The depressing thing about Starts-with-a-Bang was that from his other online information, he did actually know what he was talking about in terms of science and specifically astronomy. But he seems to have deliberately dumbed it down severely for the clickbait platforms of first Medium and then Forbes. Both of which went onto my noScript and Adblock shit lists because of him.
I note he's been quiet for a time. I hope this means that he's back in paid employment and no longer having to whore out his braincells to Medorbes or Forium.
Having dumped Windows some years ago (well done, Vista!) - and work still using WinXP and Win7 - WTF is "Edge" meant to do? (It's MS, so I assume that it does other things, including obviously "phone home" and "crash repeatedly".)
evolutionary branch of Archosaur, with the extant groups being birds and lizards,
Don't forget the turtles and crocodilians - still not extinct.
Citation? I think that "debate" is an urban myth.
Well, Alan Feduccia fought a good fight over it through most of the 1980s and 1990s. He seems to have quieted down over the last couple of decades. There was pseudo-controversy from creationist idiots too, but they're not even worth remembering names for (they all plagiarise each other in any case). See my signature for my opinion on the matter, which I've only rarely edited since about the time Feduccia ran out of constructive arguments.
the assertion of Go players and hangers-on that "Go is so much more complex than chess, so it will never be mastered by a machine".
Having been playing Go for 33 years now, and knowing people who've been trying to program Go for 32 years, I've never heard either a player or "hanger-on" make that assertion. Even in the days when the best program in the world could be beaten flat by a human with a couple of evening's teaching.
Come to think of it, I've never met a "Go hanger-on" who was not also to some degree a player. No, sorry - I tell a lie. There was one guy whose wife was brain-damaged ; she didn't play, but enjoyed the company at tournaments.
It's a pretty safe bet that the AlphaGo team has some pretty good players onboard who could seed the stealth account with some high-ranking initial opposition to establish it's strength. After that, something that shows up as a confirmed 7 or 8 dan professional would pretty soon attract more ranked opponents. If they didn't want to wade through the low ranked people, then you can set tthe minimum rank for possible opponents - or at least you could the last time I played go online (8 or 10 years ago).
People have been playing with different (larger) sized boards for decades if not centuries (ISTR that some Japanese professionals were studying 21x21 games in the 18th century ; 20x20 was considered a solution to the "mirror go" problem in the 15/ 16th century, until more elegant solutions were developed). The high-dan players who have worked on larger boards say the balance of the game between territory and influence changes considerably.
37x37 would be an unnecessary extension in size unless you're one of those people who think that "more is better". Consider the common sizes of board in use already : 5x5 has only ever been used for the most basic of teaching games and was completely evaluated for optimal play by hand in about 1990 ; 9x9 is the norm for teaching once you get beyond the rankest of beginners (in the mid-20s of kyu - a few hours of teaching) ; 13x13 is a popular size for quick games between the rounds of a tournament ; and 19x19 has been the "serious" size since around 800 BCE. People have been experimenting with 21x21 and 23x23 for centuries, but neither have ever become popular, suggesting that human exploration of 19x19 is far from complete.
you might find these Sensei's Library pages interesting : Interesting board sizes ; Different Sized Boards ; Large Boards (an interesting speculation, with grounding : "Go boards and stones were often used in fortune telling. The connection between 361 intersections and 365 days is important. " ; also some specific comments on 37x37 play). And for entertainment value, Unusual Gobans. Go players have been looking at variations to the rule sets for a long time.
Basically any game where the psychology of the other players matters as much as the rules of the game would be a better test.
That's a completely different class of game. Literally, a completely different class.
Psychology essentially means having some game-relevant information which some players know and others don't. At least some players (probably all - I've never been interested to learn how to play poker beyond what's necessary for answering statistics problems) only have partial information on the state of the game. By contrast, in a game of Go the two players both have access to all of the information on the state of the game at all times. There is absolutely no hidden information. (*)
Since the internet (or at least, my web browsing, before I started using ad-blockers) is full of adverts for online poker games, I assume that it's not actually against the rules of the game to use some technical fix (a face-obscuring mask ; or being on the other side of the world, competing through a computer ; botox ; whatever) to obscure the psychological "tells." At which point, definitely some information in the game - such as the cards in your hand - is definitely not shared with all the other players in the game at all times during the game.
Go is a game of "perfect information" ; poker isn't. Comparing strategies for playing the two types is like comparing a word processor and a microwave oven. They're different things.
(*) That includes the sequence of moves made. In the same way, a poker player knows which cards have been shown since the last shuffle, but different rule-sets for poker probably differ on whether all players get to see the cards in discarded hands.
Yeuchh! Oral service from an avian dinosaur. Between the idea of having my pecker pecked and Rule 34 of the Internet, I think I need my brain scrubbed with lye.
3) Attempt to remove it from your home, and find that no matter how many times you do so, bits of it are still left under your couch, inside the walls, glued to the ceiling...
You'd have that problem even if you applied Norton-standard pre-emptive fault finding to the device before unpacking it. (1kg of C4 explosive followed by a wash with red fuming nitric acid.)
Interesting comments on Landsat data. I'll give that another read after making my dinner.
This is where you're missing something:
so even impacting the earth it should have still left an iron signal at the point of impact unless it went through the crust and sunk into magma.
There's an alternative interpretation you're not considering. What happens to a half million tonnes (give or take) of iron when you turn around 1.5Ã--10^13 joules of kinetic energy (Earth's orbital velocity - impact velocity may have been higher or lower) into heat underneath it? (That's abut 3.5 thousand tonnes of TNT equivalent.)
To put it mildly, the iron is dispersed.
To a good approximation, for all large astronomical impactors, the energy released on impact is sufficient to blow the impactor - and a lot of other debris - out of the temporary crater and into orbit or into long-distance ballistic trajectories. Most of the impactor is vapourised on contact with the ground - regardless of whether it is dirty ice (boiling point Meteor Crater has no significant magnetic anomaly. The impactor was - to a good approximation - dispersed over the landscape. Debris was probably not confined to the North American continent, though this was, of course, an insignificant impact. The iron finds around Meteor Crater total some hundreds or even a thousand kilos, making for an ejection efficiency of around 99.9% or higher (depending on impactor mass, obviously).
Iron doesn't simply obliterate itself - it's one of the hardest things to get a fission or fusion reaction from (as in essentially impossible,)
Kinetic energy goes to heat ; nothing exotic. With enough heat generated rapidly, it is easy to get iron (or anything else) to go to somewhere else.
OK, I'll rephrase the question. If someone is seriously making this proposition and expecting people to pay it any credence, then they'll have published it somewhere under their own name in order to establish priority, and at that point they'll have included the best evidence they have in support of their hypothesis, as well as pointing out any holes in competing hypotheses.
Who is proposing this hypothesis? (Like I said, I've not heard of it at the several Gondwana-themed conferences I've attended.)
Where in the professional literature did they publish it? (You could just about squeeze Scientific American or National Geographic into "the literature". Just. New Scientist or National Enquirer, no.)
If someone doesn't do these basics, then they're not serious about their idea and not worth the effort of responding to.
I'm not saying the idea is utterly lacking in merit - it's just about possible. But I suspect that it's a mis-remembered variant on the concept that the contra coup stress concentration from the Chixulub impactor led to the eruption of the Deccan LIP (Large Igneous Province). That one has been popular for decades, but it falls apart if you try to come up with some numbers to examine it, and also has fallen further apart more recently on the dating front. Though it's popular in "science reporting" (e.g. "Discovery Channel" and the like), I can't think of a single geologist who has thought enough of the idea to attach their name and professional reputation to it.
I suspect that this is another equally poorly-founded idea (if it's not the same one resurrected). I can't think of any good reasons to think it might be true, and don't particularly fancy spending the next 30 years fighting it's Hydra-like resurfacing, as one has had to do over the Chixulub-Deccan error. If someone has assembled sufficient supporting evidence to be worth publishing, then I'll consider it. But I'm not going to waste my time and effort on it because I don't think it's worthwhile. It's Rei who brought up the idea - let him do the leg work (he's well enough aware of how science works to know what is needed).
So, what are your scales and what data from Landsat are you plotting there. There is no indication of your data apart from a mention of Landsat8 in your list of sources. Without the context, I'd read that as two horizontally bedded units - which you've flagged pale brown and bright green - the deeper (bright green unit) of which has been exposed by the impact. Impact melt (suevite) you've coloured purple.
Without your unit definitions, that's uninformative.
I've never needed to look at satellite data (I use a hand lens or binocular microscope), so I'm guessing that you're making certain criteria of (say) IR band brightness to colour brown, pink, green or whatever, and that you've got some correlation section elsewhere to justify these pick criteria. Or some a priori reasons for making those particular picks. Grain size and degree of fusion are things I would expect to have an effect on IR reflection spectra, which is why I'm postulating the pink-flagged unit as being the ejecta. And the spectra of this unit differs from the spectrum of shocked material from the pale-brown unit just how?
You do Landsat interpretation as a lucrative hobby? How do you make money out of that? Checking bullshit company reports so you can filter them out of people's portfolios (for a consultancy fee)?
For the first time in the (large) handful of times I've heard "Skyrim", I'm now intrigued enough to ctually find out what it is that you can collect books in it. [Wikis] It's some sort of dungeons & dragons game? Online, possibly? What the flying fuck has that got to do with book collecting?
I'm thinking we need an airtight dome and an almost completely closed system anyway,
Scrub the "almost" from your design brief. Things will break and leak often enough that you don't need to go around designing holes in your system.
If you're in a dome, with a closed ecology, what is the benefit of being at the bottom of a gravity well too? going to go outside on your break time and catch some rays?
Plants can tolerate much higher radiation levels and much lower pressures than humans can.
"tolerate" as in "survive", probably; but it's hardly thriving. Humans can (and do) survive extended periods in the 5.5 to 6.5 km altitude range which is above the practical limit of agriculture. Most Sherpa villages are a kilometre or more further down into the atmosphere than this precisely because their crops (barley, mostly) needs the additional air pressure.
In Martian terms, you need to concentrate the atmosphere from under a millibar to around 600 millibar for the plants, and around 500 millibar for the humans - who are then at risk of pulmonary oedema, stroke, heart attack etc. Really you need to get the pressure up to better than 850 millibar.
There are savings to be made there, but pretty minor ones.
As for solar only based sintering (on mars), I still think it is doable,
You do realise that useful fibres for construction need a fibre diameter less than their Griffith fracture length? Which is precisely why sintering isn't used in the real world, but full-on fusion, to some hundreds of degrees above the fusion temperature range, to reduce the melt viscosity. How many hundreds of samples of sintered materials did you examined under the microscope before you realised how their microstructure differs from a glass?
glass thus does not require silicon to be created. an example is oxide glass, made from 90% alumina.
Congratulations for raising the necessary temperature from about 1400 C to 1900 C and so the radiative heat loss from (relative) 1 to about 3.39. i.e., you've made the energy requirements over 3 times harder.
Can you point me towards the reports of high grade (say, 10% v/v) alumina deposits on Mars? I seem to have missed the reported analyses.
there ARE clay formations and claystone formations on mars,
Well clay-rich ; "claystone" would be a pretty useless term for an Areologist to use since it's pretty poorly defined for a geologist (hint : not less than one person in his 3-way conversation is a professional geologist, and I don't know what you or Rei does for a living).
which would produce viable glasses.
Yeah - right. That would produce the large expanses of melted clay around the many basalt lava dykes I've crossed in Skye and Mull and Knoydart and Sicily and Tenerife and Korea. You know - the deposits with the highly distinctive vitreous texture, conchoidal fracture, and other characteristics of a glass.
Oh, hang on a second - I've never actually seen that. Strange that - in the hundreds of thousands of rock samples I've examined over the decades, I've never seen that. Peculiar, that. It's almost as if the melts that form in nature are close to eutectic mixtures, and that clay minerals don't melt in those pressure-temperature regimes.
You present a nice scheme. Sadly, it's not a relevant or realistic one. Rei's idea of using basalt glass isn't terribly realistic either - the mechanical properties of basalt glass aren't as useful as those of glass fibres designed for good mechanical properties. But at least he recognises these problems ad mitigates them with construction methods in composite materials. Interesting things, composites ; but from their composite nature, dependent on the properties of the starting materials, the interfaces between materials, and the physical nature of the mixture. More complex than most people realise.
Again, though, "Martian basalt", like basalt on Earth, is not a single universal thing; the dust from the particular site would need to be sampled and analyzed on its own.
What? you mean that the reality might actually be a little bit more complex than the daydreams of people typing on internet fora? That Areology might actually be different to geology, even if both are built on fundamental chemistry? Wow - do they breed realists up there in Iceland? You're far off message.
The transient crater from a multi-km impactor hitting the Earth is tens of km deep. That wouldn't change much regardless of depth of ocean basin that was hit - which average around 4-5 km deep. The really deep toughs of the oceans are no more common than the really high areas of the mountains - very unlikely to be hit. They're also not very wide, so a 10km deep by 100km wide transient crater would extend beyond the sides of the deep ocean trench.
Big impacts don't matter if they're on the continents or on the oceans. They're really good events to watch from a different planet.
Several interesting errors in (or behind) your comment.
I must admit all my orbital experience comes from reddit and Kerbal Space Program.
These are not very good sources.
BUT isn't it highly unlikely that an asteroid would hit a polar region? Rotation of earth, as [ ] well as our trajectory around the sun and our solar systems trajectory around the galaxy all make it much easier for asteroids, especially big ones, to come at earth from the side.
Take a look at the sky one night when you can see and identify the Milky Way. (Or, if you live in a light polluted area, use a planetarium programme with some claim to accuracy. There are hundreds - because the data is free.) Once you can identify the ecliptic (the path of the Sun-Earth mutual orbit projected onto the plane of the sky ; also a +/- 10 degrees approximation to the plane containing most of the non-solar mass in the Solar System) and the centreline of the trace of the disc of the Milky Way, you'll see that they're inclined at about 60 degrees to each other. In the 200 million years (-ish) orbit of the Solar System around the galaxy, this plane will spin around the percieved sky, even after you correct for the daily rotation of the Earth on it's axis. This has happened around 22 times since the Solar System formed. With about a 2 billion year history of impacting on the continents (~120 million years on the oceans) this alone would destroy your perceived correlation.
For a second dent - consider the largest reported impact structure in the Solar System - the Martian North Polar Basin. Some 2000 km across. Centred quite closely on it's pole.
For a third dent, don't forget the 23 degree inclination of the Earth's rotation axis to the pole to the ecliptic - that too is going to smear out your perceived "zone of non-impact" by... well, 23 degrees of latitude.
Based on all the the observed craters by the lunar and planetary institute (http://www.lpi.usra.edu/science/kring/epo_web/impact_cratering/World_Craters_web/worldcraters_maps.jpg) it looks like the northern hemisphere is even more favoured to be hit.
Most of the land mass of the Earth is in the northern hemisphere. A mere 100 Myr ago, it was close to 50:50 ; 400 Myr ago (about the time of the possible Ordovician spike in impact activity) there was a bias to southern hemisphere continental land masses about as strong as our currnt northern bias. Impact structures can persist on continents for billions of years (Vredefort in.ZA is around 2.1 billion years old, and we don't even know which hemisphere it was in within the uncertainty in it's age ; Sudbury around 1.2 billion ; the putative Stac Fada impactor (where I've personally collected samples and hand-lensed the outcrops) around 1.0 billion) ; impact structures in the ocean basins last around 0.1 billion years before being subducted. You have a deeply biased sample before you consider that the northern land masses have been considerably more closely explored than the southern continents.
Your data isn't wrong, but it is inherently biased. It's like pre-1990 models of planetary systems that discounted the possibility of "hot Jupiter" planets, because we had no idea how (or why) they could form. Our data se then was biased by one odd example ; now it's biased by the ease of detecting "hot Jupiters" ; one day we hope to have a less-biased (n.b., not unbiased) data set. You've got to check for bias in your data sources.
Slashdot Mirror
I note he's been quiet for a time. I hope this means that he's back in paid employment and no longer having to whore out his braincells to Medorbes or Forium.
Having dumped Windows some years ago (well done, Vista!) - and work still using WinXP and Win7 - WTF is "Edge" meant to do? (It's MS, so I assume that it does other things, including obviously "phone home" and "crash repeatedly".)
What risk do you perceive from having a "hot" smartphone next to your eyes that you wouldn't get from living in a hot climate?
Don't forget the turtles and crocodilians - still not extinct.
Well, Alan Feduccia fought a good fight over it through most of the 1980s and 1990s. He seems to have quieted down over the last couple of decades. There was pseudo-controversy from creationist idiots too, but they're not even worth remembering names for (they all plagiarise each other in any case). See my signature for my opinion on the matter, which I've only rarely edited since about the time Feduccia ran out of constructive arguments.
That's likely the debate you're remembering.
Somebody did a TV show of Gray's Anatomy? What censorship grading did that get?
It's not the AI that lets sexbots down. It's the ... firm-but-somewhat-squishy-ware.
Having been playing Go for 33 years now, and knowing people who've been trying to program Go for 32 years, I've never heard either a player or "hanger-on" make that assertion. Even in the days when the best program in the world could be beaten flat by a human with a couple of evening's teaching.
Come to think of it, I've never met a "Go hanger-on" who was not also to some degree a player. No, sorry - I tell a lie. There was one guy whose wife was brain-damaged ; she didn't play, but enjoyed the company at tournaments.
It's a pretty safe bet that the AlphaGo team has some pretty good players onboard who could seed the stealth account with some high-ranking initial opposition to establish it's strength. After that, something that shows up as a confirmed 7 or 8 dan professional would pretty soon attract more ranked opponents. If they didn't want to wade through the low ranked people, then you can set tthe minimum rank for possible opponents - or at least you could the last time I played go online (8 or 10 years ago).
People have been playing with different (larger) sized boards for decades if not centuries (ISTR that some Japanese professionals were studying 21x21 games in the 18th century ; 20x20 was considered a solution to the "mirror go" problem in the 15/ 16th century, until more elegant solutions were developed). The high-dan players who have worked on larger boards say the balance of the game between territory and influence changes considerably.
37x37 would be an unnecessary extension in size unless you're one of those people who think that "more is better". Consider the common sizes of board in use already : 5x5 has only ever been used for the most basic of teaching games and was completely evaluated for optimal play by hand in about 1990 ; 9x9 is the norm for teaching once you get beyond the rankest of beginners (in the mid-20s of kyu - a few hours of teaching) ; 13x13 is a popular size for quick games between the rounds of a tournament ; and 19x19 has been the "serious" size since around 800 BCE. People have been experimenting with 21x21 and 23x23 for centuries, but neither have ever become popular, suggesting that human exploration of 19x19 is far from complete.
you might find these Sensei's Library pages interesting : Interesting board sizes ; Different Sized Boards ; Large Boards (an interesting speculation, with grounding : "Go boards and stones were often used in fortune telling. The connection between 361 intersections and 365 days is important. " ; also some specific comments on 37x37 play). And for entertainment value, Unusual Gobans. Go players have been looking at variations to the rule sets for a long time.
Not from Sedol. No other opinion matters.
That's a completely different class of game. Literally, a completely different class.
Psychology essentially means having some game-relevant information which some players know and others don't. At least some players (probably all - I've never been interested to learn how to play poker beyond what's necessary for answering statistics problems) only have partial information on the state of the game. By contrast, in a game of Go the two players both have access to all of the information on the state of the game at all times. There is absolutely no hidden information. (*)
Since the internet (or at least, my web browsing, before I started using ad-blockers) is full of adverts for online poker games, I assume that it's not actually against the rules of the game to use some technical fix (a face-obscuring mask ; or being on the other side of the world, competing through a computer ; botox ; whatever) to obscure the psychological "tells." At which point, definitely some information in the game - such as the cards in your hand - is definitely not shared with all the other players in the game at all times during the game.
Go is a game of "perfect information" ; poker isn't. Comparing strategies for playing the two types is like comparing a word processor and a microwave oven. They're different things.
(*) That includes the sequence of moves made. In the same way, a poker player knows which cards have been shown since the last shuffle, but different rule-sets for poker probably differ on whether all players get to see the cards in discarded hands.
Yeuchh! Oral service from an avian dinosaur. Between the idea of having my pecker pecked and Rule 34 of the Internet, I think I need my brain scrubbed with lye.
You'd have that problem even if you applied Norton-standard pre-emptive fault finding to the device before unpacking it. (1kg of C4 explosive followed by a wash with red fuming nitric acid.)
This is where you're missing something :
There's an alternative interpretation you're not considering. What happens to a half million tonnes (give or take) of iron when you turn around 1.5Ã--10^13 joules of kinetic energy (Earth's orbital velocity - impact velocity may have been higher or lower) into heat underneath it? (That's abut 3.5 thousand tonnes of TNT equivalent.)
To put it mildly, the iron is dispersed.
To a good approximation, for all large astronomical impactors, the energy released on impact is sufficient to blow the impactor - and a lot of other debris - out of the temporary crater and into orbit or into long-distance ballistic trajectories. Most of the impactor is vapourised on contact with the ground - regardless of whether it is dirty ice (boiling point Meteor Crater has no significant magnetic anomaly. The impactor was - to a good approximation - dispersed over the landscape. Debris was probably not confined to the North American continent, though this was, of course, an insignificant impact. The iron finds around Meteor Crater total some hundreds or even a thousand kilos, making for an ejection efficiency of around 99.9% or higher (depending on impactor mass, obviously).
Kinetic energy goes to heat ; nothing exotic. With enough heat generated rapidly, it is easy to get iron (or anything else) to go to somewhere else.
Who is proposing this hypothesis? (Like I said, I've not heard of it at the several Gondwana-themed conferences I've attended.)
Where in the professional literature did they publish it? (You could just about squeeze Scientific American or National Geographic into "the literature". Just. New Scientist or National Enquirer, no.)
If someone doesn't do these basics, then they're not serious about their idea and not worth the effort of responding to.
I'm not saying the idea is utterly lacking in merit - it's just about possible. But I suspect that it's a mis-remembered variant on the concept that the contra coup stress concentration from the Chixulub impactor led to the eruption of the Deccan LIP (Large Igneous Province). That one has been popular for decades, but it falls apart if you try to come up with some numbers to examine it, and also has fallen further apart more recently on the dating front. Though it's popular in "science reporting" (e.g. "Discovery Channel" and the like), I can't think of a single geologist who has thought enough of the idea to attach their name and professional reputation to it.
I suspect that this is another equally poorly-founded idea (if it's not the same one resurrected). I can't think of any good reasons to think it might be true, and don't particularly fancy spending the next 30 years fighting it's Hydra-like resurfacing, as one has had to do over the Chixulub-Deccan error. If someone has assembled sufficient supporting evidence to be worth publishing, then I'll consider it. But I'm not going to waste my time and effort on it because I don't think it's worthwhile. It's Rei who brought up the idea - let him do the leg work (he's well enough aware of how science works to know what is needed).
Without your unit definitions, that's uninformative.
I've never needed to look at satellite data (I use a hand lens or binocular microscope), so I'm guessing that you're making certain criteria of (say) IR band brightness to colour brown, pink, green or whatever, and that you've got some correlation section elsewhere to justify these pick criteria. Or some a priori reasons for making those particular picks. Grain size and degree of fusion are things I would expect to have an effect on IR reflection spectra, which is why I'm postulating the pink-flagged unit as being the ejecta. And the spectra of this unit differs from the spectrum of shocked material from the pale-brown unit just how?
You do Landsat interpretation as a lucrative hobby? How do you make money out of that? Checking bullshit company reports so you can filter them out of people's portfolios (for a consultancy fee)?
For the first time in the (large) handful of times I've heard "Skyrim", I'm now intrigued enough to ctually find out what it is that you can collect books in it. [Wikis] It's some sort of dungeons & dragons game? Online, possibly? What the flying fuck has that got to do with book collecting?
Adhere to the standards you were trained to and you'll look better by comparison each year.
Except to retards seeking other retards.
Scrub the "almost" from your design brief. Things will break and leak often enough that you don't need to go around designing holes in your system.
If you're in a dome, with a closed ecology, what is the benefit of being at the bottom of a gravity well too? going to go outside on your break time and catch some rays?
"tolerate" as in "survive", probably; but it's hardly thriving. Humans can (and do) survive extended periods in the 5.5 to 6.5 km altitude range which is above the practical limit of agriculture. Most Sherpa villages are a kilometre or more further down into the atmosphere than this precisely because their crops (barley, mostly) needs the additional air pressure.
In Martian terms, you need to concentrate the atmosphere from under a millibar to around 600 millibar for the plants, and around 500 millibar for the humans - who are then at risk of pulmonary oedema, stroke, heart attack etc. Really you need to get the pressure up to better than 850 millibar.
There are savings to be made there, but pretty minor ones.
You do realise that useful fibres for construction need a fibre diameter less than their Griffith fracture length? Which is precisely why sintering isn't used in the real world, but full-on fusion, to some hundreds of degrees above the fusion temperature range, to reduce the melt viscosity. How many hundreds of samples of sintered materials did you examined under the microscope before you realised how their microstructure differs from a glass?
Congratulations for raising the necessary temperature from about 1400 C to 1900 C and so the radiative heat loss from (relative) 1 to about 3.39. i.e., you've made the energy requirements over 3 times harder.
Can you point me towards the reports of high grade (say, 10% v/v) alumina deposits on Mars? I seem to have missed the reported analyses.
Well clay-rich ; "claystone" would be a pretty useless term for an Areologist to use since it's pretty poorly defined for a geologist (hint : not less than one person in his 3-way conversation is a professional geologist, and I don't know what you or Rei does for a living).
Yeah - right. That would produce the large expanses of melted clay around the many basalt lava dykes I've crossed in Skye and Mull and Knoydart and Sicily and Tenerife and Korea. You know - the deposits with the highly distinctive vitreous texture, conchoidal fracture, and other characteristics of a glass.
Oh, hang on a second - I've never actually seen that. Strange that - in the hundreds of thousands of rock samples I've examined over the decades, I've never seen that. Peculiar, that. It's almost as if the melts that form in nature are close to eutectic mixtures, and that clay minerals don't melt in those pressure-temperature regimes.
You present a nice scheme. Sadly, it's not a relevant or realistic one. Rei's idea of using basalt glass isn't terribly realistic either - the mechanical properties of basalt glass aren't as useful as those of glass fibres designed for good mechanical properties. But at least he recognises these problems ad mitigates them with construction methods in composite materials. Interesting things, composites ; but from their composite nature, dependent on the properties of the starting materials, the interfaces between materials, and the physical nature of the mixture. More complex than most people realise.
What? you mean that the reality might actually be a little bit more complex than the daydreams of people typing on internet fora? That Areology might actually be different to geology, even if both are built on fundamental chemistry? Wow - do they breed realists up there in Iceland? You're far off message.
Big impacts don't matter if they're on the continents or on the oceans. They're really good events to watch from a different planet.
These are not very good sources.
Take a look at the sky one night when you can see and identify the Milky Way. (Or, if you live in a light polluted area, use a planetarium programme with some claim to accuracy. There are hundreds - because the data is free.) Once you can identify the ecliptic (the path of the Sun-Earth mutual orbit projected onto the plane of the sky ; also a +/- 10 degrees approximation to the plane containing most of the non-solar mass in the Solar System) and the centreline of the trace of the disc of the Milky Way, you'll see that they're inclined at about 60 degrees to each other. In the 200 million years (-ish) orbit of the Solar System around the galaxy, this plane will spin around the percieved sky, even after you correct for the daily rotation of the Earth on it's axis. This has happened around 22 times since the Solar System formed. With about a 2 billion year history of impacting on the continents (~120 million years on the oceans) this alone would destroy your perceived correlation.
For a second dent - consider the largest reported impact structure in the Solar System - the Martian North Polar Basin. Some 2000 km across. Centred quite closely on it's pole.
For a third dent, don't forget the 23 degree inclination of the Earth's rotation axis to the pole to the ecliptic - that too is going to smear out your perceived "zone of non-impact" by ... well, 23 degrees of latitude.
Most of the land mass of the Earth is in the northern hemisphere. A mere 100 Myr ago, it was close to 50:50 ; 400 Myr ago (about the time of the possible Ordovician spike in impact activity) there was a bias to southern hemisphere continental land masses about as strong as our currnt northern bias. Impact structures can persist on continents for billions of years (Vredefort in .ZA is around 2.1 billion years old, and we don't even know which hemisphere it was in within the uncertainty in it's age ; Sudbury around 1.2 billion ; the putative Stac Fada impactor (where I've personally collected samples and hand-lensed the outcrops) around 1.0 billion) ; impact structures in the ocean basins last around 0.1 billion years before being subducted. You have a deeply biased sample before you consider that the northern land masses have been considerably more closely explored than the southern continents.
Your data isn't wrong, but it is inherently biased. It's like pre-1990 models of planetary systems that discounted the possibility of "hot Jupiter" planets, because we had no idea how (or why) they could form. Our data se then was biased by one odd example ; now it's biased by the ease of detecting "hot Jupiters" ; one day we hope to have a less-biased (n.b., not unbiased) data set. You've got to check for bias in your data sources.