- the earth has a magnetic field which protects us from the
solar wind (radiation)
many planets may have atmospheres and water
important to support complex multicellular lifeforms, but are
bathed in deadly radiation
2006-09-06 15:54:10 · 19 answers · asked by seti yeti 1 in Science & Mathematics ➔ Astronomy & Space
The corelation between mutations / extinctions and polarity reversals might support a theory that evolution is accelerated by the absense of a magnetic field.
The Earth's magnetic field switches polarity from time to time, an average of every 400,000 years. Between polarity reversals, there is a short period of about 5000 years when we have virtually no magnetic field whatsoever. During this time, our upper atmosphere is vulnerable to the heating effects of the solar wind, and drastic chaotic climate changes would be expected. Adapting to these climate changes should fasciliate the evolution of survival mechanisms.
2006-09-07 05:24:24 · answer #1 · answered by Anonymous · 0⤊ 0⤋
You've probably got it right. The magnetic field deflects a LOT of hard radiation.
A thick atmosphere or oceans WOULD provide shielding, but they would be much more ionized without a magnetic field. Whether that would be more or less condusive to life development is an unanswered question. In a less stable environment, the life forms would certainly be different.
Yes, cockroaches and other insects are less susceptible to radiation -- because they have less genetic material to mutate, the very thing that prevents them from evolving into intelligent life forms.
Then too, the magnetic lines of force may have something to do with the way ions interact in solution. This could enhance the possibility of organic chemical formation (along with heat)
2006-09-07 07:31:41 · answer #2 · answered by r_moulton76 4 · 0⤊ 0⤋
radiation is not the same thing as solar wind (which is a flow or particles).
radiation helps the evolution of life. We used to get a lot more UV radiation before we had enough oxygen up there to create an ozon layer.
living organisms have all evolved in the presence of radiation and developped mechanisms to withstand it. We get hit by a lot of gamma rays from space each day, this kills a lot of cells, they get replaced. Some insects can withstand doses of radiation over 100 times higher, per unit weight, what would kill a human being.
the earth has a magnetic field because it has metal in the core, and it has metal in the core because it is a small rocky planet around a star of 2nd or 3rd generation ie heavy elements were created by a supernova a long time ago. It is likely that this scenario happened every and anywhere else in the universe.
2006-09-06 21:34:00 · answer #3 · answered by AntoineBachmann 5 · 0⤊ 0⤋
The earth's magnetic field is the third strongest in the solar system, after the sun and Jupiter. This is in spite of its size.
The magnetic field forms a protective layer that deflects the solar wind from the earth. Thus, our atmosphere is protected from the FORCE from the solar wind. That is , the atmosphere will not get blown away like the ice cream on top the ice cream cone.
The magnetic field also protects the earth from the poisonous solar radiation as it attracts and deflects the radiation into the field. This saves the earth from the radiation.
Because of this, life as we know it, can develop freely without any interference from the strong radiaiton from the sun.
2006-09-06 18:48:29 · answer #4 · answered by Sleuth! 3 · 0⤊ 0⤋
Nope. Even without a magnetic field, with a reasonably thick atmosphere, radiation levels at the surface would be low enough for complex life forms to survive. The Earth's magnetic field funnels charged particles from space to the regions near the Earth's magnetic poles, but even there, at the surface you don't get an unhealthy dose of radiation. You need to go to an altitude of tens of thousands of feet for that. A passenger jet can fly across the North Pole from Europe to Alaska at 40 000 feet without anybody getting an unacceptably high dose of radiation. But a Concorde flying the same route on a regular basis at 63 000 feet would mean that an occasional passenger would be OK but flight crew flying regularly would get too much radiation.
2006-09-06 17:44:11 · answer #5 · answered by zee_prime 6 · 0⤊ 0⤋
It seems that way. Some radiation is obvioiusly needed to accelerate mutations and therefore evolution, but too much would kill any slightly complex life. It is possible that life can exist on bodies without their own magnetic field if they are protected by that of a larger planet (like on a moon of Jupiter).
2006-09-06 16:00:33 · answer #6 · answered by iMi 4 · 0⤊ 0⤋
Probably not. The earth's field does provide some protection from radiation, but the atmosphere does most of it.
2006-09-06 16:28:27 · answer #7 · answered by Anonymous · 0⤊ 0⤋
So far the only place we know of the has lifeforms also has a magnetic field (little place called Earth) So that is consistent with what we know so far.
2006-09-06 18:43:29 · answer #8 · answered by dam 5 · 0⤊ 0⤋
Every cell in our bodies generates a electrical potential across the cell membrane via mitochondrial, collectively this electrical charge creates an electro-magnetic field around our bodies, Cells can not live or function without this process...
2006-09-06 19:30:16 · answer #9 · answered by Anonymous · 0⤊ 0⤋
If there are oceans, the mass of the water can act as a shield, so it should be possible for complex lifeforms to evolve in the depths.
2006-09-06 16:05:05 · answer #10 · answered by novangelis 7 · 1⤊ 0⤋