Was Earth a Migratory Planet? 257
astroengine writes "Why our planet isn't a "snowball Earth" — a dilemma called the 'faint young sun paradox' — has foxed solar and planetary scientists for decades. Since the Earth's formation, a planet covered in ice should have stifled any kind of greenhouse effect, preventing our atmosphere from warming up and maintaining water in a liquid state. Now, David Minton of Purdue University has come up with a novel solution that, by his own admission, straddles science fact and fiction. Perhaps Earth evolved closer to the Sun and through some gravitational effect, it was pushed to a higher orbit as the Sun grew hotter. But watch out, if this is true, planetary chaos awaits."
Comment removed (Score:4, Informative)
Fairly stupid response (Score:5, Informative)
A substance that, when introduced into or absorbed by a living organism, causes death or injury, esp. one that kills by rapid action.
*breaths in*
That was just a bunch of CO2 I sucked in right there.
Even your argument that "everything is a poison in large quantities" is stupid, because it's not the CO2 harming you if you go in the garage and turn on the car - it's the fact you are not getting oxygen. The CO2 itself did not hurt you.
Plants also disagree with you. When you've made a plant frown how much lower can you go?
It's not that novel (Score:5, Informative)
Re:Fairly stupid response (Score:2, Informative)
I think there's a difference between carbon monoxide, and carbon dioxide.
Re:Fairly stupid response (Score:5, Informative)
That's not true. It's not merely displacement of oxygen that can harm you; CO2 also drives blood pH down and results in acidosis.
Related: The increased acidification of the oceans due to CO2 is one of those things that's often overlooked when people start talking about CO2 emissions and Global Warming and all that.
Re:Fairly stupid response (Score:5, Informative)
Re:Fairly stupid response (Score:4, Informative)
I think you mean the neutralization of the ocean as the water is going from slightly basic to slightly less basic. It isn't acidification until you cross neutral.
The Inside Scoop (Score:5, Informative)
So about five years ago my graduate school advisor and I wrote what was my very first peer-reviewed paper, which was on the subject of the Faint Young Sun Paradox. The paradox goes something like this: The early Sun was fainter than it is today, so all things being equal the Earth should have spend the first half of its life frozen over. Geologists tell us it wasn't, so something wasn't equal. What was it? We investigated the idea that the Sun may have been slightly more massive (something like 2-7% more massive), and that it had to lose most of that excess mass over a few billion years, which is at odds with measurements of mass loss of Sun-like stars. So we published it, and I went on to do other things in grad school, mostly involving trying to figure out the early impact bombardment history of the solar system, which we think may have been influenced by an early period of migration of the gas giant planets.
Fast forward to a few months ago, and a fellow at the Space Telescope Science Institute (the place they run the Hubble from) contacted me to ask if I'd like to give a talk about my old mass-losing Sun paper at a workshop that was planned to bring together astrophysicists, geologists, climate scientists, and planetary dynamicists to talk about the Faint Young Sun problem. They wanted me to also talk about planet migration and how that might fit in to the problem. Sure, why not? Revisiting the problem would be fun! The thing is, I've just started a new faculty job, and part of my job is helping get a new planetary science group built up at Purdue, so I've been extremely busy. And, well, I procrastinated. Big time. There was always some pressing thing to do that took time away from getting ready for the workshop. So the next thing I know, it's a few days before the meeting and I still haven't really thought about the faint Sun in about five years. So I dust off my old files, start futzing around with a talk, and the next thing I know I'm on a plane to Baltimore.
Late the night before the workshop is about to start, I'm racking my brain trying to come up with something new to say. You see, I've been thinking about early solar system history, and planet formation. Migration is a big deal in those early days. It's easy to get planets to move around in young solar systems. But the Faint Young Sun problem is a problem for the Earth's mid-life, not it's adolescence. Then I remembered a paper I really liked that came out a couple of years ago by Jaques Laskar and Mickaël Gastineau. They showed that our own solar system could potentially destabilize after a few billion years of seeming-stability due to Mercury's proximity to a chaotic region. It's described briefly here: http://en.wikipedia.org/wiki/Stability_of_the_Solar_System#Laskar_.26_Gastineau [wikipedia.org]
What if something like that had happened *already?* So I futzed around with an N-body gravitational dynamics code remotely from my hotel room, in my pajamas, playing around with plausible initial solar systems where Earth stared just a tad closer to the Sun, but close enough to solve the problem of being frozen over, and Venus started out as two separate planets and then went unstable after many billions of years, scattering Earth to its present location in the process. And, when I checke
Re:On the upside though (Score:5, Informative)
"We won't curb our fossil fuel use any way... there's no viable alternative"
That is a completely full of ridiculousness statement.
There is no viable alternative, By what measure, that there is already 80,000 stations selling hydrogen on every street corner for $1.22 a gallon? That you dont already have your home covered in solar?
Fools make such statements. Solar is a highly viable alternative to home energy, Even as far north as Copper harbor, MI there are off the grid homes and even state buildings that have a 5KW solar install that works even on cloudy days (that is easy to do BTW) As for cars, electric storage is coming about, and if you paid for it you could have one built that will go 300 miles on a single charge. bio-diesel, switchgrass, there are a ton of other sources of fuel for use in an Internal Combustion engine if you MUST stick with that old outdated technology.
Will it do 0-60 in 2.4 seconds and take up 3 lanes of traffic and carry 80 people? No, the canyonero gigantor truck people will have to suffer. Will it make a small 4 seater? yes it will. Even a small 4 seater 4X4 truck if you really need one because you live miles away from roads. The technology is there already, it's just most amercians are too stupid to understand it. They think they NEED 300HP and to carry 7 passengers + 40 cu FT of cargo all the time.
You dont. Just like you dont need to have 60 light bulbs in your home burning with 120Watts of light in each of them. Be realistic and suddenly alternatives start popping up everywhere.
Hell you can run a internal Combustion engine off of WOOD! Google it for some education.
Will it require americans to stop being idiots and actually learn things about daily life? yes. And if that is what you are talking about, people being required to have a solid basic education about most everything like they did in the 1800's, then that is a good thing.
none of the caravans crossing the United states, waited for AAA to change their wagon wheel.
Man Stabbed. Death Caused By Anemia. (Score:5, Informative)
Your post is neither less stupid than the GP nor informative.
Re: Sucking
It was also just a bunch of CO2 you blew out.
Re: Your ridiculous claims.
*Everything* that kills you works by disrupting something your body needs to do to live. You might as well say paralyzing venoms don't kill you, it's the lack of oxygen because your lungs aren't working. Does that mean venom isn't poison? No.
Re: Car scenario
The CO2 in your scenario doesn't kill you. The CO does that. CO2 CAN kill you, though. Maybe you've heard of hypercapnia [wikipedia.org]. (Note the URL, too.)
Re: Plants
Just because something is not poison to ONE organism does not mean it is not a poison.
Re:The Inside Scoop (Score:5, Informative)
Slashdot needs a moderation code for Awesome.
Thank you, sir!
Re:Fairly stupid response (Score:5, Informative)
So cyanide is not a poison?
Not in small enough quantities. Cyanide(s) have been used in the treatment of certain cancers, tuberculosis and even leprosy.
Re:It's not that novel (Score:5, Informative)
Re:On the upside though (Score:3, Informative)
yeah we have all this great technology but can the average person afford it? no, they cant.
we have solar here in australia. the govt provides a rebate which kind of makes it seem attractive, but the truth is that the panels will often need replacing before you've broken even on the cost.
as far as cars go, many people buy second hand cars because that's all they can afford. I suppose if people buying new cars start targetting more efficient / hybrid / greener cars then eventually the situation will change.
but so far "green" cars carry a fairly substantial tax (ie. higher purchase price compared to equivalent petrol/diesel car) which often outweighs any cost benefit you get from it.
The only thing we can deduce is that eventually the cost of petrol/diesel will climb to the point where these other technologies are cheaper...and then people will start to switch.
Re:Fairly stupid response (Score:5, Informative)
Actually, CO will kill you, CO2 just prevents you from living.
CO2 is toxic but only in very high concentration. And in general you will suffer from suffocation rather than "classic" poisoning. CO2 was the cause of many deaths in mining and wineries where the heavy gas could accumulate in closed low placed areas (like mine shafts and wine cellars), with people discovering too late that they're getting dizzy and fell unconscious from a lack of O2. Mainly, though, the death is due to blood being saturated by CO2, meaning that the CO2 produced by the body cannot be transported out.
CO is a completely different beast, and actually toxic in the classic sense. It prevents O2 from being transported into the cells by bonding to the same receptors that usually carry O2, which makes it a LOT more dangerous. If you want a bad analogy, think of it as the difference of you not getting any food compared to you not being able to flush your toilet. While the latter sure is unpleasant, you can usually survive it much longer.
Re:On the upside though (Score:4, Informative)
This was one of the most horrible events in Earths history, causing mass death and killing off nearly all life on this planet.
Let's bow for a minute of silent prayer to all the anaerobic victims of the Great Oxygenation Event [wikipedia.org]
Re:Fairly stupid response (Score:4, Informative)
H2CO3(aq) -> H+(aq) + HCO3-(aq)
Re:The Inside Scoop (Score:5, Informative)
Now as to the question of meteor bombardment: that was the topic of the last 1/3 of my talk at the workshop, but was not mentioned in TFA. I am on a paper coming out in a couple of weeks that is showing that the so-called Late Heavy Bombardment persisted on the Earth all throughout the Archean, rather than ending abruptly at the end of the Hadean, as was thought from looking at lunar samples. The bombardment rate, while much higher than present-day, was not so high as to likely have had any major direct effect on the climate over geologically interesting timescales (say an impact creating a 1000 km wide basin occurring every 200-500 million year during the Archean). However, there may have been indirect effects of impact bombardment that have yet to be explored, and we find that it is an interesting coincidence that bombardment rate pretty much drops off completely by the early Proterozoic, just as Earth began to show signs of having some oxygen in the atmosphere, and the first real evidence for any kind of major glaciation events (the Huronian snowball). Could somewhat elevated impact bombardment rate be a controlling factor in the warm and anoxic Archean? I don't know the answer to that, but were studying it.