This is delightful. I would love to start working on a project like this.
Side note, as someone who works adjacent to the RF and electronics industry, getting my Ham license was the best thing I could have done to help my CS brain understand the radio and electronics side of what we do. If you’ve ever been curious about getting your license, I highly recommend it!
Thanks for your enthusiasm. I'd been thinking about it and heard there's a group nearby, I've just reached out to them to begin the process and they have a training event in a few weeks' time. Looking forward to it!
Backblaze is one of the few services I recommend to everyone. The $5/month unlimited backup service with the 30 day versioning built on top of it is such peace of mind.
The one thing this article doesn't touch on, that I wish it had, is condition. I'm a large buyer of used books from places like AbeBooks and Amazon, and the conditions simply cannot be trusted, especially from the larger sellers like Owl Books, Thriftbooks, and Better World Books.
Almost every time I buy a book listed as "Very Good" which has a clear definition on AbeBooks' website[1], I end up getting something with clear markings, or damage.
Amazon has somewhat recently modified their definition of “very good” to allow actual damage rather than just shelf wear. I returned a book last week that had a big gouge in the spine. I’ve previously had good luck buying VG books, but now I might have to rethink buying used from Amazon at all.
That's good to know. I may also have to stop buying used from Amazon. It seems IOBA also allows for damage[1], but it must be noted, which seems to be the main issue.
Opposite for me. Every time I buy a book listed as "good", I end up getting "Very Good", which influenced me to never buy brand new books again. Thriftbooks is absolutely amazing.
I honestly don't mind the condition so long as it's not missing pages. If I'm buying used, i'm buying it to read, not collect. I'm buying it because new is too expensive or it's an old book so I care about the content more. I don't even mind some markings and usage, I personally like books that look like they have read. I just hate when it's missing pages or it's cheap, but the shipping is ridiculous!
I've found thriftbooks to generally have usable copies in their good/very good category and they don't use paper bar codes so they are easier to clean up than some other high volume sellers.
My father-in-law firmly believes that the hole in the ozone was caused by space shuttle reentry, and that's why it's patching now, and also that CFCs couldn't possibly make the hole because they are heavier than air. Does anyone have the data to refute these claims?
Ideally the person who claims something needs to provide the data to back it up.
My father-in-law doesn't believe that the moon landings took place. All the data in the world cannot convince him otherwise. The only good strategy in the face of these types of claims is to go up the crazy scale. For example when he tells me that the moon landings didn't happen, I tell him he's naive it he thinks the moon exists. The moon was blown up in the 50's due to a nuclear test gone wrong and what we're seeing now is an artificial projection.
"Chlorofluorocarbons (CFCs) are heavier than air, so how do scientists suppose that these chemicals reach the altitude of the ozone layer to adversely affect it?"
"The homosphere and heterosphere are defined by whether the atmospheric gases are well mixed. The surface-based homosphere includes the troposphere, stratosphere, mesosphere, and the lowest part of the thermosphere, where the chemical composition of the atmosphere does not depend on molecular weight because the gases are mixed by turbulence. This relatively homogeneous layer ends at the turbopause found at about 100 km (62 mi; 330,000 ft), the very edge of space itself as accepted by the FAI, which places it about 20 km (12 mi; 66,000 ft) above the mesopause."
Note that the ozone layer is well within the homosphere so CFCs readily mix into it from surface emissions.
> ... because they are heavier than air. Does anyone have the data to refute these claims?
Going up the crazy scale: Has he burst into flames? If no, then air mixes heavier and lighter components. If yes, then the 21% O2 is actually at the bottom and should be 100% as it is heavier than N2.
Gases have a thermodynamic tendency to mix, despite weight differences. The atmosphere isn't a layer cake of heavy gases below light gases. If it was, we wouldn't be able to breathe because the ~1% of argon (and all the heavier gases) would sit below the oxygen layer.
I guess I'm more looking for a response to "yes CFCs can destroy ozone even though they are heavier than air," and "here is a graph of the size of the ozone vs space shuttle reentries" that shows a non-correlation.
The hole was pretty much the size of Antarctica at its peak, how could something the size of a small aircraft flying through the atmosphere 135 times cause such a huge hole!?
Also if you lie down on the ground do you suffocate to death because of all of that heavy ozone hanging around there? No, because it's dispersed throughout the atmosphere.
Ultimately it sounds like the kind of situation where no amount of logic is going to change his mind and that you're probably better off avoiding the subject entirely for the sake of your own sanity.
Have you tried just getting him to read the Wikipedia page? It describes how those gases circulate and how it was discovered. Particularly the "Misconceptions" section. Also the shape of the depletion is not shuttle-sized AFAIK. Finally remind him of rain, or a house in a tornado. https://en.wikipedia.org/wiki/Ozone_depletion
If he's into correlations point him at http://tylervigen.com/spurious-correlations - Nicholas Cage films cause drownings, Cheese leads to bedsheet entanglement, and norway oil causes traffic accidents.
That's not a good counterexample because rain comes down. Water vapor, which goes up, is actually lighter than air by a large margin (0.804g/L versus 1.225g/L) at the same temperature and pressure.
Liquid water is certainly denser than air, and the fact that it vaporizes before rising up into the atmosphere is immaterial to the point that it ends up there anyway. The process (evaporation and subsequent fluid mixing) is not significantly different from the process which puts ozone in the upper atmosphere.
This is kind of funny. Until you realize that some people actually believe this stuff. Either way, burden of proof should always work the other way around. Other than strong believe, did this father-in-law actually offer some scientific evidence/proof to support his theory?
This is not to say that established theories would always hold scrutiny. Thinking of e.g. what we thought about tectonic plate movements/continental drift only ~100 years a go.
At the large scale of the atmosphere and in the lower layers, the relative weight of gases doesn't matter (otherwise Oxygen and Nitrogen would seperate out and there wouldn't be a mix of other gases in it either).
The makeup down here is largely controller by convection and turbulences, only farther up the relative weight starts to matter.
[1] https://homestarrunner.com/toons/backtoawebsite