July 2024

Draymond Green is not happy with how the Clippers handled the Paul George trade discussions with the Warriors.

In an extra-long episode of No Cap Room, Jake and Dan discuss LeBron returning to the Lakers, Klay Thompson signing with the Mavericks, the Lauri Markkanen trade rumors and more.

Friends, let’s talk about one of the most confusing terms you’ll see on your fitness tracker—specifically your Apple Watch. Next to REM sleep, which you’ve probably heard of, and “deep” sleep, which feels self explanatory, there’s “core” sleep. And if you google what core sleep means, you’ll get a definition that is entirely opposite from how Apple uses the term. So let’s break it down.

The root of the confusion lies in the fact that the term “core sleep” has been used in the scientific literature to mean a few different things. Importantly, it’s not a recognized sleep stage. Apple, on the other hand, decided to rename the sleep stages its watch can detect, and called one of them “core sleep”—but it bears no relation to any of the previous common uses of the term.

“Core sleep” in the Apple Watch is the same as light sleep

Let me give you a straightforward explanation of what you’re seeing when you look at your Apple sleep data.

Your Apple Watch tries to guess, mainly through your movements, when you’re in each stage of sleep. (To truly know your sleep stages would require a sleep study with more sophisticated equipment, like an electroencephalogram. The watch is just doing its best with the data it has.)

Apple says their watch can tell the difference between four different states:

Awake
Light (“core”) sleep
Deep sleep
REM sleep

These categories roughly correspond to the sleep stages that neuroscientists can observe with polysomnography, which involves hooking you up to an electroencephalogram, or EEG. (That’s the thing where they attach wires to your head). Scientists recognize three stages of non-REM sleep, with the third being described as deep sleep. That means stages 1 and 2, which are sometimes called “light” sleep, are being labeled as “core” sleep by your wearable.

In other words: Apple’s definition of “core sleep” is identical to scientists’ definition of “light sleep.” It is otherwise known as N2 sleep. (More on that in a minute.)

So why didn’t Apple use the same wording as everyone else? The company says in a document on their sleep stage algorithm that they were worried people would misunderstand the term “light sleep” if they called it that.

The label Core was chosen to avoid possible unintended implications of the term light, because the N2 stage is predominant (often making up more than 50 percent of a night’s sleep), normal, and an important aspect of sleep physiology, containing sleep spindles and K-complexes.

In other words, they thought we might assume that “light” sleep is less important than “deep” sleep, so they chose a new, important-sounding name to use in place of “light.”

A chart on the same page lays it out: non-REM stages 1 and 2 fall under the Apple category of “core” sleep, while stage 3 is “deep” sleep. That’s how Apple defined it in testing: If an EEG said a person was in stage 2 when the watch said they were in “core,” that was counted as a success for the algorithm.

What are the known sleep stages?

Let’s back up to consider what was known about sleep stages before Apple started renaming them. The current scientific understanding, which is based on brain wave patterns that can be read with an EEG, includes these stages:

Non-REM stage 1 (N1)

N1 only lasts a few minutes. You’re breathing normally. Your body is beginning to relax, and your brain waves start to look different than they do when you’re awake. This would be considered part of your “light” sleep.

Non-REM stage 2 (N2)

Also usually considered “light” sleep, N2 makes up about half of your sleep time. This stage includes spikes of brain activity called sleep spindles, and distinctive brainwave patterns called K complexes. (These are what the Apple document mentioned above.) This stage of sleep is thought to be when we consolidate our memories. Fun fact: if you grind your teeth in your sleep, it will mostly be in this stage.

Non-REM stage 3 (N3)

N3 is often called “deep” sleep, and this stage accounts for about a quarter of your night. It has the slowest brain waves, so it’s sometimes called “slow wave sleep.” It’s hard to wake someone up from this stage, and if you succeed, they’ll be groggy for a little while afterward. This is the stage where the most body repair tends to happen, including muscle recovery, bone growth in children, and immune system strengthening. As we age, we spend less time in N3 and more time in N2.

(There was an older classification that split off the deepest sleep into its own stage, calling it non-REM stage 4, but currently that deepest portion is just considered part of stage 3.)

REM sleep

REM sleep is so named because this is where we have Rapid Eye Movement. Your body is temporarily paralyzed, except for the eyes and your breathing muscles. This is the stage best known for dreaming (although dreams can occur in other stages as well).

The brain waves of a person in REM sleep look very similar to those of a person who is awake, which is why some sleep-tracking apps show blocks of REM as occurring near the top of the graph, near wakefulness. We don’t usually enter REM sleep until we’ve been through the other stages, and we cycle through these stages all night. Usually REM sleep is fairly short during the beginning of the night, and gets longer with each cycle.

How much core sleep do I need?

Using Apple’s definition, in which core sleep is the same as light sleep, it’s normal for almost half of your sleep to be core sleep. Sleep scientists give an approximate breakdown (although the exact numbers may vary from person to person, and your needs aren’t always the same every night):

N1 (very light sleep): About 5% of the total (just a few minutes)
N2 (light or “core” sleep): About 45%, so just under four hours if you normally sleep for eight hours
N3 (deep sleep): About 25%, so about two hours if you normally sleep for eight hours
REM: About 25%, so also about two hours.

Other ways people use the term “core sleep”

I really wish Apple had chosen another term, because the phrase “core sleep” has been used in other ways. It either doesn’t refer to a sleep stage at all, or if it is associated with sleep stages, it’s used to refer to deep sleep stages.

In the 1980’s, sleep scientist James Horne proposed that your first few sleep cycles (taking up maybe the first five hours of the night) constitute the “core” sleep we all need to function. The rest of the night is “optional” sleep, which ideally we’d still get every night, but which it’s not a big deal to miss out on from time to time. He described this in a 1988 book called Why We Sleep (no relation to the 2017 book by another author) but you can see his earlier paper on the topic here. He uses the terms “obligatory” and “facultative” sleep in that paper, and switched to the core/optional terminology later.

You’ll also find people using the phrase “core sleep” to refer to everything but light sleep. For example, this paper on how sleep changes as we age compares their findings in terms of sleep stages with Horne’s definition of core sleep. In doing so, they describe core sleep as mainly consisting of stages N3-N4 (in other words, N3 as described above).

From there, somehow the internet has gotten the idea that N3 and REM are considered “core” sleep. I don’t know how that happened, and I don’t see it when I search the scientific literature. I do see it on “what is core sleep?” junk articles on the websites of companies selling weighted blankets and melatonin gummies.

For one final, contradictory definition, the phrase “core sleep” is also used by people who are into polyphasic sleep. This is the idea that you can replace a full night’s sleep with several naps during the day, something that biohacker types keep trying to make happen, even though it never pans out. They use the term pretty straightforwardly: If you have a nighttime nap that is longer than your other naps, that’s your “core sleep.” Honestly, that’s a fair use of the word. I’ll allow it.

So, to wrap up: Core sleep, if you’re a napper, is the longest block of sleep you get during a day. Core sleep, to scientists who study sleep deprivation, is a hypothesis about which part of a night’s sleep is the most important. But if you’re just here because you were wondering what your Apple sleep app means by “core sleep,” it means stages N1-N2, or light sleep.

Notes is quietly one of the most useful apps in the Apple ecosystem. It’s one of the best note-taking apps for iPhone, can bring in multiple collaborators, and has plenty of additional features such as a built-in document scanner. With iOS 18, Apple is making Notes even better. Here are the best new Apple Notes features to try out for once you’ve installed the new OS.

Take Voice notes in iOS

Credit: Pranay Parab

Apple Notes now supports voice recordings in iOS 18. The app allows you to take quick voice notes and embeds them inline into your text. Plus, once a voice note is recorded, you can also share the audio file with others. This means that you don’t have to share your entire note just to pass along an audio recording. You can choose any individual voice note and share it with anyone.

To record a voice note, create a new note and tap the paperclip icon, then select Record Audio. Next, hit the red record button when you’re ready and start speaking. Tap the pause button to pause a recording or tap Done to finish.

Your iPhone will even transcribe your voice notes

With iOS 18, Notes can also transcribe your voice note for you, saving you the hassle of manually typing out everything you just recorded. This feature is available on iPhone 12 or newer and currently only supports one language—English. That said, it will work with the following regional differences:

English (Australia)
English (Canada)
English (Ireland)
English (New Zealand)
English (South Africa)
English (UK)
English (U.S.).

Oddly, iPhones also support two additional variations of English, namely English (India) and English (Singapore), but live audio transcription isn’t yet available for these.

To transcribe audio in notes, tap on any audio recording in Notes, then the quotation mark at the bottom left of your screen.

Solve math problems

Credit: Pranay Parab

Apple Notes appears to be taking a leaf out of Soulver’s book and adding a feature that lets you solve math problems. You can quickly set up a bunch of variables and define their values within notes, such as x=10, y=20, and z=30, and Notes will be able to tell you what x+y+z is. You can also assign full names to your variables and Notes will still perform your calculations just fine. Support includes common math calculations including addition, multiplication, division, and subtraction. Math in notes uses the same tech powering the new Math Notes section of the Calculator app.

Navigate large notes with ease

Notes has allowed you to break your notes down into sections for some time, but adding too many sections used to make your notes hard to skim through. In iOS 18, you can collapse the sections you want to skip, which significantly reduces the amount of scrolling needed to reach the end. Don’t worry—collapsing a section of notes won’t delete it. To use this feature, apply the Heading style to any section of notes, then tap the heading to collapse it.

Add some color to your notes

Some people like to use different colors when they’re typing. Maybe you want to make important parts of your note pop or separate out topics by color. In Notes for iOS 18, you can easily try out different colors by tapping the Aa button from the Notes toolbar above the keyboard, then selecting the circle in the second row. You can choose one of the following options: purple, pink, orange, mint, and blue.

In a viral social media post, the employee claimed that club president Jill Ellis perpetuated an abusive environment, which San Diego said was “categorically false.”

All batteries age, and the lithium ion battery in your iPhone is no exception. Overtime, the battery degrades, and, as such, can no longer hold as much of a charge as it could when new. After a few years of using the phone, you may notice you only get 70% or 80% of the time you used to after taking your iPhone off the charger.

When the inevitable happens to you, you don’t need to buy a new iPhone. Instead, you can simply replace the battery at a relatively inexpensive cost. Depending on your iPhone, you may not only notice an increase in time away from the charger, but also a boost in performance, since iOS slows down the processing power of your iPhone when its battery is too degraded.

But though replacing your battery is possible, it could certainly be easier. Apple currently secures the battery to the inside of your iPhone with strong adhesive. To remove it, you need to pull on a few tabs that are easy to break, making the removal process more precarious than it should be. The battery itself is also fragile, and you’ll need to remove and reattach some very delicate cables. Despite all of this, it’s possible to replace your battery yourself, but it’s simpler to opt to take it to a repair shop. (Apple would prefer you use one of its own.)

But if reports are correct, the process could be notably easier with the iPhone 16.

The iPhone 16 may have an easy-to-remove battery

According to a report from The Information, Apple is planning on a new battery strategy for the iPhone 16. With this new line of smartphones, Apple may wrap the battery in a metal casing, rather than a foil one, allowing for a new removal process: Rather than having to pull on tabs to release the adhesive from the battery, you would send a low voltage burst of electricity through the battery casing to release it from the iPhone. If it pans out, the process sounds much safer and easier than the current system.

Apple wouldn’t be doing this out of its concern for customers. Instead, it’s likely in response to a new E.U. law that requires smartphones to have “replaceable batteries” by 2025. Europe has had quite an influence over Apple’s decisions over the past year, requiring the company to open up many of its closed platforms, including allowing independent app stores and browsers on iOS.

Despite that pressure, only the battery will be easier to replace. There are no rumors suggesting Apple is making the rest of the iPhone repair process any simpler, so the iPhone 16 will likely still come with the usual strong adhesives on its casing that will need to be heated and broken in order to open the device.

Apple’s battery changes may also improve battery capacity

This changes may mean more than just easier battery replacements. According to noted Apple leaker Ming-Chi Kuo, Apple will also increase the battery density on the iPhone 16 line by 5 to 10%. That extra boost could result in longer battery life, but seeing as Apple is rolling out presumably power-hungry Apple Intelligence features to these new iPhones, those battery gains may quickly disappear.

In so many decluttering tutorials, we go over how to figure out what you can and should part with—and what earns the right to stay. Saying goodbye to sentimental items is really hard, and even if you’re hellbent on decluttering and organizing, there may be a few things you opt to keep.

While I’m a major proponent of untethering yourself from nostalgic items in favor of pushing forward into a brighter, tidier future, I totally get it; there are some things you just need to hold onto. If they’re that special, they should be displayed in a way that keeps them safe and out of the way. Here are some ideas for displaying those meaningful things you just can’t get rid of.

Try a high shelf

I’m not a particularly emotional person, so I don’t have too many mushy, sentimental, or nostalgic things lying around. The ones I do have, however, are far out of reach to prevent any accidental damage. If you have photos, tchotchkes, or, in my case, a pet’s ashes and a rare bobblehead, consider a corner shelf they can rest on.

I am five feet tall, so I stood on a step stool to affix my corner shelf about six feet up, so I’ll never, ever bump it or disturb it in any way, but I also took the precaution of putting it in a corner that is inaccessible and removed from daily activities. It’s simple, like this:

evron Corner Mounting Shelf,Easy to Install Wall Corner Shelf

In my opinion, anything delicate or important should be separated from other decorations, not on a larger shelf or mingling with other things. Show your sentimental pieces the respect they deserve by setting them apart.

Safe storage and display for sentimental items

If you have some photos you can’t part with, I do recommend digitizing them as the safest way to keep them forever. Still, displaying physical ones in your home can be a meaningful way to connect with fond memories, so obviously, you need picture frames. Instead of the delicate glass kind, opt for a sturdier acrylic frame with UV protection. This will prevent shards of glass from damaging the photo if it falls, and the UV protection will help prevent the image from fading or yellowing.

SimbaLux Magnetic Acrylic Picture Photo Frame with UV Protection

$25.95
at Amazon

Acrylic picture frame with UV protection

$25.95
at Amazon

For anything paper, like a child’s old artwork, a certificate, or something similar, you want something that’s easy to use, so you don’t damage the paper while you’re putting it in. A secure frame that opens on hinges and doesn’t rely on you to thread the paper through an unforgiving slit is the move.

Kids Art Frames, 8.5×11 Front Opening Kids Artwork Frames Changeable

I recommend a shadow box only if you plan to store it somewhere it won’t get touched, as they can be pretty delicate. Still, they’re good for mementos from travels, medals, and smaller trinkets, plus they look really sharp. If you have space, though, the better alternative is a protective hutch. Yes, it’s big, so there’s a risk of bumping it, but it’s so big that you’ll hopefully be aware of it and move around it carefully. For collections, expensive items, or anything delicate, this is the way to go.

Ryoko Glass Display Cabinet with Adjustable 3-Shelf Shelves, Glass Cabinet with Lock and Door, LED Light

$259.99
at Amazon

In the event you still want to display some of your meaningful or delicate possessions among your regular decor, at least consider sealing them off from everything else. Display domes come in glass or plastic, so whether you want something that looks classy or can withstand a bumping, you have options. There are even lighted versions, like this one, to keep the item safe and illuminated:

DuvinDD Glass Dome Cloche with LED Light

$19.99
at Amazon

General rules for sentimental items

Always store your things in a place that is dry and has no extreme temperature fluctuations or direct sunlight, even if they’re on display inside of some kind of vessel. Slip a silica gel packet inside the enclosure to absorb excess moisture, just to be safe. Laminate special papers, too; it won’t be that visible inside whatever frame you choose for them, but they’ll be a lot safer that way.

When I’m cleaning and it’s time to dust and wash the shelf holding my special items, I remove them and put them in a box with a t-shirt or two, so they’re on something soft and out of the way. It might seem like overkill, but I would be heartbroken if I accidentally damaged them.

On today’s episode of Zero Blitz, Jason Fitz and Frank Schwab pitch which NFL teams have the best Mount Rushmores for every position group.

Jontay Porter received a lifetime ban from the NBA earlier this season for violating its gambling policy.

Draymond ‘salty’ over how Clippers handled PG13-to-Warriors trade

LeBron James stays in L.A., Klay Thompson leaves for Dallas & NBA free agency rumors | No Cap Room

It’s Time to Learn What ‘Core Sleep’ Actually Is