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powderpig

159 karma · joined September 12, 2020

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powderpig··on Around a dozen banking apps began specifically permitting GrapheneOS
I have failed to get Curve running after installing GrapheneOS on a new device.
powderpig··on Nobody understands the point of hybrid cars [video]
The only benefit I've really made sense of with hybrids is their engine emissions aren't localised to the neighborhood where they're charged overnight. Apart from that, I can't think of anything else.
powderpig··on Blue Origin reaches orbit on first flight of its titanic New Glenn rocket
You should check out the Artemis I engineering footage.
powderpig··on Elon Musk wanted an OpenAI for-profit
Red Dragon? Falcon 9 Booster 24-hr turn around? The plethora of missed milestones required to land on the moon's surface?
powderpig··on Europe's flying taxi dreams falter as cash runs short
Metro?
powderpig··on Musicat – A sleek player for your local music library
I'm only here for the free U2 album.

"U2's latest album automatically added to your library"

powderpig··on New jet engine enables efficiency at every speed for cheaper orbital launches
Conventional jet engines run at RPMs in excess of 20000rpm. To get this same speeds for the same mass flown rates of say a J79 (F4-Phantom) you'd be looking at some massive electric motors. Conventional jet engines would be using electric motors if they were light enough already.

There is a reason Rolls-Royce UltraFan uses a speed reducing gearbox for it's fan blades and not an electric motor.

More to the point above, at hypersonic speeds, using a conventional compressor is sort or useless unless you can keep your air cool.

powderpig··on New jet engine enables efficiency at every speed for cheaper orbital launches
Virgin Orbit anyone?
powderpig··on Hyperloop One to shut down
Maintaining a pressure boundary becomes ever more difficult with increase in size, and therefore cost and engineering complexity.
powderpig··on Blender 16yo winner of UK young animator of the year
Roughly how many hours did Euan spend to complete this piece of work?
powderpig··on Clearview doesn't let Europeans delete themselves anymore
Ever heard of ITAR? As a European I find the US's reluctance to adhere to EU law double standard.
powderpig··on The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15
I highly recommend AccuBattery for Android. I have been using it for a few years now and I saw a noticeable difference on my Pixel 3a XL compared to use on previous smart phones. I now have a Pixel 6 and its nearly 2-years old and the battery lasts well beyond 30-hrs with combined use.

https://play.google.com/store/apps/details?id=com.digibites....

powderpig··on Antarctic sea-ice at 'mind-blowing' low alarms experts
How is China a problem? The way of life and the energy intensity of a single individual living in the developed world is the problem. Do I have to point out the US and Europe? (I live in the UK).
powderpig··on Why everything you buy is worse now [video]
This is essentially the Boots Theory, coined my Terry Pratchett. The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money. Take boots, for example. ... A man who could afford fifty dollars had a pair of boots that'd still be keeping his feet dry in ten years' time, while a poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet. Men at Arms. p. 32.
powderpig··on Virgin Galactic successfully flies tourists to space for first time
When's a good time to stop technology advancement for those of us who are willing to pay for it? There will never be a right time.
powderpig··on Debris Field Confirmed as Titan
There are a number of reasons why it might have failed, fatigue, deviation from process/protocol but pressure vessels are well understood and not the problem here.
powderpig··on UK: Food inflation rises to 18.2% as it hits highest rate in over 45 years
The "space" launch was using American technology, nothing about the failure was "British", in my mind. Volt on the other hand...
powderpig··on 20hrs on a Qantas plane: the future of aviation or a fresh hell in economy?
Worth noting the use of titanium at Mach 3, Mach 3.5, is really at its limit. Any faster and you'll start to see serious problems with thermal management. This pushes you into using super nickel alloys or even ceramic matrix composites, which would be necessary for use cases at Mach 5+ for sustained flight. Acknowledging planes in the last have gone faster like the X-15 but this such plane's architecture wouldn't stop for longhaul flight distances. CMCs and super nickel alloys will be very very expensive.
powderpig··on Free Parking Is Killing Cities
And I think this is one of the reasons we are seeing so many companies racing to create a commercially viable eVTOL (electric - vertical take-off & landing) product. To me, this transport system only seems to be a solution to the problem mentioned above. I can't see them ever being commercially viable (FAA regulation, power density, etc.) And yet there are a lot of companies trying to make them a reality when really the cities they have renders of with their flashy electric vehicle flying over just need better public transport systems.
powderpig··on Afghan president flees the country as Taliban move on Kabul
Like the Russians?
powderpig··on Climate change: Curbing methane emissions will 'buy us time'
> Is electricity so expensive in some countries that burning fossil fuel for heat is cheaper than using an electrical heat pump?

Yes. I can't remember the exact source but this charity covers it well. Up to 30% of Africa still burns kerosene for light.

https://solar-aid.org/news/black-carbon-and-the-kerosene-lam...

powderpig··on Why North America's killer heat scares me
I think all geo-engineering is a bad idea. The least worse idea is sucking CO2 out of the atmosphere.

The consequences of any geo-engineering ideas are not well understood.

powderpig··on Poisson's Equation
I too hate the coloured plots but I can tell you as a Stress & Structures engineer who works with ANSYS regularly, it does help when assessing material limits and strain energies. This is especially true when you're working with models where temperature is time dependent.

A great article, one to bookmark for sure.

powderpig··on Portable nuclear reactor program sparks controversy
I am afraid I don't have the numbers to back up my claim but when I was at university, my thermodynamics lecturer showed us a calculation that background dose from radioactive material at a coal powered fire station is higher than that of a nuclear power station. This is because of the shear amount of coal power stations burn through, and in that fuel, there is a trace amount of radioactive material that eventually gets out into the atmosphere.

I've previously worked on a nuclear licenced site and we were not even allowed to throw smoke alarms in the general rubbish due to there being radioactive material inside.

powderpig··on Live feed of Starship SN15 flight test [video]
I'd imagine the most complex engine ever to use the full flow staged combustion cycle has a large price tag.
powderpig··on Starship's Belly Flop Maneuver
> I can't see this ever being approved for human flight without major seeing changes.

...major design changes.

powderpig··on Starship's Belly Flop Maneuver
I cannot believe that Spacex are planning to eventually make Starship human rated and yet there still won't be a launch escape system.

I can't see this ever being approved for human flight without major seeing changes.

Even if the design is fully proved out and works flawlessly, the reliability numbers behind the Raptor engine just aren't there yet.

powderpig··on Two people killed in fiery Tesla crash with no one driving
Lithium-ion fires are hard to extinguish, especially with thermal runaways. There are flame retardant products that can extinguish lithium-ion fires, Class D extinguishers can be used.

I would guess the fire crews that responded were not equipped with this type of extinguisher.

powderpig··on Tesla owners asking what happens if 'full self driving' isn't real
Would you put any of Spacex's launch services in those widely successful projects?
powderpig··on TV detector vans once prowled the streets of England
The new chairman has apparently donated to the Tory party.

https://bylinetimes.com/2021/01/06/new-bbc-chairman-richard-...

The DG was also a former deputy chairman of Hammersmith and Fulham Conservative party.

https://inews.co.uk/news/tim-davie-new-bbc-director-general-...

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