Comment Re: power (Score 1) 69
That book presented a nonstop stream of pseudoscience as if it were hard sci-fi, and it's unfortunate that it's spread so many myths as a result.
That book presented a nonstop stream of pseudoscience as if it were hard sci-fi, and it's unfortunate that it's spread so many myths as a result.
I think your confusion stems from analogy to baking clay or ceramics. But what's happening there is sintering. You have extremely fine grains, and you're leading certain crystals to soften and merge as a "glue" between grains, so that the grains stay together.
While sintering is important in the formation of some types of sedimentary rock, this has nothing whatsoever to do with igneous rock. It's already as "together" as it's ever going to be when it a lava flow solidifies. The only thing its grains can ever become is "less together".
And even ignoring that, by definition, you're not going to be sintering something that formed at Venus temperatures, by exposing them to Venus temperatures. The process of sintering requires a radical change in conditions.
We are not capable of building anything that can withstand the surface pressures and temperatures for very long
The Venera probes have likely still not experienced any sort of crushing. You seem to be confused about how pressure works. If you don't exert stress pass the yield point of a material, the length of time until something crushes is "infinite". Which is why, say, almost all rocks buried in Earth's crust are able to remain intact over millions to billions of years.
You build of a thickness that the yield point at the design temperature is well above the amount of pressure-induced stress. The Venera probes' pressure vessels - uninsulated - hit surface temperature quite quickly (indeed, mostly during the descent itself). This did not make them crush, because their engineers were not morons who didn't do the math first when determining the probes' required specs.
All probes are designed to their environment. There is nothing magical about the nominal 92 MPa / 464 C of Venus's mean surface (note: this is for the mean surface; the highlands are significantly lower pressure and significantly cooler) that makes it impossible while, say, designing a lander to operate in the cryogenic conditions of Titan or whatnot is easy. This is 1960s tech. Steel alloys usually melt at up to 1400 C or so. Titanium at 1670 C. Tungsten at 3422 C. Some ceramics don't decompose until nearly 4000C. And pressure increases melting points. Now, it's not just the melting point that matters - higher temperatures mean lower yield strengths, so you have to design with the high temperature yield strengths in mind, not room temperature ones. But the simple fact is that various alloys and compounds can operate fine at WAY above Venus surface temperatures. It's not even close. The pressure vessel needed for the Venera probes was just a thin skin.
And to repeat: if the stress doesn't don't go above the yield point, the time to crushing is infinite. Same as any other pressure vessel, from aerosol cans to propane tanks to spacecraft in space (-1 atm).
And I'll repeat: with the same trivially-simple 1960s-tech method as the Venera probes, you can get surface residence times of a couple hours. With heat pumps, indefinitely. And "Baron_Yam at Slashdot" isn't going to override the actual NASA researchers who have worked on this topic.
The rock of Venus is dry-baked to incredible strength
The fact that you think that rock can be "baked to incredible strength" is itself a boggling concept. Not even accounting for the fact that we can literally see sand and gravel in the Venera images, and the Venera probes literally took surface samples. We can see dunes from orbit on radar. Just the very concept that you think that if you heat rock to a couple hundred celsius that makes it super hard, when the rock formed from vastly-hotter lava. Heat makes rock softer, not harder. And subliming away compounds or chemically eroding rocks makes them weaker, not stronger.
From a bulk composition perspective, Venus's surface is mostly just basalt - though there's some probable rhyolitic flows in places, possibly some unusual flows rare or nonexistent on Earth, and there's speculation that some of the highlands may contain residual granitic continental crust. The specific details of said rocks can be quite interesting, but from a bulk perspective, it's like oceanic crust. We know this because we've literally sampled it..
That's a lot of text to not mention the need to build floating cities and not die on the surface, which even NASA has not been able to do for more than a few minutes
In case you didn't notice, NASA also hasn't built cities on Mars either, despite spending two orders of magnitude more money on it in recent decades than Venus.
Anyway, we don't need the most Earthlike atmosphere, we need to survive in an environment where we actually know how to do that.
Which requires creating Earthlike conditions. Starting with reasonably Earthlike conditions certainly is a good start.
Well, it's like in Econ 101 when you studied equillibrium prices. At $3500 the number of units demanded is small, but if you dropped that to $1000 there should be more units demanded, assuming consumers are economically rational.
There is a tech adoption curve in which different groups of people play important roles in each stage of a new product's life cycle. At the stage Vision Pro is at now, you'd be focused on only about 1% of the potential market. The linked article calls these people "innovators", but that's unduly complementary; these are the people who want something because it's *new* whether or not it actually does anything useful. This is not irrational per se; they're *interested* in new shit, but it's not pragmatic, and the pragmatists are where you make real money.
Still, these scare-quotes "innovators" are important because set the stage for more practical consumers to follow. Perhaps most importantly, when you are talking about a *platform* like this people hungry for applications to run on the doorstop they just bought attract developers. And when the right app comes along the product becomes very attractive to pragmatists. This happened with the original IBM PC in 1981, which if you count the monitor cost the equivalent of around $8000 in today's money. I remember this well; they were status symbols that sat on influential managers' desks doing nothing, until people started discovering VisiCalc -- the first spreadsheet. When Lotus 1-2-3 arrives two years after the PC's debut, suddenly those doorstops became must-haves for everyone.
So it's really important for Apple to get a lot of these things into peoples' hands early on if this product is ever to become successful, because it's a *platform* for app developers, and app developers need users ready to buy to justify the cost and risk. So it's likely Apple miscalculated by pricing the device so high. And lack of units sold is going to scare of developers.
But to be fair this pricing is much harder than it sounds;. Consumers are extremely perverse when it comes to their response to price changes. I once raised the price of a product from $500 to $1500 and was astonished to find sales went dramatically up. In part you could say this is because people aren't economically rational; but I think in that case it was that human judgment is much more complex and nuanced than economic models. I think customers looked at the price tag and figured nobody could sell somethign as good as we claimed our product to be for $500. And they were right, which is why I raised the price.
Venus's middle cloud layer is the most Earthlike place in the solar system apart from Earth**, is energy-abundant, has favourable orbital dynamics, easy entry, and the simple act of storing electricity for the night via reversible fuel cells - if plumbed in a cascade - can enrich deuterium (2 1/2 orders of magnitude more abundant on Venus), a natural export commodity, if launch costs are sufficiently low. The atmosphere contains CHONP, S, Cl, F, noble gases, and even small amounts of iron. Pretty much everything you need to build a floating habitat, which can be lofted by normal Earth air, aka people can live inside the envelope. Aka, unlike on Mars, where you live in a tiny tin can pressure vessel where any access to the outside tracks in toxic electrostatic dust and you waste away from low gravity, on Venus you'd be in a massive, brightly lit hanging garden, where you could live half a kilometer from a crewmate if they really got on your nerves.
Most Earthlike? Yes. Temperature, pressure, gravity, etc all similar. Natural radiation shielding equivalent to half a dozen meters or so of water over your head. Even storms seem to be of an Earthlike distribution. The "sulfuric acid" is overblown; it's a sparse vog, with visibility of several kilometers; with a face mask, you could probably stand outside in shirtsleeves, feeling an alien wind on your skin, only risking dermatitis if you stayed outside for too long.
Indeed, it'd actually be useful if the sulfuric vog was more common (to be fair, it's still unclear whether precipitation happens, and if so, whether rains or snows; the Vega data is disputed). Why? Because it's your main source of hydrogen. Highly hygroscopic and easily electrostatically attracted, so readily scrubbed through your propulsion system. First releases free water vapour when heated, then decomposes to more water plus SO3, and if you want you can further decompose the SO3 over a vanadium pentoxide catalyst to O2 + SO2, or you can reinject it into the scrubber as a conditioning agent to seed more water vapour. Of course, if precipitation happens, collection possibilities are basically limitless.
The surface is certainly hostile, but even 1960s Soviet technology was landing on it (also, contrary to popular myth, there is no acid at the surface; it's unstable at those temperatures, the sulfur inventory is only SO2 there). But in many ways, the surface is very gentle. Mars eats probes with its hard landings, but one Venera probe outright lost its parachute during descent and still landed intact, as the dense atmosphere slows one's fall. It's been calculated that with the right trajectory, a simple hollow titanium sphere launched from Earth could arrive at Venus, enter, descend and land all intact. Simple thermal inertia (insulation + a phase change material) can keep an object cool for a couple hours; with heat pumps, indefinitely (and yes, heat pumps and power sources for the surface conditions have been designed). Even humans could walk there with insulated hard suits, like atmospheric diving suits. Indeed, some of the first space suits NASA designed for the moon (ultimately ditched for weight reasons, despite the superior mobility performance) were similarly jointed hard-shell suits.
On Venus's surface, a lander or explorer can literally fly, via a compressible metal bellows balloon. Small wings / fins can allow for long glide ratios. Loose surface material can be dredged rather than requiring physical excavation, potentially with the same fan used for propulsion. Reversible ascent back to altitude can be done with phase change balloons - that is, at altitude, a lifting gas condenses and is collected in a valved container, and the craft can descend; at the surface, when one desires to rise, the valve is opened and the gas re-lofts the lander.
On Mars, you're stuck in one location. The problem is that all minerals aren't found in the same spot; different processes concentrate different minerals. And you can't exactly just get on a train to some other spot on the planet; long-distance travel requires rockets, and all their consumables. But on Venus the atmosphere superrotates every several days (rate depending on altitude and latitude), while latitude shifts in a floating habitat or lander can be done with minimal motor requirements. So vast swaths of the planet are available to you. Furthermore, Venus is far more dramatic in terms of natural enrichment processes; wide ranges of minerals are sublimated or eaten out of rocks and then recondensed elsewhere. Temperatures and pressures vary greatly between the highlands and lowlands as well. There even appear to be outright semiconductor frosts on parts of the planet. Lava flows show signs of long cooling times, which promotes fractionalization and pegmatites. Volcanism is common, primarily basaltic but also potentially secondary rhyolitic sources. A variety of unusual flows with no earth analogies (or only rare ones) show signs of existing, including the longest "river" channel in the solar system (Baltis Vallis). While there's no global tectonic activity, there appear to be areas of intense local buckling between microplates. The surface conditions of the planet also appear to have been very different at many times in the past. It's all a perfect setup for having diverse mineral enrichment processes. Yet there's almost no overburden (unlike Mars, which is covered in thick overburden on most of the planet).
As mentioned before, Venus has significantly superior orbital dynamics to Mars, due to the Oberth effect. Venus-Mars transfers are almost as fast and almost as low energy as Earth-Mars transfers. Venus-Earth transits are super-fast, esp. with extra delta-V added. The asteroid belt is, contrary to intuition, much more accessible from Venus than from Mars. Also, gravity assists are much more common around Venus - when we want to launch probes to the outer solar system, we generally start with sending them first inwards toward Venus, then back between Venus and Earth and outwards from there.
From a long term perspective, both Venus and Mars have problems with terraforming, with some things you can do "relatively easy", and some that require megascale engineering on scales best left to fantasy. You can boil off Mars's polar caps, but the amount of CO2 there is still quite limited, and there's just not that much nitrogen inventory on the planet (it's been lost to space), which also matters to plant cultivation. You could probably engineer active radiation shielding from orbit, maybe direct more light to the surface, but you can't increase the gravity. Etc.
With Venus, one of the earliest ideas for terraforming it was from Carl Sagan, before the planet was known well; he proposed seeding it with engineered bacteria to convert CO2 to graphite and release oxygen. He later rejected his idea, on the grounds that a high temperature surface of graphite and oxygen would be a bomb. Later studies showed that the timescales for said conversion would be tens of thousands to millions of years. But in a way, that is actually a savior to his idea, in that Venus's rocks contain unoxidized minerals. In analogy to the Great Oxygen Catastrophe on Earth that created our banded iron formations, slowly exposed to oxygen, Venus's rocks would weather and sequester the oxygen and deposited carbon. Hot, high-pressure high-oxygen conditions would never have a chance to exist.
Various faster methods have been proposed. A common one is that of the soletta, a thin orbital sunshade. Another is building an "alternative surface", aka propagating floating colonies to the point that they are the new surface - and indeed, below that surface, they could exclude sunlight to the below atmosphere. Regardless of the method, the cooler the atmosphere gets, the lower its pressure gets, to the point that you can start outright precipitating out the atmosphere out as icecaps.
Just like Mars will never have high gravity and probably never much nitrogen, Venus would probably never be fully Earthlike. It would have enough nitrogen that, barring loss to weathering, people would have a constant mild nitrogen narcosis, like always being ever so slightly tipsy. It would remain a desert planet, barring massive influxes of ice (which present their own challenges and problems), or of hydrogen (pre-cooling). But then again, the very concept of terraforming anything has always required one to put on thick rose-coloured glasses
I don't say all this to diss on Mars. But our obsession with "surface conditions" has led us to ignore the fact that if you're going to the extremes of engineering an off-world habitat, having it be airborne is not that radical of an additional ask, esp. on a planet with such a big "fluffy" atmosphere as Venus. If Venus's atmosphere stopped at its Earthlike middle cloud layer, if there was a surface there, nobody would be talking about long-term habitation on Mars - the focus would have been entirely Venus. But we can still have habitats there. The habitat can, in whole or part, even potentially be its own reentry vehicle (ballute reentry), and certainly at least inflate and descend as a ballute (with a small supply of Earth-provided helium as a temporary lifting gas until an Earthlike atmosphere can be produced). Unlike with Mars entry, you're never going to be "off course", or "crash into something" because you got the location or altitude wrong.
(Getting back to orbit is certainly challenging from Venus - all that gravity that's good for your body has its downsides - but the TL/DR is, hybrid and/or air-augmented nuclear thermal rockets look by far to be the best option. Far less hydrogen needed than chemical rockets, far lighter relative to their deliverable payload, only a single stage needed, and in some designs have the ability to hover without consuming fuel. This is, of course, of great benefit for docking with a habitat, avoiding the need for descending rocket stages to deploy balloons and then to dock those to the habitat. The hydrogen and mass budgets involved are totally viable)
Titan's atmosphere is rather calm; not an issue. At the surface, the winds measured by Huygens were 0,3 m/s.
You actually can use solar power in extreme environments - even Venus's surface has been shown to be compatible with certain types solar, though you certainly get very poor power density. Dragonfly, as noted above, uses an RTG.
Planetary scientists frequently refer to moons that are large enough to be in hydrostatic equilibrium as planets in the literature. Examples, just from a quick search:
"Locally enhanced precipitation organized by planetary-scale waves on Titan"
"3.3. Relevance to Other Planets" (section on Titan)
"Superrotation in Planetary Atmospheres" (article covers Titan alongside three other planets)
"All planets with substantial atmospheres (e.g., Earth, Venus, Mars, and Titan) have ionospheres which expand above the exobase"
"Clouds on Titan result from the condensation of methane and ethane and, as on other planets, are primarily structured by circulation of the atmosphere"
"... of the planet. However, rather than being scarred by volcanic features, Titan's surface is largely shaped..."
"Spectrophotometry of the Jovian Planets and Titan at 300- to 1000-nm Wavelength: The Methane Spectrum" (okay, it's mainly referring to the Jovian satellites as planets, but same point)
"Superrotation indices for Solar System and extrasolar atmospheres" - contains a table whose first column is "Planet", and has Titan in the list, alongside other planets
Etc. This is not to be confused with the phrase "minor planet", which is used for asteroids, etc. In general there's a big distinction in how commonly you see the large moons in hydrostatic equilibrium referred to as "planets" and with "planetary" adjectives, vs. smaller bodies not in hydrostatic equilibrium.
Why?
NASA's obsession with Mars is weird, and it consumes the lion's share of their planetary exploration budget. We know vastly more about Mars than we know of everywhere else except Earth.
This news here is bittersweet for me. I *love* Titan - it and Venus are my two favourite worlds for further exploration, and dragonfly is a superb way to explore Titan. But there's some sadness in the fact that they're launching it to an equatorial site, so we don't get to see the fascinating hydrocarbon seas and the terrain sculpted by them near the poles. I REALLY wish they were going to the north pole instead
At least if it lasts for that long it'll have done a full transition between wet and dry cycles, which should last ~15 years. So maybe surface liquids will be common at certain points, rare in others.
Technically speaking the crime of fraud has three elements: (1) A materially false statement; (2) an intent to deceive the recipient; (3) a reliance upon the false statement by the recipient.
So, if you want to lie to people and want to avoid being charged with fraud, it's actually quite simple. You lie by omission. You distract. You prevaricate (dance around the facts). You encourage people to jump on the bandwagon; you lead them to spurious conclusions. It's so easy to lie without making any materially false statements that anyone who does lie that way when people are going to check up on him is a fool.
Not only is this way of lying *legal*, it happens every time a lawyer makes an closing statement to a jury. It's not a problem because there's an opposing counsel who's professionally trained to spot omissions and lapses of logic and to point them out. But if a lawyer introduces a *false statement of fact* to a trial that's a very serious offense, in fact grounds for disbarrment because that can't be fixed by having an alert opponent.
We have similar standards of truthfullness for advertising and politics because in theory there's competition that's supposed to make up for your dishonesty. In practice that doesn't work very well because there is *nobody* involved (like a judge) who cares about people making sound judgments. But still, any brand that relies on materially false statements is a brand you want to avoid because they don't even measure up to the laxest imaginable standards of honesty.
Now investors have lots of money, so they receive a somehat better class of legal protections than consumers or voters do. There are expectations of dilligence and duties to disclose certain things etc. that can get someone selling investments into trouble. But that's still not as bad as committing *fraud*, which is stupid and therefore gets extra severe punishment.
If I understand your argument properly, you're suggesting that things will be OK with the reefs because "survival of the fittest" will produce a population of corals better adapted to warmer conditions.
Let me first point out is that this isn't really an argument, it's a hypothesis. In fact this is the very question that actual *reef scientists* are raising -- the ability of reefs to survive as an ecosystem under survival pressure. There's no reason to believe reefs will surivive just because fitter organisms will *tend* to reproduce more, populations perish all the time. When it's a keystone species in an ecosystem, that ecosystem collapses. There is no invisible hand here steering things to any preordained conclusion.
So arguing over terminology here is really just an attempt to distract (name calling even more so) from your weak position on whether reefs will survive or not.
However, returning to that irrelevant terminology argument, you are undoubtedly making an evolutionary argument. You may be thinking that natural selection won't produce a new taxonomic *species* for thousands of generations, and you'd be right. However it will produce a new *clade*. When a better-adapted clade emerges due to survival pressures, that is evolution by natural selection. Whether we call that new clade a "species" is purely a human convention adopted and managed to facilitate scientific communication.
You don't have to take my word for any of this. Put it to any working biologist you know.
... are we putting blatant pseudoscience on Slashdot? Are we becoming Natural News? Ir InfoWars maybe?
I've probably done tens of thousands of legit, constructive edits, but even I couldn't resist the temptation to prank it at one point. The article was on the sugar apple (Annona squamosa), and at the time, there was a big long list of the name of the fruit in different languages. I wrote that in Icelandic, the fruit was called "Hva[TH]er[TH]etta" (eth and thorn don't work on Slashdot), which means "What's that?", as in, "I've never seen that fruit before in my life"
The author has no clue what they're talking about:
Meta said the 15 trillion tokens on which its trained came from "publicly available sources." Which sources? Meta told The Verge that it didn't include Meta user data, but didn't give much more in the way of specifics. It did mention that it includes AI-generated data, or synthetic data: "we used Llama 2 to generate the training data for the text-quality classifiers that are powering Llama 3." There are plenty of known issues with synthetic or AI-created data, foremost of which is that it can exacerbate existing issues with AI, because it's liable to spit out a more concentrated version of any garbage it is ingesting.
1) *Quality classifiers* are not themselves training data. Think of it as a second program that you run on your training data before training your model, to look over the data and decide how useful it looks and thus how much to emphasize it in the training, or whether or not to just omit it.
2): Synthetic training data *very much* can be helpful, in a number of different ways.
A) It can diversify existing data. E.g., instead of just a sentence "I was on vacation in Morocco and I got some hummus", maybe you generate different versions of the same sentence ("I was traveling in Rome and ordered some pasta"
B) It allows for programmatic filtration stages. Let's say that you're training a model to extract quotes from text. You task a LLM with creating training examples for your quote-extracting LLM (synthetic data). But you don't just blindly trust the outputs - first you do a text match to see if what it quoted is actually in the text and whether it's word-for-word right. Maybe you do a fuzzy match, and if it just got a word or two off, you correct it to the exact match, or whatnot. But the key is: you can postprocess the outputs to do sanity checks on it, and since those programmatic steps are deterministic, you can guarantee that the training data meets certain characteristics..
C) It allows for the discovery of further interrelationships. Indeed, this is a key thing that we as humans do - learning from things we've already learned by thinking about them iteratively. If a model learned "The blue whale is a mammal" and it learned "All mammals feed their young with milk", a synthetic generation might include "Blue whales are mammals, and like all mammals, feed their young with milk" . The new model now directly learns that blue whales feed their young with milk, and might chain new deductions off *that*.
D) It's not only synthetic data that can contain errors, but non-synthetic data as well. The internet is awash in wrong things; a random thing on the internet is competing with a model that's been trained on reems of data and has high quality / authoritative data boosted and garbage filtered out. "Things being wrong in the training data" in the training data is normal, expected, and fine, so long as the overall picture is accurate. If there's 1000 training samples that say that Mars is the fourth planet from the sun, and one that says says that the fourth planet from the sun is Joseph Stalin, it's not going to decide that the fourth planet is Stalin - it's going to answer "Mars".
Indeed, the most common examples I see of "AI being wrong" that people share virally on the internet are actually RAG (Retrieval Augmented Generation), where it's tasked with basically googling things and then summing up the results - and the "wrong content" is actually things that humans wrote on the internet.
That's not that you should rely only generated data when building a generalist model (it's fine for a specialist). There may be specific details that the generating model never learned, or got wrong, or new information that's been discovered since then; you always want an influx of fresh data.
3): You don't just randomly guess whether a given training methodology (such as synthetic data, which I'll reiterate, Meta did not say that they used - although they might have) is having a negative impact. Models are assessed with a whole slew of evaluation metrics to assess how good and accurately they respond to different queries. And LLaMA 3 scores superbly, relative to model size.
I'm not super-excited about LLaMA 3 simply because I hate the license - but there's zero disputing that it's an impressive series of models.
Top Ten Things Overheard At The ANSI C Draft Committee Meetings: (5) All right, who's the wiseguy who stuck this trigraph stuff in here?
