Comment I see what you did there... (Score 1) 258
so only time will tell.
so only time will tell.
You have it backwards. When the USB charger voltage droops, the phone (or other recharging device) will dissipate more heat as the phone's charging process becomes less efficient. Apple's USB chargers generally don't sag like some cheap equivalents do.
It's easy to monitor this using simple and cheap USB tools like this one which report both voltage and current:
https://www.amazon.com/PortaPo...
(or many other equivalents)
Charge control is done within the phone, generally by a dedicated chip which also monitors battery temperature. In some cheap 'power bricks', the charge control is done via a microprocessor rather than a dedicated charge control chip, but this isn't common in more valuable products.
Li ion batteries have a separate protection circuit which monitors over voltage, under voltage and over-current (either direction). It opens the circuit when triggered.
Battery safety is controlled by IEC 62133, which was generated in the EU, but has been adopted in the US, too.
Susskind wrote a very interesting book on this topic, too. The Black Hole War, subtitled, "my battle with Steven Hawking to make the world safe for Quantum Mechanics". I was hoping someone in the thread would know if Steven Hawking's announcement was an acceptance of Susskind's position, or similar to it, or something else.
Your primary duty is to your child. I promise you, responsible parents agonize about the best options for their children. Sometimes private, sometimes public.
We started private and then left. The early years at private were probably worthwhile. I tell myself that. They were expensive.
But we've been delighted with the quality of our public schools. They operate from one third the budget of the private school (per pupil). The buildings and landscaping are dramatically tougher, but we're happy with the change. The teachers have been high quality, highly dedicated to the job and responsive to us. My kids are engaged and enjoy their schools.
You have essentially no control over the private school or the public school. In both cases, you will monitor your kids' work, talk regularly to their teachers, meet their friends and their friends' parents. Your recourse in both cases is to find a different school.
No one should demonize a parent for trying to do the best they can for their child. Your first duty is to your child. Social welfare and activism should come after family.
I really liked Stephen Hawking's, "A Brief History of Time" for an accessible description of Special and General Relativity.
This makes some sense. Homo Sapiens may have evolved through particularly rapid evolution. If viruses (virii -- what a word) play a role in genetic mutation, which I think is now a commonly held theory, Homo Sapiens might have 'stabilized' by boosting their immunity with some Neanderthal genes.
It's easy to imagine that slower-evolving species would have better immunity, if the virus theory is right.
Subsequent natural forces would probably discriminate against the offspring which were stupid, giving the best of both worlds -- smart and comparatively immune.
I'm not trained in biology -- just remembering other 'stuff that matters'. (early Homo Sapiens were sickly and smart? And then came to rule the world? I'd say that's News for Nerds.)
There is a lot of confusion among the early commenters. Some think this is a form of differential GPS, some think this is a network of WiFi devices, or a hybrid of WiFi and FM radio.
It appears to be none of the above.
It most likely is a pseudo-lite (a terrestrial device which mimics a satellite), except that it does not operate in the GPS (L1 or L2) band(s). The government, researchers, FAA and Air Force (which runs GPS) are working on real pseudolites which may run in the GPS bands. But this private company couldn't get rights to do that, so they are transmitting in 'the same band(s) used by WiFi. That is, they are broadcasting spread spectrum signals in the ISM band(s).
They apparently scatter a number of these, at highly precise locations, and a compatible user device would then listen to several and calculate its own position. Since their geometry is as flat as the nearby terrain, they will have very poor altitude accuracy, but because they don't have bending or delays in the atmosphere (or rather, those inaccuracies are trivial in comparison), they will likely have very good 2D accuracy.
Notice that things flying over the top of these devices would likely have good 3D (the geometry improves for them).
What is less clear is why this is preferable to using DGPS. DGPS is a 'station' at a known location which can measure the errors of each satellite (including bending/delay) and transmits corrections to nearby devices. DGPS is a government service in many areas, I believe, but can be set up as a private service, too.
The one real liability to the new Locata system, if I understand it (and I probably don't) is that they don't necessarily use GPS time. One of the really fabulous things about GPS is that it established a world-wide synchronous, highly accurate clock. In many applications that may not matter. It does for a lot of systems which rely on GPS time (too many to mention nowadays).
Modeling paged and segmented memories is tricky business. -- P.J. Denning