Autor Tópico: Supernovas and their traits in evolution  (Lida 747 vezes)

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Offline Wallchs

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Supernovas and their traits in evolution
« Online: 24 de Maio de 2016, 16:43:22 »
 Could any supernova have influenced life on Earth? So, I recently this week was talking to a friend about evolution and, he asked me if a supernova cold influence live on Earth.

      When I read the book Origins Neil Grasse Tayson, I had a brief moment of clarity, enthusiasm, and how things are connected. The beauty that is in nature show us, how precious we are, and how and how we are insignificant.

     Returning to the point, we can influence small developments such as occurred in dogs, and in some bacteria.   But in the case of a supernova would work more like a cleansing process by removing our ozone layer and destroying some beings who depend on it,  perhaps after thousands of years the waste this supernova could be recycled by the Earth's climate itself providing a new type of material so that other single-celled organisms could take advantage of these ingredients. Taking a new step in that evolution occurs naturally. 

  The complexity generated by these events can trigger never seen aspects in existing beings or that of our planet, but for all that radiation would not make anyone today a superhero.

Offline Gigaview

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Re:Supernovas and their traits in evolution
« Resposta #1 Online: 24 de Maio de 2016, 18:41:04 »
The expanding shock waves from supernova explosions can trigger the formation of new stars, including Sun-like stars.


http://adsabs.harvard.edu/abs/2008ApJ...686L.119B
"Never attribute to malice that which can be adequately explained by stupidity, but don't rule out malice." -Heinlein’s Razor

Offline Buckaroo Banzai

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Re:Supernovas and their traits in evolution
« Resposta #2 Online: 24 de Maio de 2016, 20:22:19 »
Citar
[...]Take the more recent supernova period identified by Wallner and colleagues, which matches up with the Pliocene-Pleistocene boundary – right around when the most recent Ice Age was swinging into full, frigid force.

“We do not know if there is a link between supernova activity and colder temperature,” Melott said. However, he added, “This climatic variation may be one of the conditions that led to human evolution. Ionization of the atmosphere by supernovae may also lead to an increase in lightning and possibly other climatic effects.”

[...]

http://www.latimes.com/science/sciencenow/la-sci-sn-supernovas-nearby-earth-life-climate-20160406-story.html


Great. Now the planeteers are going to propose taxes for satellite-shields against supernovae. But they still won't admit anything other than CO2 could be (supposedly) warming the Earth's average temperature. [/not seriously]

Offline Sdelareza

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Re:Supernovas and their traits in evolution
« Resposta #3 Online: 25 de Maio de 2016, 22:23:36 »
Some speculate that radiation coming from supernova may favor mutations in living things. Life on Earth was for a long time limited just to algae and simple beings (jellyfish, small fish). In the Cambrian period,  the first vertebrates appeared, animal species multiplied and became bigger and more complex, perhaps as the result of a supernova that occured near Earth.

Offline Buckaroo Banzai

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Re:Supernovas and their traits in evolution
« Resposta #4 Online: 25 de Maio de 2016, 23:48:38 »
I'd think that a massive extraterrestrial mutagenic force would more likely just cause mass extinctions, rather than any "x-men"/"poke-men" type of evolution, even though mass extinctions do dramatically alter the course of evolution anyway.

But there are some researchers who posit a "positive" correlation with supernovae and biodiversity, but I suspect it may be more analogue to just "energy", like solar energy at the equator correlates with more biodiversity. I think it's nothing like that either, apparenlty somehow nearby supernovae cools the planet, and yet it has a positive effect on the ocean's biodiversity, or something like that:

Citar
http://www.ncbi.nlm.nih.gov/pubmed/11607506

Could a nearby supernova explosion have caused a mass extinction?
Ellis J1, Schramm DN.
Author information
Abstract
We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by paleontologists. We discuss the possible rate of such events in the light of the recent suggested identification of Geminga as a supernova remnant less than 100 parsec (pc) away and the discovery of a millisecond pulsar about 150 pc away and observations of SN 1987A. The fluxes of gamma-radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer are discussed. A supernova explosion of the order of 10 pc away could be expected as often as every few hundred million years and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs at the "KT boundary." The recent argument that the KT event was exceedingly large and thus quite rare supports the need for other catastrophic events.



Citar
http://arxiv.org/abs/1210.2963

Evidence of nearby supernovae affecting life on Earth

Henrik Svensmark (National Space Institute, Technical University of Denmark, Lyngby, Denmark)
(Submitted on 10 Oct 2012)
Observations of open star clusters in the solar neighborhood are used to calculate local supernova (SN) rates for the past 510 million years (Myr). Peaks in the SN rates match passages of the Sun through periods of locally increased cluster formation which could be caused by spiral arms of the Galaxy. A statistical analysis indicates that the Solar System has experienced many large short-term increases in the flux of Galactic cosmic rays (GCR) from nearby supernovae. The hypothesis that a high GCR flux should coincide with cold conditions on the Earth is borne out by comparing the general geological record of climate over the past 510 million years with the fluctuating local SN rates. Surprisingly a simple combination of tectonics (long-term changes in sea level) and astrophysical activity (SN rates) largely accounts for the observed variations in marine biodiversity over the past 510 Myr. An inverse correspondence between SN rates and carbon dioxide (CO2) levels is discussed in terms of a possible drawdown of CO2 by enhanced bioproductivity in oceans that are better fertilized in cold conditions - a hypothesis that is not contradicted by data on the relative abundance of the heavy isotope of carbon, 13C.



Offline Wallchs

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Re:Supernovas and their traits in evolution
« Resposta #5 Online: 09 de Junho de 2016, 15:21:17 »
I'd think that a massive extraterrestrial mutagenic force would more likely just cause mass extinctions, rather than any "x-men"/"poke-men" type of evolution, even though mass extinctions do dramatically alter the course of evolution anyway.

But there are some researchers who posit a "positive" correlation with supernovae and biodiversity, but I suspect it may be more analogue to just "energy", like solar energy at the equator correlates with more biodiversity. I think it's nothing like that either, apparenlty somehow nearby supernovae cools the planet, and yet it has a positive effect on the ocean's biodiversity, or something like that:

Citar
http://www.ncbi.nlm.nih.gov/pubmed/11607506

Could a nearby supernova explosion have caused a mass extinction?
Ellis J1, Schramm DN.
Author information
Abstract
We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by paleontologists. We discuss the possible rate of such events in the light of the recent suggested identification of Geminga as a supernova remnant less than 100 parsec (pc) away and the discovery of a millisecond pulsar about 150 pc away and observations of SN 1987A. The fluxes of gamma-radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer are discussed. A supernova explosion of the order of 10 pc away could be expected as often as every few hundred million years and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs at the "KT boundary." The recent argument that the KT event was exceedingly large and thus quite rare supports the need for other catastrophic events.



Citar
http://arxiv.org/abs/1210.2963

Evidence of nearby supernovae affecting life on Earth

Henrik Svensmark (National Space Institute, Technical University of Denmark, Lyngby, Denmark)
(Submitted on 10 Oct 2012)
Observations of open star clusters in the solar neighborhood are used to calculate local supernova (SN) rates for the past 510 million years (Myr). Peaks in the SN rates match passages of the Sun through periods of locally increased cluster formation which could be caused by spiral arms of the Galaxy. A statistical analysis indicates that the Solar System has experienced many large short-term increases in the flux of Galactic cosmic rays (GCR) from nearby supernovae. The hypothesis that a high GCR flux should coincide with cold conditions on the Earth is borne out by comparing the general geological record of climate over the past 510 million years with the fluctuating local SN rates. Surprisingly a simple combination of tectonics (long-term changes in sea level) and astrophysical activity (SN rates) largely accounts for the observed variations in marine biodiversity over the past 510 Myr. An inverse correspondence between SN rates and carbon dioxide (CO2) levels is discussed in terms of a possible drawdown of CO2 by enhanced bioproductivity in oceans that are better fertilized in cold conditions - a hypothesis that is not contradicted by data on the relative abundance of the heavy isotope of carbon, 13C.



That it is increble

 

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