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Mercury Has Shrunk Even More than Planetary Scientists Thought

14 September 2026 at 19:41
This color image of Mercury was generated from three MESSENGER images taken through filters sensitive to light in different wavelengths. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington.

The Solar System’s smallest planet has contracted by nearly 19 km (12 miles) across, as crater debris masked telltale wrinkles on its surface, according to new research led by the German Aerospace Center’s Institute of Space Research.

The post Mercury Has Shrunk Even More than Planetary Scientists Thought appeared first on Sci.News: Breaking Science News.

DeepCool AK620 and AK400 G2 Review: Quiet and powerful, with woodgrain or a digital display

11 August 2026 at 13:05

DeepCool has been delivering innovative, interesting, and often budget-conscious PC cases and cooling products for more than a decade. Its current lineup includes air and AIO coolers, computer cases, keyboards, power supplies, and other accessories.

We were impressed by the company’s AK620 and Assassin VC Elite air coolers in the past. In 2024, the Beijing-based company was banned from selling products in the U.S., but has continued to produce and improve its cooling products for markets elsewhere. US consumers also have the option of importing the cooler, if you don’t mind paying for extra shipping costs.

Here, we’re looking at DeepCool’s second-generation AK series coolers, the AK400 G2 and AK620 G2. These are available in two styles: one with woodgrain top covers, the other featuring a digital display.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Let's take a look at the specifications and features of the coolers, then we’ll go over thermal and noise benchmarks and decide if DeepCool’s AK G2 series coolers deserve to make our list of the best CPU coolers.

DeepCool AK620 G2/AK400 G2 specifications

Cooler

DeepCool AK620 G2/AK400 G2

Colors

Black or white, with woodgrain or digital display options

MSRP

N/A

Lighting

None

Warranty

3 years

Socket Compatibility

AMD AM5/AM4
Intel 1700/1851/1200/115x

Heatsink dimensions

AK620 G2: 125 (L) x 115 (W) x 159mm (H)

AK400 G2: 130 (L) x 92 (W) x 151 (H)

Maximum TDP (Our Testing)

>251W with AMD’s Ryzen 9 9950X3D for the AK620 G2, >244W for the AK400 G2

Features of DeepCool’s AK G2 Air coolers

▶️ Heatpipes and heatsink

With the single-tower AK400 G2, four slightly staggered direct-touch copper heatpipes are embedded in the base to transfer heat from the CPU into the heatsink and its fins.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The larger, dual-tower AK620 G2 features six evenly spaced copper heatpipes.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The heatsink fin designs are similar in both models. The front ends feature a jigsaw-type design, shown below.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The exhaust side features the checkerboard matrix style DeepCool’s air coolers are known for, a design choice which the company says improves static pressure.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

▶️ High-performance 120 mm fans

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

There’s more to a cooler than just the heatsink. The included fans directly impact noise levels and cooling performance. The fans included on both AK400 and AK620 G2 models are essentially the same – but the AK400’s single fan runs up to 10% faster than the two fans included with the AK620 G2.

Fan Speed

AK400 G2: 2200 RPM (± 10%)
AK620 G2: 2000 RPM (± 10%)

Airflow

AK400 G2: 63.4 CFM
AK620 G2: 57.76 CFM

Air Pressure

AK400 G2: 3.33 mmAq
AK620 G2: 2.78 mmAq

▶️ Woodgrain and digital display styles available

Both the AK400 and AK620 are available in black or white, but there are two sub-choices for the aesthetic. The versions we’ve tested for this review feature woodgrain, a motif that’s been increasing in popularity in DIY PCs since the release of Fractal’s North computer case.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

If you don’t like woodgrain, DeepCool also includes a checkerboard black cover that you can use in place of the woodgrain covers.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

There’s also the Nyx version of the AK620 G2 available, which features a digital display showing CPU performance metrics – temperature, frequency, power consumption, and overall CPU usage.

DeepCool AK620 and AK400 G2

(Image credit: DeepCool)

▶️ RAM Clearance

The AK400 G2's design is such that it doesn’t overhang or interfere with the DIMM slots, ensuring that all sizes of RAM, no matter how tall, are compatible.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Standard-height DDR5 sticks 40mm tall fit well under the larger AK620 G2, but taller sticks won’t fit perfectly underneath. Our current CPU cooler test bench incorporates TeamGroup’s Sakura Rose T-Force Xtreem DDR5-7200 sticks, which are 48.8mm (1.92 inches) tall.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

If you also use taller RAM DIMMs, you’ll have to raise the intake fan’s placement by a few millimeters for things to fit properly, as we did (see image, above). This might result in slightly lower cooling performance in certain scenarios. But even so, the AK620 G2 performed excellently, as you’ll see in the benchmarks section.

▶️ Packaging

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The outer packaging is typical of DeepCool products: a basic brown box with a blue line and DeepCool’s logo, covered by a wraparound showing a picture of the cooler.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The heatsink and fans are protected by molded foam, and the accessories are contained in a small cardboard box. Included with the package are:

  • Mounting hardware for AMD and Intel platforms
  • Alternative top covers
  • Screwdriver (AK620 G2 only)
  • The AK620 G2 includes a tube of thermal paste; the AK400 G2 includes pre-installed thermal paste
  • Single-tower (AK400 G2) or dual-tower (AK620 G2) heatsink
  • 120 mm fans and fan clips
  • Installation manual

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

▶️ AK620 G2 AM5 Installation

You’ll need to first remove the default AM4/5 retention mechanism and then place the mounting studs around the exposed screw holes.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The next step is to place the mounting bars on top of the studs, securing them with the included screws, and then apply the included thermal paste. If you’re not sure how to do that, we have a handy thermal paste application guide that covers the different methods you can use. Afterwards, place the heatsink tower against the CPU and mounting bars, and use a screwdriver to secure it.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Once the heatsink is secured, attach the 120 mm fans to the heatsinks. Lastly, connect the PWM cables of the fans to the corresponding headers of your motherboard.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Real-world testing configuration – AMD AM5 platform

We’ve tested coolers with both the Ryzen 9950X3D and its non-V-Cache sibling, the 9950X. There are some differences in how the 9950X and 9950X3D CPUs are impacted by thermal events. While the heat output of the CCDs of AMD’s 9950X3D is relatively balanced, the 9950X has one CCD that runs much hotter than the other, with a difference of over 10 degrees Celsius in some scenarios, shown below.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The benchmark results shared in these reviews may differ from others because I emphasize results that are comparable to real-world use. This means I generally test CPU coolers inside of a closed desktop case, which increases cooling difficulty compared to other testing methods.

Many reviewers test coolers on an open test bench, which has lesser airflow needs and lowered ambient temperatures. This results in weak coolers appearing stronger than they really are. Some have also used generic thermal plates to test cooling solutions. I feel that these methods don’t accurately reflect real-world cooler conditions.

CPU

AMD Ryzen 9 9950X3D

GPU

MSI Ventus 3X RTX 4070Ti Super

RAM

TeamGroup Diamond Rose T-Force Xtreem DDR5-7200

Motherboard

MSI X870E Carbon Wifi

Case

Tryx Flova F50

Our latest testing setup uses the Flova F50 computer case from Tryx.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

This case features a unique “crossflow” fan that pulls air from the side, which the company claims is more effective than traditional intake fans. For air cooling tests, we’ve added a single Noctua NF-A12 G2 intake fan.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

PBO Performance and maximum noise levels

We’re going to start by focusing on a traditional maximum performance test, with the CPU cooler’s fans allowed to reach their fastest speeds, for the best cooling possible.

Turning on PBO allows AMD’s Ryzen 9 9950X3D to stretch its legs to an extent, and all air coolers I have tested with PBO enabled using MSI’s X870E Carbon Wifi motherboard reach the maximum CPU temperature of 95 degrees Celsius (203 degrees Fahrenheit) and thermally throttle to some extent.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Results from the liquid coolers we’ve recently tested aren’t shown above because they are able to keep AMD’s Ryzen 9 9950X3D under TJ Max, and as such, power consumption figures aren’t quite comparable.

The performance of DeepCool’s AK620 G2 is simply excellent, outperforming every air cooler we’ve tested on our current test bench. Its little sibling, the AK400 G2, also does fairly well for a single-tower air cooler, slightly outperforming Sudokoo’s SK620V and only trailing ID-Cooling’s AK620 SLK by 2.4W!

To give a wider variety of comparison examples, I’ve included a chart of the same tests from our last AMD Ryzen 9 9950X3D cooling test bench. But keep in mind these results aren’t 100% comparable, due to a different case and fans being used; the ambient temperature is also slightly higher with the results below.

Our newest test bench used for this and other recent reviews incorporates a Tryx crossblade intake fan as well as a single Noctua NF-A12 G2 intake fan, which results in better air cooling performance.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Some coolers perform well in maximum strength tests, but require running loudly to maintain said performance, but that’s not the case with DeepCool’s AK G2 air coolers. With measurements of 42.4 and 41.9 dBA respectively, their maximum noise levels put them among the quietest coolers featured in our charts.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

200W thermal benchmarks

For the next thermal test, I leave the motherboard settings at their defaults, which results in a power limit of 200W when running Cinebench R23.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

With this thermal test, DeepCool’s AK620 G2 slips to the second best result we got from any air cooler. The single tower version, the AK400 G2, still performs well in comparison to dual-tower products, besting Sudokoo’s SK620V and just a bit behind Montech’s NX600 with its powerful E28 fans.

150W + GPU thermal results, noise levels

Our next test runs Cinebench on the CPU with a 150W power limit, while also running Furmark on MSI’s RTX 4070 Ti Super Ventus 3x OC. This causes the GPU to consume ~295W of power. This test is designed to emulate the thermals of games, which primarily stress the CPU and GPU.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

At first glance, you might think the results above – when tied to the default fan curve of MSI’s X870E Carbon motherboard – are a little underwhelming compared to the competing coolers shown in the chart.

But thermals are only part of the story. Noise levels, especially when you’re gaming, are far more important here. With a noise level of only 38.9 dBA measured, the loudness of these coolers won’t be an issue while you’re gaming. Your GPU fans and / or your case will likely be making more noise in most setups.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Noise-normalized testing

Most testing is performed with the cooler tied to the default fan curve of our MSI X870E Carbon motherboard, but many prefer tests with the noise levels of coolers equalized. This is especially important to those of you who prefer silent computers. This next benchmark has the CPU cooler noise-normalized to 38.9 dBA, with PBO enabled for the Ryzen 9 9950X3D CPU.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The results here are pretty good. With an average of 242.5W cooled during the course of testing, DeepCool’s AK620 G2 shows the second-best performance of the air coolers in this chart. The single-tower AK400 G2 is our bottom result, but even so, its performance is basically on par with Montech’s NX600. That’s fairly impressive for a single-tower air cooler.

Karhu DDR5 RAM thermals testing!

Your CPU cooler does not operate in isolation. It has an impact on not just your CPU’s temperatures, but also the other components in your build, like your RAM and GPU. To that end, I’ve run the Karhu RAM stress test. This places a load of ~153W on the CPU and ensures system RAM (DDR5 in my case) is fully stable. In this type of scenario, most AIOs tend to produce worse results than air coolers.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

The DDR5 temperature recordings from this test seem to be within expectations compared to other dual-tower air coolers. Temperatures with DeepCool’s AK620 G2 were an average of 21.9C above ambient. Curiously, DeepCool’s single tower AK400 G2 showed the best RAM temperatures in this scenario of any air cooler.

The thermals of the CPU in this test were about as expected, with the AK620 G2 showing some of the best temperatures and the AK400 G2 running warmer than most of the dual-tower coolers here, but notably still outperforming Sudokoo’s SK700V.

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

Conclusion

DeepCool AK620 and AK400 G2

(Image credit: Tom's Hardware)

DeepCool continues to impress with its second-generation AK air coolers, the AK620 G2 and AK400 G2, delivering strong thermal performance and low noise levels. Our only major complaint is that these coolers aren’t easily available for purchase in the USA. If you’d rather not go through the hassle of importing, our recommendation would be Thermalright’s Royal Pretor 130, which offers similarly strong thermal performance and low noise levels, at a more affordable price of $50 USD.

Modder pumps liquid directly over bare GPU silicon via 3D-printed block — drops RTX 2060 Super load temps to 28°C despite initial leaks

9 August 2026 at 15:15

The fearless TrashBench has been testing direct die water cooling of graphics cards. The inevitable twist here is that they removed the metal waterblock from the equation. Despite initial leaky results and much concern of water damage to the expensive parts thrown into the mix, some of the end results are eyebrow-raising in a good way.

“In my pursuit of the perfect water block, I realized, why do we need metal at all?” queried the antipodean host of the punk-rock GPU death lab. “Why can't we just pump water directly over the bare silicon? Makes sense to me.”

TrashBench began this project well aware that leaks might be a problem. Thus, a non-working GeForce RTX 3060 was chosen for the initial feasibility tests. It was measured up for a 3D printed water block which would direct the coolant directly over the GPU die. Our hardware adventurer covered any surface-mount components beside the GPU with nail polish to prevent water damage/shorting.

Some tried and trusted plumbing measures were then applied, with the design incorporating washers, gaskets, and hose clamps (worm-screw equipped jubilee clips). Water pipe fittings were melted into the block, which was fastened using the retaining clamp mechanism that the air cooler had previously used.

This initial test sprang a leak, or two, so TrashBench decided to add epoxy adhesive to secure and seal the 3D printed block to the GPU. This worked, but then some water was spotted oozing from the tube fittings, so they got a dose of epoxy too. At last, we had the first non-leaky prototype…

After some live runs using a powered-up GTX 980 were successful, it was time for the main event with fitting, testing, and benchmarking using an RTX 2060 Super. On the way, it was noticed that the choice of 3D print material used on TrashBench’s Bambu Lab 3D printer wasn’t trivial. Some materials leaked from the edges, and others were actually slightly porous. During live power tests, the TechTuber wisely used a PCIe riser cable so any leaks wouldn’t immediately drip onto the motherboard.

Was it worth it?

If you like to live dangerously, it could be argued that the TrashBench results show some value in this cooling methodology. The headlining technique was compared against the stock cooler and a clamped-on AiO cooling solution.

GeForce RTX 2060 Super: 'Heaven' benchmark temperatures table

Cooling solution

Observed temperature (°C)

Stock

70

AiO

36

Direct water

28

Going by the numbers above, you can see that direct water cooling could be interesting, as long as you can ensure long-term confidence about leakage. In the video, you can also see some interesting extras, like running this system using -28°C coolant. The same trick is also tested using an Intel i5-7600K CPU. That was chosen as “it’s not a particularly hot CPU, but if it dies, I don’t care.”

The eventual conclusion was that chamber size matters (most clearly illustrated by the CPU cooling test), but pumping water directly over silicon can work.

Compact urban high-rises intensify humid heat from vegetation transpiration

2 August 2026 at 04:58

A new study is challenging one of the most comforting assumptions in urban climate design: that adding vegetation to dense cities always makes hot weather safer. Research published in npj Urban Sustainability reports that compact, high-rise urban forms can amplify humid heat risks associated with vegetation transpiration—a process usually considered an essential cooling service. The finding does not suggest that trees and plants should be removed from cities. Instead, it reveals that the success of green infrastructure depends heavily on building geometry, airflow, humidity, and the way heat and moisture move through the urban atmosphere.

Vegetation transpiration occurs when plants release water vapor through microscopic openings in their leaves. This process consumes energy and can lower leaf and surrounding air temperatures, much like evaporation from human skin. In a well-ventilated environment, the added moisture may be dispersed efficiently, allowing evaporative cooling to provide a net thermal benefit. But in tightly packed high-rise districts, the same moisture can become trapped between buildings. The result is a more humid microclimate in which the body’s ability to cool itself through sweating is weakened.

That distinction matters because humid heat is more dangerous than air temperature alone suggests. The human body relies on evaporation to transfer heat away from the skin. When atmospheric moisture is already high, sweat evaporates more slowly, forcing the body to work harder to maintain a stable internal temperature. Heat-stress indicators such as wet-bulb temperature and the Wet-Bulb Globe Temperature account for this interaction between heat and humidity. A neighborhood with slightly lower temperatures but substantially higher humidity can therefore feel more oppressive—and pose greater health risks—than a drier location with hotter air.

The study focuses on the urban “canyon” effect created by tall buildings arranged close together. These structures can obstruct wind, reduce the exchange of air with the atmosphere above, and alter the amount of sunlight reaching streets and façades. When vegetation in such spaces transpires, the released water vapor may accumulate rather than disperse. The compact geometry can also create complex circulation patterns, with warm and moist air repeatedly moving through pedestrian-level spaces. In this setting, greenery may cool surfaces while simultaneously increasing the moisture burden experienced by people outdoors.

This is a crucial refinement of the popular idea that urban greening is universally beneficial. Plants perform several valuable functions: they provide shade, intercept solar radiation, reduce surface temperatures, store carbon, and improve the visual and psychological quality of public space. Yet their cooling performance is not fixed. It changes with species, soil moisture, canopy density, irrigation, wind conditions, building height, street width, and background humidity. The new research emphasizes that these factors must be evaluated together rather than treating vegetation as an isolated solution to urban heat.

The implications are particularly significant for rapidly growing cities where vertical development is being used to accommodate rising populations. High-rise construction can reduce land consumption, but dense towers may produce localized atmospheric conditions that differ dramatically from those in surrounding neighborhoods. A cooling strategy designed for an open suburban street may behave differently in a narrow urban canyon surrounded by tall façades. Planners could therefore face a difficult balancing act: maximizing shade and ecological benefits without creating stagnant pockets where moisture and heat combine into dangerous conditions.

The findings also raise questions about how cities measure the success of climate adaptation projects. A street may record a lower surface temperature after trees are planted, yet still expose pedestrians to greater physiological stress if humidity increases and air movement declines. This means future assessments should include multiple variables, including air temperature, relative humidity, wind speed, radiant heat, and human thermal response. Satellite observations and conventional weather stations may not fully capture conditions at street level, where building walls, tree canopies, pavement, and human activity interact within a few meters.

The research is likely to intensify debate over “smart” urban greening rather than green infrastructure in general. Possible responses include selecting vegetation according to local humidity and wind conditions, designing wider or better-connected ventilation corridors, combining trees with reflective or permeable surfaces, and ensuring that shaded areas do not become poorly ventilated enclosures. Building orientation and spacing may be as important as the number of trees planted. Irrigation practices could also matter, since additional water supplied to vegetation may increase transpiration during precisely the periods when atmospheric moisture is already high.

For residents, the message is both cautionary and practical. A leafy street can still be healthier than an exposed one, particularly when shade reduces direct solar radiation. But during extreme heat, people should not assume that every green space offers the same level of protection. Dense, humid, windless areas may require additional measures such as cooling centers, drinking-water access, timed outdoor activities, and heat alerts that account for humidity. The study’s central contribution is to show that urban climate risk is not determined by temperature alone—or by the presence of greenery alone—but by the interaction between city form, plant physiology, and human vulnerability.

As climate change increases the frequency and intensity of heat extremes, these interactions could become more consequential. The research presents cities with a deceptively simple lesson: cooling the urban environment is not just a matter of adding more plants. It requires understanding where the water released by vegetation goes, how buildings control its movement, and how the resulting air feels to a human body. In the race to make cities greener, the next generation of design may need to be equally focused on keeping them breathable.

Subject of Research: The relationship between compact high-rise urban form, vegetation transpiration, humidity, and humid heat risk.

Article Title: Urban high-rise compact form amplifies humid heat risk from vegetation transpiration.

Article References: Zhang, Y., Yang, K., Zhu, Y. et al. “Urban high-rise compact form amplifies humid heat risk from vegetation transpiration.” npj Urban Sustainability (2026). https://doi.org/10.1038/s42949-026-00459-1

Image Credits: AI Generated

DOI: 10.1038/s42949-026-00459-1

Modder der8auer builds 110cm 3D-printed chimney to passively cool Ryzen 7 9800X3D without fans, cuts temps by 19C — radically simple PC mod uses the 'stack effect'

Mechanical pressure serves as a better system to design computers around than natural buoyancy, but a new experiment from der8bauer is attempting to challenge that notion. The legendary modder recently built a chimney to exploit the "stack effect," which uses temperature differences to catalyze natural convection to the point where it becomes effective again. As a result, the CPU in his test bench saw temperatures drop by 19 degrees Celsius without any fans.

The video above explains the concept of the stack effect pertaining to its foundation, natural convection, in great detail. Also known as the chimney effect, it relies on differences in indoor-to-outdoor air density, which are dictated by differences in temperature and humidity. The bottom of the chimney becomes a low-pressure zone, sucking in cold air that escapes through the low-pressure exit at the top.

Mounting a 110cm-tall chimney atop a radiator to passively cool down a CPU

(Image credit: der8auer on YouTube)

In the experiment, der8auer uses a fog machine to show how a radiator can't "pull" air without fans attached to it; the hot air dissipating from the other side is forced to fall back on natural convection. The test bench was water-cooled and consisted of an AMD Ryzen 7 9800X3D, so he added a temperature probe to the fittings to monitor the water temp as well. The experiment then begins with the first 3D-printed chimney that's 10cm tall — it barely works, but temps already start to drop by 0.5 degrees.

At this point, the water was at 61°C and der8auer added another 20cm chimney atop the previous one, making the enclosure 30cm tall in total. This made the temps drop by another 5 degrees over a 30-minute stabilization period. The fog machine didn't really show any difference in the airflow, however. Now, it was time for the big boy: an 80cm tall chimney made up of 4x 20cm parts, bringing the total height to 110cm.

Right away, temperatures began dropping below 55°C before the modder could even set up his camera for the ultrawide framing this setup warranted. Just five minutes later, the water had hit 50°C, but the visual demonstration really sealed the deal. Turning on the fog machine underneath the radiator showed air being pulled through the chimney as if there were fans facilitating airflow on top.

Mounting a 110cm-tall chimney atop a radiator to passively cool down a CPU

(Image credit: der8auer on YouTube)

The CPU temperatures had peaked at 90°C previously, but the "big tower" had now brought them down to just 71°C, as reported by HWiNFO. The experiment was a raging success. The video ends with der8auer actually tying the stack effect back to how we use fans in modern PCs to synthesize air pressure, since they achieve the same goal — a pressure differential — just more reasonably. So, unless you want to redefine what a tower PC means, sticking to regular, boring old fans is enough.

Apple ramps up vapor chamber orders for foldable iPhone Ultra and Twentieth Anniversary iPhone

16 July 2026 at 16:00
iPhone 17 Pro and Pro Max feature a new thermal management system includes an Apple-designed vapor chamber, delivering exceptional performance.
iPhone 17 Pro and Pro Max feature a thermal management system that includes an Apple-designed vapor chamber, delivering exceptional performance.

Apple has significantly boosted its orders for vapor chamber cooling systems, primarily to support production of its highly anticipated first foldable iPhone, according to a Chinese supply chain leaker. The move also points to advanced thermal management in the company’s upcoming Twentieth Anniversary iPhone slated for 2027.

The information comes from the Weibo account “Fixed Focus Digital,” a source that has previously shared details about Apple’s foldable device. The increased orders will first go toward manufacturing the book-style foldable iPhone, internally referred to as the “iPhone Ultra,” which is on track for a September 2026 debut alongside the iPhone 18 Pro lineup.

Apple has reportedly instructed suppliers to prepare around 10 million units of the foldable iPhone for 2026, an increase from earlier projections of 7–8 million. This ramp-up signals strong confidence in the device’s production readiness despite the complexities of its folding mechanism.

Advanced Cooling for a Challenging Form Factor

Fixed Focus Digital previously indicated that the foldable iPhone would feature “impressive” vapor chamber cooling, with Apple “going all out” on its thermal design. This makes sense given the device’s expected thin profile when unfolded (rumored around 4.5–5mm) and the space constraints of a foldable chassis, which could limit traditional heat dissipation options.

Apple first introduced vapor chamber technology in the iPhone 17 Pro models last year. The system uses a small amount of deionized water to efficiently transfer heat away from the powerful A-series chip and spread it across the device’s aluminum frame, helping sustain high performance without thermal throttling.

The same cooling approach is now expected to extend to the foldable iPhone Ultra and potentially the 2027 anniversary iPhones, which are rumored to feature dramatic edge-to-edge displays with glass curving around all four sides for a nearly borderless look.

Broader Context and Timeline

The foldable iPhone is expected to include a 7.8-inch inner display, a 5.5-inch cover screen, an A20 chip, and a Touch ID power button, with pricing likely starting near $2,000. Recent reports confirm that mass production is underway, with key components like OLED panels already in production at Samsung Display.

Meanwhile, Apple’s 20th-anniversary iPhones are planned for two sizes similar to the iPhone 18 Pro models. These devices could mark a major redesign, potentially returning to an all-glass enclosure.

MacDailyNews Take: This latest leak aligns with Apple’s aggressive push into new form factors while maintaining the performance and reliability standards users expect from its flagship devices. As the September launch approaches, more details on the iPhone Ultra’s final specifications are likely to emerge from the supply chain.


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AI’s Growing Appetite for Energy and Water Sparks a New Cooling Solution Beneath the Earth

1 July 2026 at 21:05

Researchers at the University of Illinois Urbana-Champaign say underground aquifers could offer an unexpected solution to one of artificial intelligence’s fastest-growing environmental challenges: cooling the massive data centers that power the technology.

As protests and debates continue over the rapid expansion of AI data centers around the world, researchers are exploring new ways to manage the enormous amounts of energy and water required to keep these facilities running. To meet such demands, the University of Illinois Urbana-Champaign team has proposed an innovative solution: using underground aquifers as natural “thermal batteries” to cool data centers while reducing their environmental footprint.

Critics have raised concerns ranging from the vast quantities of water consumed by AI infrastructure to the ethical implications of job displacement and the broader societal impacts of artificial intelligence. Against that backdrop, designing AI systems that reduce their climate impact could represent an important step toward more sustainable computing.

Researchers Yu-Feng Lin, Andrew Stumpf, and postdoctoral researcher Upasana Pandey from the Prairie Research Institute’s Illinois State Geological Survey explored the potential of Aquifer Thermal Energy Storage (ATES) as a cooling strategy for data centers. The team suggests underground water systems could provide an efficient alternative to traditional cooling methods. Their findings were published in the peer-reviewed journal Groundwater.

“Data centers use large amounts of electricity, and 10 to 40% of that energy can go just to cooling, depending on the design,” Pandey said in a statement. “They also consume tremendous volumes of water, often through cooling methods where water is evaporated and effectively lost from the local supply.”

To address both challenges, the researchers propose using groundwater stored beneath Earth’s surface as a reusable thermal energy storage system. ATES can provide direct or supplemental cooling by circulating groundwater through underground pipes. Cool groundwater absorbs heat through a heat exchanger before the warmed water is returned to the aquifer for seasonal storage. The system can also store excess summer heat for winter heating and preserve cold winter water for use during the summer months.

An operational schematic of an aquifer thermal energy storage system illustrating operations in the summer, left, and winter, right. Credit: Graphic courtesy Upasana Pandey.

“In places like Illinois, where we experience seasonality, and when the subsurface geology is ideal, instead of constantly trying to moderate the outdoor temperatures that swing from 90°F in summer to minus 10°F in winter, we can tap into the Earth’s near-constant temperature,” Stumpf said. “You’re no longer adjusting from 90°F to 70°F; you’re adjusting from about 55°F to 70°F. That’s a huge energy savings.”

Illinois is particularly well-suited for aquifer thermal energy storage because of its pronounced seasonal temperature swings, favorable aquifer characteristics, and suitable subsurface geology. The system can utilize non-potable water sources, including deep saline aquifers, contaminated groundwater, and even abandoned mines.

According to the researchers, the primary barriers to broader adoption are the high upfront installation costs and relatively short investment timelines, rather than technical feasibility.

“Data centers sit at the center of the water-energy nexus: If you try to reduce energy use, you often use more water, and if you reduce water use, you may need more energy,” Lin said. “Our work looks for solutions that address both together.”

“Water is a magic material in this context because it has high heat capacity and can be a good thermal carrier with flow,” he adds.

“That combination is rare, and in groundwater, we can tap those same properties for energy storage.”

Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.

Forests’ Cooling Power Limited by Rising Dryness

17 June 2026 at 13:11

As Earth’s climate system evolves with unprecedented rapidity, forests — vital guardians of global ecological balance — are undergoing complex transformations that extend far beyond the mere sequestration of carbon. Emerging research has begun to unravel the subtle yet profound ways in which climate change reshapes the biophysical interactions between forested landscapes and their surrounding environments, particularly regarding land surface temperature dynamics. A recent groundbreaking study delves deep into these dynamics, revealing starkly contrasting trends that underscore the dualistic nature of forests as climate regulators amidst rising atmospheric dryness. This nuanced revelation challenges long-held assumptions about the uniform benefits of forest cooling and opens new frontiers for understanding ecosystem-climate feedbacks in the Anthropocene.

Forests have long been recognized as crucial climate buffers, primarily through their capacity for carbon storage and evapotranspiration-driven cooling effects. The new research pivots attention to a complementary biophysical mechanism: the difference in growing-season land surface temperature (LST) between forested areas and adjacent open lands, designated as ∆LSTgs. By systematically quantifying ∆LSTgs globally across a span of more than two decades (2001–2023), the researchers uncovered contrasting temporal patterns that vary profoundly with geography and changing atmospheric conditions. Notably, these patterns defy a simplistic narrative of consistent forest cooling, instead revealing a dynamic response heavily modulated by atmospheric humidity levels.

Central to these divergent forest temperature dynamics is the rising vapor pressure deficit (VPD), a measure of atmospheric dryness that quantifies the difference between the amount of moisture in the air and its saturation point. The study identifies VPD as the predominant driver behind the observed variations in ∆LSTgs, exerting a stronger influence than other conventional climatic factors such as temperature, precipitation, or solar radiation. This finding shines light on the critical role that atmospheric moisture stress plays in forest surface energy exchanges, fundamentally altering the cooling potential traditionally attributed to forests under wetter conditions.

However, the forest response to this intensifying atmospheric dryness is far from uniform across global biomes. The research highlights a pivotal interaction between VPD fluctuations and plant hydraulic traits, particularly stomatal regulation strategies embodied by anisohydricity, a measure of plants’ ability to regulate water loss through stomata under drought stress. Forests exhibiting high anisohydricity maintain more open stomata even under dry conditions, enabling continued transpiration and evaporative cooling but at increased risk of hydraulic failure. In contrast, isohydric forests tightly conserve water by closing stomata earlier, reducing cooling at the leaf surface.

Intriguingly, this stomatal regulatory behavior correlates with latitude, delineating distinct forest cooling trajectories. Tropical forests near the equator tend to display more isohydric characteristics. Here, rising VPD often surpasses the hydraulic safety threshold of these ecosystems, leading to stomatal closure and a consequent weakening of forest cooling effects. This trend portends a diminished capacity of tropical forests to mitigate local heating as atmospheric dryness intensifies, potentially accelerating heat stress on these already vulnerable ecosystems.

Conversely, high-latitude forests manifest a more anisohydric strategy, maintaining open stomata under increasing VPD levels that nonetheless remain within their hydraulic safety margins. As a result, these boreal and temperate forests continue to sustain transpiration-driven cooling, which paradoxically intensifies with rising VPD. This phenomenon enhances the biophysical benefits of northern forests, amplifying their role as regional climate coolants and underscoring the heterogeneous nature of forest climate feedbacks across latitudes.

This nuanced physiological interplay yields profound implications regarding future forest-climate interactions under global warming. It underscores that elevated atmospheric dryness will not only influence ecosystem carbon dynamics but also significantly alter the biophysical feedback mechanisms by which forests regulate surface temperatures. As VPD continues to climb worldwide, the traditional ecological services of forests, particularly their cooling benefits, may become compromised in many parts of the globe, particularly within tropical zones critical for biodiversity and global climate regulation.

Moreover, the study’s integrative approach—which combines satellite observations of surface temperature with detailed climatological measurements and physiological trait data—provides a comprehensive framework to understand how climatic stressors mediate forest cooling effects. By leveraging large-scale data spanning two decades, the researchers offer robust evidence that forest cooling is not static but dynamically contingent on complex interactions among atmospheric moisture, plant hydraulics, and geographic distribution, emphasizing the need for ecosystem-specific climate mitigation strategies.

The findings challenge the prevailing optimism about forests’ capacity to offset warming through biophysical means alone. In vulnerable tropical regions, the erosion of cooling benefits linked to stomatal closure under heightened VPD may exacerbate heat stress, increase fire risk, and undermine forest resilience. This could trigger feedback loops accelerating tropical forest degradation and amplifying global warming, raising alarm over the future of these essential carbon sinks.

Conversely, the sustained or even enhanced cooling in high-latitude forests might partially offset regional warming trends, but the balance of such compensatory effects at the global scale remains uncertain. These complexities highlight an urgent need to integrate physiological and biophysical forest attributes into predictive climate models, allowing for more accurate assessments of forest contributions to local and global temperature regulation.

Crucially, the research points to the hydraulic safety margin as a vital threshold parameter dictating the tipping points at which forests transition from cooling to warming agents. This insight offers potential pathways for management interventions aimed at bolstering forest hydraulic resilience, such as selective species planting or conservation strategies tailored to optimize ecosystem-level responses to rising VPD.

In a broader context, the study underscores that atmospheric dryness—often overshadowed by temperature-centric perspectives on climate change—constitutes a formidable and multifaceted challenge for forest ecosystems worldwide. Rising VPD alters not only physiological processes at the leaf level but also cascades through landscape-scale energy budgets, with cascading impacts on regional climate patterns, hydrology, and ecosystem services.

As the global community contemplates reforestation and afforestation policies as climate mitigation tools, these findings call for a recalibrated understanding that accounts for the limits imposed by plant hydraulic behavior and atmospheric moisture constraints. The simplistic paradigm of “more trees equal cooler climate” must evolve into a sophisticated appreciation of when, where, and how forest ecosystems can be expected to maintain their biophysical cooling contributions in a drying and warming world.

Ultimately, this pioneering research adds a critical dimension to our grasp of climate-vegetation feedbacks, illuminating the complex, sometimes counterintuitive outcomes of drying atmospheres on forested landscapes. By highlighting the paramount role of VPD and stomatal regulation across global latitudinal gradients, it informs the scientific community, policymakers, and conservationists alike about the nuanced realities shaping the future of Earth’s green lungs and their vital climate services.

Understanding these relationships better will be indispensable to crafting adaptable and resilient conservation strategies capable of sustaining the biophysical cooling functions of forests. The study’s revelations lay groundwork for future research probing genetic, species-specific, and ecosystem-level hydraulic traits, as well as remote sensing advancements to monitor forest physiological stress and energy exchanges in real time under changing climates.

As atmospheric dryness intensifies in the coming decades, the fate of forests as biophysical climate modulators will hinge on the delicate balance between environmental stressors and intrinsic plant water regulation mechanisms. This research presents an urgent clarion call to incorporate these intricate biophysical and physiological insights into forest management and climate policy frameworks, lest the cooling benefits of the planet’s forests risk becoming relics of a less-dry past.


Subject of Research:
Forest biophysical effects on land surface temperature under changing atmospheric dryness and climate conditions.

Article Title:
Globally constrained forest biophysical cooling benefits under rising atmospheric dryness.

Article References:
Zhang, C., Su, Y., Liao, Z. et al. Globally constrained forest biophysical cooling benefits under rising atmospheric dryness. Nat. Clim. Chang. (2026). https://doi.org/10.1038/s41558-026-02677-y

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41558-026-02677-y

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