15-09-2014, 03:29 PM
11
Re: Geniuses predict how the world will end, and how to avoid it
Do I care??http://www.youtube.com/watch?v=HaZJigUdo_Q
17-09-2014, 02:29 PM
13
Re: Geniuses predict how the world will end, and how to avoid it
I was watching Seven ages of Starlight on BBC4 the other night, great stuff but above my head, judging by the bits I understood we are all doomed indeed, our Sun is now middle aged and barring a sudden stroke or a massive heart attack, in 5 billion years time it will become a 'Red Giant' swell in size and eat up our planet and the rest of our neighbouring planets, then in another couple of billion years it becomes a 'White Dwarf', then something small and very dense, (thats what the wife calls me sometimes) and finally a bottomless black hole, yes I’m afraid if you’re planning to hang on until your 20 billion years of age there is no hope for you at all.
17-09-2014, 04:40 PM
14
Re: Geniuses predict how the world will end, and how to avoid it
Hi Jem, our sun isn't massive enough to form a black hole, it needs to be at least 10 times heavier. It would then explode as a supernovae what was left would collapse to form a 'Neutron Star'. If it was really massive it would then undergo total gravitational collapse and form a singularity with an 'event horizon' surrounding it ... a 'black hole'.I'm afraid our sun is doomed to a long boring old age in the tens of billions of years range. I know the feeling
21-09-2014, 09:41 AM
15
Re: Geniuses predict how the world will end, and how to avoid it
Depends whether we're talking about the end of the real world, or the end of the human world - the one we deluded species think is so desperately important. I'm sure we'll finish ourselves off long before the death of the sun. Overpopulation will do it the soonest I suspect, barring strikes from outer space of course, and that could never be allowed to happen in Middle England - just wouldn't be cricket don't you know...22-09-2014, 01:54 PM
16
Re: Geniuses predict how the world will end, and how to avoid it
I suspect that if so-called 'Global Warming' continues at its current (and increasing) rate and the polar icecaps continue to melt, then we will see the inundation of low lying islands and coastal areas (where major population centres tend to be located). This will lead to massive migrations of people to less susceptible areas of the world, with the consequence of major resource shortages and eventually 'food wars'. Civilisation will break down and will not become stable again until a new population/resource equilibrium is attained. Estimates vary but if we assume total melting of the ice caps with the resultant increase of average sea levels of several hundred feet then the total land mass of the world could be reduced by 10-20%. Absence of the polar ice caps would reduce the total reflectivity of the earth (albedo) which would increase global warming even further and possibly push the earth past the metastable state in which it currently exists, possible resulting in a runaway greenhouse effect.
22-09-2014, 02:06 PM
17
Re: Geniuses predict how the world will end, and how to avoid it
Originally Posted by Rob B
->
Absence of the polar ice caps would reduce the total reflectivity of the earth (albedo) which would increase global warming even further and possibly push the earth past the metastable state in which it currently exists, possible resulting in a runaway greenhouse effect.
Who is to say whether that will be sufficient to cool the planet?
The ice ages covered massive swathes of land in reflective ice yet they came to an end (several times) and the planet warmed up again.
22-09-2014, 02:34 PM
18
Re: Geniuses predict how the world will end, and how to avoid it
You're right Bruce, we don't know (and probably never will) enough about the complex interactions in a 'chaotic' system such as climate. But we do exist in a metastable state which can be tipped one way or the other and result in a positive feedback effect which would result in one of two scenarios - either runaway greenhouse or the so-called 'snowball earth'. It all depends on how resilient the climate is to change and whether the balance is tipped beyond the point of no return.29-09-2014, 04:33 PM
19
Re: Geniuses predict how the world will end, and how to avoid it
The maths of quantum physics left me bewildered,serious philosophy has me wondering who,what when and why? But time does move on-when I was 50 I assumed I would get a bus pass at 60,when I got to 60 it was 64.Some buggar warped the time/space continuum
|
|
