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2nd January 2021, 19:18
#76
Senior Member
And on the other hand: This is closer to my simple thought regarding Extraterrestrial civilizations and I've concluded that the author is a debbie downer and a loser and a not much better writer than he is a scientist. The first property of the scientist author sucks and the second is forgivable ... put together he is off my Christmas list.
The celebrated physicist alan Guth has presented a rather different cosmological argument to show we are alone. The argument is based on one of the key underpinning concepts in cosmology: inflation. Guth and others came up with the concept of inflation during the 1980s in order to explain several observed features of the universe that are puzzles within the traditional Big Bang picture. The basic idea is that the universe began as a sort of vacuum fluctuation, a small patch of spacetime that underwent a brief period of exponential expansion---inflation---that took it almost instantaneously from a subnuclear-sized object to an object the size of an apple. Once inflation stopped, the "traditional" Big Bang expansionary phase took over, Inflation explains how the universe got to be so big, so smooth, so flat. In addition to explaining these observations (and various other properties of the universe), inflation strongly suggests that our universe is part of a multiverse---there are an infinite number of "local universes" or "bubble universes", of which ours is just one. In the particular bubble universe we inhabit the inflationary expansion ceased after a tiny fraction of a second; in other regions of this vast landscape the expansion continues, spawning bubble universes as it does so. In other words, once inflation starts it never stops; it's eternal.
There are many different specific models of inflation, but it's difficult to avoid the general conclusion that eternal inflation creates vast numbers of universes. Guth considers one model in which there are good reasons to suppose that every second the number of bubble universes is multiplied by a factor of e raised to 1037--a number that makes the googol look vanishingly small. This is an insanely large rate of universe production: you start with one universe, a second later there are e raised to 1037 universes, and a second after that you have to multiply by the same factor. It boggles the mind, but it's the sort of picture one has to contemplate when discussing cosmological inflation. And in this picture, young universes vastly outnumber old universes. Assuming this scenario holds true, Guth Poses the question: is there another civilization in the visible universe (that is, the bubble universe we inhabit) that's as advance as ours?
Suppose it takes a definit minimum time tciv to develop an advanced civilization. (It doesn't doesn't really matter how we define "advanced" here; equally, although a sharp minimum development time is unlikely to be realistic, we don't have to define a more convincing measure. The numbers involved outweigh these considerations.) Since we exist, the age t0 of our bubble universe must satisfy the constraint t0> tciv. Now suppose an ETC exists somewhere in our bubble universe, and that it's one second more advanced than us. Our bubble universe would then also have to satisfy the constraint t0> tciv + 1s. However, in the scenario we are considering, there are e raised to 1037 more bubble universes that satisfy the first constraint than satisfy the second constraint. Since we know we live in a bubble universe that satisfies t0> tciv we are overwhelmingly unlikely to find that our bubble universe also satisfies t0> tciv + 1s. The conclusion is that we are alone in our own particular part of the multiverse.
Guth wryly points out that although this argument might explain the Fermi paradox, a more plausible interpretation is that we don't fully understand how the formulate probabilities when discussing the infinity of bubble universes that arise in eternal inflation.
The cosmology-based argument of Alan Guth suggests that there might be infinitely many ETCs in the wider universe, but none whith which we can communicate. Effectively, we are alone.
“El revolucionario: te meteré la bota en el culo"
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Aianawa (31st January 2021)
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3rd January 2021, 16:05
#77
Senior Member
Listen to this video and then start listening to the conspiracy theorists. The other day I read one poor sap on PA state that the people like them were going to save the world. So far their plan is not working but then a lot of mental energy is expended trying to track the tentacle endings of the latest plot to defeat them.
“El revolucionario: te meteré la bota en el culo"
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The Following 3 Users Say Thank You to Emil El Zapato For This Useful Post:
Aianawa (31st January 2021), Aragorn (4th January 2021), Elen (4th January 2021)
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3rd January 2021, 19:00
#78
Senior Member
This is excellent. A presentation of one of the pre-eminent genetics scientists, Svaante Paabo. He has a very good explanation of risk factors and how they relate to blood types and Neanderthal genes. I think Aragorn this explores the factors that you mentioned sometime back.
Last edited by Emil El Zapato, 3rd January 2021 at 19:08.
“El revolucionario: te meteré la bota en el culo"
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The Following 3 Users Say Thank You to Emil El Zapato For This Useful Post:
Aianawa (31st January 2021), Aragorn (4th January 2021), Elen (4th January 2021)
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4th January 2021, 13:07
#79
Senior Member
Chromosome 3, if someone has the Neanderthal gene variant and they get sick they die ...
“El revolucionario: te meteré la bota en el culo"
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The Following 3 Users Say Thank You to Emil El Zapato For This Useful Post:
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8th January 2021, 20:42
#80
Senior Member
There have in geological times been 5 major extinctions: Ordovician, Devonian, Permian, Triassic and Cretaceous. There is one more actually that doesn’t get much attention and it is called the Holocene.
The Holocene Extinction
It would be wrong to discuss past mass-extinction events without mentioning the Holocene extinction. The Holocene epoch encompasses the last 10 millennia up to the present day. In other words, we’re living through a mass-extinction event. In this case the cause is clear: human activity. We hunt species to extinction; we cause havoc by introducing alien species into ecosystems; and, most importantly, we destroy habitats. It doesn’t feel as if we’re in the midst of a mass-extinction because, on an individual scale, 10,000 years is a long time. On a geological scale, though, it is an instant. Under some estimates, the rate at which species are becoming extinct is now 120,000 times the “normal” or “background” rate. Many of the species made extinct by our destruction of rain forests have never even been documented. If the current rate of extinction is maintained, and the destruction of the rain forests continues, then global atmospheric and climate effects seem certain to occur. It’s then quite possible that ours will be one of the species that joins the extinction. Harking back to a previous solution discussed in the book, perhaps a general evolutionary law is that intelligence extinguishes itself.
- Stephen Webb - “Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life”
“El revolucionario: te meteré la bota en el culo"
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The Following 4 Users Say Thank You to Emil El Zapato For This Useful Post:
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8th January 2021, 22:29
#81
Senior Member
I read today that there is a Neandertal gene variant on Chromosome 12 originating in Croatia ... I have some DNA from that region. So maybe 23andMe was correct. Which means some Neandertals might have survived Covid-19 after all. I hate being almost wrong.
Actually about a total of 24% which is more than I realized.
Last edited by Emil El Zapato, 9th January 2021 at 15:38.
“El revolucionario: te meteré la bota en el culo"
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The Following 4 Users Say Thank You to Emil El Zapato For This Useful Post:
Aianawa (31st January 2021), Aragorn (9th January 2021), Dreamtimer (30th January 2021), Elen (9th January 2021)
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10th January 2021, 01:30
#82