which we could tell must be a seriously huge river when the icecap is melting.
You mean during a jÃkullhlaup? When a volcano under an ice cap melts a lot of water, which then melts out the side of the ice cap. Regular jÃkullhlaups often match the flow of the amazon, and large ones match the rest of the freshwater flow on the planet. Briefly.
Should graphing calculators also "remain in their locker during school hours"?
Yes.
Anyone who has been paying attention during their maths lessons can look at the function, derive the inflexion points and axis crossing points and sketch the curve within a few seconds. If you don't understand the maths, then you have already failed your maths test and that's your education over and finished. I'll have fries with that burger.
If your school curriculum is so fucked up that your Physics course demands things that your Maths course hasn't already provided, then you've got an issue to take up with the school management. And you did take it up when you read the course description at the start of the year. Because you read the paperwork before signing up. Didn't you?
"Queue" - somewhere where Britons wait for other Britons to get seagull shit on them. "Cue" - a stage direction for someone to come on stage from the wings and start singing, dancing, blowing the lead actress or whatever. Quite what you're trying to say isn't clear.
I noticed that it's in the flea pit next month some time, but as I walked past, thought about it and (1) the last couple of Star Wars certainly weren't worth the ticket price of the first one, so the odds aren't good ; and (2) it's American, so it's probably not somewhere I'd want to send my money anyway.
he reflex of answering -- built so deeply into people who grew up in 20th-century telephonic culture -- is gone.
Nope, not relevant. I didn't get a phone until about 1994, and I never developed that reflex. Someone calls, I let it ring out then do a last-caller ID and if I recognise the number, call back and say I was on the shitter. If I don't recognise the number, no call back. It was never difficult, and got easier when I got a handset with a screen that displayed the incoming number.
OK, I was 31 when I started living with a phone - maybe other people developed different habits if they had a phone in their twenties or teens. But even so, it's just a habit, not a reflex.
To get more to the point, yes, the cut is very important in
destroying the appearance of the gem stone.
OK, if you want a bland bit of colourless shit on your finger, necklace, or mineral collection, then sure, you can buy a diamond and have 60% of it cut away and almost all of it's interesting characteristic features ground away. But don't waste your effort trying to sell that shit to me. Diamonds are fascinating, complex minerals, each rich in their own history. I just don't understand this sill idea of cutting them into identical bits of white shit, throwing away all the interesting bits. I certainly wouldn't buy one.
Next your going to say mammals are still reptiles or birds are still dinosaurs.
Birds are dinosaurs - see the signature which I haven't edited for years.
Mammals-vs-reptiles is a thornier question. ultimately it's an apples-vs-oranges. "Mammal" is a reasonably closely defined category with particular properties (fur, feeds infants with milk) which includes all descendants of an original mammal - a property we call "monophyletic". But the category "reptile" is much harder to define monophyletically. If you take the defining characteristic of "reptiles" as being the amnion (a waterproofing membrane in the egg), then mammals are also reptiles, because their eggs also have an amnion (despite mostly being implanted in an uterus and never being exposed to desiccating conditions). Which most biologists would be uncomfortable. But a different way of defining "reptile" which doesn't make mammals reptiles has so far eluded the wit of taxonomists.
The biologists have learned from Pluto. This is a can of vermes which they really don't want to open.
so it does not matter if he does not run for a double dip.
You're referring to running for President a second time? (I'm not an American, so I don't waste much effort on the details of their political system.) I'm expecting him to go for the third election, followed by hereditary appointment of which-ever of Ivanka, Donald Junior or Jared isn't in jail at the time.
I am aware that there is some sort of paperwork in the way - that "constitution" thing which Trump has been using for arse-wipe. I don't see that lasting long, once he tweets that gun-toting Mexican illegals are plotting a school shooting in support of (whichever constitution clause bans a third Presidency).
It's a good strategy, which has the Vladimir seal of approval.
Most brown dwarfs we know about don't orbit anything... except you want to count systems with multiple stars.
Approximately HALF of all stars are in multiple systems - which if you think about it means that about 2/3 of star systems are singletons like the Sun, one third are double stars (approximately matching the number of singleton stars), and then there are a small proportion of triples, quadruples and upwards also bumping the numbers to approximate parity. That is a result that has ben known about for... well back into the early days of photographic astronomy, and is nothing to do with exoplanets, brown dwarfs or anything. It is a hard number to get a good census on, because it requires observations over a large time span (for distantly-spaced multiples), and often the brightness ratio is large leaving the minor component(s) obscured by the glare of the primary.
In line with this, and because of the relative ease of (1) spotting stars which are not brown dwarfs and (2) showing the the mass of a putative brown dwarf is in the right range, it is only relatively recently - a few years ago - that the first brown dwarf was found which was not in a binary or higher system. There may have been more discoveries now - but given the observational biases above, they're likely to remain relative rarities. And getting an accurate count is going to be even harder than for (e.g.) small red dwarfs.
Because brown dwarfs are considered to have formed by direct gas-cloud collapse like other stars, you'd expect their mass distribution function to follow that for higher-mass stars, and so be strongly biased to lower-mass stars. Similarly you'd expect the multiplicity distribution to also reflect that of larger stars, with around a half of them being singletons and the rest in larger systems. But the observability bias would remain.
No scientist I know of thinks that panspermia is impossible - just (1) very unlikely, and (2), not a useful contribution to the question of the origin of life.
With an origin of life on Earth then we've got a reasonable handle on the conditions under which it happened, the materials available, and we can perform relevant, falsifiable experiments to test our theses. If we then move our origin of life to some other planet somewhere else in the universe, we've got almost no idea of plausible conditions of chemistry, temperature and pressure which rather scuppers the idea of performing falsifiable experiments to test our hypothesis.
"I just rolled a triple-6!"
"I don't believe you, you just threw the dice down that well."
"But they landed triple-6, I'm sure!"
And argument which I'm just waiting to hear come out of the mouth of a White House Official Spokesperson some day soon.
and see how long it took for them to alter the chemistry of the moon enough that we could detect it from orbit.
Orbit around where? Europa - or Proxima Centauri B?
Considering that the available liquid on Europa is under 50-odd km thickness of water ice - and that stuff flows at thicknesses of hundreds of metres under Europan gravity - your only real prospect of detection is from any debris included in plume debris - exactly as is being considered as an exploration target.
How long would it take terrestrial bacteria to adapt to Europan "geo-"chemistry? That's a hard question. While the likely sources of carbon chemicals are probably going to be reasonably familiar (carbon dioxide, some simple carbohydrates and/ or amino acids, and the old "concentration problem" of myriads of other more complex structures, the credible sources of electron acceptors are not ones that would be metabolically familiar to many terrestrial organisms. Super-oxide and/ or peroxide produced by radiation impact on the ice surface (followed by convection and basal re-melting in the subsurface ocean to release into the water column) - well they're the #1 fingered compounds fingered in suspicions over the origination of aging and cellular damage leading to senescence. Not a good start. Sulphide released from primordial meteorite dust in the "dirty snow balls" ? Well, the chemistry exists, but generally it's antithetical to the presence of superoxides, so you're going to have to pick your organisms "right" first time. Which means characterising the environment a lot better than it is characterised already.
I think it would take a long time - geologically (say some millions of years, and probably several attempts) before you got orbit-detectable changes from an inoculation attempt.
There are a lot of unknowns when trying to do photometry (measurement of brightness) from photographic plates. For a start, you don't know the sensitivity of each emulsion on each and every pixel on a plate (literally - even if you batch process a pile of plates, you don't know if the "baking in an oven flooded with hydrogen" step has applied the same across every plate in the oven - see photographic hypersensitisation ; then you get onto the vagaries of chemical flow across the surface in the darkroom). Life got terrifically simpler with the introduction of large-area CCDs, but by that point we had Charon to take the uncertainties out of the system. That it was really hard to do photometry on an object near the limit of detectability should surprise no one who has actually worked in a darkroom.
When Charon took the uncertainties away, it was visible as a non-circularity in the 20-odd micron diameter of the plate image. A decade later - during the era of mutual occultations - the resolution had increased to give around 50 pixels for the deconvolved image. That's just ever-so-slightly a big improvement.
Around the time of Charon's discovery - I don't have the reference to hand - there was a rather tongue-in-cheek paper describing the problem : since the discovery of Pluto, as photometric methods improved, estimates of it's absolute magnitude and mass had decreased, steeply, with the conclusion that shortly Pluto would disappear. Charon saved it from that fate, but it remains tiny. A large asteroid.
Who made that list up for you?
IF you tried to use it as a definition for a planet, then the proposed "Planet Nine" of Brown & Batygin 2016-01 would fail on criteria 1 and 3.
That took several decades for people to work out. The question of it's albedo left it's diameter and mass in considerable doubt until the discovery of Charon.
and its orbit is quite different then the rest.
That however was realised to be very odd almost from day one. With the exception of some asteroids (a group of bodies that got demoted from "planet" status in about 1860), nothing else had a slightly similar orbit. Until the discovery of the first Centaur, at almost the same time as the discovery of Charon.
But most people will never see Saturn during their live time. In ancient times because they statistically died to early in our times because of light pollution (and Saturn is statistically only twice during your live close enough to be seen with the naked eye)
Where the fsck did you get that? I don't have particularly good vision - my limiting magnitude is about 5.6 to 5.7 - but I see Saturn tens of times most years.
Actually... you could be thinking about Uranus - which does occasionally get to the point of being naked-eye visible (up to magnitude 5.5) and was recorded in at least one pre-instrumental star catalogue in the right place and magnitude - but not identified as moving. Or possibly Ceres, which can just pull the same trick, allegedly.
A brown dwarf star is a "star" that is a bit bigger than Jupiter, but not big enough to ignite fusion.
No. A planet is a body large enough to be doing the throwing-around amongst it's regions orbiting bodies (rather than being one of the "thrown around") AND which is too small to ignite ANY form of fusion ; a brown dwarf is an orbiting body which (temporarily) achieves deuterium fusion (which is hard to tell, but does leave a noticeable depletion of lithium compared to primordial matter - observationally tricky, but do-able) ; and a star is something that achieves fusion of 1-hydrogen into helium.
The orbiting criterion is tricky to define, since half of all hydrogen-fusing stars are in binary or higher-order multiples.
Of course you could have a "brown dwarf" as a planet or companion of a main star...
Until some time last year, all the brown-dwarf candidates were in binaries (or higher) - because then it's much easier to measure the masses. But A free-floating brown dwarf was reported last year. Which makes it hard to get the spectroscopic data to prove that the lithium has been depleted.
Slashdot Mirror
Yep, its Slashdot - they're mangling small-Latin-o-umlaut to large-Latin-a-bar. It's still ridiculous that I can't type a thorn here.
... says the man who used to have a thorn in his signature.
You mean during a jÃkullhlaup? When a volcano under an ice cap melts a lot of water, which then melts out the side of the ice cap. Regular jÃkullhlaups often match the flow of the amazon, and large ones match the rest of the freshwater flow on the planet. Briefly.
Yes.
Anyone who has been paying attention during their maths lessons can look at the function, derive the inflexion points and axis crossing points and sketch the curve within a few seconds. If you don't understand the maths, then you have already failed your maths test and that's your education over and finished. I'll have fries with that burger.
If your school curriculum is so fucked up that your Physics course demands things that your Maths course hasn't already provided, then you've got an issue to take up with the school management. And you did take it up when you read the course description at the start of the year. Because you read the paperwork before signing up. Didn't you?
"Queue" - somewhere where Britons wait for other Britons to get seagull shit on them.
"Cue" - a stage direction for someone to come on stage from the wings and start singing, dancing, blowing the lead actress or whatever.
Quite what you're trying to say isn't clear.
Economic bust - doesn't surprise me.
There are notches at 1cm intervals along the casing? Or, for American models, 1 cm on the intermediate edge and 1in on the long edge?
By the six balls of Jesus, Mary, Joseph and the donkey, just how incompetent are Apple users?
And so?
Uber policy is that they're not employees, they're independent freelance contractors. So Uber can't dictate their behaviour in their own work place.
Of course, if Uber want to accept that they are employees, then yes, they do have that power over employees. But not over independent sub-contractors.
Nope, not relevant. I didn't get a phone until about 1994, and I never developed that reflex. Someone calls, I let it ring out then do a last-caller ID and if I recognise the number, call back and say I was on the shitter. If I don't recognise the number, no call back. It was never difficult, and got easier when I got a handset with a screen that displayed the incoming number.
OK, I was 31 when I started living with a phone - maybe other people developed different habits if they had a phone in their twenties or teens. But even so, it's just a habit, not a reflex.
destroying the appearance of the gem stone.
OK, if you want a bland bit of colourless shit on your finger, necklace, or mineral collection, then sure, you can buy a diamond and have 60% of it cut away and almost all of it's interesting characteristic features ground away. But don't waste your effort trying to sell that shit to me. Diamonds are fascinating, complex minerals, each rich in their own history. I just don't understand this sill idea of cutting them into identical bits of white shit, throwing away all the interesting bits. I certainly wouldn't buy one.
Your basic thesis may be correct, but your spelling checker has Auto-Incorrected "marketing cunts" to "scientists".
Birds are dinosaurs - see the signature which I haven't edited for years.
Mammals-vs-reptiles is a thornier question. ultimately it's an apples-vs-oranges. "Mammal" is a reasonably closely defined category with particular properties (fur, feeds infants with milk) which includes all descendants of an original mammal - a property we call "monophyletic". But the category "reptile" is much harder to define monophyletically. If you take the defining characteristic of "reptiles" as being the amnion (a waterproofing membrane in the egg), then mammals are also reptiles, because their eggs also have an amnion (despite mostly being implanted in an uterus and never being exposed to desiccating conditions). Which most biologists would be uncomfortable. But a different way of defining "reptile" which doesn't make mammals reptiles has so far eluded the wit of taxonomists.
The biologists have learned from Pluto. This is a can of vermes which they really don't want to open.
You're referring to running for President a second time? (I'm not an American, so I don't waste much effort on the details of their political system.) I'm expecting him to go for the third election, followed by hereditary appointment of which-ever of Ivanka, Donald Junior or Jared isn't in jail at the time.
I am aware that there is some sort of paperwork in the way - that "constitution" thing which Trump has been using for arse-wipe. I don't see that lasting long, once he tweets that gun-toting Mexican illegals are plotting a school shooting in support of (whichever constitution clause bans a third Presidency).
It's a good strategy, which has the Vladimir seal of approval.
Very informative, thank you for your work.
Approximately HALF of all stars are in multiple systems - which if you think about it means that about 2/3 of star systems are singletons like the Sun, one third are double stars (approximately matching the number of singleton stars), and then there are a small proportion of triples, quadruples and upwards also bumping the numbers to approximate parity. That is a result that has ben known about for ... well back into the early days of photographic astronomy, and is nothing to do with exoplanets, brown dwarfs or anything. It is a hard number to get a good census on, because it requires observations over a large time span (for distantly-spaced multiples), and often the brightness ratio is large leaving the minor component(s) obscured by the glare of the primary.
In line with this, and because of the relative ease of (1) spotting stars which are not brown dwarfs and (2) showing the the mass of a putative brown dwarf is in the right range, it is only relatively recently - a few years ago - that the first brown dwarf was found which was not in a binary or higher system. There may have been more discoveries now - but given the observational biases above, they're likely to remain relative rarities. And getting an accurate count is going to be even harder than for (e.g.) small red dwarfs.
Because brown dwarfs are considered to have formed by direct gas-cloud collapse like other stars, you'd expect their mass distribution function to follow that for higher-mass stars, and so be strongly biased to lower-mass stars. Similarly you'd expect the multiplicity distribution to also reflect that of larger stars, with around a half of them being singletons and the rest in larger systems. But the observability bias would remain.
If they're not going to stick around long enough for us to recoup our investment in training them, they'll just go into the circular file of CVs.
With an origin of life on Earth then we've got a reasonable handle on the conditions under which it happened, the materials available, and we can perform relevant, falsifiable experiments to test our theses. If we then move our origin of life to some other planet somewhere else in the universe, we've got almost no idea of plausible conditions of chemistry, temperature and pressure which rather scuppers the idea of performing falsifiable experiments to test our hypothesis.
"I just rolled a triple-6!"
"I don't believe you, you just threw the dice down that well."
"But they landed triple-6, I'm sure!"
And argument which I'm just waiting to hear come out of the mouth of a White House Official Spokesperson some day soon.
Orbit around where? Europa - or Proxima Centauri B?
Considering that the available liquid on Europa is under 50-odd km thickness of water ice - and that stuff flows at thicknesses of hundreds of metres under Europan gravity - your only real prospect of detection is from any debris included in plume debris - exactly as is being considered as an exploration target. How long would it take terrestrial bacteria to adapt to Europan "geo-"chemistry? That's a hard question. While the likely sources of carbon chemicals are probably going to be reasonably familiar (carbon dioxide, some simple carbohydrates and/ or amino acids, and the old "concentration problem" of myriads of other more complex structures, the credible sources of electron acceptors are not ones that would be metabolically familiar to many terrestrial organisms. Super-oxide and/ or peroxide produced by radiation impact on the ice surface (followed by convection and basal re-melting in the subsurface ocean to release into the water column) - well they're the #1 fingered compounds fingered in suspicions over the origination of aging and cellular damage leading to senescence. Not a good start. Sulphide released from primordial meteorite dust in the "dirty snow balls" ? Well, the chemistry exists, but generally it's antithetical to the presence of superoxides, so you're going to have to pick your organisms "right" first time. Which means characterising the environment a lot better than it is characterised already.
I think it would take a long time - geologically (say some millions of years, and probably several attempts) before you got orbit-detectable changes from an inoculation attempt.
When Charon took the uncertainties away, it was visible as a non-circularity in the 20-odd micron diameter of the plate image. A decade later - during the era of mutual occultations - the resolution had increased to give around 50 pixels for the deconvolved image. That's just ever-so-slightly a big improvement.
Around the time of Charon's discovery - I don't have the reference to hand - there was a rather tongue-in-cheek paper describing the problem : since the discovery of Pluto, as photometric methods improved, estimates of it's absolute magnitude and mass had decreased, steeply, with the conclusion that shortly Pluto would disappear. Charon saved it from that fate, but it remains tiny. A large asteroid.
Who made that list up for you? IF you tried to use it as a definition for a planet, then the proposed "Planet Nine" of Brown & Batygin 2016-01 would fail on criteria 1 and 3.
So, you haven't been paying attention to the data being returned from the Dawn mission over the last year and a bit?
I worked the numbers on this last week. Well, the Jupiter one I've had in my head for years. Jupiter/Earth is 318 (by mass) ; Earth/ Pluto is 458.2.
That took several decades for people to work out. The question of it's albedo left it's diameter and mass in considerable doubt until the discovery of Charon.
That however was realised to be very odd almost from day one. With the exception of some asteroids (a group of bodies that got demoted from "planet" status in about 1860), nothing else had a slightly similar orbit. Until the discovery of the first Centaur, at almost the same time as the discovery of Charon.
Where the fsck did you get that? I don't have particularly good vision - my limiting magnitude is about 5.6 to 5.7 - but I see Saturn tens of times most years.
Actually ... you could be thinking about Uranus - which does occasionally get to the point of being naked-eye visible (up to magnitude 5.5) and was recorded in at least one pre-instrumental star catalogue in the right place and magnitude - but not identified as moving. Or possibly Ceres, which can just pull the same trick, allegedly.
No. A planet is a body large enough to be doing the throwing-around amongst it's regions orbiting bodies (rather than being one of the "thrown around") AND which is too small to ignite ANY form of fusion ; a brown dwarf is an orbiting body which (temporarily) achieves deuterium fusion (which is hard to tell, but does leave a noticeable depletion of lithium compared to primordial matter - observationally tricky, but do-able) ; and a star is something that achieves fusion of 1-hydrogen into helium.
The orbiting criterion is tricky to define, since half of all hydrogen-fusing stars are in binary or higher-order multiples.
Until some time last year, all the brown-dwarf candidates were in binaries (or higher) - because then it's much easier to measure the masses. But A free-floating brown dwarf was reported last year. Which makes it hard to get the spectroscopic data to prove that the lithium has been depleted.
No, it's not the world's most wonderful taxonomy.