darkmighty

If you don't curb incivil behavior somehow, you are effectively encouraging it -- that's because often they have something to gain from it. Despite morals and goodness of people, if something incivil unequivocally leads to gain, it will become the norm. A social backlash is a collective way to fight it and align the ethical with the "rational" (in the many situations where the law isn't applicable).

Skimming the articles it estimates there are 42000 tons of mega(large) plastics, of which 86% would be fishing nets, so 36120 tons. Didn't find the per annum data, but that's certainly much more than 4 tons a year (else it would've taken 9030 years to get current weight), I'd guess at least 2000 tons per year.

Interesting how they're marketing it: as a glasses-free 3D display instead of a holographic (lightfield or w/e) display. That's probably due to the chosen field of view and resolution tradeoff, where you can see only a narrow field of view and angular variation is small (so there are less artifacts, better image quality/"resolution") -- it's a quasi-binocular range field.

However, this seems like a poor strategy: most people already know 3D (binocular) displays and there's not much demand for it, I bet few people would be willing to pay significantly more for lower quality just to get rid of glasses (for those who even crave binocular content). Compare to the potential of having wide viewing angle holograms (even if a little fuzzy) in your living room.

Unrelated: Your blog posts are awesome and you should submit more often to HN ;)

With lenticular arrays you don't even need eye tracking (in theory), since you can directly synthesize a geometric light field (that is, a bundle of rays around each point with different colors for every direction), but you'd probably need quite a few pixels per lens. If the lenses are <1mm diameter, and you need say >10x10 pixels per lens, that's at least 100ppcm, or >250ppi, preferably a lot more. Latest phones do seem to reach that level.

In the end the satisfaction level needs to be evaluated experimentally of course, I wonder how nice one would be with current technology (say, an iPad Pro display), did you build a prototype?

If you want a top flagship, I agree Apple is a solid choice. What Xiaomi and Android does well in general is midrange. I've got a ~$150 phone (Xiaomi Redmi Note 4, now superseded) that has fantastic performance (never had any issues with tens of tabs in browsers, multitasking, games, etc), fingerprint sensor, battery lasts for 2/3 days, etc. You can tell it's not a flagship: the camera is just tolerable, it's got a plastic back (which doesn't break after repeated falls); but overall it's insane value/cost.

It's nice to surf the wonders of billion-scale device mass-manufacturing if you don't need the latest and greatest.

I find the bearing more significant than the wheel: without a good bearing its utility is limited. They have a rich history it seems:

https://en.wikipedia.org/wiki/Bearing_(mechanical)#History

Not to mention it's impossible to even charge for this service. I guess you could encrypt the stream, but a single key leak compromises everything (unless you assume devices are connected to the internet, which defeats the purpose of the system).

Correct! Concentration is technically called energy flux, and is measured in W/m².

That's not important at all; what's important is that black body radiation has a fixed maximum flux -- its spectrum or lack of coherence isn't why you can't heat another body to a greater temperature. It comes back to etendue, or if you prefer the 2nd law.

You could reproduce any fixed black body spectrum (to arbitrary accuracy) from a set of thermal sources and filters (or a set of lasers, LEDs, etc. with random phases) to arbitrary fluxes just like a laser has, and use this light to heat objects to arbitrary temperature. But if the original emission is of black-body type, you cannot -- the flux is given by the quantum mechanical process and a function of local temperature only. From then it follows from etendue conservation you cannot achieve higher temperatures.

By imperfect it's sufficient to be diffuse. You can verify the Moon is diffusive to a good approximation because of the approximately uniform appearance of the full Moon.

The idea is that you can "organize" or "revert" any ray bundle from a system of non-absorbing lenses and specular reflectors, but if your reflector has billions of tiny irregularities it's not viable to build such a system (it's equivalent to an ideal diffuser, in which light is isotropically reflected). The ideal diffusion process is clearly not reversible by itself: if you shine a beam onto a diffuser it spreads the light; if you expose it to the same light (with reversed directions), it again diffuses it instead of reverting to the original beam. In theory again the physical laws of electromagnetism are time reversible, but in practice the effort to revert some systems might be too demanding (you can even do better -- see Maxwell's demon); manipulation of physical apparatus and information acquisition/manipulation itself has a cost that surpasses any gains.

Well, we have general purpose processors. You can prove they can run any algorithm you want (i.e. are Turing complete), but also, for practical problems (i.e. the ones encountered in engineering solutions in our planet and in our universe), they give reasonable max-min performance. Analogously I don't think 'AGI' is entirely useless -- you'd expect an AGI to have some properties like being able to solve reasonably well problems found in nature and society, maybe have a motivational framework distinguishing it as a separate entity, some knowledge about the world, etc.

edit: In terms of Turing-completeness analogues, the best candidate for AGI I think would be simply brute force capability: can this agent try all possible solutions until it solves this problem? (obviously using a heuristic to prioritize) -- that is, it'd employ a form of Universal Search[1] (aka Levin Search). Humans don't necessarily pass this test rigorously because we'd always get bored with a problem and because we have finite memory. But then CPUs are not truly Turing complete either (it's "just" a good model).

[1] http://www.scholarpedia.org/article/Universal_search

You'd be able to tell if every brain structure was replicated by a NN analogue (and we understood them sufficiently well). Otherwise you can only use behavioral replication (i.e. Turing tests) to infer it.

It will be a whole other issue only once we can make waste disposal 100% effective (if we can even expect that to happen). Until then waste is not a trivial problem.

My calculations are larger by a factor of 2.5 (you've probably used density of water but I think that's a bit optimistic, don't know much about garbage compaction).

I mostly agree it's not as bad as it seems; however that doesn't account for the <100% disposal effectiveness (a certain % will realistically always make it to streets, rivers, oceans), or as others mentioned some chance of environmental leakage of landfills (an associated issue is energy efficiency and energetic cost of packaging and disposal) -- i.e. I wouldn't dismiss waste in total as an absolute non-issue.

If that's the case, I wonder if controller failure could be prevented by ECC controller memory? Or would software failure recovery be sufficient to make a highly reliable controller?

I'm not an expert, so take it with a grain of salt.

Electrons in molecules have discrete energy states they can occupy, per quantum mechanics (the discrete set of wafunction solutions)[1]. Consequently they can only transition between states by absorbing or emitting photons of specific energy values (I believe it doesn't have to be exact due to scattering and various QED dynamics, but it has to be very precise). If your molecule is exposed to broadband light, a few photons will match those ionization energies, however the quantity should be small[2]. If your light source contains peaks though, and there happens to be important molecules whose energy transition matches your source (a big if), you're going to get a lot of ionization.

I should have mentioned a more established issue is fluorescent lamps emit more blue/violet and UV than LEDs (LEDs are usually packaged in plastic anyways, so even if the emitted there'd be no risk of uv exposure). In common molecules the more prevalent ionization energies are UV and beyond, that's why the risk is greater.[3]

[1] https://en.wikipedia.org/wiki/Energy_level

Electron states are central to molecular dynamics and chemistry.

[2] Infinitesimal ideally, just small in reality because of tolerances as mentioned

[3] https://en.wikipedia.org/wiki/Fluorescent_lamps_and_health#U...

https://www.scientificamerican.com/article/can-compact-fluor...

Having made a cheap DIY spectrometer[1], I found the spectrum of LED around my house quite good, not completely smooth as sunlight, but smooth enough (you can gain some efficiency for not being totally smooth by better matching eye receptors). It's a far cry from fluorescent spectra that have extremely sharp concentrated spectra (and I suspect the risk from narrow spectra of causing biological damage is greater, since it could in theory disrupt very efficiently some molecular energy transition that happens to be well matched with that frequency).

[1] See e.g. https://ocw.mit.edu/courses/electrical-engineering-and-compu...

https://lavinia.as.arizona.edu/~mhammer/outreach/cdSpectrome...

(diffraction spectrometer from used CD/DVDs, very easy to make, and it costs ~$0)

I believe it's transflective LCD display

If you don't expose your plants to the sun, you're going to need a lot of energy to power their illumination. I'm not sure solar panels-> tuned led illumination is any more efficient than direct exposure, nor could it be any cheaper (and because solar irradiation on Earth is finite of course the amount of food you can grow is also finite). Then there's the profit per m^2 of agriculture isn't that high -- how much does a structure cost? I'd say at least $400/m^2. If your profit is <$10/m^2, you'd need decades to recoup costs (not a viable investment currently) -- that's only for the structure discounting all the other necessary additional infrastructure, lightning, irrigation, etc. Unless we switch to radically different/more efficient food growing than plants (say direct cell cultivation, or direct nutrient synthesis), then the current approach is probably the best (still with room for some automation and significant genetic improvements on crops, I'd say).

I think direct nutrient synthesis probably has potential, but it will take a very long time to understand nutrition and synthesis of organic mollecules -- not an expert by any means, but I'd be surprised if it took less than several decades to develop the necessary tech/science. Even then the gains in efficiency will probably not be that large -- plants/life in general have been optimizing synthesis for billions of years, they're already quite efficient. What we would gain is minimizing to its limit parts of the plant we don't consume, and concentrate on the essentials/optimal nutrients.

RTT measurements can give proof-of-proximity (due to relavity), but I think they're quite hard to get right (you'd need nanosecond RTT resolution in a cheap keyfob) -- I think analog signal repeaters would't add significant RTT. It's not impossible though, GPS decoders work in a similar fashion.

Requiring user iniciation seems like the adequate solution here...

> "Whether nasal, as opposed to mouth, breathing can improve people’s long-term memories unrelated to odors — or otherwise enhance cognition — is still in doubt"

It seems an odd choice to use scent here (if they intended any generalization), since there is direct influence in scent from breathing through mouth or nose. Even having something plugging your nose (even if you breathed through your mouth normally) I imagine could influence your memory temporarily.

Psychology experiments are hard.

The hardener would need to get into the crevices too, which would be difficult (especially since the vacuum insertion would no longer work, and it would harden near the surface before you'd have enough time for a good mix).

Oh thanks. I hadn't actually plugged in the numbers, shame on me :P

It seems the maximum efficiency in this case is ~94.8%, so the claim does seem plausible at least.

edit: actually, I'm wrong, see below

You're right, I believe. I don't have time to investigate, but if the claim is 90% efficiency w.r.t. total radiation input, it's certainly wrong. Doing so would violate the 2nd law. For example, room temperature thermal radiation has significant emmitance in the radio range of the spectrum. Needless to say nobody can build radio antennas to turn this energy into work.

If it is 90% of the thermodynamic limit, then maybe. But then I think multijunction cells are already significantly close to the thermodynamic limit (much better than 22% claimed).

https://en.wikipedia.org/wiki/Carnot%27s_theorem_(thermodyna...

(obs1: substituting Tsun as Th and Tearth as Tc left as an exercise to the reader ;) )

(obs2: try changing Tc to CMB temperature! )

This technology is inherently less efficient unfortunately, because the ion velocity is very high. The thrust-to-energy ratio goes to 0 as exhaust velocity increases:

mv/mv^2 ~ 1/v

You could lower ion energy by lowering the voltage, but then the thrust-to-weight is going to be prohibitively low (and at one point you won't be able to ionize air anymore?).

High efficiency flight means either wings or slow moving propellers (and aircraft itself preferably). You'd need to look no further than a glider to fullfil the potential claimed here. Overall flapping wings are probably superior though, since they allow vertical takeoff and high manueverability; but they're much harder to develop and maintain.

I don't think we can renounce humanism. I don't think we should, at least. If you've ever seen something beautiful, if you've ever lived with someone really beautiful, in their values, their actions, their character, intelligence, personality, appearance, if you've ever heard truly moving music, I think you'd be betraying yourself by being anything less than a fierce humanist -- all this beauty doesn't belong to the immortal, perennial, indifferent universe, isn't a fruit of the economic system, isn't a product of machines, of the eternal structure of the cosmos, or anything else, even life itself. It lies singularly in the human mind, the beholding eye, and in the presence of other humans to share it.

This demands faith in a certain human ideal -- high above the corruptible idiocy in display in politics -- the basis which produced those indefectible experiences, feelings and ideas most people had a chance of experiencing, or at least had a small glimpse. No matter what happens, one can't lose faith or abandon this defense of the basic human ideal (if only your own humanity) in favor of anything else, or nothing else. It's not about optimism (although optimism can be an important tool in this persistence), it's about maintaining all that is good in the universe (again at least in your own life and loved ones, if it comes to that).

We may go (indeed we will go eventually), but let us go living, and fighting, for what's worth living and fighting for; hollow ones (worshippers of gods or capitals, nihilists and ignoramus) be damned.

Be safe, friend. And Don't you dare go hollow :)

Honestly, scientific literacy does jeopardize the "personal God" concept, and in particular obviously the Christian mythology. There are still plenty of christian scientists though, some more keen on the moral teaching and community aspect of the religion, some interpret the texts as non-literal (a tiny minority I presume cling to literal texts).

I mean, I'm all for more engagement and scientific literacy, but let's not pretend there isn't some conflict here; specially for the more hardline churches -- while catholicism in particular seems happy to transition its role (into important lessons and social support) and turn dogma into allegory.

I suspect if you rely on certain analog properties (with some good precision) then the elements won't scale down very well (down to current transistor scale). At the very limit of element size I would think reliable elements inevitably degrade to binary gates, which are the simplest elements in behavior (at one point even binary gates become impossible of course due to phenomena like leakage, quantum tunelling, etc).

The brain as far as I understand does so much with large, slow elements (neurons) by having them fill a volume, be sparsely activated (i.e. mostly a huge memory), and other advanced communication methods (temporal pulse position modulation/frequency from spiking? neurotransmitters?).

Current ML is more densely activated, high-frequency networks. I'm not sure we could revert to the brain-like architecture unless we could get the cost of sillicon manufacturing several orders of magnitude down, enough that we could just fabricate a large block of stacked complex elements. A large part of the philosophy of nodes would need to be reworked (much lower frequency, lower leakeage, lower power consumption), as processes are optimized for >100MHz freqs; just so internal memory elements would keep at acceptable temperatures. Currently you could fit about 2000 GPUs in a 10cm^3 space (assuming 1mm die thickness), which would cost about $1.5M usd. And couldn't do much, because it would quickly overheat on reasonable loads, and because I don't think we have the technology to interconnect it all.

I really think scientists should speak up more about the situation. They'll be accused of "alarmism" by right wing media in any case. But they should be much more political and emphatic on necessity of swift action. Because what we've been doing so far isn't working. Emissions aren't being cut. We're still going almost full speed to a very bleak natural future.

In fact I think it's a duty of anyone with a basic scientific education to try and inform about the basic scary consequences (highlighted in this article) and propagate this information to their vicinity. Most people I talk to have no idea of the breadth of consequences. And then the second step is using democracy and voting specifically on candidates that are fighting to address the issue -- not only on national level but whatever level you can get (county,city,state).

Finally if massive change isn't detected in a few years (I'm skeptical) the higher organizations (UN, UNSC, etc.) need to start aggressively punishing emissions on a global level. Something like a mandatory carbon tax on every country seems like a good start.

This works remarkably well:

http://sci-toys.com/scitoys/scitoys/light/cd_spectroscope/sp...

https://lavinia.as.arizona.edu/~mhammer/outreach/cdSpectrome...

(diffraction spectrometer from used CDs!), very easy to make, and it costs ~$0.

It has enough resolution to distinguish individual lines of fluorescent lamps (by using a narrow aperture). Highly recommended (very nice as an educational tool also, to impress folk with the hidden spectra of light around us ;) ).