Well, if you want to get handwavey instead of siency, that's your choice. It doesn't strengthen your arguments in the slightest.
Without getting into essential complexities (e.g., the orbits are not circular, but elliptical), there's one very simple check that you don't seem to have considered. The 1.3 difference in orbital inclination between Earth and Jupiter means that the projection of the Earth's magnetotail out to Jupiter's orbit will be up to 23 million km (nearly 1/4 AU) above or below the line of Jupiter's motion. Without doing the maths (but eventually the maths must be done), I'm not at all convinced that the magnetotail of Earth encounters the magnetic bow-shock of Jupiter with any degree of frequency. I'm also sceptical that if such an interaction occurs (more than a few times a millennium) then the forces involved are going to be any appreciable fraction of the varying forces projected from the Solar wind onto the magnetic field of Jupiter.
You do raise a sort-of plausible scenario. but if you were saying this across the desk from your MSc or PhD supervisor, they'd tell you to go away and do the maths to estimate the frequency of such an interaction in the real Solar system, and the forces generated compared to stochastic variations. It's called doing a feasibility study.
The Ulysses probe probably has some of the best data for you to consider, in respect of actual measurements of magnetic interactions in the middle part of the Solar system.
"The Knowledge" is a quaint artifact of a bygone era. Today we have GPS and navigation apps with real time traffic information.
.... which 'knowledge' cabbies routinely beat, by significant margins. You see, maps don't contain everything, and real-time traffic information can't tell you what the traffic is likely to be in 15 minutes from now.
I have no idea why people want to buy brown diamonds.
You probably don't understand why people want uncut, on-matrix diamonds either, despite them being vastly more interesting than the shit DeBeers sell.
Why are you asking women about diamonds? They're only associated with women in particular due to some shit from some advertising campaign somewhere. When I got engaged, I looked for and found a very interesting piece starring an olivine (a very interesting mineral) and the fiancee loved the fact that I'd actually spent several hours thinking about our engagement ring instead of sucking from the dick of some advertising fuckwit.
But I haven't done any critical reading on the subject.
There does seem to be a correlation between Jupiter's orbital period and the sunspot cycle as both are roughly 11 years. But if there is an underlying mechanism
I'd advise you to do your critical reading. Look at the numbers and you'll find that the range of solar sunspot cycles is from 8.8 years to 14 years ; the corresponding orbital period for Jupiter is 11.875 years - 4331 days - with a variation of a lot less than a day. Remember that Ole Roemer was using apparent errors in the position of Jupiter's moons to prove that the speed of light is finite in the 1720s, for which they needed to know the orbital period of Jupiter to better than 10 minutes (~0.7% of a day).
We all know the line about "correlation is not causlity" ; but you don't even have a correlation.
It would be slightly more accurate to say that the European plate (built on the Fennoscandian and Ukrainian shields) is sutured against the Asian plate with a full-thickness low-lying trans-crustal fault with negligible remnant movement on it. The fault is still visible, and the differences on either side of it, but it has very ow activity levels. It's what we geologists call a "suture".
The Iapetus suture runs through Norway, southern Scotland, Ireland, and displaced by the Atlantic, off into Newfoundland and is similarly quiet. Not completely quiet, but we get fewer earthquakes than Oklahoma or New Madrid (for the last couple of centuries).
However, many models for terrestrial abiogenesis have it occurring in hydrothermal circulating systems and only using chemotrophic processes, not photosynthetic processes. Photosynthesis seems to be hundreds of millions of years, or maybe a billion years later.
So if they aren't going to be using the main engine for a major trajectory shift, does this mean that more fuel is available for the thrusters?
Maybe, maybe not ; for a number of possible reasons.
(1) Do the main and attitude drive systems use the same fuels? For the large number of anticipated firings for the attitude thrusters, you'd maybe go for reliably hypergolic fuel/ oxidiser couples (i.e., on contact, they ignite). But for the main engine with only a handful of planned firings you might choose a monoprop with electrical ignition. That question is readily amenable to research.
(2) Is there a cross-feed system from main thruster fuel tanks and pressurisation to attitude thruster fuel tanks and pressurisation? Or, to rephrase the same question - is there a mission-critical need for such a cross-feed? Because if the system isn't absolutely essential, it would have not been designed. Remember that every valve (not "most" but "every") and every joint in a pressurised fluid system is a potential leak point. Again, if you find the plumbing design drawings, it's the work of moments.
It'd be fantastic to get some really good pictures of Europa (life!)
Any life on Europa which isn't considerably more technologically advanced than ours is going to be on the underside of 30-50km of ice. Now, ice pictures can be pretty, but it's a monomineralic rock with a coarse grain due to regular resublimation and/ or refreezing. Even under crossed polars and thick sections, "dull" is going to come to mind. (OK - I've probably done a few hundred thousand rock descriptions more than you. I've a higher "dull" threshold than most people for rocks. But "dull" will come.
and Io (volcanoes!).
Now you're tempting me. But not strongly enough.
Or just put it in a relatively distant parking orbit around Jupiter and (because it's solar powered) let it monitor the Jovian system for (hopefully) decades
Nowhere near enough. Decades isn't remotely good enough. When we're talking about (potentially) wiping out the only other origin of life in the universe from our own... I'd put the "you fuck with not" time scale at several times the duration of our genus. Ten million years is a reasonable round number to start upwards from.
NASA would seem to agree with me - hence the dive into Jupiter.
this is the kind of banal reply I predicted the GP would get. Don't you think everybody and their dogs already know what you wrote?
Shooting an anti-science ignoramus like hcs_$reboot in the arse is generally a positive contribution - to humanity in general and Slashdot in particular. Unlike your utterly useless comment.
I thought exactly the same too. And I've spent years hanging my life (and other people) off "self-driving bolts" driven into limestone cliffs etc.
The "self-driving" designation, for Hilti, at least, refers to "in this package are a combination of hole-cutting bit and permanent anchor" ; you're still expected to supply the power (elbow grease), holding tool (a sort of cold chisel body), and final connector (which threads into the bolt, and has a head of your choice for your application).
Actually, Hilti still supply the final connectors, but not the single-use bits. And I can understand why. They take real care from the end-user.
If you brought it on a credit card, and the company in question was selling it prior to it receiving it's CE/ EN approvals, then you've got grounds for a chargeback on the credit card, and let their 363kg (800lb) legal gorillas argue it with the manufacturers/ importers.
But those approvals concern electrical safety - which hasn't been challenged. Whether the CC company would take the manufacturer/ importers failure to realise that data protection laws apply.... much more dubious. But you're better positioned with a 363kg gorilla leading your fight. If you paid by diect debit or whatever, you're pretty fucked. try to sell them to Americans. NSA staffers for their family's kids, perhaps. You might even cover your arse by making the "supplier's packaging" that describes it as a "covert spy doll" with more decorative interior layers of packaging for the target to see.
Let me respond... as an actual, real life, genuine, pure-blooded... recovering Jew... I can't tell whether I should take offense to this or laugh my ass off at it.
Surely you can do both? Public ridicule is one of the most effective responses to offending events.
And then you can use the fence for something useful.
Old joke :
Masochist to Sadist : "Bite me, beat me, fuck me! Come in my arse and tell me you hate me!"
Sadist (with the sneer of a British Butler to an under-gardener's assistant) : "No."
In reality, there was probably a set of reasons more like
(1) we've decided to use these chips because they're cheap and promised to be available for shipping in 8 weeks ; here are prototypes.
(2) Software Div. needs to write this sort of data in 32bit words and read this in 64bit words. So we'll do that.
(3) Testing called on Friday about last week's version ; on memory block #4 they get errors because the readout isn't fast enough, so if we mirror that to here we can do interlaced async reads and get 30% better readout rate. So have that ready for Wednesday. And Software want blocks #6 and #8 to be 32bit ROM words but block #7 to be 64bit RAM.
(4) the chip fabbers say they should get 3% higher bus stability, but we don't have time to deal with that and we'll assume the production chips will be as unstable as the preproduction examples we've got. Get to it!
f I actually wanted any of the extra benefits like medical. I don't go to the doctor in the last 5 years, because I have too much work to do.
At least one person in this exchange doesn't understand the meaning of "insurance", and I spent a year at college doing Statistics with second highest exam results for the year.
Which is understandable, I suppose, if you have "free at the point of use" healthcare which is paid for through general taxation ; you may mistake the medical premiums as being "payment for the doctor", while in fact they're a fixed fee for there being a doctor (hospital, MRI, oncologist, whatever) to call. You know how your car insurance covers claims over a certain amount (the "excess", in our terminology ; yours may differ, but the concept will be there) ; well your medical insurance does similarly, but with a more complex list of exclusions.
Creating such an artificial environment in space "from scratch" may be much harder, than using the readily-made planet.
Do you have any idea of the gigatonnages of material needed to terraform a planet like Mars to Everest-summit-at-the south-pole levels?
For Mars, to bring it up to an average atmosphere that is merely lethal (0.1 bar - your tears would boil - followed by your blood) you'd need to deliver around 800kg of suitable gasses per square metre. That's around 2*10^19 kg for the whole planet. Something like 1% of mass of the asteroid belt, if it's as volatile-rich as the gassiest areas seen by Dawn on Vesta.
Essentially, you're going to need to mine most of the asteroid belt for gases to terraform Mars. And you're seriously going to propose that level of exploitation without - as a pure side line - learning how to live in space? Not going to happen.
(Another tiny factor for terraformers to contemplate : Earth surface = 511 million sq.km ; adding Mars would get you another 144 million sq.km (neglecting any Martian oceans - which I can't envisage you having a vaguely stable environment without), less than 30% of our current land area, or around 2 gigapeople worth.
What benefit are you expecting from terraforming Mars again? Or is it total wish-fulfilment fantasy?
Doesn't change the fact that everyone says AC and BC.
This is flat out untrue. It could only be true if you spoke to no-one in your "real life" experience who had any background or interest in one of the historical sciences. It's possible that you have such a benighted existence, but I hope you have a more varied life than you imply.
I really doubt you (yes, you as a person) say in real life CE
I do say CE / BCE in real life. Whenever we're talking about historical matters at the pub - e.g. with the digger-driver with his collection of locally found stone tools. Or when talking about the several Neolithic to possibly Iron Age burial structures in the area.
Why would you not use the correct terminology? The one thing we can be sure about is that the arrow-knappers and burial-makers were not Cleesian due to this being centuries to millennia before the claimed life of Cleese
The change from Nicene terminology ("Anno Domini" & "Before Christ") to Common Era terminology is certainly not an American-versus-RestOfTheWorld question, nor even a particularly religious question.
Hanging a dating system off on specific person's birth date has certain problems for historical work, in particular, some historical facts are needed about this person (call him Cleese, and we can all perform the Parrot Sketch before shuffling off) - such as the day of year that Cleese was born on (not in any of the manuals - indications of winter, maybe around the winter solstice?) ; also the year would be a good idea (from 1952 to 1957 BP, as defined above, even according to people who accept the next point) ; and finally, it would be a good idea to be confident that this Cleese person actually existed.
To get around these multiple problems of historical detail, the Common Era is set up to align with the astronomical measures with 0 CE being 4713 years after the last time that the Solar, Metonic and indiction cycles of eclipses and the Moon combined. Simple.
It's only since (approximately) 1750 CE that people have built kin's out of "fire brick", loaded them with prepared forms (with glazes, etc), spent days firing them up and cooling them down, then carefully emptied the debris and successful product out of the kiln before re-use.
Before then, the kiln was built around the charge of forms using basically the same clay as the forms, the fire started in the integrated hearth (chimney also integrated to draw the fire), and the charge fired up over several days before the fire was put out and the kiln allowed to cool to the point it could be torn down to unload. Posh kilns with a lot of clay supply might make a hearth and kiln floor of fire brick for re-use, but generally it was as efficient a system as building a space ship then throwing it into the ocean after using it once.
Using magnetostratigraphy (field strength changes compared to a standard - usually ocean core sediments - with a magnetism-independent dating method, such as biostratigraphy or tephra beds) is old hat. The new idea here is that the tax seals provide a date for each sample, and the magnetic traces in the pottery provide an estimator of the field strength at that time, increasing resolution of the variation in the geomagnetic field in the past.
To be clear are you suggesting there is a measurable amount of cancer caused by radiation from space?
This has been known for decades - since the start of regular flying at high altitude (above much of the atmosphere's protection) and over the pole (away from a lot of magnetic shielding) on routes like London-Tokyo. Crews have noticeable health deficits, including cancers, and it became a workplace hazard their employers must manage. Which they do by rota-ing, moving people between routes, etc.
There's a dose-response relationship. It's not the cleanest in the universe, but [meh].
Actually, there have been a couple of cases where the decades-to-centuries cooling duration of lava intrusions (less variable than lava flows ; more accurately modelled) has suggested that reversals can take place in the decades or so time scale... but they were single dat points. This method looks considerably more scalable.
There's at least one professional geologist in this conversation. That geologist thinks that almost always, rocks are dated by correlation of either fossil content, or stratigraphical arguments to rocks that have better fossil suites than your target rocks.
Sure, radiometric dating may give you an answer - to which question : the age of the sediment grains (as if they might not differ by a couple of billion years between the quartz and the feldspars) ; or the age of the minerals deposited in the original pore space of the rock (up to hundreds of millions of years after the sediment was deposited) ; or minerals formed in weathering of the original cement over the last few tens of millions of years.
Quoth [physics Nobel] John Wheeler, "not even wrong".
he's going to be running the whitehouse.ru website.
Oh - Rule 34 alert! Whether or not it's a pr0n site, let alone a "tiny hands and hard sports" site, I don't know. But I'm seeing that domain linked to two addresses in 90.156.201.xxx
No idea who is cybersquatting on it, but props for forethought and planning.
Slashdot Mirror
Without getting into essential complexities (e.g., the orbits are not circular, but elliptical), there's one very simple check that you don't seem to have considered. The 1.3 difference in orbital inclination between Earth and Jupiter means that the projection of the Earth's magnetotail out to Jupiter's orbit will be up to 23 million km (nearly 1/4 AU) above or below the line of Jupiter's motion. Without doing the maths (but eventually the maths must be done), I'm not at all convinced that the magnetotail of Earth encounters the magnetic bow-shock of Jupiter with any degree of frequency. I'm also sceptical that if such an interaction occurs (more than a few times a millennium) then the forces involved are going to be any appreciable fraction of the varying forces projected from the Solar wind onto the magnetic field of Jupiter.
You do raise a sort-of plausible scenario. but if you were saying this across the desk from your MSc or PhD supervisor, they'd tell you to go away and do the maths to estimate the frequency of such an interaction in the real Solar system, and the forces generated compared to stochastic variations. It's called doing a feasibility study.
The Ulysses probe probably has some of the best data for you to consider, in respect of actual measurements of magnetic interactions in the middle part of the Solar system.
.... which 'knowledge' cabbies routinely beat, by significant margins. You see, maps don't contain everything, and real-time traffic information can't tell you what the traffic is likely to be in 15 minutes from now.
You probably don't understand why people want uncut, on-matrix diamonds either, despite them being vastly more interesting than the shit DeBeers sell.
Why are you asking women about diamonds? They're only associated with women in particular due to some shit from some advertising campaign somewhere. When I got engaged, I looked for and found a very interesting piece starring an olivine (a very interesting mineral) and the fiancee loved the fact that I'd actually spent several hours thinking about our engagement ring instead of sucking from the dick of some advertising fuckwit.
I'd advise you to do your critical reading. Look at the numbers and you'll find that the range of solar sunspot cycles is from 8.8 years to 14 years ; the corresponding orbital period for Jupiter is 11.875 years - 4331 days - with a variation of a lot less than a day. Remember that Ole Roemer was using apparent errors in the position of Jupiter's moons to prove that the speed of light is finite in the 1720s, for which they needed to know the orbital period of Jupiter to better than 10 minutes (~0.7% of a day).
We all know the line about "correlation is not causlity" ; but you don't even have a correlation.
The Iapetus suture runs through Norway, southern Scotland, Ireland, and displaced by the Atlantic, off into Newfoundland and is similarly quiet. Not completely quiet, but we get fewer earthquakes than Oklahoma or New Madrid (for the last couple of centuries).
However, many models for terrestrial abiogenesis have it occurring in hydrothermal circulating systems and only using chemotrophic processes, not photosynthetic processes. Photosynthesis seems to be hundreds of millions of years, or maybe a billion years later.
Maybe, maybe not ; for a number of possible reasons.
(1) Do the main and attitude drive systems use the same fuels? For the large number of anticipated firings for the attitude thrusters, you'd maybe go for reliably hypergolic fuel/ oxidiser couples (i.e., on contact, they ignite). But for the main engine with only a handful of planned firings you might choose a monoprop with electrical ignition. That question is readily amenable to research.
(2) Is there a cross-feed system from main thruster fuel tanks and pressurisation to attitude thruster fuel tanks and pressurisation? Or, to rephrase the same question - is there a mission-critical need for such a cross-feed? Because if the system isn't absolutely essential, it would have not been designed. Remember that every valve (not "most" but "every") and every joint in a pressurised fluid system is a potential leak point. Again, if you find the plumbing design drawings, it's the work of moments.
Any life on Europa which isn't considerably more technologically advanced than ours is going to be on the underside of 30-50km of ice. Now, ice pictures can be pretty, but it's a monomineralic rock with a coarse grain due to regular resublimation and/ or refreezing. Even under crossed polars and thick sections, "dull" is going to come to mind. (OK - I've probably done a few hundred thousand rock descriptions more than you. I've a higher "dull" threshold than most people for rocks. But "dull" will come.
Now you're tempting me. But not strongly enough.
Nowhere near enough. Decades isn't remotely good enough. When we're talking about (potentially) wiping out the only other origin of life in the universe from our own ... I'd put the "you fuck with not" time scale at several times the duration of our genus. Ten million years is a reasonable round number to start upwards from.
NASA would seem to agree with me - hence the dive into Jupiter.
Shooting an anti-science ignoramus like hcs_$reboot in the arse is generally a positive contribution - to humanity in general and Slashdot in particular. Unlike your utterly useless comment.
The "self-driving" designation, for Hilti, at least, refers to "in this package are a combination of hole-cutting bit and permanent anchor" ; you're still expected to supply the power (elbow grease), holding tool (a sort of cold chisel body), and final connector (which threads into the bolt, and has a head of your choice for your application).
Actually, Hilti still supply the final connectors, but not the single-use bits. And I can understand why. They take real care from the end-user.
But those approvals concern electrical safety - which hasn't been challenged. Whether the CC company would take the manufacturer/ importers failure to realise that data protection laws apply .... much more dubious. But you're better positioned with a 363kg gorilla leading your fight. If you paid by diect debit or whatever, you're pretty fucked. try to sell them to Americans. NSA staffers for their family's kids, perhaps. You might even cover your arse by making the "supplier's packaging" that describes it as a "covert spy doll" with more decorative interior layers of packaging for the target to see.
Surely you can do both? Public ridicule is one of the most effective responses to offending events.
And then you can use the fence for something useful.
Masochism?
Both?
Old joke :
Masochist to Sadist : "Bite me, beat me, fuck me! Come in my arse and tell me you hate me!"
Sadist (with the sneer of a British Butler to an under-gardener's assistant) : "No."
In reality, there was probably a set of reasons more like
(1) we've decided to use these chips because they're cheap and promised to be available for shipping in 8 weeks ; here are prototypes.
(2) Software Div. needs to write this sort of data in 32bit words and read this in 64bit words. So we'll do that.
(3) Testing called on Friday about last week's version ; on memory block #4 they get errors because the readout isn't fast enough, so if we mirror that to here we can do interlaced async reads and get 30% better readout rate. So have that ready for Wednesday. And Software want blocks #6 and #8 to be 32bit ROM words but block #7 to be 64bit RAM.
(4) the chip fabbers say they should get 3% higher bus stability, but we don't have time to deal with that and we'll assume the production chips will be as unstable as the preproduction examples we've got. Get to it!
At least one person in this exchange doesn't understand the meaning of "insurance", and I spent a year at college doing Statistics with second highest exam results for the year.
Which is understandable, I suppose, if you have "free at the point of use" healthcare which is paid for through general taxation ; you may mistake the medical premiums as being "payment for the doctor", while in fact they're a fixed fee for there being a doctor (hospital, MRI, oncologist, whatever) to call. You know how your car insurance covers claims over a certain amount (the "excess", in our terminology ; yours may differ, but the concept will be there) ; well your medical insurance does similarly, but with a more complex list of exclusions.
Do you have any idea of the gigatonnages of material needed to terraform a planet like Mars to Everest-summit-at-the south-pole levels?
For Mars, to bring it up to an average atmosphere that is merely lethal (0.1 bar - your tears would boil - followed by your blood) you'd need to deliver around 800kg of suitable gasses per square metre. That's around 2*10^19 kg for the whole planet. Something like 1% of mass of the asteroid belt, if it's as volatile-rich as the gassiest areas seen by Dawn on Vesta.
Essentially, you're going to need to mine most of the asteroid belt for gases to terraform Mars. And you're seriously going to propose that level of exploitation without - as a pure side line - learning how to live in space? Not going to happen.
(Another tiny factor for terraformers to contemplate : Earth surface = 511 million sq.km ; adding Mars would get you another 144 million sq.km (neglecting any Martian oceans - which I can't envisage you having a vaguely stable environment without), less than 30% of our current land area, or around 2 gigapeople worth.
What benefit are you expecting from terraforming Mars again? Or is it total wish-fulfilment fantasy?
This is flat out untrue. It could only be true if you spoke to no-one in your "real life" experience who had any background or interest in one of the historical sciences. It's possible that you have such a benighted existence, but I hope you have a more varied life than you imply.
I do say CE / BCE in real life. Whenever we're talking about historical matters at the pub - e.g. with the digger-driver with his collection of locally found stone tools. Or when talking about the several Neolithic to possibly Iron Age burial structures in the area.
Why would you not use the correct terminology? The one thing we can be sure about is that the arrow-knappers and burial-makers were not Cleesian due to this being centuries to millennia before the claimed life of Cleese
Hanging a dating system off on specific person's birth date has certain problems for historical work, in particular, some historical facts are needed about this person (call him Cleese, and we can all perform the Parrot Sketch before shuffling off) - such as the day of year that Cleese was born on (not in any of the manuals - indications of winter, maybe around the winter solstice?) ; also the year would be a good idea (from 1952 to 1957 BP, as defined above, even according to people who accept the next point) ; and finally, it would be a good idea to be confident that this Cleese person actually existed.
To get around these multiple problems of historical detail, the Common Era is set up to align with the astronomical measures with 0 CE being 4713 years after the last time that the Solar, Metonic and indiction cycles of eclipses and the Moon combined. Simple.
Before then, the kiln was built around the charge of forms using basically the same clay as the forms, the fire started in the integrated hearth (chimney also integrated to draw the fire), and the charge fired up over several days before the fire was put out and the kiln allowed to cool to the point it could be torn down to unload. Posh kilns with a lot of clay supply might make a hearth and kiln floor of fire brick for re-use, but generally it was as efficient a system as building a space ship then throwing it into the ocean after using it once.
The PhD is out there waiting for you to come along and fund it.
Clear as mud now?
It's on PNAS Early - Sci-hub.io should be fine with it.
WIYF
Sorry it has taken so long to answer your (perfectly reasonable) question. Been on vacation.
This has been known for decades - since the start of regular flying at high altitude (above much of the atmosphere's protection) and over the pole (away from a lot of magnetic shielding) on routes like London-Tokyo. Crews have noticeable health deficits, including cancers, and it became a workplace hazard their employers must manage. Which they do by rota-ing, moving people between routes, etc.
There's a dose-response relationship. It's not the cleanest in the universe, but [meh].
Actually, there have been a couple of cases where the decades-to-centuries cooling duration of lava intrusions (less variable than lava flows ; more accurately modelled) has suggested that reversals can take place in the decades or so time scale ... but they were single dat points. This method looks considerably more scalable.
There's at least one professional geologist in this conversation. That geologist thinks that almost always, rocks are dated by correlation of either fossil content, or stratigraphical arguments to rocks that have better fossil suites than your target rocks.
Sure, radiometric dating may give you an answer - to which question : the age of the sediment grains (as if they might not differ by a couple of billion years between the quartz and the feldspars) ; or the age of the minerals deposited in the original pore space of the rock (up to hundreds of millions of years after the sediment was deposited) ; or minerals formed in weathering of the original cement over the last few tens of millions of years.
Quoth [physics Nobel] John Wheeler, "not even wrong".
Oh - Rule 34 alert! Whether or not it's a pr0n site, let alone a "tiny hands and hard sports" site, I don't know. But I'm seeing that domain linked to two addresses in 90.156.201.xxx
No idea who is cybersquatting on it, but props for forethought and planning.