So you didn't actually read the fucking article. The central core ("pit") of the bomb was removed before flight leaving the considerably less dangerous and less radioactive outer parts of the bomb (but most of the mass.
You probably don't know much about radioactivity, so you probably can't use the half lives of the isotopes (U-238 ~ 4470000 thousand years; U-235 ~ 700000 thousand years; Pu-239 24 thousand years) to calculate the (relative) activity. You'd probably be terrified if I gave you a shot of fine single-malt whisky in a vintage 1930s luminous green glass tumbler (with it's 3-5% of undepleted uranyl oxide colouring the glass). You would also be un-reassured by the fact that I let you choose which glass to use, and then drank from the other.
I like the great outdoors too - though it's tried to kill me on more than a few occasions. On the other hand, I get to work in pressurised aluminium tubes and work in steel boxes bolted to a steel boat on the sea.
By the time there have been people living in $Colony$ for several generations, then there might possibly be a faint chance of having sufficiently terraformed a Venus-analogue planet that you could survive (briefly) on the surface in an armoured atmosphere suit (pressure suit, but with lower pressure inside than outside). Terraforming a Mars-analogue... you might have got a couple of percent into the process of adding atmosphere by cometary bombardment (or you might still be building the infrastructure to deliver the thousands of necessary comets to the planets surface.
If you're lucky enough to have an Earth-analogue planet in your system, with a lovely disequilibrium (e.g. oxygen and methane co-existing) atmosphere, your AI managing the embryo-tanks would probably be keeping the number of contaminants (lifeforms) to the absolute minimum and building infrastructure for landing profoundly sterile biolabs onto the surface and beaming the data back to "home" (the Solar system, if that was home). Sample return to Earth would probably be in the process of being built too. Humans can wait - or be kept to the absolute minimum, if they're necessary.
There would be no novelty about living in space habitats. It would be a choice of that, or dying.
Without immense amounts of Unobtanium-115, nobody who has ever walked on the Earth's surface is ever going to walk on a planet that orbits another star. OK - caveat on that : in some 70 or 80 thousand years we'll have a star (I forget the designation) passing by at around a light year. It's just conceivable that a person with mud on their feet could walk on one of that star's planets. If it has any. Oh, sorry, it's Scholz's star, and it was 70kyr ago, not 70kyr in our future. The next closer is probably 1.3 to 1.4 Myr in the future.
Precisely. Spend a few years reading the actual papers that scientists publish for their peers to read and you'll realise that people don't say much about it because it's probably not true. "Our" Solar System has been a pretty violent place in the past, and could be in the future (remember the study that raised a couple of % probability of Venus and Earth swapping places in the order from the Sun and Mercury or Mars being ejected from the system? If that's a possible result of the "protection" of the gas giants... maybe it's not that much protection.
Really, we need a less-biased sample of planetary systems (our detection methods are severely biased), and then each one needs a lot of orbital modelling - once we're reasonably sure of the distribution of masses and orbits in each system. Then you need to re-do the modelling with different distributions of plausible initial matter. For each system.
Currently, we're at the "stamp collecting" stage of the process. We're trying to reduce the biases in the detection methodologies. On case-by-case basis, we're looking at the systems we can measure, but we're still discovering new systems.
When Kepler finally breaks down irretrievably and there's no new data coming in (apart from a small amount of detail work from JWST and ALMA, but not surveying work), then more work will be done on the existing data set.
How do mission planners take into account solar systems with unknown number of planetary bodies with varying masses?
Well for starters, there's no reason to fly in the plane of the ecliptic of the target system. So you'd never come particularly close to any of the planets.
Secondly, you're sending a probe to this system instead of that or the other system. So, you've got some reasons for doing that (alternative : your bosses trust you so much that they're going to spend billions of EuroPoundDollars of tax payer's or investor's money on your whim, completely unsupported by any evidence. I wouldn't like to be in your shoes if that were the case, because I'm not monomaniacally self-confident.).
Your most likely reason for making that choice is going to be one of (1) transit observations ; (2) radial velocity observations or (3) direct imaging with a coronograph. Method (1) means that we (sol) are within a degree or several of the ecliptic of that system. Method (2) will give you a minimum planetary mass in "m sin(i)" where the i is the inclination of the planet's orbit (and therefore, approximately, the plane of the ecliptic of that system) and the line of sight to it. This method is insensitive to systems with the inclination perpendicular to the line of sight. Method (3) has no major biases apart from for closer systems. So, you'd apply all three of those techniques, to spot the larger planets. You'd do modelling to work out if the system has had a lot of planets moving around - which will probably reduce the amount of small material in the inner system. You'll look for dust - as evidence for the presence of small stuff.
Oh - were you looking for planets? I wasn't. We'll build these technologies in space, with people living most or all of their lives in space. Once you're really living in space, what use do you have for groundlings on planets? Why would you look for a planet? (Commentators, please be imaginative enough to not bring out the trope that "radiation is too high", or "you need gravity to bring a foetus to term" ; both of these are (a) unproven, and (b) amenable to engineering, e.g. by rebuilding km-scale asteroids.
Just an assembler which makes larger assemblers, guided by signals from home.
Only the very highest level of control from "home" (see end note) would be necessary. Near total autonomy would be necessary.
The first humans to make the trip would be essentially teleported to their destination.
Hmmm, The amount of data to be transmitted, and the error-checking needed to ensure that a "personality" had actually been sent, is high. A pretty steep obstacle. Why bother? Why not just send some tissue cultures, some nutrients (most being derived as by-products of the mechanised construction of a space industry by the first Von Neumannn achines), and some sperm and eggs of various species, including humans. Then grow the new inhabitants at the far end. Eventually of course you'd lose "control" of the colony, but since that has always happened before after at most a few generations, you knew that was going to happen when you started on the colonisation programme. (If you didn't know, you've just been told.)
What is your actual purpose behind your colonisation programme? It seems to be different to mine. I just want to see life spread, and possibly our descendants (well, your descendants) will eventually meet other life forms.
[End note] Since an autonomous space industry would need to be built by the colonisation probe while collecting materials for growing the colonists (and that's probably a 30 year project already), there's nothing to even slow that system from building the infrastructure for building the ext set of colony ships. Even if they didn't do it automatically, within a few generations I'm sure the colonists would do it themselves. So, after the first few colonies are established, then for the average colonisation probe, "home" becomes increasingly unlikely to be "Earth".
In the history of the Solar system - the only example we have a good understanding of - the orbital interactions of Jupiter and Saturn were (probably) responsible for the "Late Heavy Bombardment" (LHB) of the inner solar system. But the oldest fossils are found from times not long (~ 1/5 to 1/4 of the then-age of the solar system) after that, and there are hints (well, two hints, both moderately controversial and disputed) of life affecting the carbon cycle considerably before then. Clearly the LHB didn't kill off life - we're here. Arguably, the LHB may have been necessary for the development of life (certainly the argument has been made. Not everyone accepts it.)
But to stay on the point of the "space guard" role of the gas giants. What "guard" role? Yes, Jupiter in particular does throw a lot of objects out into the Oort cloud and Kuiper Belt. The ones in the Kuiper Belt come back as comets at some later date - which may or may not hit anything on the way back. The ones in the Oort cloud also seem to come back - as long period comets, or ones with "hyperbolic" orbits. I can't do the celestial mechanics calculations myself, but I don't think that the gas giants do anything other than delay the dangers from any particular object.
If you want a "space guard", how about the Sun. By impacting every iceball in the inner Solar system with light, then it gradually erodes their mass and so reduces the potential damage they can do to anything they hit.
Yes, I have seen claims like this on things like the Discovery Channel (back when I had that channel - I didn't think it worth paying for). I've even seen it coming out of the mouths of perfectly respectable astronomers and planetary scientists. And when you read technical papers from those same scientists... it's not there. I think it's the sort of sound bite that TV producers like to try to get, and then they use it when they get it, discarding the more cautious statements to the cutting room floor as being not-sexy-enough.
advanced intelligence probably needs a certain level of energy intensity across the spectrum in order to develop
Do you have a rationale for making this suggestion. E.G. some biological process unique to "advanced intelligence" and which requires... well it sounds as if you mean green- or blue- coloured light?
I know of no biological process unique to "advanced intelligence", for a start. Onegaishimasu - educate me.
Could we build a ship with the existing one, assume again unlimited power reactor somehow and then fire the thing up, would I be right in thinking this thing would incredibly slowly start moving the ship and over a ridiculous amount of time, eventually be moving very rapidly and in theory (?) just keep on accelerating?
We've had around a half-dozen (I'm not counting any more) spacecraft launched with ion-drive systems. None launched by ion drives of course - the power levels needed are far above what ion drives an provide. But if you look at the mission profiles for some of the deep space ion drive missions, you'll get an idea about the prospects for this sort of drive.
Of course for the trip to be reasonable you have to turn around and start decelerating at some point.
That depends on the purpose of your mission. If you're only looking to do passive viewing of the target, why slow down? At c/3, you'd have about 34 hours to cover the space inside Pluto's orbit. Depending on what you know from mission planning (a lot!) and from viewing before the flyby, you'll be able to learn a lot in that flyby. Witness New Horizons.
Would we see a passive probe doing a c/3 flyby of the Solar system? I see no reason to expect so.
Well assuming that this was a late draft of the paper to be published, I'm now much more informed about what the system proposed is. And it's a lot different to what I'd thought. For a start, there seems to need to be this "test object" in the throat of the frustrum (not "conical") wave guide. That changes my mental image of the system by a lot.
Well let's see what the engineers have to say. There should be enough information in the reports for someone to replicate the results. Though the availability of metre-plus vacuum chambers is not likely to be high.
Agree with Sarusa (104047) - that's excellent. Just spent over a quarter hour trying to get the PDF onto my hard drive - which was starting to make me suspicious, but it's finally worked. And then I find that it's a scan of the document, so to do text search etc I need to jump through hoops of OCR. Obviously this is not from anyone actually anywhere near the actual data.
Damn. The guy obviously writes on a system with a different code page to either mine, Slashdot's, or both. And we all know how broken Slashdot's assumptions about it's users and their languages are. And just for Rei, here's a thorn : (AltGr+p)þ ; (character entity "& THORN;" which should also be UNICODE 00DE) ; (character entity "& thorn;" which should also be UNICODE 00FE) ; and there's one in my thumb too.
People who take Ubers are not always sober, nor always fluent in English, but at least they know their own first name.
Assuming that they have a first name. Not all cultures do.
[Searches for link] Here it is : Falsehoods Programmers Believe About Names, from which several relate directly to your incorrect assumptions (note from the numbers how far down the list your assumptions are ; there are much more fundamental mistakes you can make, e.g. that people have names):
18. Peopleâ(TM)s names have an order to them. Picking any ordering scheme will automatically result in consistent ordering among all systems, as long as both use the same ordering scheme for the same name.
19. Peopleâ(TM)s first names and last names are, by necessity, different.
20. People have last names, family names, or anything else which is shared by folks recognized as their relatives.
21. Peopleâ(TM)s names are globally unique.
22. Peopleâ(TM)s names are almost globally unique.
Also, to predict one of your likely objections,
29. Confound your cultural relativism! People in my society, at least, agree on one commonly accepted standard for names.
What do you want Uber to do? Assign a randomly generated nickname or password to each passenger.
Or even a user-provided nickname and/ or password?
Hey, Slashdot let me choose my user name nearly 20 years ago (actually, shouldn't the 20th anniversary be coming up soon? Quick Wiki : "Launched October 5, 1997; "). From the increasing desperation of noob's user names, there is probably some effort to avoid close similarities with existing user names. If Slashdot can do it for nearly 20 years, it's probably not terribly difficult.
The first ship to a remote star could be very small. Just an assembler which makes larger assemblers
Frozen wombs (and associated heart-lung machines) with a bucket full of frozen sperm and eggs. The technology is here already.
It's a "6 vs 2x3" question if we'd improve the technology in the millennium or two while the machine (plus eggs and sperm) was in flights, but fundamentally that's a software issue not the hardware in flight. If the labs on Earth come up with a better way of treating the gametes, upload it (after testing) and in a few generations you might see an answer.
Yes, what indeed is the problem? 'It isn't Kansas any more' as some dog who never went to school once said. If the environment is within the liquid range of water (NB - pressure not counted ; H.sap is moderately labile in this respect, and as long as you don't change presure at more than a factor of 2 per month... small fucking deal.)
Oh, it's unfamiliar. Well [hand gestures indicating "big", "mammalian sexual activity", and "redistribution of cards between players".
[Atmosphere condenses at pole-of-cold] First approximation. Second approximation is that there is heat transfer. Third approximation is that it's a complicated question. And that's before you look at complicated orbits, and complex geology.
Yes, freezing out on the cold-of-pole isn't impossible. But it's by no means inevitable.
Thinking about Earth I would expect that a constant pattern of air streams could form which transfers the heat between hot to cold areas.
Stop dragging reality into a discussion about reality - you'll drag Slashdot (kicking and screaming) into reality.
Which is why the first thing one does before landing an amphibious assault force is to remove any blades of grass by bombardment with high-explosive shells from your seaborn and airbrn forces.
Mass invasion is a different thing to landing sabotage / Fifth column forces. Neither Germany nor Japan was within some thousands of mile of close enough to non-Alaskwiian USA mainland for it to be a plausible scenario. Possibly you might wish to enquire why Ghengiz Khan didn't invade Japan by sending forces to California (from Szechuan) and invading from there.
I was actually thinking (very vaguely) of Aldiss' Heliconia (books, and planet). Though I suspect that attaining sufficient environmental stability in a complex system might be challenging for a narratively interesting planet, biologically spending a lot of time in hibernation / aestivation with brief periods of activity when the environment allows, is an effective strategy.
Never having read a word of it, or seen a second of it, I thought "Game of Throwns" was set on Earth?
Slashdot Mirror
It would be worse if they killed the kittens but did not eat them, meaning their deaths were a total waste.
You probably don't know much about radioactivity, so you probably can't use the half lives of the isotopes (U-238 ~ 4470000 thousand years; U-235 ~ 700000 thousand years; Pu-239 24 thousand years) to calculate the (relative) activity. You'd probably be terrified if I gave you a shot of fine single-malt whisky in a vintage 1930s luminous green glass tumbler (with it's 3-5% of undepleted uranyl oxide colouring the glass). You would also be un-reassured by the fact that I let you choose which glass to use, and then drank from the other.
By the time there have been people living in $Colony$ for several generations, then there might possibly be a faint chance of having sufficiently terraformed a Venus-analogue planet that you could survive (briefly) on the surface in an armoured atmosphere suit (pressure suit, but with lower pressure inside than outside). Terraforming a Mars-analogue ... you might have got a couple of percent into the process of adding atmosphere by cometary bombardment (or you might still be building the infrastructure to deliver the thousands of necessary comets to the planets surface.
If you're lucky enough to have an Earth-analogue planet in your system, with a lovely disequilibrium (e.g. oxygen and methane co-existing) atmosphere, your AI managing the embryo-tanks would probably be keeping the number of contaminants (lifeforms) to the absolute minimum and building infrastructure for landing profoundly sterile biolabs onto the surface and beaming the data back to "home" (the Solar system, if that was home). Sample return to Earth would probably be in the process of being built too. Humans can wait - or be kept to the absolute minimum, if they're necessary.
There would be no novelty about living in space habitats. It would be a choice of that, or dying.
Without immense amounts of Unobtanium-115, nobody who has ever walked on the Earth's surface is ever going to walk on a planet that orbits another star. OK - caveat on that : in some 70 or 80 thousand years we'll have a star (I forget the designation) passing by at around a light year. It's just conceivable that a person with mud on their feet could walk on one of that star's planets. If it has any. Oh, sorry, it's Scholz's star, and it was 70kyr ago, not 70kyr in our future. The next closer is probably 1.3 to 1.4 Myr in the future.
Really, we need a less-biased sample of planetary systems (our detection methods are severely biased), and then each one needs a lot of orbital modelling - once we're reasonably sure of the distribution of masses and orbits in each system. Then you need to re-do the modelling with different distributions of plausible initial matter. For each system.
Currently, we're at the "stamp collecting" stage of the process. We're trying to reduce the biases in the detection methodologies. On case-by-case basis, we're looking at the systems we can measure, but we're still discovering new systems.
When Kepler finally breaks down irretrievably and there's no new data coming in (apart from a small amount of detail work from JWST and ALMA, but not surveying work), then more work will be done on the existing data set.
Well for starters, there's no reason to fly in the plane of the ecliptic of the target system. So you'd never come particularly close to any of the planets.
Secondly, you're sending a probe to this system instead of that or the other system. So, you've got some reasons for doing that (alternative : your bosses trust you so much that they're going to spend billions of EuroPoundDollars of tax payer's or investor's money on your whim, completely unsupported by any evidence. I wouldn't like to be in your shoes if that were the case, because I'm not monomaniacally self-confident.).
Your most likely reason for making that choice is going to be one of (1) transit observations ; (2) radial velocity observations or (3) direct imaging with a coronograph. Method (1) means that we (sol) are within a degree or several of the ecliptic of that system. Method (2) will give you a minimum planetary mass in "m sin(i)" where the i is the inclination of the planet's orbit (and therefore, approximately, the plane of the ecliptic of that system) and the line of sight to it. This method is insensitive to systems with the inclination perpendicular to the line of sight. Method (3) has no major biases apart from for closer systems. So, you'd apply all three of those techniques, to spot the larger planets. You'd do modelling to work out if the system has had a lot of planets moving around - which will probably reduce the amount of small material in the inner system. You'll look for dust - as evidence for the presence of small stuff.
Oh - were you looking for planets? I wasn't. We'll build these technologies in space, with people living most or all of their lives in space. Once you're really living in space, what use do you have for groundlings on planets? Why would you look for a planet? (Commentators, please be imaginative enough to not bring out the trope that "radiation is too high", or "you need gravity to bring a foetus to term" ; both of these are (a) unproven, and (b) amenable to engineering, e.g. by rebuilding km-scale asteroids.
Untrue. It might be good enough for your limited little life, but that's your deficiency, not my problem.
Only the very highest level of control from "home" (see end note) would be necessary. Near total autonomy would be necessary.
Hmmm, The amount of data to be transmitted, and the error-checking needed to ensure that a "personality" had actually been sent, is high. A pretty steep obstacle. Why bother? Why not just send some tissue cultures, some nutrients (most being derived as by-products of the mechanised construction of a space industry by the first Von Neumannn achines), and some sperm and eggs of various species, including humans. Then grow the new inhabitants at the far end. Eventually of course you'd lose "control" of the colony, but since that has always happened before after at most a few generations, you knew that was going to happen when you started on the colonisation programme. (If you didn't know, you've just been told.)
What is your actual purpose behind your colonisation programme? It seems to be different to mine. I just want to see life spread, and possibly our descendants (well, your descendants) will eventually meet other life forms.
[End note] Since an autonomous space industry would need to be built by the colonisation probe while collecting materials for growing the colonists (and that's probably a 30 year project already), there's nothing to even slow that system from building the infrastructure for building the ext set of colony ships. Even if they didn't do it automatically, within a few generations I'm sure the colonists would do it themselves. So, after the first few colonies are established, then for the average colonisation probe, "home" becomes increasingly unlikely to be "Earth".
I'm not sure that there is such a role.
In the history of the Solar system - the only example we have a good understanding of - the orbital interactions of Jupiter and Saturn were (probably) responsible for the "Late Heavy Bombardment" (LHB) of the inner solar system. But the oldest fossils are found from times not long (~ 1/5 to 1/4 of the then-age of the solar system) after that, and there are hints (well, two hints, both moderately controversial and disputed) of life affecting the carbon cycle considerably before then. Clearly the LHB didn't kill off life - we're here. Arguably, the LHB may have been necessary for the development of life (certainly the argument has been made. Not everyone accepts it.)
But to stay on the point of the "space guard" role of the gas giants. What "guard" role? Yes, Jupiter in particular does throw a lot of objects out into the Oort cloud and Kuiper Belt. The ones in the Kuiper Belt come back as comets at some later date - which may or may not hit anything on the way back. The ones in the Oort cloud also seem to come back - as long period comets, or ones with "hyperbolic" orbits. I can't do the celestial mechanics calculations myself, but I don't think that the gas giants do anything other than delay the dangers from any particular object.
If you want a "space guard", how about the Sun. By impacting every iceball in the inner Solar system with light, then it gradually erodes their mass and so reduces the potential damage they can do to anything they hit.
Yes, I have seen claims like this on things like the Discovery Channel (back when I had that channel - I didn't think it worth paying for). I've even seen it coming out of the mouths of perfectly respectable astronomers and planetary scientists. And when you read technical papers from those same scientists ... it's not there. I think it's the sort of sound bite that TV producers like to try to get, and then they use it when they get it, discarding the more cautious statements to the cutting room floor as being not-sexy-enough.
Do you have a rationale for making this suggestion. E.G. some biological process unique to "advanced intelligence" and which requires ... well it sounds as if you mean green- or blue- coloured light?
I know of no biological process unique to "advanced intelligence", for a start. Onegaishimasu - educate me.
No, the next step would be building one of these systems in a form which could survive launch into space.
Take a look at the paper. This device is a long, long way from "flight ready".
We've had around a half-dozen (I'm not counting any more) spacecraft launched with ion-drive systems. None launched by ion drives of course - the power levels needed are far above what ion drives an provide. But if you look at the mission profiles for some of the deep space ion drive missions, you'll get an idea about the prospects for this sort of drive.
Is that made of foamed or sheet unobtanium?
That depends on the purpose of your mission. If you're only looking to do passive viewing of the target, why slow down? At c/3, you'd have about 34 hours to cover the space inside Pluto's orbit. Depending on what you know from mission planning (a lot!) and from viewing before the flyby, you'll be able to learn a lot in that flyby. Witness New Horizons.
Would we see a passive probe doing a c/3 flyby of the Solar system? I see no reason to expect so.
Well let's see what the engineers have to say. There should be enough information in the reports for someone to replicate the results. Though the availability of metre-plus vacuum chambers is not likely to be high.
Off to read the thing now.
[Signs "Science" up for spam from "memory foam mattress" touts.]
Damn. The guy obviously writes on a system with a different code page to either mine, Slashdot's, or both. And we all know how broken Slashdot's assumptions about it's users and their languages are. And just for Rei, here's a thorn : (AltGr+p)þ ; (character entity "& THORN ;" which should also be UNICODE 00DE) ; (character entity "& thorn ;" which should also be UNICODE 00FE) ; and there's one in my thumb too.
Assuming that they have a first name. Not all cultures do.
[Searches for link] Here it is : Falsehoods Programmers Believe About Names, from which several relate directly to your incorrect assumptions (note from the numbers how far down the list your assumptions are ; there are much more fundamental mistakes you can make, e.g. that people have names) :
Also, to predict one of your likely objections,
Or even a user-provided nickname and/ or password?
Hey, Slashdot let me choose my user name nearly 20 years ago (actually, shouldn't the 20th anniversary be coming up soon? Quick Wiki : "Launched October 5, 1997; "). From the increasing desperation of noob's user names, there is probably some effort to avoid close similarities with existing user names. If Slashdot can do it for nearly 20 years, it's probably not terribly difficult.
They are employees, it's just that Uber don't want to admit it.
Frozen wombs (and associated heart-lung machines) with a bucket full of frozen sperm and eggs. The technology is here already.
It's a "6 vs 2x3" question if we'd improve the technology in the millennium or two while the machine (plus eggs and sperm) was in flights, but fundamentally that's a software issue not the hardware in flight. If the labs on Earth come up with a better way of treating the gametes, upload it (after testing) and in a few generations you might see an answer.
Yes, what indeed is the problem? 'It isn't Kansas any more' as some dog who never went to school once said. If the environment is within the liquid range of water (NB - pressure not counted ; H.sap is moderately labile in this respect, and as long as you don't change presure at more than a factor of 2 per month ... small fucking deal.)
Oh, it's unfamiliar. Well [hand gestures indicating "big", "mammalian sexual activity", and "redistribution of cards between players".
[Atmosphere condenses at pole-of-cold] First approximation. Second approximation is that there is heat transfer. Third approximation is that it's a complicated question. And that's before you look at complicated orbits, and complex geology.
Yes, freezing out on the cold-of-pole isn't impossible. But it's by no means inevitable.
Stop dragging reality into a discussion about reality - you'll drag Slashdot (kicking and screaming) into reality.
Mass invasion is a different thing to landing sabotage / Fifth column forces. Neither Germany nor Japan was within some thousands of mile of close enough to non-Alaskwiian USA mainland for it to be a plausible scenario. Possibly you might wish to enquire why Ghengiz Khan didn't invade Japan by sending forces to California (from Szechuan) and invading from there.
Which is not what I said.
Never having read a word of it, or seen a second of it, I thought "Game of Throwns" was set on Earth?