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The Fermi Paradox

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Are We Alone In The Universe?

So far, we have no evidence to the contrary, and yet the odds that not one single other planet has evolved intelligent life would appear, from a statistical standpoint, to be quite small. There are an estimated 250 billion (2.5 x 10?? ) stars in the Milky Way alone, and over 70 sextillion (7 x 10?? ) in the visible universe, and many of them are surrounded by multiple planets. The shear size of the known universe is staggeringly and inconceivably vast. The odds of there being only one single planet that evolved life among all that unfathomable vastness seems so incredible, that it is all but completely irrational to believe. But then “where are they?” asked physicist Enrico Fermi while having lunch with his colleagues in 1950.
Fermi questioned, if there are other advanced extraterrestrial civilizations, then why is there no evidence of such, like spacecraft or probes floating around the Milky Way. His question became famously known as the Fermi Paradox. The paradox is the contradiction between the high estimates of the probability of the existence of extraterrestrial civilizations and yet the lack of evidence for, or contact with, any such civilizations. Given the extreme age of the universe, and its vast number of stars, if planets like Earth are at all typical, then there should be many advanced extraterrestrial civilizations out there, and at least a few in our own Milky Way. Another closely related question is the Great Silence, which poses the question: Even if space travel is too difficult, if life is out there, why don’t we at least detect some sign of civilization like radio transmissions?
Milan Cirkovic of the Astronomical Observatory in Belgrade, points out that the median age of terrestrial planets in the Milky Way is about 1.8 gigayears (one billion years) greater than the age of the Earth and the Solar System, which means that the median age of technological civilizations should be greater than the age of human civilization by the same amount. The vastness of this interval indicates that one or more processes must suppress observability of extraterrestrial communities.
Since at this point, there is no direct and/or widely apparent evidence that extraterrestrial life exists, it likely means one of the following:
We are (A) the first intelligent beings ever to become capable of making our presence known, and leaving our planet. At this point, there are no other life forms out there as advanced as us. Or perhaps extraterrestrial life does exists, but for some reason extraterrestrial life is so very rare and so very far away we’ll never make contact anyway—making extraterrestrial life nonexistent in a practical sense at least.
Or is it (B) that many advanced civilizations have existed before us, but without exception, they have for some unknown reason, existed and/or expanded in such a way that they are completely undetectable by our instruments.
Or is it (C) There have been others, but they have all run into some sort of “cosmic roadblock” that eventually destroys them, or at least prevents their expansion beyond a small area.
The ancients once believed that Earth was the center of the universe. We now know that Earth isn’t even at the center of the Solar System. The Solar System is not at the center of our galaxy, and our galaxy is not in any special position in contrast to the rest of the known universe. From a scientific viewpoint, there is no apparent reason to believe that Earth enjoys some privileged status. Since Earth’s placement in space and time appears to be unremarkably random, proposition “A” seems fairly unlikely. Assuming humans evolved like other forms of life into our present state due to natural selection, then there’s really nothing all that mystical, special or remarkable about our development as a species either. Due to the shear numbers, there are almost certainly other planets capable of supporting at least some form of life. If that is so, then for Earthlings to be the very first species ever to make a noticeable mark on the universe, from a statistical perspective, is incredibly unlikely.
For proposition “B” to be correct would defy all logic. If potentially thousands, or even millions of advanced extraterrestrial civilizations exist in the known universe, then why would all of them, without exception, choose to expand or exist in such a way that they are completely undetectable? It’s conceivable that some might, or perhaps even the majority, but for all of them to be completely undetectable civilizations does not seem likely either.
Proposition C in some ways, appears to be more likely than A or B. If “survival of the fittest” follows similar pathways on other worlds, then our own “civilized” nature could be somewhat typical of extraterrestrial civilizations that have, or do, exist. Somehow, we all get to the point where we end up killing ourselves in a natural course of technological development and thereby self-inflict our own “cosmic roadblock”. “Perhaps the most disturbing aspect of the Fermi Paradox is what it suggests for the future of our human civilization. Namely, that we have no future beyond earthly confinement and, quite possibly, extinction. Could advanced nanotechnology play a role in preventing that extinction? Or, more darkly, is it destined to be instrumental in carrying out humanity’s unavoidable death sentence?” wonders Mike Treder, executive director of the Center for Responsible Nanotechnology (CRN).
Treder believes that some of the little understood new technologies now being developed such as nanotech, and others, could well be either our salvation or just as likely end up causing our ultimate destruction. “Whatever civilizations have come before us have been unable to surpass the cosmic roadblock. They are either destroyed or limited in such a way that absolutely precludes their expansion into the visible universe. If that is indeed the case—and it would seem to be the most logical explanation for Fermi’s Paradox—then there is some immutable law that we too must expect to encounter at some point. We are, effectively, sentenced to death or, at best, life in the prison of a near-space bubble,” suggests Treder. “Atomically-precise exponential manufacturing could enable such concentrations of unprecedented power as to result in either terminal warfare or permanent enslavement of the human race. Of course, that sounds terribly apocalyptic, but it is worth considering that the warnings we heard at the start of the nuclear arms race, and the very real risks we faced in the height of the Cold War, were but precursors to a much greater threat posed by an arms race involving nano-built weaponry and its accompanying tools of surveillance and control.”
When we consider the chronological history of life on Earth, humans have only existed for a small fragment of time and our existence has always been precarious. The entire time we’ve existed, we been banding into various groups and attempting to kill each other—or at least are constantly in the process of developing more effective ways of killing each other—just in case. The US government, for example, spends on “Defense” (including “preemptive” warfare) and Homeland Security, 8 times what it spends on educating the next generation. There is enough nuclear weaponry in storage around the world to kill every living creature on the planet several times over. Clearly, we’re a species with poor odds of surviving indefinitely.
Our self-destructive natures aside, curiosity may end up killing more than the cats. The faster technology is advancing, the more our “leap now, look later” nature appears to grow as well. If evolution on Earth serves as a somewhat typical template for evolution of other life forms, then becoming a truly advanced civilization must be a very daunting task indeed and a very rare, if not impossible, achievement. In fact, Sir Martin Rees, Great Britain’s Astronomer Royal and respected professor of astrophysics at Cambridge University has estimated that humans have only a 50-50 shot of making it through the 21st century. If Rees is right, and our standing on the planet is as precarious as he and others believe it is, then we may be alone due to a built-in evolutionary self-destruct button. Others have come before and others will exist after, but the cosmic roadblock may be an innate, finite nature, which only allows sentient life forms to exist for a very small window of time—windows of life which may be too small for our civilization to match up with the small windows of other civilizations that have been before or will come after.
In a contrary point of view, Milan Cirkovic believes that highly efficient city-state type of advanced technological civilizations could easily pass unnoticed even by much more advanced SETI equipment, especially if located near the Milky Way rim or other remote locations.”

– http://www.dailygalaxy.com/

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Planet formation captured in photo

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A protoplanetary disc has formed around the young star HL Tau

The clearest ever image of planets forming around an infant star has been taken by the Alma radio telescope.

In a vast disc of dust and gas, dark rings are clearly visible: gaps in the cloud, swept clear by brand new planets in orbit.

The sun-like star at the centre, HL Tau, is less than a million years old and is 450 light years from Earth in the constellation Taurus.

The image was made possible by Alma’s new high-resolution capabilities.

Because the process of planet formation takes place in the midst of such a huge dust cloud, it can’t be observed using visible light.

Source: BBCNews Read and see more

Welcome back, Pluto!

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Galaxy’s guardians make the case: upgrade Pluto back to planet-size!

Eight years ago it was relegated to dwarf planet status. But Harvard astrophysicists are arguing that being small shouldn’t disqualify it

Just cos I’m small … Pluto, several billion miles from where you’re sitting. Photograph: Alamy

Age: 4.6bn years old.

Appearance: Slightly different to its appearance last week.

You know, I thought that too. Has it had its hair done? No, not that, you idiot. Between you and me I think it might look a little more, well … planet-y than usual.

Surely that can’t be the case. We’ve been through this before, remember? I know, I know. Pluto had been a planet since its discovery in 1930, only to be unceremoniously relegated to dwarf planet status by the International Astronomical Union in 2006. And yet …

And yet what? And yet the Harvard-Smithsonian Centre for Astrophysicists is lobbying hard for Pluto to become a planet again.

Why? We’ve just had all the textbooks reprinted. It’s all about the definition. According to the Harvard-Smithsonian news blog, even if Pluto is a dwarf planet, we should still treat it as a planet because: “A dwarf fruit tree is still a small fruit tree, and a dwarf hamster is still a small hamster.” The centre had a debate, and then there was a vote, and the result was overwhelmingly in favour of Pluto’s reinstatement as a planet.

What happens if we do let Pluto back in? Well, there’s a chance that other distant trans-Neptunian objects – such as Triton or Eris or 50000 Quaoar or 90377 Sedna – could also qualify for official planetary status.

But this is madness! The floodgates will open! We’ll never be able to turn back the tide of shifty-looking would-be planets looking to get an unjustified cut of our solar system! All right, Farage, rein it in.

Fine. But does any of this actually matter? If you’re a member of the International Astronomical Union or the Harvard-Smithsonian Centre for Astrophysicists – basically the Sharks and the Jets of the planetary-definition game – then yes.

And what does Pluto make of all this? Pluto is a massive clump of rock and ice trapped in a lonely silent orbit through the dark recesses of space several billion miles away from Earth. As such, it could not be reached for comment.

Do say: “Welcome back to the solar system, Pluto. We’ve missed you.”

Don’t say: “Now get out. We’ve changed our minds again.”

Is it time to leave… again?

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I have read several accounts that strongly suggest we (humans) are not from this planet. There is some evidence and conjecture that we may have come here from Mars after we had made the planet inhabitable, but that we aren’t even from there, but further afield. Suggesting the possibility that we are in fact a race of space nomads.

If we are not from here, that would explain why they can’t find the so called ‘missing link’ between us and apes; there isn’t one.

We have succeeded in stripping this planet and making it uninhabitable, is this why we are searching so far and wide in the galaxies at great expense to find the next port of call?

solongandthanksforallthefish

Was Douglas Adams spoof ‘Hitchhiker’s Guide to the Galaxy‘ terribly far off the mark? “So long and thanks for all the fish!”

Maybe we’ve found our next home…

Star is crowded by super-Earths

An impression of what the sky might look like from the exoplanet Gliese 667Cd, looking towards the parent star and featuring, at top, the other super-Earths in the habitable zone

Scientists have identified three new planets around a star they already suspected of hosting a trio of worlds.

It means this relatively nearby star, Gliese 667C, now has three so-called super-Earths orbiting in its “habitable zone”.

This is the region where temperatures ought to allow for the possibility of liquid water, although no-one can say for sure what conditions are really like on these planets.

Gliese 667C is 22 light-years away.

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22 light-years, just next door really.

 

Neighbours

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Earth-like planet found ‘next door’

Astronomers say they have found a planet in the Alpha Centauri B star system similar to Earth in location and size

How a planet orbiting Alpha Centauri B might look. Scientists claim to have discovered an Earth-like planet there a mere 25 trillion miles away. Photograph: L Calcada/AP

Astronomers say they have found a nearby planet that is similar to Earth in location and size.

It is the type of planet they have been searching for across the Milky Way galaxy and was found circling a star ‘right next door’ – 25tn miles (40tn kilometres) away in the Alpha Centauri B star system. But the Earth-like planet is so hot, its surface may be like molten lava.

The team of European astronomers who found it say it is likely there are other planets circling the same star, and that those planets could orbit in the not-too-hot, not-too-cold region around the star that astronomers sometimes call the Goldilocks zone.

The research was released online in the journal Nature on Tuesday.

All this searching deep space, and it was just down the road all the time. 25tn miles away, spatially speaking, that’s right under our noses. We could almost hop on a bus to visit.

Star is caught devouring planet

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The team thinks the planet was destroyed as its ageing star expanded in size

Astronomers have found evidence for a planet being devoured by its star, yielding insights into the fate that will befall Earth in billions of years.

The team uncovered the signature of a planet that had been “eaten” by looking at the chemistry of the host star.

They also think a surviving planet around this star may have been kicked into its unusual orbit by the destruction of a neighbouring world.

Details of the work have been published in Astrophysical Journal Letters.

 

The US-Polish-Spanish team made the discovery when they were studying the star BD+48 740 – which is one of a stellar class known as red giants. Their observations were made with the Hobby Eberly telescope, based at the McDonald Observatory in Texas.

Rising temperatures near the cores of red giants cause these elderly stars to expand in size, a process which will cause any nearby planets to be destroyed.

“A similar fate may await the inner planets in our solar system, when the Sun becomes a red giant and expands all the way out to Earth’s orbit some five billion years from now,” said co-author Prof Alexander Wolszczan from Pennsylvania State University in the US.

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