A-L-E-X wrote:

Source of the post are we going to have these new minimoons just discovered in the program?

If you mean '2020 CD₃', probably not, because it does not have a stable earth orbit and will not remain in the Earth's sphere of influence for long.

But here it is as an asteroid:


(Put this file in 'addons\catalogs\planets'.)

Thanks, JD!  That object is quite small!

But unfortunately I made a mistake. I took the average diameter as the radius. In reality, the object is only half as big as in my script!
(But somehow I think this doesn't really matter.)

Betelgeuze wrote:

Source of the post Astronomers discovered most nearest black hole just 1000-light years from Earth that can also seen from naked eye https://www.eso.org/public/news/eso2007/

Look here: viewtopic.php?t=45&start=1020#p33594

Betelgeuze wrote:

Astronomers discovered most nearest black hole just 1000-light years from Earth that can also seen from naked eye https://www.eso.org/public/news/eso2007/

the black hole can be seen with the naked eye? or the main star of the system can?

A-L-E-X wrote:

Source of the post or the main star of the system can?

Only the two stars. The black hole itself cannot be seen, especially since it probably does not have an accretion disk.

A-L-E-X wrote:

Betelgeuze wrote:

Astronomers discovered most nearest black hole just 1000-light years from Earth that can also seen from naked eye https://www.eso.org/public/news/eso2007/

the black hole can be seen with the naked eye? or the main star of the system can?

Given the characteristics of this system, it is not even possible for the Hubble telescope to see the black hole. In this case, the system can be seen with the naked eye, but it will look like a sole weak star. Using an amateur telescope, it is possible to identify that the system is actually binary. However, using a poweful telescope during several years allows you to see that one of those stars is actually moving around something you cannot be seen. That something is the black hole we are talking about.

News coming out of the UK, the Brits ran some sort of cosmic evolution program on a supercomputer and came to the conclusion that there are on average 36 sentient civilizations in the typical galaxy and based on their calculations, there should be an average separation of 17,000 light years between sentient civilizations.  Yikes!

A-L-E-X wrote:

Source of the post ran some sort of cosmic evolution program on a supercomputer and came to the conclusion that there are on average 36 sentient civilizations in the typical galaxy

If the average is 36, what is the uncertainty?   ?    How did they treat the propagation of uncertainty in their program?

Indeed it has been published in the ASS. If anyone is interested, their research can be read here. Taking their assumptions they get a final value of [math]36_{-32}^{+175} extraterrestrial civilizations in our galaxy.

A-L-E-X wrote:

Source of the post the Brits ran some sort of cosmic evolution program on a supercomputer

No, they didn't used a supercomputer nor they did a complex cosmic evolution simulation. In fact I see this article as interesting but quite the same as many before it: starting with a fancy introduction about the Drake Equation (which IMO is only useful in outreach and pop-science), then they introduce their speculative assumptions and plug the numbers. I see a lot of good and bad assumptions here and the Drake Equation is well known for allowing almost any kind of result you want. Between the bad asumptions I see the idea of any suitable planet that allows for life will develope life (which they claim is a fair assumption because of the Copernican Principle, which is nothing more than a convoluted pattern-recognition in historical trends in science which tells nothing about nature itself). Well that could be a fair assumption if we define what a suitable planet for life is, but again they conceive o suitable planet only by a few parameters; habitable zone, metallicity of star etc... Nothing is said about the need of a magnetosphere, plate tectonics, etc... (which are probably quite important to assertain if a planet can harbour life at all). Also they assume the galaxy to be an homogenous landscape of various stellar populations, but in fact we know that the high radiation, high stellar density and high supernova rate environment of the buldge and the inner parts of our galaxy (where the majority of stars lives) is probably an inhibitor for life or for the long-duration regular conditions life needs for evolution to get to complex life-forms. Also I find some arguments about how life ultimately yields intelligence after enought time an unscientific idea. Evolution has no purpose, if complex life emerged on our planet it wasn't because it was the ultimate goal of simple microbial life but because a very specific set of conditions created evolutionary incentives to do that. The same can be said about intelligence: there's only one intelligent lifeform on this planet (so maybe intelligence is not a typical example of convergent evolution even on Earth). We know that, with the process of encephalization in hominins, a lot of the energy had to be devoured by the increasing brains, which changed our body structure and digestion in a non-evidently net positive way. Even giving birth became extremely dangerous for humans because of the larger brains and larger gestation periods (which ultimately had to be extended outside the womb with basic care, which is also a non-trivial developement). There are very strong deterrents for intelligence from an evolutionary perspective and in fact we are the only case where this has happened. It is very likely that a very specific set of conditions has to be put in place for the net evolutionary incentive to develope larger brains to be positive against all the disadvantages it creates in the way. Also the incentives might dissapear as the brain grow larger so it probably happened because of some positive feedback (for example: larger brains mean larger heads, which mean problems when giving birth, which means assistance in givin birth to other humans, which mean creating some social need for mutual care, which probably mean some advanced way to coordinate between individuals, which means more developed language skills or face gestures interpretation skills, which mean the need for larger brains... compelting the feedback loop). If the conditions for some positive feedback where not in place one might evolve certain brains to a point (in fact we haven't go further) and that point could be quite a low standard. Also there are huge incentives to decrease brain size in evolutionary terms (in a nutrient-scarce environment brains probably consume too much energy for the small advantage of conceptualizing more advantageous ways of elaborating food). Many are the arguments but none are adressed by this paper, and IMO this is a huge error. I said that this is unscientific because it goes with the Orthogenetic viewmore than a Darwinian view of the evolution of life.

In my opinion, the fact that they came up with just 36 communicating extraterrestrial intelligences in our galaxy with those very weak assumptions is in fact an indicator that we might be much more alone. Any additional ingredient you throw to their model might decrease that number to zero, and there are many ingredients we could fairly propose.

How I read the articles is that the scientists say that it's currently impossible to do the calculations, but if it were possible, the most likely number would be 36.  I hope that is a kind of reasoning that doesn't make it through peer review.

midtskogen wrote:

Source of the post  I hope that is a kind of reasoning that doesn't make it through peer review.

Indeed it is surprising. I love these kind of speculations but when the authors publish them in the corresponding journal and with the corresponding premises (like explicitly explaining this is wild guesses). The fact that it has survived peer review might be due to the second author to be "a Scientific Editor for the Astrophysical Journal and since 2018 the Lead Editor of the Galaxies and Cosmology corridor for the American Astronomical Society (AAS) Journals". This article was published in the AAS coincidentaly.

FastFourierTransform wrote:

midtskogen wrote:

Source of the post  I hope that is a kind of reasoning that doesn't make it through peer review.

Indeed it is surprising. I love these kind of speculations but when the authors publish them in the corresponding journal and with the corresponding premises (like explicitly explaining this is wild guesses). The fact that it has survived peer review might be due to the second author to be "a Scientific Editor for the Astrophysical Journal and since 2018 the Lead Editor of the Galaxies and Cosmology corridor for the American Astronomical Society (AAS) Journals". This article was published in the AAS coincidentaly.

It's an interesting set of assumptions they made to arrive at that number, but piling up assumptions upon assumptions leads to a huge margin of error.... especially when we really dont know what conditions are necessary......earth is a sample size of one, so making assumptions based on just us is bound to have a HUGE margin of error.
But by far the most interesting aspect of the whole thing (for me) was that even if there are as many as three dozen of these civilizations, the average distance between them of 17,000 light years is far too much for us to know of their existence.  So we should ask a different kind of question instead......."What is the necessary average distance between home planets of sentient civilizations for us to know of the existence of at least one other?"  And I dont believe the SETI method will work, because there were assumptions made there also....not to mention the timeframe for detecting that kind of signal may be too small (in our case when we went digital our signal leak lessened significantly.)  

About your very interesting speculation on the chances of evolution resulting in intelligence....isn't it true that dinosaur brains were getting larger and larger as the Cretaceous went on and they were approaching the intelligence of upper echelon mammals (as long as acquiring other traits of theirs, like being warm blooded, giving birth to live young and taking care of those young, as well as hunting in packs, like modern wolves do?)  So perhaps evolving intelligence is more likely than we think- particularly when there are other highly intelligent animals, like elephants, dolphins, some parrots, chimps, bonobos, dogs, cats, pigs, etc.  All of these have at least the intelligence of a 5 yr old.

I would make a contrary suggestion, that given billions of years for evolution to occur, that once multicellular life forms, it will inevitably lead to "intelligence"- and that there were other intelligent animals that came before humans and there are other intelligent animals that live with us today.  This of course assumes that nothing occurs in the mean time to make the planet uninhabitable.

Their lower limit of 4 seems to be more along the lines of what I'm thinking....... because so-called "intelligent" species once they reach our level of development, probably have a higher propensity to destroy themselves.   I strongly believe we are headed down that same dark road (but there will most probably be other highly intelligent species that come after us, unless in the process of destroying ourselves we also render the planet uninhabitable, which is a definite possibility.)   I would also add one more requirement in addition to the ones you listed....the need for a proportionately large moon......its tidal influences were necessary to bring marine life onto land.  The sun alone would not be enough.  In addition our large moon shielded us from a ton of impactors that could have rendered our planet uninhabitable.

A-L-E-X wrote:

Source of the post In addition our large moon shielded us from a ton of impactors that could have rendered our planet uninhabitable.

Not really, see last part of post here.  Right now the Moon blocks 0.0005% of asteroids that would hit Earth.  Even in the very distant past when it was much closer to Earth, the most it could block was still much less than 1%.

People often underestimate how small and far away the Moon is.  It is not a good shield. It has a lot of craters on it, but we don't see all the impacts that Earth had since geologic processes have erased most of them.