Month: September 2018

Enlarge / A military version of the Leonardo AW139 flown by the Qatar Emiri Air Force. A US version, built in partership with Boeing, has won the US Air Force's nuclear security helicopter competition. (credit: Boeing)

Just in time to avoid the end of the fiscal year, the US Air Force has finally selected a successor to the aged UH-1 Hueys used by the Air Force's nuclear missile security force: the MH-139, a militarized version of the AgustaWestland AW139 from the Italian aerospace and defense company Leonardo. The MH-139 was a joint bid by Leonardo and Boeing and will be built in the United States at Leonardo's facilities in Philadelphia. The award this morning is for $375 million, covering delivery of the first four helicopters. But the overall program could be worth up to $2.4 billion, delivering up to 84 helicopters, as well as training systems and support equipment.

The MH-139 beat out two separate bids to provide helicopters based on the Lockheed Martin Sikorsky H-60 Blackhawk—one from Lockheed for a new variant based on the helicopter being built for the Air Force's special operations squadrons, and another from Sierra Nevada Corporation that would have refurbished retired US Army UH-60s with new avionics. The competition had been held up by a pre-award protest by Lockheed Martin, and there had been concern that the Air Force would not be able to make a selection in time to avoid having to go back to Congress for reauthorization of the purchase.

The Blackhawk was the original pick to win the program, which the Air Force had intended to simply sole-source to Sikorsky. But then the service's procurement team decided to put the program up for bid, and the competition paid off for the Air Force. The overall price tag of the helicopter program came down considerably from what the Air Force originally expected to pay—an estimated $4.1 billion. "Strong competition drove down costs for the program, resulting in $1.7 billion in savings to the taxpayer,” said Secretary of the Air Force Heather Wilson in a statement on the award.

WinFuture

Huawei's latest flagship smartphone will be the Mate 20 Pro, and the first images of it have leaked. German site WinFuture has posted press images of the upcoming smartphone, which will be announced on October 16th.

The pictures show a mostly cookie-cutter smartphone design on the front. There's a sizable notch on the top and a bit of a "chin" bezel at the bottom. In the pictures, only the earpiece and a single front camera is visible in the notch, although it's a safe bet that there are sensors for proximity and brightness in there. Things get interesting on the back, where the triple-camera layout forms a big black square.

Enlarge / Neither of these steam engines get close to the Carnot efficiency. (credit: Les Chatfield)

Almost all of modern physics comes down to understanding steam engines. Yes, we have all sorts of fancy laws about the Universe and atoms, but thermodynamics rules them all (and not in Sauron’s benevolent dictatorship style). When thermodynamics slaps you, you feel it.  In a new theory paper, a pair of physicists have risked a slapping by nature. They’ve proposed a heat engine that may be practical—for a given value of practical—and operate very close to the limits of physical law. 

Carnot rules

One famous limit of thermodynamics is that heat engines, like steam engines and internal combustion engines, must be less efficient than a Carnot heat engine (a heat engine cycle designed by French engineer Carnot). Although the Carnot efficiency is very easy to calculate, building an engine that operates at that efficiency is highly impractical.

It's not just the impractical mechanics of such an engine. The very nature of the engine suggests that the ideal operating efficiency is achieved only for zero output power. Not very useful, in so many words. But it gets even less useful than that. By delving into the details, you find that as the output power approaches zero, the fluctuations in output power get very large. In other words, even if we could construct such an engine, it would run erratically and drive the operator insane.

Enlarge / iFixit opens up the Apple Watch Series 4. (credit: iFixit)

Apple announced a number of features that got people excited for the Apple Watch Series 4, and its redesigned internals show how much thought the company put into its latest smartwatch. iFixit tore down the Series 4 and found a few interesting tidbits about the Watch that prove it represents a thorough redesign of the original device, making it a more repairable wearable.

Despite having the same estimated battery life as the Series 3, the Series 4's new battery stands out among the details of the teardown. A 1.113Whr battery powers the Series 4, which is larger than the 1.07Whr battery in last year's 38mm Series 3 but smaller than the 1.34Whr of the 42mm Series 3 (iFixit tore down a 44mm Series 4, which is the new equivalent to a 42mm Series 3).

It appears Apple tried to achieve a solid middle-ground with the battery's size, while relying on other hardware and software improvements to do extra work in maintaining overall battery life for both the 40mm and 44mm models. Both are expected to last up to 18 hours on a single charge.