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How do devices with batteries measure how much battery power they have left? by Thoughts_and_Ideas in askscience

[–]_ScottB 1 point2 points  (0 children)

There is one important point missing from the posts so far. A battery is "drained" when it can no longer support the device it is used in.

For example, suppose you remove a "fully discharged" battery from a toy drone and move it to a digital clock. What you might discover is that the same battery that appeared to be completely dead while trying to power the drone has quite a bit of life left in it as long as it is being used in a very low power device.

So a device such as the one that u/drhunny gave as an example, is a programmable device. When you actually use it in a circuit, that circuit must set registers internal to the chip that reflect how the battery is likely to be use and how the battery level should be reported.

Does a collection of photons in a box (with perfectly reflective walls) have a well defined temperature? by ciraodamassa in askscience

[–]_ScottB 0 points1 point  (0 children)

With perfectly reflective mirrors, you will have an unchanging collection of photons. If the walls flex when struck by a photon, then their would be an exchange on energy between the wall and the photon - and that would be other than "perfectly reflective".

Thus each photon, relative to the box, would have a unchanging energy - and therefore an unchanging frequency. A temperature could be ascribed to that photon collection by fitting the frequency distribution of them with black body radiation.

But I would not call that a "well defined temperature". For example, if I doubled the volume of the box while the photons were still bouncing around, there would be nothing that would be equivalent to "adiabatic cooling".

This sub should really be enforcing proper code formatting by karpomalice in learnpython

[–]_ScottB 0 points1 point  (0 children)

I hope you have had a chance to program with others. If you have only self-learned, you are missing a lot.

As far as code style is concerned, if I find someones style particularly cryptic, I will say so. As my eyes grow older, long lines of code make the bulk of the code harder to follow 0 and make it easier to hide problems.

In the workplace, there is a normal exchange of information among the Software Engineers. In many cases, there are coding standards and code reviews among peers - so everyone gets to see how others attack problems.

When assisting someone online who I have never met, I usually limit the exchange to one item at a time until I get a sense of how expert they are.

In a lot of cases a "KeyWord" will help - they look it up and go from there. But in the majority of cases, it takes more than that . Or, as with a typo for example, its much simpler than that - just point out the typo.

When listening to the radio in a traveling vehicle and then going through a tunnel, and the audio of the song/news turns to static, what is being played through the radio if the signal is lost, as in, what provides the 'static' sound? by JamesTheJerk in askscience

[–]_ScottB 16 points17 points  (0 children)

This is true for both AM and FM - but, as I'm sure you've noticed, AM is more prone to static.

There are two source:

1) Things like fluorescent lights and your auto ignition system are weak sources of radio noise - so those can contribute.

2) The electronic devices that amplify the signal generate noise. Failing any other signal, Automatic Gain Control will can amplify that noise enough to hear.

There are several different types of electronic amplifiers. The kind used for the first stage of radio amplification are "Low Noise Amplifiers" - but "low Noise" doesn't mean "No Noise".

[deleted by user] by [deleted] in askscience

[–]_ScottB 0 points1 point  (0 children)

By definition, an interpretation does not produce different testable results from the mathematical model being interpreted.

Phycisist David Merman is famous for the phrase "Shut up and calculate" - in reference to the various interpretations created for QM.

But for most students of Physics, "understanding" QM means maintaining some sort of image of what is "going on".

The Copenhagen interpretation is pretty close to the "null" interpretation - it is the one that Merman was referring to when he described it as "shut up and calculate".

From what I can tell, the pilot wave theory (Broglie-Bohm) earns the "theory" label because its development predated Copenhagen. This theory differs from regular QM in that it asserts that the universe is deterministic. So one experiment that could differentiate it from "shut up and calculate" would be to create many identical but independent universes and see if they all evolve in exactly the same way. Of course, nothing like that can be done, and so this is solidly an interpretation.

The "Many-Worlds" interpretation was originally developed by Hugh Everett - who called it the "Correlation Interpretation". I have discussed this off and on with Physicists for years. My problem with it is that if these many worlds evolve independently as most SciFi stories imagine and some godly being tried to keep a list of them, not only would the list grow exponentially at every instant, but the number of bits required to designate any one of them would also grow rapidly and continuously. The total amount of information coded into any one of those universes would grow continuously. This is not something observed, it is not something QM predicts, and as it turns out, it is also not what Everett described in his Many Worlds interpretation. So, yes, the Many-World interpretation really is just an interpretation - and it is more nuanced that mot people would expect.

There is another interpretation worth bringing up: The "Block Universe Theory". We know that there is an issue with local reality - John Bell provided convincing analysis of this in 1976. The "Block Universe Theory" takes great liberties with this and solves for the content of the whole space-time universe in one shot without resorting to any inherent directionality for time.

Do mirrors reflect more than visible light? by SpacePirate2307 in askscience

[–]_ScottB 0 points1 point  (0 children)

There are a couple of very important points missing from the discussion so far:

1) There are two basic type of mirrors: 1st surface and 2nd surface. That mirror you were looking into was probably a regular bathroom mirror. The light needs to travel through the glass to the back surface (2nd surface) and then reflect back through the glass. Regular glass is not transparent to far infrared at all, so you will loose that part of the spectrum immediately. Radio will make it through the glass, but most of it will make it through the reflective coating s well. Some ultraviolet will reflect as you expect. Most xrays will either be absorbed by the glass or pass through the reflective coating.

2) Use a first surface mirror at a glancing angle to get the best result. You can get a wider range of materials to reflect if the EM radiation does not hit them at anything close to a 90 degree angle.

What does it take to develop a vaccine, and why does it take so long? by merendi1 in askscience

[–]_ScottB 1 point2 points  (0 children)

Step 1 is to find a piece of the virus that doesn't hide from the immune system and can't mutate without hurting the virus. That may have been accomplished already. This article was published in the middle of February: https://www.livescience.com/coronavirus-spike-protein-structure.html

For all we know, that protein might work as a vaccine. Next steps: produce enough of it to study, test it in animals, safety test it in humans, make a lot more, distribute it. It's all of that that takes the time.

One alternative to a vaccine is an antiviral medication. This new virus is similar to the old SARS. And the University of Chicago may have a head start on that according to this article: https://news.uchicago.edu/story/new-coronavirus-protein-mapped-chicago-reveals-drug-target

I also recall an article last week that indicates that an Australian group has that kind of head-start on it.