"Tactical sanity"? I don't know enough about what you're saying to even be able to tell if it's a joke or not.
If you're not making a joke... no, there's no realistic way for "swinging around a star" to just reverse the direction of a relativistic craft like Starshot. Even with a very close flyby, gravity's effect on its trajectory would be minimal.
I'm really interested in understanding more about dolphin communication. Because we know that they "point" at things with their sonar, and listen in to each others' sonar returns (they're one of the few animals that "points" at things as a form of communication). How far does it go? One theory I've seen is that the burst pulsed sounds can mimic sonar returns, and thus can utilize a rough pictoral communication. Whistling had long been the main focus for communication (with the assumption that burst pulsed sound was part of echolocation), but the main critique I've seen for that is that it would imply that non-whistling dolphin species don't communicate at all. Furthermore the bursts appear to be far too fast to be useful for echolocation - there's no waiting for a return, so it seems only to be useful for conveying a signal. We know that the pulsed sounds appear to form specific patterns in specific contexts, such as aggression or courtship, potentially varying depending on the species. We just don't know how to interpret them.
On a related note, my parrot literally tells me when he wants company, when he wants to be scratched, when he wants to go to bed, and when he wants a treat, and he's not happy if you do the wrong thing.
Basic single-concept communication seems to be an ability that a wide range of animals are capable of. We seem unusual in our skill at combining concepts. Some animals show a degree of limited ability at this (Pepperberg's work with Alex for example, showed that he could understand qualities of objects, differentiate based on multiple properties at once, etc), but the ability to readily convey whole thought processes seems to be what set us on the road that we ended up on versus our less successful relatives.
If we want to get into speculation, it's worth noting that Neanderthals appeared to be quite intelligent - making axes, fire, dwellings, even watercraft... yet their technology seems to have advanced little over the course of 200k years. Yet then comes Cro-Magnon man whose technology advances rapidly even as he expands his range over ~20k years - it's really astounding fast all of these new inventions come into play (musical instruments, deep sea fishing, domestication of dogs, painting, rope, pottery, harpoons, saws...). While there's evidence of some potential interbreeding with Neanderthals, by and large they replaced the species. Why did a clearly intelligent species get replaced so readily? Why did Cro-Magnon's technology improve while Neanderthal's was mostly static? How did Cro-Magnon manage to organize its larger social groups? All of this points at better communication - better ability to convey complex ideas from one individual to the next.
They mentioned in the study related research on teaching horses to navigate mazes. Horses learned the maze at different rates, but they all eventually learned it, and once they learned it they never forgot it, no matter how long it was between maze runs. Seems directly applicable to the "milk route" case.
If you want the exact wording, it doesn't say "out of the field of view", but "stepped 2-3 meters aside... standing passive to avoid giving the horse any cues". They later go further into the details of how they monitored the horse's attention and discussion of the Clever Hans effect. They also alter the sides that the different symbols were on to avoid side preferences.
There is of course a difference between being in one's field of vision and being the object focused on, which can be seen by a variety of factors, e.g. where they're pointing their head, their ears, whether there's any hesitation about the action (aka looking for outside cues), etc.
Clever Hans was an extremely well studied case. The concept that any reviewer is not going to be familiar with it and how to control for it is beyond silly.
Its still just training/conditioning to the environment and 'response and reward'
Something not disputed by the study. The top keyword in the article summary is "Operant conditioning" (followed by "Blanket", "Rug", "Thermoregulation", "Cognition" and "Clicker training"). You'd do well to read the study. The key takeaways are:
1) Horses can be conditioned via use of visual symbols 2) Horses can use this to initiate communicated preference rather than just as a response 3) Horses learned much faster using the approach in this study than others 4) Horses understood the link between wearing / removing a blanket and their eventual body temperature for the given weather conditions 5) Different horses took different lengths of time to learn the connection with the symbols, but all managed to learn it, and once it was learned it was understood effectively 100% and not forgotten with time
It's also worth mentioning that most human behaviors are also learned through operant conditioning. That's how we all learned as children. There is no simple line between human and non-human in this regard. E.g., you stick your fingers on a hot burner, you get burned, you learn to avoid hot burners without even having to think about it. Your parent holds up an alphabet block with a "Q" on it, you say "Q", you get praise. The father of operant conditioning, B.F. Skinner, mainly wrote about it with a focus on its effects on human behavior, not animal behavior in general.
Reading over the study, in case you're curious: they discuss the Clever Hans effect, how it manifests (the horse observes the trainer or audience and does what it needs to get a reward based on the audience's reaction). In this study, the trainer was off to the side, out of the field of view of the horse, and they monitored where the horse was looking to ensure it was only looking at the symbols when making its choice. Then the horse was given a reward regardless of what symbol it chose; it simply had to choose one to get a treat. The symbol touches were easy to record and unambiguous, so there was no "interpretation" of the horses behavior in question. The researchers also observed side behaviors. For example, once the horses had learned to use the symbols to control their blanketing status they often became very eager to go into the testing facilitity (before the phase where treats were on offer). It was observed that horses that sought to have their blanket removed in this manner tended to be sweaty underneath it, while those that didn't seek it out weren't.
To be fair, there's even more that could be done. I really liked the controls that Pepperberg did in her studies of Alex (the African Grey parrot). She had it set up so that the person asking a question didn't know the answer, and neither did the person scoring the result. In this case here, clearly the trainer knew the weather and thus what would be the "optimal" blanketing status. But by paying attention to where the horse's focus is, whether it's hesitating, etc, and giving it a reward either way, I agree that that's some pretty good controlling for the Clever Hans effect.
Humans have instinctual behaviours towards pattern recognition, anthromorphism, self-delusion, and rationalisation, thus experimential methods must be very carefully designed to remove these influences.
And given that it's been peer-reviewed, the presumption is that they designed their methods to do just that, rather than "peer reviewers in animal behavior aren't aware of the caveats involved in animal studies"
That doesn't mean 100% that the presumption is correct - peer review is hardly a flawless process. But it is the presumption until shown otherwise.
Q: "Hey horse - how come Christians are allowed to draw pictures of their prophets and Muslims aren't?"
A: "I don't know. I am a horse, and, as such, have no knowledge of the intricacies of Islamic theology. I assume you're asking me because I am a brown horse? In which case, go to hell."
... host notably because concrete is by definition a hydrated cement aggregate. Heating hardened cement = driving out the water = turning it back into its raw form. More to the point, portland cement is made from limestone by heating in the first place. And not only are you reducing the set cement back to dry cement, but by driving out the water you're creating steam pressure, aka making it vulnerable to spall. Have a fire on it long enough and you soften the rebar as well.
2) Who do you think owns SpaceX's competitors, starving orphans?
3) You're sitting here writing this enjoying the fruits of the orbital launch market (communications, gps, monitoring satellites, etc) while damning it. That last satellite that SpaceX lost? Most of its communications channels were allocated to providing remote areas of Africa internet service, trying to uplift a continent. But... damn them!
4) The amount of CO2 released by a Falcon 9 launch is roughly the equivalent of one transpacific flight of a 747. Which do you think does more good, a single transpacific flight or a typical satellite? Or in some cases, many satellites - the Iridium cluster for example is launched half a dozen or more at a time. They launch 6-9 per year. Think 6-9 transpacific 747 flights per year is even remotely in the ballpark of relevance in terms of global CO2 emissions?
Given that none of the articles, as far as I saw, said anything about faster than light communication, and one explicitly disavowed the concept, I think you're projecting your own mistaken conceptions here.
And your friend is correct - quantum teleportation has nothing to do with faster than light communication, as you can neither determine to what form the waveform has collapsed, nor whether one side has already collapsed it. It's effectively** equivalent to having two identical letters containing a random message sealed in an envelope, taking them to different locations, and opening them at the same time. Both sides will get the same random message at the same time, but it provides no means for conveying information faster than light. It is however useful for keysharing.
** In the real world, what is written inside the "envelopes" isn't determined until it's actually observed. But it works out to the same net effect.
Meh, so long as the facility is back to normal before their return to flight, this might even be good for them. As it stands it's only delaying ULA, increasing the already heavy global backlog on launches and making it harder for customers to bail (It's been a boom period for demand in launches, and providers were already struggling to keep up). The Russians are also suffering delays.
given that some other EU member states have a growing movement also wanting to leave
Support for leaving fell significantly in other European states in the wake of the BRexit vote. The post-BRexit chaos and hits to the market weren't exactly a shining beacon.
The UK makes up about 1/6th of the EU's trade. The EU makes up about 50% of the UK's trade. One side has leverage in these negotiations, and it's not the UK.
The EU has made one thing and one thing alone abundantly clear: there will not, under any circumstances, be access to the single market without corresponding free movement of people. And no, Norway doesn't have that (neither do we here in Iceland). It's one of the founding principles of the EU, and it will not be compromised on.
The UK can of course leave the EU and choose to allow free movement of people in exchange for access to the single market. Whether that's acceptable to UK voters is a whole different story. And playing by the regulations of the single market also kind of defeats the point of the whole brexit thing. Countries like Iceland and Norway still have to obey the vast majority of EU regulations - we just don't get a say in making them.
Check out Fig. 2 for an example. Compare, for example, the altitude range for aerobraking vs. aerocapture on Venus, versus the altitude range for aerobraking vs. aerocapture for Mars. On Mars you have very narrow altitude windows in order to get a specific deceleration profile, and error within those windows has significant consequences. Furthermore, on Venus you have no specific location to "land" on, just a specific latitude, while on Mars, your choice of landing site is highly critical.
Basically, Venus is a lot more forgiving of mistakes. You'll note that the Soviets had terrible results with Mars probes, but did quite well with Venus.
1) The winds are very mild at the ~90 bar level. You're thinking of the ~1 bar level.
2) The winds are fast relative to the surface in the cloud deck, but thats irrelevant because you're not anchored to the surface. The surface is over 50 kilometers away from you in the cloud deck. Think airplanes flying in the jet stream - it's actually more stable than flying near the surface.
What matters is turbulence, not velocity with respect to the surface. And in that regard, Venus's cloud deck seems to be roughly similar to Earth's troposphere. However, Venus has been so neglected as a destination it's hard to say that with certainty, we really need a much longer balloon probe than VEGA to help quantify it.
Refs for ballute entry: 12. Let me know if you'd like more:)
While I find the idea of a research station floating in the Venusian atmosphere really cool, I care most about what we can do now... Why aren't we doing that?
For some proposals in various stages of development to look up, check out VAMP, VEVA, VEP, EVE, VESSR, VISE, VME, VER, SAGE, Zephyr, Venera-D and VALOR:) I'm sure I'm missing a bunch. About half of those are balloons.
It's all about money. Mars gets the lion's share of NASA's robotic exploration budget. Everywhere else fights over the scraps.
I'm a bit skeptical of this landing in the atmosphere thing. You have to aerocapture the probe, let it slow down to a manageable speed, and then INFLATE A BALLOON?
Actually, we've already done this before, with Vega;) But the Vega approach doesn't scale to habitat-sizes. With the large scale you need to use a ballute. One of the neat things about ballutes is that there's been a lot of research showing that not only can they decelerate and inflate you in the atmosphere, but they can outright replace an aeroshell for reentry. Venus has been one of the prime targets for ballute research.
Note that the initial inflation and final gas mixture do not need to be the same. Also, with ballute entry, part of your inflation is in the ionosphere which is dominated by light gases.
Also note that at entry, a habitat would be vastly lighter than its ultimate mass. The envelope, propulsion, etc aren't that heavy. Even the mass of people, water plants, industrial hardware, etc - aka, things that come later - isn't that heavy. The real load is all of the propellant needed for your return rocket - many dozens of tonnes for even a minimal ascent rocket (Venus is almost as deep of a gravity well as Earth... gravity is a great thing for human health but not so much for escaping;) ). Since propellant is something produced locally (except in the HAVOC case, but HAVOC has some weird design decisions...), it's not an entry load.
Lastly, do remember that there are limits to the applicability of comparing to craft on Earth. On Earth, material costs are the limiting factor. In space applications, mass is generally the limiting factor. You choose much more expensive materials where they can save you mass (and advanced fabrics can indeed save a tremendous amount of mass versus commodity ones). Some of the prototypes Venus balloons are literally an order of magnitude lighter than you encounter for balloons on Earth of the same size.
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"Tactical sanity"? I don't know enough about what you're saying to even be able to tell if it's a joke or not.
If you're not making a joke... no, there's no realistic way for "swinging around a star" to just reverse the direction of a relativistic craft like Starshot. Even with a very close flyby, gravity's effect on its trajectory would be minimal.
They did move the symbols around. You know, the paper was linked in the summary...
Yeah, I totally believe you're an American. Totally. Look, this is my not-being-sarcastic face.
I'm really interested in understanding more about dolphin communication. Because we know that they "point" at things with their sonar, and listen in to each others' sonar returns (they're one of the few animals that "points" at things as a form of communication). How far does it go? One theory I've seen is that the burst pulsed sounds can mimic sonar returns, and thus can utilize a rough pictoral communication. Whistling had long been the main focus for communication (with the assumption that burst pulsed sound was part of echolocation), but the main critique I've seen for that is that it would imply that non-whistling dolphin species don't communicate at all. Furthermore the bursts appear to be far too fast to be useful for echolocation - there's no waiting for a return, so it seems only to be useful for conveying a signal. We know that the pulsed sounds appear to form specific patterns in specific contexts, such as aggression or courtship, potentially varying depending on the species. We just don't know how to interpret them.
On a related note, my parrot literally tells me when he wants company, when he wants to be scratched, when he wants to go to bed, and when he wants a treat, and he's not happy if you do the wrong thing.
Basic single-concept communication seems to be an ability that a wide range of animals are capable of. We seem unusual in our skill at combining concepts. Some animals show a degree of limited ability at this (Pepperberg's work with Alex for example, showed that he could understand qualities of objects, differentiate based on multiple properties at once, etc), but the ability to readily convey whole thought processes seems to be what set us on the road that we ended up on versus our less successful relatives.
If we want to get into speculation, it's worth noting that Neanderthals appeared to be quite intelligent - making axes, fire, dwellings, even watercraft... yet their technology seems to have advanced little over the course of 200k years. Yet then comes Cro-Magnon man whose technology advances rapidly even as he expands his range over ~20k years - it's really astounding fast all of these new inventions come into play (musical instruments, deep sea fishing, domestication of dogs, painting, rope, pottery, harpoons, saws...). While there's evidence of some potential interbreeding with Neanderthals, by and large they replaced the species. Why did a clearly intelligent species get replaced so readily? Why did Cro-Magnon's technology improve while Neanderthal's was mostly static? How did Cro-Magnon manage to organize its larger social groups? All of this points at better communication - better ability to convey complex ideas from one individual to the next.
They mentioned in the study related research on teaching horses to navigate mazes. Horses learned the maze at different rates, but they all eventually learned it, and once they learned it they never forgot it, no matter how long it was between maze runs. Seems directly applicable to the "milk route" case.
If you want the exact wording, it doesn't say "out of the field of view", but "stepped 2-3 meters aside ... standing passive to avoid giving the horse any cues". They later go further into the details of how they monitored the horse's attention and discussion of the Clever Hans effect. They also alter the sides that the different symbols were on to avoid side preferences.
There is of course a difference between being in one's field of vision and being the object focused on, which can be seen by a variety of factors, e.g. where they're pointing their head, their ears, whether there's any hesitation about the action (aka looking for outside cues), etc.
Clever Hans was an extremely well studied case. The concept that any reviewer is not going to be familiar with it and how to control for it is beyond silly.
Something not disputed by the study. The top keyword in the article summary is "Operant conditioning" (followed by "Blanket", "Rug", "Thermoregulation", "Cognition" and "Clicker training"). You'd do well to read the study. The key takeaways are:
1) Horses can be conditioned via use of visual symbols
2) Horses can use this to initiate communicated preference rather than just as a response
3) Horses learned much faster using the approach in this study than others
4) Horses understood the link between wearing / removing a blanket and their eventual body temperature for the given weather conditions
5) Different horses took different lengths of time to learn the connection with the symbols, but all managed to learn it, and once it was learned it was understood effectively 100% and not forgotten with time
It's also worth mentioning that most human behaviors are also learned through operant conditioning. That's how we all learned as children. There is no simple line between human and non-human in this regard. E.g., you stick your fingers on a hot burner, you get burned, you learn to avoid hot burners without even having to think about it. Your parent holds up an alphabet block with a "Q" on it, you say "Q", you get praise. The father of operant conditioning, B.F. Skinner, mainly wrote about it with a focus on its effects on human behavior, not animal behavior in general.
Reading over the study, in case you're curious: they discuss the Clever Hans effect, how it manifests (the horse observes the trainer or audience and does what it needs to get a reward based on the audience's reaction). In this study, the trainer was off to the side, out of the field of view of the horse, and they monitored where the horse was looking to ensure it was only looking at the symbols when making its choice. Then the horse was given a reward regardless of what symbol it chose; it simply had to choose one to get a treat. The symbol touches were easy to record and unambiguous, so there was no "interpretation" of the horses behavior in question. The researchers also observed side behaviors. For example, once the horses had learned to use the symbols to control their blanketing status they often became very eager to go into the testing facilitity (before the phase where treats were on offer). It was observed that horses that sought to have their blanket removed in this manner tended to be sweaty underneath it, while those that didn't seek it out weren't.
To be fair, there's even more that could be done. I really liked the controls that Pepperberg did in her studies of Alex (the African Grey parrot). She had it set up so that the person asking a question didn't know the answer, and neither did the person scoring the result. In this case here, clearly the trainer knew the weather and thus what would be the "optimal" blanketing status. But by paying attention to where the horse's focus is, whether it's hesitating, etc, and giving it a reward either way, I agree that that's some pretty good controlling for the Clever Hans effect.
And given that it's been peer-reviewed, the presumption is that they designed their methods to do just that, rather than "peer reviewers in animal behavior aren't aware of the caveats involved in animal studies"
That doesn't mean 100% that the presumption is correct - peer review is hardly a flawless process. But it is the presumption until shown otherwise.
How elaborate can this Q&A get?
Q: "Hey horse - how come Christians are allowed to draw pictures of their prophets and Muslims aren't?"
A: "I don't know. I am a horse, and, as such, have no knowledge of the intricacies of Islamic theology. I assume you're asking me because I am a brown horse? In which case, go to hell."
... host notably because concrete is by definition a hydrated cement aggregate. Heating hardened cement = driving out the water = turning it back into its raw form. More to the point, portland cement is made from limestone by heating in the first place. And not only are you reducing the set cement back to dry cement, but by driving out the water you're creating steam pressure, aka making it vulnerable to spall. Have a fire on it long enough and you soften the rebar as well.
The deluge system is important! :)
Actually, salmon wouldn't be a bad choice for a fish-based rocket. It's a fatty fish, and fats burn well in hybrid rockets.
You of course couldn't have a kerosene and salmon rocket, since you need to burn the fish with an oxidizer. But you could have a lox-LOX rocket ;)
1) Falcon 9 is entirely LOX / RP-1, not LOX / LH
2) Who do you think owns SpaceX's competitors, starving orphans?
3) You're sitting here writing this enjoying the fruits of the orbital launch market (communications, gps, monitoring satellites, etc) while damning it. That last satellite that SpaceX lost? Most of its communications channels were allocated to providing remote areas of Africa internet service, trying to uplift a continent. But... damn them!
4) The amount of CO2 released by a Falcon 9 launch is roughly the equivalent of one transpacific flight of a 747. Which do you think does more good, a single transpacific flight or a typical satellite? Or in some cases, many satellites - the Iridium cluster for example is launched half a dozen or more at a time. They launch 6-9 per year. Think 6-9 transpacific 747 flights per year is even remotely in the ballpark of relevance in terms of global CO2 emissions?
Data that to an observer is 100% random is not "transmitted information" in a physics context. Or in an information theory context either
Given that none of the articles, as far as I saw, said anything about faster than light communication, and one explicitly disavowed the concept, I think you're projecting your own mistaken conceptions here.
And your friend is correct - quantum teleportation has nothing to do with faster than light communication, as you can neither determine to what form the waveform has collapsed, nor whether one side has already collapsed it. It's effectively** equivalent to having two identical letters containing a random message sealed in an envelope, taking them to different locations, and opening them at the same time. Both sides will get the same random message at the same time, but it provides no means for conveying information faster than light. It is however useful for keysharing.
** In the real world, what is written inside the "envelopes" isn't determined until it's actually observed. But it works out to the same net effect.
Meh, so long as the facility is back to normal before their return to flight, this might even be good for them. As it stands it's only delaying ULA, increasing the already heavy global backlog on launches and making it harder for customers to bail (It's been a boom period for demand in launches, and providers were already struggling to keep up). The Russians are also suffering delays.
If the brush fire has plans to limit itself to existing within the combustion chambers and expansion nozzles then that's an excellent point!
Support for leaving fell significantly in other European states in the wake of the BRexit vote. The post-BRexit chaos and hits to the market weren't exactly a shining beacon.
The UK makes up about 1/6th of the EU's trade. The EU makes up about 50% of the UK's trade. One side has leverage in these negotiations, and it's not the UK.
The EU has made one thing and one thing alone abundantly clear: there will not, under any circumstances, be access to the single market without corresponding free movement of people. And no, Norway doesn't have that (neither do we here in Iceland). It's one of the founding principles of the EU, and it will not be compromised on.
The UK can of course leave the EU and choose to allow free movement of people in exchange for access to the single market. Whether that's acceptable to UK voters is a whole different story. And playing by the regulations of the single market also kind of defeats the point of the whole brexit thing. Countries like Iceland and Norway still have to obey the vast majority of EU regulations - we just don't get a say in making them.
Check out Fig. 2 for an example. Compare, for example, the altitude range for aerobraking vs. aerocapture on Venus, versus the altitude range for aerobraking vs. aerocapture for Mars. On Mars you have very narrow altitude windows in order to get a specific deceleration profile, and error within those windows has significant consequences. Furthermore, on Venus you have no specific location to "land" on, just a specific latitude, while on Mars, your choice of landing site is highly critical.
Basically, Venus is a lot more forgiving of mistakes. You'll note that the Soviets had terrible results with Mars probes, but did quite well with Venus.
This is incorrect, on several regards.
1) The winds are very mild at the ~90 bar level. You're thinking of the ~1 bar level.
2) The winds are fast relative to the surface in the cloud deck, but thats irrelevant because you're not anchored to the surface. The surface is over 50 kilometers away from you in the cloud deck. Think airplanes flying in the jet stream - it's actually more stable than flying near the surface.
What matters is turbulence, not velocity with respect to the surface. And in that regard, Venus's cloud deck seems to be roughly similar to Earth's troposphere. However, Venus has been so neglected as a destination it's hard to say that with certainty, we really need a much longer balloon probe than VEGA to help quantify it.
Refs for ballute entry: 1 2. Let me know if you'd like more :)
For some proposals in various stages of development to look up, check out VAMP, VEVA, VEP, EVE, VESSR, VISE, VME, VER, SAGE, Zephyr, Venera-D and VALOR :) I'm sure I'm missing a bunch. About half of those are balloons.
It's all about money. Mars gets the lion's share of NASA's robotic exploration budget. Everywhere else fights over the scraps.
Actually, we've already done this before, with Vega ;) But the Vega approach doesn't scale to habitat-sizes. With the large scale you need to use a ballute. One of the neat things about ballutes is that there's been a lot of research showing that not only can they decelerate and inflate you in the atmosphere, but they can outright replace an aeroshell for reentry. Venus has been one of the prime targets for ballute research.
Note that the initial inflation and final gas mixture do not need to be the same. Also, with ballute entry, part of your inflation is in the ionosphere which is dominated by light gases.
Also note that at entry, a habitat would be vastly lighter than its ultimate mass. The envelope, propulsion, etc aren't that heavy. Even the mass of people, water plants, industrial hardware, etc - aka, things that come later - isn't that heavy. The real load is all of the propellant needed for your return rocket - many dozens of tonnes for even a minimal ascent rocket (Venus is almost as deep of a gravity well as Earth... gravity is a great thing for human health but not so much for escaping ;) ). Since propellant is something produced locally (except in the HAVOC case, but HAVOC has some weird design decisions...), it's not an entry load.
Lastly, do remember that there are limits to the applicability of comparing to craft on Earth. On Earth, material costs are the limiting factor. In space applications, mass is generally the limiting factor. You choose much more expensive materials where they can save you mass (and advanced fabrics can indeed save a tremendous amount of mass versus commodity ones). Some of the prototypes Venus balloons are literally an order of magnitude lighter than you encounter for balloons on Earth of the same size.