Night before dawn is 6 hours and 47 minutes,
Dawn starts at 6:47 am and runs for 30 minutes,
Sunrise is at 7:17 am which is 4 hours and 42 minutes before noon,
High noon, the transit of the sun, is at 12:07 pm,
From twelve noon to the sunset at 4:56 pm is 4 hours and 56 minutes,
Dusk lasts for 29 minutes concluding at 5:26 pm,
Leaving 6 hours and 33 minutes until midnight.
As the COVI-19 vaccine rolls out, three big questions loom. irst, can someone who has been vaccinated still spread the disease? Second, will the vaccine remain effective as the virus itself evolves? And third, how long will the vaccine's protection last?
Answers to these questions lie in our immune systems. And the answers aren't straightforward because our immune systems are both remarkably adept and remarkably challenging to predict.
Let's start with the first question, about whether people who are vaccinated can still spread the disease. Marion Pepper, an immunologist at the University of Washington, says that's not just an open question for this vaccine, but for vaccines in general.
This is a very interesting article about some of the unknowns with the CORONA.
All diodes violate ohms law as they are inherently non linear loads - which is why you can't use ohm's law to understand solar power or LEDs as they are diodes which conduct electricity in a non linear fashion.
If solar panels were linear their output would would be the same regardless of load but the silicon junctions are more efficient at certain current levels. That's why people use buck and boost converters to maximize their efficiency - and why most larger solar systems use MPPT controllers.
Likewise, if you limit the current and under drive LEDs they can be much more energy efficient and last longer. For example, two LEDs each driven at 10 mA will produce much more light than one LED driven at 20 mA, even though ohms law says that's impossible. This important - if you pack more LEDs in a light bulb and run them at lower current you can boost efficiency and lifespan at a greater cost of building the bulb.
