• Early Earth Should Have Been A Snowball, But Wasn't
    33 replies, posted
[quote]When our sun first got going, some 4.5 billion years ago, it wasn't the same blazing star we know today--its warmth and brightness grew gradually as more and more of its fuel ignited. So, for Earth's first two billion years, our planet was bathed in a light 25 percent dimmer than it receives today. If the sun dropped back down to that magnitude today, our planet would plunge into an ice age dramatic enough to bury the continents in miles-thick ice sheets and freeze the oceans solid. But according to the geological evidence, ancient Earth was not frozen: It was covered in vast liquid oceans and dotted over with arcs of island chains that sprouted up from undersea volcanoes and then wore back down again in the rain. Scientists have been working to resolve this troubling paradox for decades: how, they have asked, could a faint young sun have kept Earth out of an ice age for two billion years, when several ice ages have come and gone in more recent times, under a much brighter star? The answer, they reasoned, must lie in the planet's early atmosphere--the air must have been packed with enough heat-trapping greenhouse gas to compensate for the lack of sunlight. But which greenhouse gas was it? Evidence from ancient soils suggested that carbon dioxide levels weren't high enough to do the job alone, and theories pointing to methane as ancient Earth's chief atmospheric insulator fell apart under close scientific scrutiny. (Water vapor--today's biggest greenhouse gas--was out from the beginning, because air needs to be warm to begin with to hold large amounts of the stuff). Now, researchers at the University of Chicago have come up with a new theory: the greenhouse gases that provided Earth with extra warmth weren't CO2 or methane or any of the usual suspects--they were nitrogen and hydrogen. Though H2 and N2 don't normally soak up the sun's light, collisions between the molecules can energize them, prompting them to absorb infrared energy. Based on computer simulations, the researchers found that, if the early atmosphere were composed of 10 percent hydrogen, the warming effect from those molecular collisions could have been enough to raise the planet's temperature by as much as 60 degrees fahrenheit--enough to keep liquid water falling on the young, dimly-lit planet during the first part of its life. [img]http://www.popsci.com/files/imagecache/article_image_large/articles/snowballearth.png[/img][/quote] Source: [url]http://www.popsci.com/science/article/2013-01/why-early-earth-should-have-been-snowball-wasnt[/url]
It's because we have a moderate amount of greenhouse gases that keeps us warm
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] Because an artist made the picture, not the scientists that did the work. Silly artist. Nice catch though, didn't notice at first.
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] I think it's supposed to represent what would happen if the sun was 25 percent dimmer, as it once was long ago.
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] The picture is showing what would happen if the sun was dimmer NOW not back then, if you'd read the article.
It would be pretty cool to see the earth covered in snow like that in real life
Related somewhat to a snowball Earth [url]http://en.wikipedia.org/wiki/Snowball_Earth[/url] Learnt about it in college a few weeks ago
Life finds a way and that other stuff.
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] Pangea formed several hundreds of millions of years ago. The time the article is describing is a few billion years ago. We have no clue (more or less) to what the earth looked like that long time ago.
[QUOTE=Blazyd;39100437]It would be pretty cool to see the earth covered in snow like that in real life[/QUOTE] You can pretty much already do that, Pack your shit and head to Antarctica.
[QUOTE=BCell;39100105]It's because we have a moderate amount of greenhouse gases that keeps us warm[/QUOTE] because I'm sure scientists hadn't considered that.
[QUOTE=Blazyd;39100437]It would be pretty cool to see the earth covered in snow like that in real life[/QUOTE] It wouldn't [i]just[/i] be cool. It'd be fucking freezing, that's what.
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE]That's probably what it'd look like if it was snowball planet today.
Early Earth Should Have Been A Snowball, But Wasn't v:v:v Title just sounds like a bad joke lol
Greenhouse gasses saved the Earth
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] Pangea is the supercontinent that existed before the dinosaurs, not at the creation of earth.
[QUOTE=Blazyd;39100437]It would be pretty cool to see the earth covered in snow like that in real life[/QUOTE] It definitely wouldn't, I don't want to be so cold that coughing comes with a risk of my frost bitten bollocks falling off.
I'm not talking about [I]living [/I]in a world like that, just looking around
[QUOTE=BCell;39100105]It's because we have a moderate amount of greenhouse gases that keeps us warm[/QUOTE] The radioactive molten ball of iron a few thousand kilometers beneath your feet certainly helps...
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] You wouldn't be able to see it for the ice caps covering the entire planet.
[QUOTE=Spot of Tea;39102089]Greenhouse gasses saved the Earth[/QUOTE] Greenhouse gasses are still saving the Earth.
[QUOTE] how, they have asked, could a faint young sun have kept Earth out of an ice age for two billion years, when several ice ages have come and gone in more recent times, under a much brighter star?[/QUOTE] this sentence sounds a lot cooler if you imagine the Sun as a badass action hero keeping the planet safe and cozy then fuckin nitrogen and hydrogen had to go and steal the show
[QUOTE=Blazyd;39100437]It would be pretty cool to see the earth covered in snow like that in real life[/QUOTE] And then after a new long-ass time some new humanoid species would find the entire human civilization fossilized. [editline]5th January 2013[/editline] We would be like the dinosaurs, except we never found their technology.
Okay guys, the reason they made the earth in the photo as today's instead of sometime in the geological past is to connect the reader more so to the article. Reading the article and seeing a picture of some foreign planet isn't really interesting, but if you read it and see a picture of today, it gets the reader thinking, "hmm, what if..."
[QUOTE=Oicani Gonzales;39100135]why isnt it pangea in that picture[/QUOTE] Because this was before Pangea. Both would've been incorrect!
Pictured: Eeloo.
Could it be that the majority of water came from objects impacting the earth? This was only another theory, but it helps tie in the fact that they may not have yet struck, hence not much water to be frozen, etc.
What was the atmosphere made of back then?
[QUOTE=Killer monkey;39110288]What was the atmosphere made of back then?[/QUOTE] air
[QUOTE=Petrussen;39104061]Pictured: Eeloo.[/QUOTE] More like Hoth.
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