I think they meant how you can’t get a permalink to your feed/timeline view-state[1], so other people can see exactly what you see (not just what’s in the viewport but also the surrounding/offscreen content and broader context).
[1]: something like a link specifying the contents of my feed at a specific date+time and scroll-position.
…whereas with old-school SSR paging it’s right there in the querystring paging params (page-size, page-index or item-offset, and an optional results anchor for stability).
I’ll concede that a well-designed infinite-scrolling (or “click to load more inline” button) feature could use history.pushState to dynamically update the browser’s address with new query params but I don’t think I’ve ever actually seen anyone do that - which is a shame.
“Anchor + Offset” is stable because the anchor param should uniquely identify a specific record from which the offset is applied; a sort-order, direction, and page-size may also be optimally specified.
No it's not stable. You also need the query/filter, and a snapshot of the state of all posts at the exact moment you want to grab the link, since posts can be created/deleted/changed. That's also assuming that your anchor still exists and wasn't deleted or changed.
The only stable way to share what you're seeing is with a screenshot.
The reason infinite scroll is bad has nothing to do with the technicalities of the HTML behind it. You could always implement a technical solution for these technical issues but that wouldn't fix the real problem.
It's addictive. There is no "one more page and I'm done" because the page never ends and you're never done. You get to the bottom, more content loads automatically and people say "this looks interesting, let me scroll some more". That's why it's doom scrolling because all you do is scroll, no need for any other input. The bait is always there right in front of you and I'll bet that the algorithm make sure the first couple of posts that load every time you get to the bottom are the "juiciest" ones to make sure you take that bait and keep scrolling.
Pagination hides the juicy bait. It's still there waiting for you but it's hidden until you ask for it. That's a big difference.
It's very much a slot machine, maybe the next short video will be interesting. Maybe not, who knows, but you keep scrolling through shorts and binge watching.
Google search or a traditional paginated forum doesn't provide that either. No guarantee that page 15 of thread X will contain the same posts as it does now when the moderators wake up and delete the flame war.
Launching a gossamer thin mirror in space is not very expensive. Broad strokes claiming anything launched to space is going to be a more expensive solution has to level with the fact that GPS and quite a lot of telecommunications and Earth observation seem to have incredible leverage if launched to space instead of just using ground based solutions.
For this use, "gossamer thin" is unlikely. You want to control where you point the mirror, it needs a structure that not only doesn't flop around when you torque your spacecraft, but also doesn't have surprise vibrational modes that squeeze and expand the illumination zone.
(Things I'm learning while researching what is now looking like an eight thousand or more word blog post about why a different space thing, data centres, is also not a good investment; my guess is this would be less of a problem if you used mirrors like this to cool the earth by reflecting sunlight away instead of towards).
I know for a fact it is gossamer thin. It does need structure, but there’s a fundamental limit to how small your spot size is anyway due to Conservation of Etendue, so small deformations aren’t a huge problem.
You know "for a fact" anything about a tech which is currently in the experimental stage (or even "press release before first experiment" stage), in a field which has a famously large gap between theory and practice, confidently enough to assert it will definitely not suffer from the problems that mean the large sheet materials we already launch to space (space-qualified PV arrays) are much heavier than bare cells?
> Conservation of Etendue,
Sounds like you think I have in mind something like an Archimedes' heat ray. I do not see anything close to that for the presented satellites.
I would aver that the presented design is so far from being useful that making it useful requires solving enough engineering challenges to also enable an Archimedes' heat ray; but again: what is actually shown is not that.
The numbers I see from Reflect Orbital suggest they have an expectation of the apparent brightness fluttering by 5x from internal motion of the reflector. At the scale involved, may be easier to consider the imperfections/ripple as behaving the same as if some of the specular reflection becomes diffuse reflection.
I know for a fact because I’ve dug deep into the field, colleagues work on it every day, and I’ve met and talked to the founders of Reflect, saw material samples of their mirror tech.
Unless you've also both massed the support structure (easy) and demonstrated that the support structure is sufficient in practice rather than theory (requires launching it), you're missing the point I was making by a mile.
orbital mirrors make very poor weapons because Conservation of Etendue means you fundamentally cannot concentrate very high unless your fill factor is very high (which would require millions of tons in orbit). Lasers are far more effective as weapons as a single aperture launched on a single rocket is sufficient to get high concentration. Microwaves also.
The military application would just be illumination.
Not every possible thing has real situations where it's better. There are legitimately terrible solutions to problems, that are dominated by better ones in every situation.
This is a misconception. It’s more fundamental than that. There’s a fundamental connection between (Shannon) information theory and thermodynamics. The Landau Limit, whether blackholes can destroy information or not, quantum mechanics, etc.
Information is actually tangible. It’s not just an analogy or a coincidence that the word “entropy” is a word used in both physics and computer science (information theory). Thermodynamics, mind you, is perhaps THE most fundamental elements of physics and how the universe works.
Information and computation are not the same thing. I was very specifically talking about Turing machines and other theoretical models of computation.
That said, you are still making the same mistake I pointed out, elevating human symbolic information to a higher plateau than it deserves. I think it's because you're being too vague about the connection, when it's fairly mundane. The "fundamental connection" is that physical quantities are information, and on the other hand information is always a large collection of semi-independent semi-stochastic physical objects and can be profitably modelled by some sort of statistical mechanics. Information theory is relevant all over physics because human agents collect all sorts of physical information. The universe "doesn't care" about information in and of itself. Shannon entropy and Boltzmann entropy have similar formulas because they measure precisely the same thing; put another way, a goofy but formally equivalent way to model a gas would be a noisy radio channel communicating each molecule's kinetic energy.
The problem with the black hole information paradox isn't that information is destroyed per se, but that it appears to be destroyed in a way that violates quantum mechanics (destroying quantum state without a measurement). The theoretically predicted destruction of information points to a more general problem.
The Laundauer limit is no more fundamental to the universe than "a mechanical crane cannot violate the laws of pulleys." It says that no matter how you design your binary (or whatever) computer, it must involve an ensemble of binary states, and statistical mechanics puts an absolute floor on how little heat is required to alter such states. Whether these states are gas molecules or the written symbols "0" and "1" is immaterial.
A more concise explanation is that, computation is the transformation of information. Any transformation of information is computation, and is thus subject to some theory of computation. A physical process involves the transformation of information, so can be studied with a theory of computation.
> A physical process involves the transformation of information, so can be studied with a theory of computation.
A rock rolling downhill has state-dependent future behavior you could describe informationally, but nothing is gained by modeling it with automata theory instead of Newtonian mechanics, and it isn't computing in any substantive sense.
But that just takes us even further from physical relevance / universal fundamentals. Kolmogorov complexity is fundamental in computation, but its relevance in physical science is pretty selective.
Best way to show this is to implement information in multiple physical substrates. Make a book out of paper and make it out of clay. Same information. The physical substrate doesn’t matter.
Landauer’s Principle (a direct consequence of the Second Law of thermodynamics) shows there’s a very clear physical manifestation of information and information theory, it is not just human perception and preference. https://en.wikipedia.org/wiki/Landauer's_principle
This is the way. But what is interesting to contemplate is _why_ smart people try to reinvent religion. I think it reflects their deep need for meaning and immortality. Religion in the naive sense, a bunch of stories, myths and bearded gods, if obviously silly and childish. The modern rationalist who has not managed to shed his reflex/need for religion, then reifies (or perhaps better said... "deifies") information, and thus introduces all kinds of potential immortality and an ideal realm. Just like the myths of religion did, in a more naive sense, since time immemorial.
This. I'll never understand people who reify "information" as though it is some object with independent existence from man.
No information without an interpretation. The "amount" of information is completely dependent on the observer.
You'd think people who work constantly with abstraction wouldn't fall prey to reifying abstractions but they actually seem more susceptible to it than anyone else.
I think you are prematurely dismissing something deeper here.
The more I learn about the fundamental nature of the electron, probability in quantum mechanics, and the wave function in general... the more information being fundamental substrate makes sense.
I'm not saying it is... just that it makes more sense the deeper you get.
Yeah, but my point is that "information" is not really a substantive concept. It is an abstraction. It is a useful technical tool. For the record, I am a nominalist when it comes to mathematics. Thinking that information is some "real thing" with meaning independent of theoretical context and interpreters is a definitely Platonisist perspective (the idea that our mathematical representations are not merely useful technical models but that they correspond to some real substantive elements of the real).
Claiming that "information" is the underlying basis of the real is the same as effectively saying that "stuff" is the underlying basis of existence. It's essentially Platonism. It is not informative. What is informative is the operational use of the mathematical concept of information as defined by Shannon to understand real things or to structure theories. But this is a very different thing than identifying a substance that exists, independently of us in the universe. This "making real" of what is ultimately a mathematical abstraction is precisely reification.
This stance is very tempting because it appears so straightforward and no-nonsense. But there are issues which undermine it in my mind. Because, at a closer inspection, it itself doesn't seem informative, in the end coming down to a question of semantics, i.e. how we define the word "reality". Which then determines whether it encompasses the realm of mathematics or not. I wonder what definition you favor, but the language you use points towards something like "the totality of all things" or "everything that's made from a physical substance". Yet platonists and other realists wouldn't argue that numbers are made from a substance as you imply.
Physical reality is a slippery thing. Yes, at the level of our daily life it all seems very solid and obvious, but inspecting that foundation revealed a bewildering world of relativity and uncertainty. And one of the most intriguing ways out of this bewilderment seems to be the "it from bit" trend in physics, which makes information the fundamental reality.
I personally don't feel the need to tie the notion of reality to physical phenomena. I prefer something more along the lines of Philip K. Dick's "reality is that which doesn't go away when you stop believing in it", or, as you put it, "something which exists independently of us". The fact that there are an infinite number of primes, is such a fact. Surely any alien civilization would know this fact. Maths doesn't go away when we look away, and neither does the notion of computation. Sure, Turing machines are a human construct, and there can be others as well. But the Church-Turing thesis speaks about how these constructs all ultimately describe the same underlying reality.
Let me try again. We use miles to measure distance. Hopefully you agree with me that, miles, being a system of measurement to express relationships of distance, have no ontological existence themselves. I would find it completely bizarre, for example, for someone to argue passionately that, "no miles are the real deal and something that exists in the universe and meters are a fabrication". Distance surely is a real phenomenon, but "miles" are a system of expression.
Bits and information are the same thing. They are a system of measurement to express relationships of difference. Difference and change as physical phenomena exist, but bits do not.
So, yes, pointing out that the limits of computation give us some useful facts about the way things change in reality is a useful perspective. Going further and saying something like "computation is the basis of reality" or similar extremes is too reductive and too abstract to really be a useful piece of knowledge in my view. Finally, to claim that information is somehow the important fundament of existence is patently absurd to me, since it would've similar to arguing that miles have some very special epistemic and ontological status.
Yes, separating symbols/descriptions from the physics is a common conflation, rightfully avoided and called out here, but I think you might be overcorrecting unconflating the concepts too much.
Quantum information is strange precisely because the theory treats information-like relationships as physically consequential.
Entanglement, path dependent stuff, cloning theorum, black hole information paradox... There are so many areas you run into where its information-centric descriptions appear to fit unreasonably well.
Again, I'm not saying the symbolic representation is "real" per se (not saying it's not either, I simply don't know what it is).
I agree bits are just nomenclature, but I don't agree that "bits" and "information" are the same thing. Like distance, "information" has a deeper and general architecture to it.
And it's also weirdly physical in places that I wouldn't expect it to be, for reasons I simply don't understand at the moment.
I don't know enough about the quantum level to really understand whether or not that would change my view of things.
From Shannon's theory, it's abundantly clear that "information" is just a mathematical description of difference and expectation. I can frame anything as information. If I know who my parents are, a statement about who they are is not informative to me because it constitutes no difference. The entropy and expectation/surprise is low. If someone approaches me with a compelling argument that no, actually, my parents are not my parents I was adopted and my real parents are so and so, this is informative. The entropy is high.
Crucially, this all depends on me my personal history, and my status as an observer. It is in this sense that I find information to be a communications concept (which is how it started!) or semiotic concept more than a useful abstraction for organizing our knowledge about other parts of reality. Yes, the abstraction might still be useful if e.g. quanta end up behaving in some way according to shannon's laws, that is interesting, but to me uh at is not an argument that turns information into some kind of "universal substrate" of the real—it is just a surprising applicability of laws in one domain to another. Is it surprising that empirical data fit the model? Maybe. Idk, lots of empirical data can be made to fit all kinds of models (there are ways in which hI can reasonably take a Newtonian view of various aspects of my life and the data generally won't contravene the laws).
> From Shannon's theory, it's abundantly clear that "information" is just a mathematical description
That's a very narrow and technical definition of information. It's what people refer to by the word when they discuss things like: communication, medium, surprise, compression, etc. in a technical context. Otherwise one should refer to the dictionary definition, so we don't end up talking past each other.
If you'd like to get a better intuitive sense of what "it from bit" points at, check out David Deutsch's Constructor Theory and the Stephen Wolfram Physics Project. Also, Bernardo Kastrup, on the philosophy front.
> Finally, to claim that information is somehow the important fundament of existence is patently absurd to me, since it would've similar to arguing that miles have some very special epistemic and ontological status.
As the sibling comment says, no, it is like arguing that distance/space/extension has a special ontological status — which it does. "It from bit" is just using the word "bit" for the rhyme, the theory is quite profound and compelling, at least to me.
Then there's also Max Tegmark's "Mathematical Universe" idea, which makes the symbolic world the fundamental one. It goes a bit far for my taste, but it has its own internal coherence.
> It’s not just an analogy or a coincidence that the word “entropy” is a word used in both physics and computer science (information theory).
Shannon asked von Neumann what to call it, and von Neumann said "You should call it entropy, for two reasons: In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, nobody knows what entropy really is, so in a debate you will always have the advantage."
Um, only the second part was a joke. The first part was confirmation of your statement that it's not just an analogy or coincidence ... and Shannon followed von Neumann's advice (not joke).
Thank you. I’ve been thinking about this for a while now and couldn’t express what I was thinking about… but when you linked information theory to thermodynamics, it clicked.
Given the quantum fields were collapsed in the early universe, I’m now wondering how information theory looked like during the different phases on the universe
You can say things like, “In the domain of physics, X,” “Assuming the scientific method, X,” or “Assuming the premises of logic, X.”
But “computation is a fundamental aspect of the universe”, in the way it's being understood in this thread (as opposed to the article) does not remain within any of those frameworks. It makes a claim about reality as a whole.
Once you make that kind of universal claim, all the assumptions built into “computation” - about identity, distinct states, lawful transitions, causation, logic, etc. - become part of the claim. You cannot use those assumptions silently and then present the conclusion as framework-independent.
And those frameworks come with consequences. Using the language of computation, they come with "lossiness" wrt modelling "reality".
(see Aristotle Metaphysics -> Kant CoPR -> later Wittgenstein)
The Church-Turing thesis (the fact that all models of computation we've been able to come up with are equivalent) gives the necessary weight to that claim.
The Church-Turing thesis is a statement about symoblic processes, and symbolism is simply not fundamental to the universe. It is fundamental to how humans understand the universe. That's the distinction.
That’s because there’s no political will for ground forces by the US because it’s a dumb war. If there was political will, then the area around the Hormuz strait would’ve been seized, as well as the nuclear sites secured. Carpet bombing, too, not just surgical strikes.
It's not merely that the US has not, will not, and/or can not put boots on the ground.
It's that regional bases and sea-based platforms from which the US has operated with impunity in previous conflicts, as recently as a decade ago, are no longer safe from retaliation. This puts the US, its forces, and perhaps more significantly its friends and allies in the region at risk in both the present and any future conflict(s).
>“When you talk about conventional technologies on a booster like you see other people doing, and being able to recover and reuse that booster 15 times with relatively minimial refurbishmoent costs, that’s pretty darn challenging, and maybe not the right place, in our view, to start on that problem,” Bruno said.
This doesn't really sound like doubting any claim; he's talking about how his organization was approaching it given their limited resources.
I think that misremembers or misrepresents history.
The DC-X was program developed in the early 1990s expressly to prove the feasibility of orbital rocket vertical landings and rapid turn-around/reuse. It never made it to the full orbital regime because it was scrapped early, but it was considered successful in proving the proof-of-concept. It was also managed by the predecessors of ULA (McDonnel Douglas, which later merged with Boeing).
> “We have not really changed our assessment over the last couple of years because we have yet to see the other forms of reusability—flyback or propulsive return to Earth—demonstrate economic sustainability on a recurring basis. It’s pretty darn hard to make that actually save money… We’ve seen nothing yet that changes our analysis on that,” the ULA CEO said.
> The ULA CEO’s points about the possible lack of savings on reusable rockets put him in stark contrast with other noteworthy leaders in the space industry. Apart from SpaceX CEO Elon Musk, fellow billionaire Jeff Bezos of Blue Origin is also intently focused on using reusable rockets. Even Rocket Lab CEO Peter Beck, whose company designs and launches small rockets, has embraced the idea of reusing previously-flown boosters.
Economic viability is not the same goal. One is a business goal, one is a scientific/technological one. The goal from the DC-X 35+ years ago was the latter. Certainly, we'd expect the economics to improve since then.
The technological viability was shown with the proof of concept. If you meant strictly economic viability was unknown, I agree with you. This isn't meant to disparage SpaceX. They're doing great. I would say there is a risk that isn't often talked about which is the quality risk. Early on, SpaceX disregarded well-known quality control checks, presumably because they didn't think they were worth the time/cost. When that burned them, they integrated those checks. Do that enough times, the economic viability erodes.
Not in scientific edge domains. Eg: quantum computing is shown to be scientifically feasible right now, but nowhere close to having economic viability in a business sense. Same with fusion etc etc
Engineers became really jaded by Shuttle and the failure o X-33. Many of them, inappropriately, started claiming it was impossible. You still hear people claiming things are impossible today that are “merely” very hard, like full reuse, getting launch costs same order of magnitude as transpacific air freight, orbital datacenters, terraforming Mars, space settlement in general, travel to other star systems, etc.
Again, what do you mean by “it”? Economic viability? I already stated I agree with that. Technologically viable? I disagree, since the proof of concept was shown decades earlier. We don’t need to to keep going around and around this point.
Nope. Technological possibility of landing on a droneship was claimed to be impossible. And yes, of course it was never actually impossible. The technical expert was obviously wrong even at the time, kind of shockingly so, but you see similar kinds of claims of impossibility today by so-called experts.
Annnd…we’re full circle. Again, DC-X was considered a successful proof of concept. Almost 40 years ago. Musk himself said SpaceX was “just continuing the great work of the DC-X project."
Nah, it was everything. Everyone expects aerospace timelines to slip. That wasn’t the issue. I had an aerospace greybeard (guidance and navigation expert… nice guy, btw) from a civilian space agency that you would recognize tell me that booster landing on a droneship was “impossible.”
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