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

The Apple Watch Series 11 Could Share the Stage at Next Week’s Event

The Series 11 will likely headline, but rumors and iOS clues point to additional models joining the lineup at Apple’s September 9 launch event.

All eyes are on Apple’s September 9 «Awe Dropping» event, where a fresh batch of Apple Watches is expected to take center stage alongside the new iPhone 17 lineup. While the Series 11 will almost certainly headline, Apple may have already tipped its hand on the next Ultra. Imagery found in the iOS 26 public beta (first spotted by MacRumors ) shows display specs that don’t match any current model, and the two-year update cycle only strengthens the case that the rugged Apple Watch Ultra 3 is on the horizon.

With the clues stacking up, here’s a look at everything we know, suspect and can reasonably expect from Apple’s 2025 smartwatch lineup.

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How many Apple Watches will we get?

Based on the usual update cycle and now the latest clues in iOS 26, we’re at least getting a flagship (Series 11) and an Apple Watch Ultra 3 as revealed by a reference in Watch OS 26. Also likely is the possibility of getting a next-gen SE model, according to a report from Bloomberg’s Apple analyst Mark Gurman. The Apple Watch Ultra and the cheaper SE line haven’t exactly followed a predictable upgrade cycle but last year’s absence could prove a strong clue that 2025 could be the year that we get all three again.

According to Gurman, the new Ultra and Series 11 are mostly expected to look the same, while the SE could get a refreshed exterior. The Ultra could also get satellite connectivity and 5G RedCap network access that would bring even the most remote adventures «on the grid.»

Apple Watch Series 11 price and availability

Traditionally, new models go on sale anywhere from a few days to a couple of weeks after the keynote. This year, that could mean preorders opening on Friday, Sept. 12, with availability starting the following Friday, Sept. 19. That said, recent years have seen delays because of production issues and it’s still unclear how newly imposed tariffs might affect the launch timing and pricing in 2025. For context: the Series 10 starts at $399 for the base model, while the Ultra 2 comes in at $799. The other question is what the most expensive variant will be — solid gold, diamond-encrusted Hermès, anyone?

Apple Watch Series 11 design

The Series 11 is expected to keep the slim, flat-edged design introduced on the Series 10 (42mm and 46mm), but Apple’s new Corning partnership means all of the glass protecting the display will be made in the US. Not only does the news make for a great marketing bullet; it could also hint at improved durability, sustainability benefits and, potentially, faster repair turnarounds if replacement glass is sourced domestically.

If the leaked iOS 26 imagery holds true, the Ultra 3 will also have a similar design and slightly larger screen with a 422×514-pixel resolution (up from the Ultra 2’s 410×502 pixels). This could be achieved by slimming down the bezels while keeping the same overall case size, in keeping with Apple’s tradition of maximizing screen real estate without making the already-large Ultra any bulkier.

According to MacRumors, the Apple Watch could also get a more energy-efficient screen, maybe an improved LTPO display with higher resolution and better brightness, which, on paper, could help improve the battery life. This could be reserved for the higher-end Ultra 3, which will likely otherwise keep its original design.

Meanwhile the more affordable SE could see a more extensive design overhaul; it would keep the body of the Series 8 and, according to Gurman, get several upgrades from the Series 10, like an always-on display.

Apple Watch Series 11 processor

Apple typically bumps up the processor with every new smartwatch, so we should see an Apple S11 chip this time around for at least the Series 11 and Ultra 3. The Ultra 3 is also rumored to get satellite connectivity and 5G support, but according to Gurman, these features likely won’t make it to the Series 11. Considering last gen’s upgrade cycle, my personal bet would also be on the SE getting a processor bump up to the S9 chip, currently found in the Ultra 2 and the Apple Watch Series 9.

Apple Watch Series 11 battery

If there’s one thing on everyone’s wishlist, it’s better battery life. The Series 10 introduced faster charging — 0% to 80% in just 30 minutes compared with 90 minutes on previous models — but there’s room for improvement in battery capacity itself.

While there aren’t any rumors indicating that new Apple Watches will get a longer battery life, I truly hope Apple addresses the battery because its smartwatches are falling behind. Some Android models use dual chipsets to divide tasks and optimize battery life. I’d like to see Apple adopt a similar strategy and finally push battery life to two full days on a single charge for regular models. I hope the Ultra, which currently gets a full 72 hours on a charge, gets the faster charging of the Series 10 and pushes its battery life limits beyond three days.

Apple Watch health and fitness upgrades

There’s been a persistent rumor about blood pressure tracking finally making its way to the Apple Watch, but it’s unclear when it will be ready. According to a March report from Gurman, Apple has already been testing the feature in its smartwatch but has run into problems. Other wearables health companies like Omron and Med-Watch have proven it’s possible to measure blood pressure from the wrist, but adding this feature would likely require new sensors and a bulkier design. It would also be less precise than dedicated health devices like Omron’s and measure baseline metrics like the Galaxy Watch 7 and Ultra (which isn’t supported on Samsung watches in the US).

Blood pressure and glucose monitoring have also been thrown in the mix but the latter might not be fully baked for this cycle, according to Gurman.

A WatchOS glow-up on the Series 11

Apple also gave us a preview of the new interface for the Apple Watch with WatchOS 26 at its developers conference in June. The new UI update includes a new «Liquid Glass» display with glassy, transparent design language that mimics the one seen in visionOS.

The redesign features clear overlays for icons and notifications, resulting in a more uniform look and feel across Apple’s ecosystem. Google made a similar move with its redesigned UI, Material 3 Expressive, for Android phones and smartwatches with Wear OS 6.

Want a full breakdown of everything Apple announced, including the new iOS 26 and its eye-catching Liquid Glass design? Here’s everything you missed at WWDC 2025.

Health and fitness coaching

WatchOS 26 also introduced an AI-powered Workout Buddy to the Apple Watch, offering encouragement and real-time feedback during specific workouts. Most of the heavy lifting will happen on the iPhone, meaning the feature requires pairing the watch with a newer Apple Intelligence-enabled iPhone. The Series 11 (and Ultra 3) could push this further by leveraging their more powerful chipset.

This could include coaching that goes beyond just the workout app, potentially debuting on the Series 11 and then also rolling out to compatible Apple Watches. According to Gurman, Apple has been working on a major Health app revamp, code-named Project Mulberry, that would bring AI recommendations and actionable health and fitness insights to users. The new «Health Plus» app would likely arrive as part of an iOS 19 update, working in tandem with WatchOS 11 to gather and process data.

Health coaching is something other competitors, like Garmin and Fitbit, offer through their platforms via premium (paid) subscriptions. It’s not clear whether Apple would charge extra for these features, or if they’d be baked into the standard Health app at no additional cost.

Additional future Apple Watch surprises

There’s another rumor floating around that the Apple Watch could get a camera — not for selfies, but for AI-based image recognition. With the release of Apple Intelligence, Apple introduced a visual search tool on the iPhone that uses the camera to provide relevant information about objects and places.

According to a report by Gurman, Apple is exploring this option, and even if the company decides to move forward with the technology, it likely wouldn’t make its way to the Apple Watch until the 2027 models. While it’s not expected for this launch, it could hint what kind of AI integration will arrive with WatchOS 12. By contrast, WatchOS 11 lacks any Apple Intelligence features.

An even further-fetched clue hints at a foldable Apple Watch with two cameras. A recent Apple patent, first uncovered by Patently Apple, and published by the US Patent and Trademark Office in March, details an Apple Watch design featuring a foldable screen and another with a dual-screen display that either folds or slides out. The additional screens could give the Apple Watch more real estate to expand its functionality and make it less reliant on the iPhone. The same patent also points to the possibility of two cameras on this dual-screened watch for either AI processing or video calls. Apple often files patents well before any related technology appears in an actual product, so even if this concept does live to see the light of day, we’re not expecting it to make its public debut anytime soon.

Technologies

Major Amazon Prime Benefit Faces Crackdown Next Month

Amazon plans to end its Prime Invitee program soon. Here’s how this could affect your deliveries.

If you’re using a friend or family member’s free Prime shipping and you don’t live in the same household, you might need to pay another monthly cost. According to Amazon’s updated customer service page, first reported by The Verge, the retail giant is ending its Prime Invitee benefit-sharing program on Oct. 1.

Amazon isn’t the first company to prevent membership sharing between family and friends. The e-commerce giant is just the latest to follow Netflix’s account-sharing crackdown. We also saw it done with Disney-Plus last year. While it’s unclear whether this change will work for Amazon, Netflix gained over 200,000 subscribers following its policy change.

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Amazon’s Prime Invitee program is being replaced by Amazon Family, which includes many of the same benefits. However, Amazon Family only works for up to two adults and four children living in the same «primary residential address» — a shared home. While you’ll still be able to use free shipping to send gifts elsewhere, your Prime Invitees will no longer be able to use the perk.

Read more: More Than Just Free Shipping: Here Are 19 Underrated Amazon Prime Perks

What this means for you

If you’re the beneficiary of someone else’s Prime Invitee benefits, you have one more month to take advantage of the current program before the changes take effect.

Starting in October, you’ll have to get your own Amazon Prime subscription in order to benefit from the company’s free shipping program. First-time subscribers get a year of Prime membership for $15, but you’ll be stuck shelling out $15 a month to maintain your subscription thereafter.

Read more: Your Free Pass to Prime Day Deals (No Membership Required)

Why is Amazon ending the Prime Invitee program?

This move follows shortly after Reuters reported that Amazon’s Prime account signups slowed down recently despite an extended July Prime Day event. While the company reported blowout sales numbers, new Prime subscriptions didn’t meet internal expectations. In the US, they fell short of last year’s signup metrics.

According to Reuters, Amazon registered 5.4 million US signups over the 21-day run-up to the Prime Day event, around 116,000 fewer than during the same period in 2024, and 106,000 below the company’s own goal, a roughly 2% decline in both metrics.

By forcing separate households to have their own subscriptions, Amazon could be looking to attract more Prime accounts after previously failing to do so.

The new Amazon Family program (previously known as Amazon Household) offers Prime benefits to up to two adults and four children in a single home, including free shipping, Prime Video, Prime Reading, Amazon Music and more. The subscription also includes benefits for certain third-party companies, such as GrubHub.

Impulse Buys Under $25 on Amazon That Make Surprisingly Great Gifts

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Technologies

Premiere Pro for Free: How Adobe’s New iPhone App Will Let You Edit Videos at No Cost

Adobe Premiere users will only have to pay for extra AI credits and cloud storage.

Thanks to social media apps like TikTok and Instagram, everyone is an video editor these days. And soon you won’t have to sit down at a laptop to use one of the most popular video editors on the market.

Adobe announced on Thursday that it is releasing a new video editing iPhone app named Premiere on Sept. 30. You can preorder the app now in the Apple App Store, with an Android app currently in development.

The iOS app should feel familiar to Premiere users, with its multitrack timeline and preview screen. The app can be used for all your usual video editing: trimming clips, overlaying audio and adding synchronized captions. You can also use Adobe’s new voice-to-sound effects tool and record voiceovers.

Premiere should be a big upgrade for Adobe users who have only used Premiere Rush, a barebones version of its video editor. As more content creators become mobile-first, Adobe is hoping to draw them in with revamped mobile apps.

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You should be able to use the Premiere iOS app for free. Adobe says you may need to pay for generative AI credits and additional storage, like through Adobe Creative Cloud, though more pricing info is expected closer to the Sept. 30 launch. This is very different from the desktop app, which starts at $23 per month.

A truly free Premiere mobile app would be a win for content creators, especially for anyone who wants to explore editing in Premiere but doesn’t want to pay for another subscription.

In an era of mobile-first content creators, tech companies have raced to introduce user-friendly mobile editing apps. TikTok creators use the ever-popular CapCut, with Meta adding its own contribution, a new app called Edits. Adobe has long been the industry standard for professional content creation and editing, but its mobile offerings were usually less feature-packed versions of its flagship programs under different names.

That changed this year as Adobe released true mobile versions of Photoshop and Firefly AI. The new Premiere app helps Adobe make a competitive entrance in a crowded market, in addition to giving loyal Adobe users a new way to access their tools on the go.

Adobe has also been focused on integrating generative AI into its software. Premiere Pro got its first-ever AI tool, generative extend, which uses AI to add a few extra seconds to clips you upload. It’s meant to help smooth transitions between clips, particularly when you might have turned off the recording a smidge too early and need a few extra seconds of film.

AI is a contentious issue among creators, with some voicing concerns over the training and deployment of AI models. Adobe’s Firefly AI has been fully integrated into the new Premiere iOS app, though the company’s AI guidelines state that it never trains on customer data and that its AI-generated content is commercially safe.

For more, check out what to know about the iOS and Android Photoshop apps and good alternatives to CapCut.