By the way, I just wanted to also say I love big chunks of this whole comments section; so much pure positivity and human beauty in one place, so soothing, uplifting, and inspiring to me. Thanks hereby to everyone sharing around here how they're consciously recognizing and acting in various amazing ways on the good they received.
If you find this interesting, definitely consider checking out contraction hierarchies. One of the early algorithms used by mapping software to enable calculating fastest routes between any pair of places. It's exact, and it's orders of magnitude faster than graph search algorithms like Dijkstra.
(I had the joy of implementing this in Python with OSM data a few years ago. Planning a three hour car trip with software I wrote and having it come back with the same path recommended by Google Maps in a matter of milliseconds was a very rewarding feeling.)
To be fair, this is a mistake that started with the Google paper, and everyone else just copies the mistake.
The paper calls them Macaroons as a play on (browser) Cookies with layers (of caveats) - so clearly they meant macarons as well, since a macaroon doesn't have layers. Or at least, that's always been my interpretation of the name. It's possible it was just an arbitrary play on hMAC cookies and not the layers?
I had that thought, although according to another comment the definitions have crossover. Probably because people so frequently confuse the two, but here we are.
Used to use some of this data for analyzing cellular service coverage. The info on cellular data (e.g., LTE) availability is provided by the cell providers and is usually... very optimistic.
I'd assume the terrestrial fiber/cable/DSL data is more accurate, though?
Not really, up until the past year or so, the cable ISPs would count an area serviced if they could get one house per zip code. I think this is stricter now, but these maps will help keep them accountable if we update and flag incorrect listings.
Google still does this! They seem to use some sort of generative neural net to produce fake names, descriptions, and even reviews for the trap locations.
You can report the location to Google as "bad data" and they'll delete it, but then a totally different fake location will re-appear in its place a few days later.
I worked once with a contractor who did not have a physical location for their business. They simply worked out of a minivan which they drove to wherever they were needed. But they pretended, to google, yelp, and probably others, to have a business location.
It's worth pointing out that the conventional bombing raid of Tokyo on March 9, 1945 was deadlier than either Hiroshima or Nagasaki, depending on whose counts you use...
The objection I've usually heard is less about farm land being used for pasture instead of growing crops, and more about the amount of crops that have to be grown to feed the cattle... Growing corn to feed cows to feed humans is massively less efficient than growing corn to feed humans, or at least that's how the story goes.
Is there not an efficiency problem there that we could improve on?
Not expert either but from forums, I think its a bit of both. People treat pasture country like it would be good for cropping in theoretical climate discussions, and the more correct growing corn/grain/hay etc to feed cattle to feed humans.
Another factor is cattle feed is often poor quality human food, so the reject stuff. That wheat that was harvested a bit early to avoid storms and no good for the flour is great for cattle.
Also, to the main topic of this thread, I wonder if its good for food security we grow extra crops to feed livestock. If there is a food supply shortage, cattle can go to slaughter and there is plenty of extra corn or other about for humans. We eat less meat for a few years while we fix the supply chains type thing.
The way we see supply shortages from COVID, Id hope we never become too efficient in the food supply chain. The consequence of something creating lower food production is far worse than limited computer chips. Its not a system we want to be over optimised for the good times.
Sure, but go back to pasture based systems. Cows are a fantastic way to turn grass into human edible nutrients. That will probably reduce the amount of meat on the market, but no where near the drastic levels some people talk about.
All land is not fungible, we need to use the best tools for the job, and that will be a mix of a bit of everything, including animal meat.
Lemur Pro owner here. I personally have super-mixed feelings about the machine.
Pros: Battery life is excellent. Used it for 12 hours while walking around a factory doing an IT system install, never had to charge it. Slim form factor is nice. With an upgrade to an i7, additional RAM, SSD, etc., performance is good for any task not requiring a GPU. It would easily be the best laptop I've ever owned, except for...
Cons: WiFi chipset died within months of purchase and had to be replaced. Battery swelled by year 2 to the point that the mouse was unusable, so battery had to be replaced as well. The machine shipped with Ubuntu 20.04 LTS, which had a Linux kernel bug that caused the machine to freeze when trying to throttle up/down the i7 CPU for power management purposes. I contacted System76 about the problem, and they didn't know anything about it... I ended up having to troubleshoot it myself, at which point I told them the issue, and they sent out an email about the fix to (what I assume was) all Lemur Pro owners. I thought buying a Linux laptop from a company that specializes in making Linux laptops would let me avoid these kinds of nagging issues around things like drivers and power management bugs, but alas it did not. More startlingly, I would have expected a company that specializes in Linux laptops to at least be AWARE of such an issue on their machines, but it seems they had no idea... I feel like I would have been just as well off going with a Thinkpad.
Related final pro: It was frustrating to have to replace multiple parts in this machine (especially so early in its life), but I have to give credit to System76's self-install policy. They sent me the parts and detailed instructions for doing the repairs myself. Saved so much headache.
Overall, I really want to love my System76, but I'd have to think really hard before buying another one.
I'm not even convinced that there will be a "marginal increase in mining required for battery production," nor that there will be an associated increase in localized environmental damage.
Lithium mines produce localized environmental damage, _but so does fossil fuel extraction_. Think about environmental damage from mountaintop removal coal mining, fracking, offshore oil spills, etc.
With fossil fuels, you get localized environmental damage, _plus_ climate change.
With lithium, you get localized environmental damage, but you hopefully support a transition to renewables.
No, not at all. In the past year, they attempted to shut down one of last remaining paper mills that is keeping the beleaguered forestry industry alive by ordering the removal of a dam that alteady had had a fish ladder installed at great cost, because it might possibly still impact the spawning of a miniscule subpopulation of salmon.
There's been enormous conflict about simply building a high voltage transmission line across the boondocks of the western mountains to bring cheap green power down from the Quebec Hydro dams.
> It is unfortunate that in the public mind, hydrogen as a lifting gas is associated with the Hindenburg disaster. Actually, hydrogen filled airships were extremely difficult to set alight. Just ask the Brits in WWI.
> The RAF could easily hit the German airships with gun fire, but couldn’t get them to ignite until they developed special phosphorus filled ammunition. They used sustained machine gun fire to rip a section of the gas bags to get the hydrogen to mix with air at their surfaces. Then, the small number of phosphorus burning bullets could ignite this hydrogen air mix. Even then, the RAF brought down very few of them.
> Because of this knowledge of how difficult it is to get a hydrogen filled airship to burn, there has been much speculation that the Hindenburg was sabotaged, set to burn deliberately, in a very public act of terrorism / economic / public relations warfare against the NAZI regime (and who could blame them?).
I had no idea that there were controversies regarding the cause of the disaster, nor that hydrogen was (arguably, at least) dangerous more in the public eye than in reality. I'd be interested to hear other modern engineering perspectives on the hydrogen issue...
I don't know much about the Hindenburg disaster, but the fact that it is difficult to set something alight with bullets traveling through a thin fabric and then (flammable) air (as opposed to having sparks generated by bullets hitting e.g. metal and even then, there's not a lot of sparks) is not really evidence of hydrogen's safety. It's really really hard to make even normally flammable things catch fire with normal bullets or even tracer bullets. You could shoot at a gas tank all day and it won't explode. Even absolutely riddling a gas tank with tracer rounds often won't set it alight. It is far far far easy to set something alight with a single match than it is even with full magazines of bullets, all the more so if it's a patch of air that the bullet goes straight through.
Hydrogen is still widely acknowledged to be extremely flammable (see all the references here https://en.wikipedia.org/wiki/Hydrogen_safety). We have had many many disasters with hydrogen explosions pre and post-Hindenburg.
> to having sparks generated by bullets hitting e.g. metal and even then, there's not a lot of sparks
Just wanted to chime in on this - it's impossible for most bullets to cause a spark, unlike what TV and movies show. Most projectiles (including the .303 round the British were using back then!) are lead with a copper plating, which are both non-ferrous metals.
Some Soviet era and US military ammunition (specifically m855 rounds) have a steel core, and those can cast sparks, but almost all handguns, and most rifles, aren't using ammunition capable of doing do.
Sparks no, but a spall can be hot. Fabric will not spall but whether by spark or spall, bullets hitting solid objects can generate enough heat to ignite things they touch.
Note that regardless of what you do, a container of fuel (without its own oxidizer) would never successfully light/sustain fire without first having displaced the majority of the fuel with atmospheric air to provide the necessary oxidizer. That’s why you can’t light a full container even with tracer rounds.
Otherwise, you are only be able to light the part of the fuel that leaked into the atmosphere.
I think people have done experiments with gasoline exposed to open air or with a chamber of air and even then it is quite difficult to ignite, especially if the bullet has nothing to impact against, but travels through the vapor.
This is interesting to contrast with my experience as a former tank commander doing range gunnery with wooden targets and dry brush. Range fires due to machine gun fire happened all the time. They were not remotely uncommon or difficult to cause.
I know next to nothing about chemistry or materials science, so offer no explanation of why this would be the case but a gas tank is difficult to ignite. The only layman intuitive answer I can think of is that a high speed projectile traveling through wood generates a lot more friction than one traveling through a liquid or gas, and something has to happen to that energy.
Yeah as soon as you have a solid chunk of something to hit it's a lot easier to start a fire. E.g. it's actually quite easy to start a fire by shooting a lot of bullets into a gas station pump rather than a thin barrel.
I read (I forget where) that the Hindenburg's skin is where it started burning. The skin was fabric, painted with flammable shellac, and the shellac contained a lot of aluminum powder.
This is a major plot line in the kids series "Pendragon". One of the books centers around the blowing up of the hindenburg. I guess the author was onto this as a conspiracy and decided their own explanation! (If your child liked Artemis Fowl, they might like this series)
if you go down this rabbit hole on google, just be wary that while the hindenburg sabotoge conspiracy theory actually seems fairly plausible, most of the people you'll find talking about it are right at the top of this chart:
A bit off topic but I'm a little sad to see "Covid-19 made in lab" in the "dangerous to yourself and others" tier, especially with how much public view has evolved. Very few people will ever know for certain, it seems, but it could very well have naturally mutated from an existing virus in captivity and then escaped accidently. We have to be careful how we approach framing conspiracies because you risk to alienate and smother valid discussion.
(Scientist chiming in, albeit not working in a relevant field for this discussion)
In fact, several well-respected scientists are calling for a scientific and unbiased debate on the origin of covid, as it is now almost impossible for scientists to simply mention lab origin as a possible origin to study.
Here is one of the last papers I've seen on this subject:
I'd say right on the speculation line. It's far-fetched to say he can totally see, but he may very well experience some limited optical sensation, albeit one of such limited utility that we can't really call it sight.
The story about him seeing Shaq is an interesting example. If you already know that Shaq lives in your apartment building, how much visual acuity do you need to make an educated guess that the large form waiting for the elevator is probably Shaq? There's also no one to tell us if he ever stood there talking to thin air thinking it might be Shaq ;)
It also seems like the kind of thing that would be difficult to give a satisfactory description of, so being coy about it is probably for the best.
NOVA did an episode recently that demonstrated how the Hindenberg could have burned based on a confluence of the weather and coincidences. No sabotage or conspiracy is necessary.
If your hydrogen-filled airship is flying through heavy anti-aircraft fire, you likely have bigger problems.
This scenario also fails to address the numerous failure modes of airships, including but not limited to the extraordinarily wide range of explosive mixes of hydrogen and air, as well as the rapidity and violence of hydrogen combustion and explosions.
