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Heard on the radio today: First evidence of an exomoon. Estimated to be the size of Neptune, orbiting a planet the size of Jupiter. First clues sifted from Kepler data; more obtained from Hubble; but the astronomers say they need more Hubble observation time to be sure.

 

Heard on the radio yesterday: A trans-Neptunian object dubbed "The Goblin" strengthens the case for a Ninth Planet that's deflecting TNOs into bizarre orbits. IIRC, the Goblin's orbital period is 40,000 years, and it never comes closer to the Sun than about twice Pluto's orbit.

 

Sep. 22, 2018 issue of The Economist has an article on experiments to see if antimatter has negative gravity. That is, will it fall up instead of down? Most physicists are pretty sure it won't, but they need to find some way that antimatter is not the perfect opposite of normal matter. According to current theories, the Big Bang should have produced matter and antimatter equally, which should have annihilated each other just as quickly. The existence of the Universe represents a significant experimental error.\ that requires explanation. The technical challenges of testing the gravitational properties of antimatter are... extreme.

 

Dean Shomshak

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Heard on the radio today: First evidence of an exomoon. Estimated to be the size of Neptune, orbiting a planet the size of Jupiter. First clues sifted from Kepler data; more obtained from Hubble; but the astronomers say they need more Hubble observation time to be sure.

 

Heard on the radio yesterday: A trans-Neptunian object dubbed "The Goblin" strengthens the case for a Ninth Planet that's deflecting TNOs into bizarre orbits. IIRC, the Goblin's orbital period is 40,000 years, and it never comes closer to the Sun than about twice Pluto's orbit.

 

Sep. 22, 2018 issue of The Economist has an article on experiments to see if antimatter has negative gravity. That is, will it fall up instead of down? Most physicists are pretty sure it won't, but they need to find some way that antimatter is not the perfect opposite of normal matter. According to current theories, the Big Bang should have produced matter and antimatter equally, which should have annihilated each other just as quickly. The existence of the Universe represents a significant experimental error.\ that requires explanation. The technical challenges of testing the gravitational properties of antimatter are... extreme.

 

Dean Shomshak

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10 hours ago, DShomshak said:

Heard on the radio today: First evidence of an exomoon. Estimated to be the size of Neptune, orbiting a planet the size of Jupiter. First clues sifted from Kepler data; more obtained from Hubble; but the astronomers say they need more Hubble observation time to be sure.

 

Heard on the radio yesterday: A trans-Neptunian object dubbed "The Goblin" strengthens the case for a Ninth Planet that's deflecting TNOs into bizarre orbits. IIRC, the Goblin's orbital period is 40,000 years, and it never comes closer to the Sun than about twice Pluto's orbit.

 

Sep. 22, 2018 issue of The Economist has an article on experiments to see if antimatter has negative gravity. That is, will it fall up instead of down? Most physicists are pretty sure it won't, but they need to find some way that antimatter is not the perfect opposite of normal matter. According to current theories, the Big Bang should have produced matter and antimatter equally, which should have annihilated each other just as quickly. The existence of the Universe represents a significant experimental error.\ that requires explanation. The technical challenges of testing the gravitational properties of antimatter are... extreme.

 

Dean Shomshak

 

I've seen discussions (a number of years ago) about other possibilities for how to detect exomoons.  Under certain circumstances, those can show up in terms of changes in the exoplanet orbit.  I haven't yet seen the tech paper with this exomoon announcement.

 

The preliminary designation for the trans-neptunian object is "2015 TG387", which simply reflects when it was discovered.  That's what you type into the search box if you go to the JPL Small Body Database Browser.

 

I've read recent papers about spectroscopy experiments with antihydrogen (and that checks on the electric force, not on gravity), and those confirm that antimatter does behave just like regular matter in terms of how it interacts with light.  The antihydrogen is a by-product at LHC/CERN; among the fragments that emerge from the particle collisions there are antiprotons, which you can collect, combine with positrons, and make antimatter hydrogen atoms, which you can store and subsequently perform experiments upon.

 

But yeah, gravity experiments are much, much harder, since gravity so much weaker a force.

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Yeah, the article tells how CERN makes antihydrogen. It's a pretty amazing process all by itself.

 

The October, 2018 issue of Discover has an article about the Lucy mission to the Trojan asteroids, scheduled to launch in 2021. The article says we know very little about these two groups of asteroids. It's possible, though, that they may be a better sample of primordial planetesimals than the asteroids in the Main Belt. Lucy will crisscross the Solar System, with no less than three gravitational assists from Earth in its looping path, to visit both "camps" of asteroids (at Jupiter's L4 and L5) -- including the double asteroid of Patroclus and Menoetius, in 2033.

 

The issue also has an amusing little article about "16 Times We Didn't Find ET," a history of SETI false alarms.

 

Dean Shomshak

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It is not easy to get to the outer Solar System.  People forget that the Galileo mission to Jupiter was hamstrung because its high gain antenna failed to deploy, they think because of the long multi-pass grav assist trajectory around the inner Solar System.  They ended up doing everything via the low gain antenna, including replacing the onboard OS en route to Jupiter after the last assist plunge by Earth (only then did they try and fail to deploy the high-gain antenna) over the 1-baud link that the low gain system imposed.

 

Solar array tech has improved so that if you're clever you can operate by solar power at Jupiter on an extended basis, so you aren't dependent on Russian Pu-238 for RTGs for such a mission.  But that's for instruments, not propulsion.

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Speaking of astronomical paradoxes past... Some years back, Scientific American published a nifty article about why many astronomers initially rejected heliocentrism. It was more than just religious dogma: Whatever advantages the theory offered for describing the Solar System seemed outweighed, they thought, by the difficulties it created for describing the stars. I *think* this is a link; I couldn't follow it with my crappy slow connection.

 

The Case against Copernicus - Scientific American

 

Short version: Parallax Lost. Astronomers measured the angular size of the stars. It's very tiny, but nevertheless a measurable disk. (Easier once they had telescopes, of course.) OTOH, they could not measure a parallax. That gave them a minimum distance for the stars and, therefore, a minimum size for the stars.

 

In a geocentric cosmos, there would only be a daily parallax -- a displacement of apparent position based on the rotation of the Earth. By that calculation, stars were about as big as the Sun.

 

Heliocentrism added a second, yearly parallax. A much longer baseline meant that stars had to be much farther away for no parallax to be measured with the instruments available. Correspondingly, that meant stars had to be much bigger. In fact, every star had to be thousands of times bigger than the Sun!

 

Astronomer George Airy resolved the paradox when he realized that when a very thin beam of light passes through a lens, it spreads a little. Doesn't matter whether it's the lens of the eye or the lens of a telescope. Thus, the paradox was based on a systematic error in measurement: The angular size of the stars was wrong. Eventually, telescopes and instruments got good enough to measure yearly parallax and the true distance to the stars was known, and therefore their true sizes. Paradox gone.

 

I keep this history in mind when I read about dark energy, inflationary cosmology, and other "frontier" topics in astronomy. Even things we think are straightforward measurements might be wrong.

 

Dean Shomshak

 

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The October 13, 2018 issue of The Economist has a little article on the Fermi Paradox in what it says is the current preferred form: not "Why haven't aliens visited?" but "Why haven't radio telescopes detected them?" It notes an argument made in 2010 by Jill Tarter, that the Milky Way is so huge that radio searches to date have been the equivalent of dipping a drinking glass in the ocean at random and hoping you get a fish. A paper published last month in arXiv by astronomer Jason Wright and colleagues updates the argument. They find Dr Tarter's estimate is too stingy: They say human efforts at alien-hunting amount to dunking a bathtub.

 

Dean Shomshak

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How long has life existed on this planet? How old is homo sapiens? And in all that time, how long have we been using radio signals to communicate? The odds of any sapient race in space being at a point in their history/evolution to broadcast such signals, proximate enough for us to detect them, during the period in which we've been trying to, is vanishingly small.

 

OTOH I tend to be willing to believe some stories of alien abduction, because they sound so much like what we do to less intelligent animals on our own planet in the name of scientific research: capture a specimen, measure it, take tissue samples, tag it for future reference, then release it back into its environment to track its progress. Recapture it periodically to measure its development. We rarely think about how our treatment of it may traumatize it.

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7 hours ago, Lord Liaden said:

How long has life existed on this planet? How old is homo sapiens? And in all that time, how long have we been using radio signals to communicate? The odds of any sapient race in space being at a point in their history/evolution to broadcast such signals, proximate enough for us to detect them, during the period in which we've been trying to, is vanishingly small. 

That asumes there is some other form of longrange communicaiton that is actually viable.

Thus far the only thing we found to be faster then light is Quantum Entanglement. And we have not tested it over interplanetary scales or if it is really interference free with a lot of users.

 

Also the original Fermi Paradox was about more then just radio. It was about colonization:
Homo Sapiens is 2 Million years old
With current technology it should take about 1 Billion years to colonize the whole Galaxy.

With likely possible technology, that should drop to about 1 Million Years.

 

So they had a 1 million year window to get to this stage before us. And then visit us while we were pre-nuclear armed.

 

7 hours ago, Lord Liaden said:

OTOH I tend to be willing to believe some stories of alien abduction, because they sound so much like what we do to less intelligent animals on our own planet in the name of scientific research: capture a specimen, measure it, take tissue samples, tag it for future reference, then release it back into its environment to track its progress. Recapture it periodically to measure its development. We rarely think about how our treatment of it may traumatize it.

Those aliens would need one heck of a superiority complex to think us like animals.

And one heck of a cloaking/defense technology, considering we are nuclear armed animals.

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6 hours ago, Christopher said:

That asumes there is some other form of longrange communicaiton that is actually viable.

Thus far the only thing we found to be faster then light is Quantum Entanglement. And we have not tested it over interplanetary scales or if it is really interference free with a lot of users.

 

Also the original Fermi Paradox was about more then just radio. It was about colonization:
Homo Sapiens is 2 Million years old
With current technology it should take about 1 Billion years to colonize the whole Galaxy.

With likely possible technology, that should drop to about 1 Million Years.

 

So they had a 1 million year window to get to this stage before us. And then visit us while we were pre-nuclear armed.

 

Those aliens would need one heck of a superiority complex to think us like animals.

And one heck of a cloaking/defense technology, considering we are nuclear armed animals.

 

I feel I should point out the assumptions you're making. What we know about faster-than-light communication possibilities is, by definition, only what we currently know to be possible. You're also assuming that another species would find interstellar colonization both practical and desirable. You seem to be overlooking the distinct possibility that, over such a vast span of time, other sapient species could easily have gone extinct, long before we're in a position to look for them, or they for us.

 

Think of what militaries armed with contemporary technology could have done to the nations of Earth as they were even a hundred years ago. Now try to extrapolate that over a gap of thousands or millions of years. Nuclear weapons are a big deal to us; to a more advanced technology they may be the relative equivalent of firecrackers.

 

It's well established that we're able to communicate simple concepts with our closest relatives, the great apes. Yet we still mostly treat them as animals, because they're measurably "less intelligent" than us, at least by our measurements of intelligence. Your perspective appears to be that we would be on the same basic level as any existing aliens in our capacity to understand, with only a technological gap. There simply isn't enough evidence to either support or deny that perspective.

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2 minutes ago, Lord Liaden said:

I feel I should point out the assumptions you're making. What we know about faster-than-light communication possibilities is, by definition, only what we currently know to be possible. You're also assuming that another species would find interstellar colonization both practical and desirable. You seem to be overlooking the distinct possibility that, over such a vast span of time, other sapient species could easily have gone extinct, long before we're in a position to look for them, or they for us. 

Once a species becomes multiplanet or even multi-sytem, it is really hard for them to go extinct. Planetary Nuclear war can not kill your species if you are on more then 1 planet. Even just colonizing mars would be a huge security blanket for our species. The vaccum of space acts as a wonderfull Isolator against Extinction Level events.

 

That nothing moves faster then light is something that we know since Einstein. All experimental data confirms it. The only exception thus far was Quantum Entaglement - or "spooky action at a distance" as Einstein called it. and we ahve not figured out how to utilize it for Communication.

 

The possibility that there are unknown reasons against Interstellar Colonization (even at STL speeds) is of coruse still in the room. That is already acounted for in the Paradox. But thus far we have not found that "great filter".

 

12 minutes ago, Lord Liaden said:

It's well established that we're able to communicate simple concepts with our closest relatives, the great apes. Yet we still mostly treat them as animals, because they're measurably "less intelligent" than us, at least by our measurements of intelligence. Your perspective appears to be that we would be on the same basic level as any existing aliens in our capacity to understand, with only a technological gap. There simply isn't enough evidence to either support or deny that perspective. 

My only asumption regarding alien life is that humans are "the bog Standart Way" of evolving intelligent life in the Universe.

 

14 minutes ago, Lord Liaden said:

What we know about faster-than-light communication possibilities is, by definition, only what we currently know to be possible.

I asume that all Life will develop the Convergent, Instrumental goal of "Fill all niches it can reach".

It does not mater where the species come from. It does not mater where it goes. "Fill all niches" is a usefull instrumental goal. And something every single lifeform on earth knows how to do.

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My thoughts on the matter are that we just haven't collected enough information yet. Remember that of all the astronomical bodies in the universe, we've been to only TWO. As a wise man once said, "It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts."

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14 hours ago, Zeropoint said:

My thoughts on the matter are that we just haven't collected enough information yet. Remember that of all the astronomical bodies in the universe, we've been to only TWO. As a wise man once said, "It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." 

We have been tomore of that:
The Luna and Mars Rovers are the two you are thinking about propably.

 

But we also send:
Mariner 10 to Mercury

Several Probes to and into the Atmosphere of Venus. Wich is not a nice place to be. Indeed we are not certain the first one even made it to the ground.

A whole "Armada" to Halleys comet

Rosetta to a Meteorite

Deep Impat to a Comet

Pretty sure we send something into one of the gas giants as well.

 

So we got a lot of confirmation for our theories on how Gas Giants and Venusian planets atmospheres work. Wich gives us a pretty good grasp of solar formation mechanics. The only  thing we are uncertain about right now is "how much of a accident was earth"?

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I guess I could have been more clear; I meant that we've only been to two astronomical bodies in person: Earth and the moon.

 

10 hours ago, Christopher said:

The only  thing we are uncertain about right now is "how much of a accident was earth"?

 

That is hugely relevant to the Fermi Paradox. :)

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That reminds me: A few weeks ago, All Things Considered interviewed Sarah Stewart of UC-Davis, one of this year's Macarther "Genius Grant" winners. Dr. Stewart models planetary collisions by firing cannonballs at each other (which is cool enough to deserve a Genius Grant right there). Her research tests various notions about how the Earth and Moon formed from the collision of two proto-planets. Based on it, she believes that the collision did not result in a "Big Splash" (you may have seen computer animations of this). She thinks the two bodies actually vaporized each other, and the Earth and Moon condensed out of the resulting cloud of debris.

 

Dunno how this affects the frequency of Earthlike planets (and I am not convinced by the "Rare Earth" argument that complex life can only appear on a world that is a near-double of Earth), but it may have some relevance. Or at least interest.

 

Dean Shomshak

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On 10/20/2018 at 2:43 PM, Christopher said:

Once a species becomes multiplanet or even multi-sytem, it is really hard for them to go extinct. Planetary Nuclear war can not kill your species if you are on more then 1 planet. Even just colonizing mars would be a huge security blanket for our species. The vaccum of space acts as a wonderfull Isolator against Extinction Level events.

 

That nothing moves faster then light is something that we know since Einstein. All experimental data confirms it. The only exception thus far was Quantum Entaglement - or "spooky action at a distance" as Einstein called it. and we ahve not figured out how to utilize it for Communication.

 

The possibility that there are unknown reasons against Interstellar Colonization (even at STL speeds) is of coruse still in the room. That is already acounted for in the Paradox. But thus far we have not found that "great filter".

 

My only asumption regarding alien life is that humans are "the bog Standart Way" of evolving intelligent life in the Universe.

 

I asume that all Life will develop the Convergent, Instrumental goal of "Fill all niches it can reach".

It does not mater where the species come from. It does not mater where it goes. "Fill all niches" is a usefull instrumental goal. And something every single lifeform on earth knows how to do.

 

Those last two are REALLY big assumptions, though. Human intelligence as the "bog standard way" is completely unsupportable from a sample size of one. A single species adapts to fill whatever niche is available, either unoccupied or occupied by something it can dominate and push out. Yet the history of our planet overflows with species that were once very successful, but then died out in changing circumstances they couldn't adapt to. But our species no longer adapts to fit our environment, we adapt our environment to fit ourselves. The long-term results of that approach on this planet are proving decidedly mixed.

 

We don't know what happens if a species attempts to become multi-planet. What changes may occur when we try to plant ourselves on a completely alien environment and, perhaps. eco-system? That may have a very different outcome from just moving to another part of our own biosphere. No way to tell until we try. But at the rate we're using up the Earth, how much time do you think we have to make Mars habitable before Earth no longer is?

 

Einstein's theory is still a theory, the best we have currently to fit observed phenomena. But it doesn't explain everything, and we still can't observe everything. "More to heaven and earth, Horatio..."

 

All you say could prove to be accurate, but to this point none of it is sufficiently tested.

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48 minutes ago, Lord Liaden said:

Those last two are REALLY big assumptions, though. Human intelligence as the "bog standard way" is completely unsupportable from a sample size of one.

I am asuming our species is in no way special or unique in the universe. That any evolution like ours, can happen in any biospheres remotely like ours.

At least to my understanding, that is the smalest and least amount of asumption anybody can make.

 

52 minutes ago, Lord Liaden said:

But our species no longer adapts to fit our environment, we adapt our environment to fit ourselves.

Colonisation of another planet is meerely a larger step in "adapt environment to fit us".

 

The beauty of convergent, instrumental goals is: You can asume them without needing any asumptions about the specific instance (person, species, biosphere). And you are still right often enough to make it worthwhile. I actually learned of this in a AGI related discussion:

 

 

The drive to "fill all niches" is something that is ingrained in any life on this planet. From the smalest virus, to us and our whole "adapt environment to fit us" thing. WE simply have the intelligence to do more about it.

 

"Fill all niches" + "General Intelligence" = building civilisation and space colonisation (if possible).

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On ‎10‎/‎20‎/‎2018 at 2:43 PM, Christopher said:

 

My only asumption regarding alien life is that humans are "the bog Standart Way" of evolving intelligent life in the Universe.

 

 

Even if that were the only assumption you make, that alone is a HUGE assumption to make.

Lucius Alexander

 

The palindromedary says it's not just HUGE , it's :mars::saturn::jupiter: Astronomical

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Yeah, I'd like to explore that point for a moment. Let's look at "any biospheres remotely like ours." If Earth had had a little less gravity and a little higher atmospheric oxygen content, insects could have evolved large enough for complex brain functions to support self-awareness and reason. What could have developed from a sapient ant or termite? Rather than being based around small family groups like mammals, with a lot of individual initiative to action, social insects are part of large collectives with the individual subsumed to the goals of the whole, and with functions in that whole genetically predetermined. Sex and reproduction are not driving forces for the great majority of the population. Compared to mammals vision is severely limited, but smell is vastly expanded for both sensory input and communication. What would such a creature consider normal social interaction? Would the distinction between "I" and "We" even make sense to it? What activities would it consider positive and valuable? Would it even equate "progress" with "change," or consider that to be a good goal?

 

We can make guesses for these things based on our own imaginations and the limited examples of non-sapient insects, but that's a poor substitute for actually experiencing a thought process completely alien to our species. And that's just one possibility drawn from our own familiar ecosystem.

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3 hours ago, Lord Liaden said:

If Earth had had a little less gravity and a little higher atmospheric oxygen content,

the Earth has had a higher oxygen content in the past, and this has not led to sapient centipedes

 

I'm thinking that some brain structures may have inbuilt ceilings on how sophisticated they may become.

 

Of course alien insects may have totally different brains to our insects.

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