Researcher links mass extinctions to 'Planet X'

Post by marvy » Sun, Apr 03, 2016, 11:14 PM UTC

onetimePete wrote: post #43

pitchka wrote: post #32

Earlier quoted context omitted.

It's weird how we seem to understand exponential growth of technology but have a hard time grasping the exponential build-up of excess greenhouse gases due to the exponential growth of human population and economy. I wonder how these thousand years might look if currently there have been temperature difference of extremes by 20 degrees, with average already raised by 2. For example, mass extinction of oceanic ecosyst…

Presuming, we don`t have some AI that bio-upgrades whole ecosystems via DNA-update. Your seahshell of 2050 might be made of carbonfibre. Still its a race..

Post by Tiquor » Mon, Apr 04, 2016, 12:12 AM UTC

pitchka wrote: post #32

Chronic51 wrote: post #27

Earlier quoted context omitted.

That's fine. We still have a thousand years or two. We should be off this planet by then.

It's weird how we seem to understand exponential growth of technology but have a hard time grasping the exponential build-up of excess greenhouse gases due to the exponential growth of human population and economy. I wonder how these thousand years might look if currently there have been temperature difference of extremes by 20 degrees, with average already raised by 2. For example, mass extinction of oceanic ecosyst…

Post by CamperBob2 » Mon, Apr 04, 2016, 1:10 AM UTC

tremon wrote: post #36

Retra wrote: post #29

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>People who don't get addicted to chemical drugs don't get addicted because they have things in their lives (rewarding work, good relationships/sex, religion and other forms of self actualization) which gives them dopamine triggers that are more enjoyable than the drug. That sounds like something you should back up with unambiguous evidence.

I urge you to look up that evidence for yourself, it is easily found. There is both empirical evidence, from e.g. rats, and sociological experiments, from rehab centers. Also, I reject your use of "unambiguous". Ambiguity is a given, we're not discussing a mathematical proof here.

Post by dietrichepp » Mon, Apr 04, 2016, 1:21 AM UTC

tomr_stargazer wrote: post #50

dietrichepp wrote: post #42

Earlier quoted context omitted.

If its mass is 10 times Earth but it has similar density, its diameter would be 10^1/3 times Earth's, or 2.75 x 10^7 m. 1000 AU is 1.50 x 10^14 m. Their ratio is equal to the angular size in radians, since atan(x) = x to within our desired precision, giving 2.75e7/1.5e14/2pi 360 60*60 = 0.0378 arcseconds. The Keck observatory has angular resolution of 0.04 arcseconds at best, according to Wikipedia. So, by this back…

In your above calculation, you're assuming that an object needs to be resolved to be visible. To the contrary, telescopes are able to see un-resolved objects (objects whose angular size is below the angular resolution of the telescope) all the time -- they are called "stars". The relevant parameter here isn't angular size, but flux[0] (brightness). [0] https://en.wikipedia.org/wiki/Radiative_flux

Post by greglindahl » Mon, Apr 04, 2016, 2:34 AM UTC

fsiefken wrote: post #12

It seems like a variant of the Nemesis theory: https://en.wikipedia.org/wiki/Nemesis_%28hypothetical_star%2... which according to Adrain Mellott and Richard Bambach the regularity of the mass extinctions cannot be due to a dark star or brown dwarf or other large mass as it's orbit would have been perturbed by close encounters with other stars long ago. https://www.technologyreview.com/s/419809/the-death-of-nemes...