here Are the Most Popular Letters Used in English Words

What are today’s Connections answers?

The yellow words in today’s Connections

The theme is cultural symbols of the US. The four answers are American flag, apple pie, bald eagle and baseball.

The green words in today’s Connections

The theme is collide with. The four answers are bump, butt, knock and ram.

The blue words in today’s Connections

The theme is blue things. The four answers are jeans, lapis lazuli, ocean and sky.

The purple words in today’s Connections

The theme is Lees of Hollywood. The four answers are Ang, Bruce, Christopher and Spike.

Technologies

Today’s NYT Strands Hints, Answers and Help for Feb. 5 #704

Here are hints and answers for the NYT Strands puzzle for Feb. 5, No. 704.

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 is a fun one, once you clue in on the theme. Some of the answers are difficult to unscramble, so 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: Quint-essential.

If that doesn’t help you, here’s a clue: Not four, or six.

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:

DAYS, GIVE, WOVE, DOVE, LOVE, DOGS, SCONE, STOLE, GEEK, LODE, SIEGE, SLEW, HENS

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 have 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:

TOES, OCEANS, SENSES, VOWELS, BOROUGHS, WEEKDAYS

Today’s Strands spangram

Today’s Strands spangram is GIVEMEFIVE. To find it, start with the G that’s three letters to the right on the top row, and wind down.

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

Technologies

The Motorola Signature Is the Moto Phone I’ve Wanted for Years

Motorola’s new phone is its best flagship yet and could be the Galaxy S26 Plus rival that Samsung didn’t see coming.

At CES 2026, among the AI humanoids, flashy concepts and next-gen foldables, was a Motorola phone that I didn’t expect to be a CES highlight. And no, I’m not talking about theMotorola Razr Fold. While it was the talk of the town (after all, it is the company’s first-ever book-style foldable), there’s a premium smartphone with top specs and a sophisticated design: the Motorola Signature.

Recent high-end Motorola phones have had good-looking hardware, but they don’t compete with the Galaxy S25 Ultras or Pixel 10s of the world. They fall short in one or more areas, including display, performance, cameras, software or battery. The Motorola Signature is the company’s first flagship phone that looks confident enough to take on heavyweights like the upcoming Galaxy S26 Plus and the current iPhone 17, without faltering on either hardware or software.

I’ve been using it for a couple of days now, and this Motorola phone doesn’t have any major downsides, especially for the price. The biggest one could be availability: It won’t be coming to the US, but it is now available for purchase in India at an unbeatable price. It undercuts the OnePlus 15, iPhone 17 and the Pixel 10 by almost $150 or more (directly converted from INR).

With the ever-increasing prices of premium phones, the Motorola Signature is the flagship killer we’ve been waiting for. At about $660 (INR 59,999), it is hard to beat, and I can admit I’m finally excited about a Motorola phone that’s not a Razr.

Motorola Signature is lightweight, slim and rugged

The Motorola Signature has a 6.8-inch 1,264×2,780-pixel resolution AMOLED display with support for a 165Hz refresh rate. It is an LTPO panel, so it can be set to 1Hz for an always-on display (like the iPhone 17 series and Galaxy S25 Ultra), thereby saving battery life. Its resolution might not be as high as the Galaxy S25 Ultra’s, but it is a promising screen for gaming and content consumption.

I couldn’t find a game to test its 165Hz refresh rate, but watching YouTube videos, Instagram Reels and reading ebooks — both indoors and outdoors — was a pleasing experience. The screen remains legible in all lighting conditions.

Motorola’s new phone is powered by the Qualcomm Snapdragon 8 Gen 5 chipset and is paired with 16GB of RAM and 512GB of storage. While it’s not the highest-end chip available (that’d be the Snapdragon 8 Elite Gen 5), it packs plenty of power. I had no issues in day-to-day use, occasional multitasking or gaming. My only complaint was with the camera shutter in low light, but we’ll get to it in a bit.

The Motorola Signature ships with Android 16 with the company’s in-house Hello UI on top. It is a comparatively clean interface with plenty of customization options to fine-tune your experience. One of my favorite features, Moto gestures (twist to open the camera or make a double-chop motion to turn on and off the flashlight) is always handy in unexpected ways.

You get an AI Key on the left side of the phone to trigger Moto AI (uses Perplexity or Microsoft Copilot), but it can only be triggered once you create a Motorola account. You can configure the button to do other shortcuts, like double-press it to take notes and press and hold to trigger Moto AI. But in reality, I didn’t use any of these features in my daily life and would’ve preferred the ability to remap them to a shortcut. Google’s Gemini assistant is also available.

The Signature has a 5,200-mAh silicon-carbon battery and supports 90-watt wired charging and 50-watt wireless charging. Should those speeds hold up, that battery might fill up quickly using either method. It lasted me an entire day on medium use, but on another day, I had to charge it twice when I pushed it with streaming, browsing, Google Maps navigation for 30 minutes and active camera usage. It doesn’t compete with OnePlus 15’s massive 7,300-mAh cell but does well to reduce battery anxiety.

All of this sounds more impressive when you take the Signature’s design into context: The flagship Qualcomm processor’s power, 5,000-mAh plus battery, big AMOLED screen and three 50-megapixel cameras housed in a slim and lightweight design. The new Motorola phone is 6.99mm thick and weighs just 186 grams. For context, the Galaxy S25 Plus, with a smaller battery, measures 7.3mm thick and weighs 190 grams, while most recent big phones weigh 200 grams or more.

I shifted from the iPhone 17 Pro Max and enjoyed using the Motorola Signature because it weighed less. But I didn’t expect it to be so light. The Signature feels good in my hand. I’m glad it doesn’t have sharp flat sides like the Galaxy S25 Ultra. Plus, I love its linen-inspired finish on the back, which sets it apart from the competition. Like its Edge siblings, the Signature is rated IP68 and IP69 for dust and water resistance (meaning it can survive being submerged under a meter of water for 30 minutes and high-pressure water jets), so there’s no fear of dust and water damage.

Improving on the 2 weakest links

Most Motorola phones that I’ve used in recent years, including the $1,300 Razr Ultra have one or two downsides: software support and/or cameras.

The Signature marks a new beginning for the brand as it joins the ranks of Samsung and Google with seven years of Android OS software and security updates. This is on par with Google Pixel and Samsung Galaxy phones and better than what OnePlus offers. I hope this new software update policy is implemented on more Motorola phones launching in 2026.

Secondly, the Motorola Signature (finally!) introduces an impressive camera system. On the back, you get three cameras: a 50-megapixel main camera with OIS, paired with a 50-megapixel telephoto camera with a 3x zoom lens and OIS, and a 50-megapixel ultrawide camera. This is the first Motorola phone with cameras that I wouldn’t trade for another setup during my vacations.

Photos from the primary and telephoto cameras have better color accuracy than previous Moto shooters. Images have a slightly warmer tone and are saturated — not as much as the OnePlus 15, which delivers much more saturated tones. I prefer Signature’s look in most scenarios.

However, the ultrawide-angle camera retains fewer details, and OnePlus does better in that regard.

The telephoto lens struggles with edge detection in low-light portraits, but I loved using it for architecture shots and capturing scenery around me. It can deliver some stunning shots even in 6x. Mind you, it has 3x optical zoom, but I shot the above photo in 6x, and it has a nice bokeh, good details and an overall pleasing look.

Motorola Signature final thoughts

Overall, the Signature has solid cameras for the price and the best optics yet for a Motorola phone. But there’s one hindrance: The camera shutter in low light is slow to process images. For instance, I wanted to snap a few action shots during a badminton game, but I missed some great smashes because the camera wouldn’t allow me to capture images faster.

The Motorola Signature marks a solid flagship comeback for the brand. It has a big and bright display, a capable processor, a versatile camera setup and good battery life. This phone is hard to fault in its price segment.

The Signature is now available to purchase in India at a starting price of INR 59,999 (approximately $660) for the 256GB variant. It will go on sale in Europe for €999 (approximately $1,170) with 512GB storage in the base version. Motorola has plans to launch its new flagship phone in more countries across the Middle East, Africa, Latin America and Asia-Pacific regions. However, the Motorola Signature won’t be coming to the US.