Nick @internic@qoto.org

@mdione I enjoy the videos @acollierastro makes, but I think that at least the ones I've seen are designed to give you some high-level idea about some topics but not to systematically teach you physics in detail. And while they're interesting, I think a lot of times the understanding you feel like you have from a video like that is illusory, because to really understand the topic you have to go into a lot more detail, and you have to apply your understanding to work through problems yourself as you learn. Indeed, I think that point was sort of made in her video "why you can't explain QCD."

The good news is that if you're really interested in putting in the sort of work needed there are multiple open source textbooks and open courses available to you online. @j_bertolotti

@polotek My impression (and that's all it is, so it could be selective memory) is that more of such complaints come from people on smaller instances who seem to expect to be more surrounded by certain types of people. Whereas it seems like people on mastodon.social have to accept that there are going to be lots of different types of people and they'll just have to ignore, block, or mute them as necessary.

@jgg I remember the early, largely ad-free web. It was cool, but much, much smaller, and only of limited practical use. And it was an experiment, while people tried to learn how it could be used and how to make money off of it. It was never a sustainable state. Likewise, the current situation on Mastodon is not a sustainable state. It takes money to keep a site online, and people who work on them or produce the content they host have to eat. A vibrant web cannot exist without some way for people to get paid.

The vast majority of the browser market runs on WebKit and Blink, so if Google and Apple come to some mutually agreeable arrangement, they can force pretty much whatever they want on the rest of us. That's precisely why we need a resurgent #Firefox or other 3rd rendering engine.

I understand you seem to think that no one is willing to put up with ads in any form, but I think you may be over-generalizing your own attitudes. People widely use Google services (including Chrome and Android) and commercial social media sites, which are well known to make all their money off advertising and surveillance. Free apps (which necessarily make money primarily off advertising and surveillance) dominate mobile app stores. I might like to live in a world where most normal people won't put up with advertising (because that's my own attitude), but we simply don't live in that world.

Subscriptions can work for some very popular/large site or niche sites with a very committed audience, but they don't work for sites in general because there are too many. That would only potentially work with a functional micropayments infrastructure that does not exist. It's also debatable whether it's working for news sites, at least in the US, other than the few largest outlets.

It seems like your solution is to let the open web diminish to a shadow of its former self, starved of resources. I agree that's an option, but I'm not sure it's a desirable one. But, in any case, I think it's clear that won't be the position of people making a web browser, so then it is rational for them to seek some form of privacy-preserving advertising as an alternative, and it doesn't make sense for people to vilify them for that (as I've seen here and elsewhere); they're just trying to explore one of the few open avenues for a vibrant open web to continue. It might not work in the end, but it's a reasonable thing to try.

@mdione It's of course correct that, as @j_bertolotti says, to fully understand what's going on you have to learn electrodynamics. That being said, you can understand a ton of things with simpler models like ray optics or Huygens' principle. It's just that if you want to connect them to what's going on with atoms and electrons, then you have to involve electrodynamics.

If we go back to your question in the original post, it was "how does a reflected ... photon know the _angle_ at which it should go?" If you want to understand it through a simple model, first of all I'd avoid any talk of photons, to really understand those you need quantum electrodynamics and that really makes it complicated. I'd stick to thinking of light as rays or as waves.

As rays, there's just a rule that the reflected angle equals the incident angle, but that model isn't detailed enough to really offer an explanation of why. However, note that if you were to, say, bounce a tennis ball off a hard wall it would follow the same law (because it's an kinetic-energy-conserving collision that doesn't impact the component of the motion parallel to the surface, so it's not too far fetched at least.

In a wave model, the basic answer is that the incident wave front comes into the mirror at an angle, so one side of the wave front hits the mirror first, followed by the point next to it, and so on, as shown in the video, and it's this timing that causes the specific angle of the outgoing light. Huygens' principle shows geometrically that the angle should match the law we assume in ray optics.

But once you start asking why Huygens' principle is true or works the way it does, that's when you have to delve into more detailed wave physics or even electrodynamics (especially if you want to link it back to what atoms are doing).

@grimalkina Have you also started distributing magical swords to people?

@jgg As you can see in my post to which you're replying, I don't like online advertising and I think it's bad for that to the the basis of funding the web, so there's no point arguing about that, because we already agree there. However, what I'm saying is that it *is* the current financial basis of the web, and changing that won't be accomplished tomorrow or even next year.

So long as advertising is the life blood of the web, it won't really matter if we like it. We will either have to accept it in some form or kill the open web (by either driving sites to close or driving them to make most of their content available only via propriety app). Meanwhile Google is flirting with integrating features into the browser that will effectively allow websites to prevent ad blocking.

For the time being, a small minority can use effective ad blocking and privacy tools, so long as it's not enough to really hurt revenues. But if it remains a small minority then web technology can change to make it untenable, and if it becomes a larger proportion of people then sites will basically have to fight back against losing all their revenue, which won't result in any better outcome.

So the only sustainable path is to offer another option, which is what #Mozilla is trying to do. Maybe that option isn't the right one, but I think they're correct to try something in that area.

While I'm not crazy about crypto, one thing I liked about the idea of BAT in Brave is that it would naturally create the option of micropayments to sites in instead of having to get ads, so it could theoretically create more privacy-respecting ads and also a path away from ad-based revenue. Unfortunately websites didn't seem to pick up integration (to get the payments), Brave turned out to maybe not be all that trustworthy, and Brave is based on Google's rendering engine so it still allows Google a lot of de facto power over web standards.

Pondering the state of climate change, the increasing inability to decern fact from fiction, and the rising tide of authoritarianism across the world. Current mood:
https://youtu.be/kpEDSvaP_-8