Earth's Magnetic Field: Life, Solar Winds & Astronauts

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Discussion Overview

The discussion revolves around the relationship between Earth's magnetic field and life on Earth, as well as the implications for astronauts in space regarding protection from solar winds and the potential need for pulsed electromagnetic fields (PEMF) in spacecraft. The scope includes theoretical considerations, implications for life, and practical aspects of space travel.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants suggest that while the Earth's magnetic field protects against solar winds, life could still exist without it, although human life on the surface would be more vulnerable.
  • There is uncertainty about the meaning of PEMF, with some proposing it stands for pulsed electromagnetic field.
  • One participant notes that the ISS remains within the Earth's magnetic field, indicating that additional shielding may not be necessary for astronauts.
  • Concerns are raised about the South Atlantic Anomaly (SAA) and its impact on radiation exposure for astronauts, with a mention of the limitations of current radiation shielding methods.
  • Some participants express opinions about the duration and effects of magnetic field reversals, with one suggesting that a "zero" field may not exist for long during reversals, while another claims evidence supports a gradual process over thousands of years.
  • A later reply discusses the potential impact of a lack of a magnetosphere on the evolution of complex DNA and atmospheric stability, raising questions about the design and integration of a PEMF for future space missions.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of the Earth's magnetic field for life and the implications for astronauts. There is no consensus on the effects of magnetic field reversals or the need for PEMF in space travel.

Contextual Notes

Participants acknowledge the complexity of the relationship between the magnetic field and life, as well as the challenges of radiation exposure in space. Some points raised are based on personal opinions rather than established evidence.

dysond
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Hi I have two questions.
1. is all life on Earth reliant on energy from the Earth's magnetic field- Iknow it protects us from solar winds.
2. do astronauts need pemf in their capsules or space staions?
 
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No, no.
 
dysond said:
Hi I have two questions.
1. is all life on Earth reliant on energy from the Earth's magnetic field- Iknow it protects us from solar winds.
2. do astronauts need pemf in their capsules or space staions?

I'd say that shielding us from solar winds and such is helpful, but I'd bet on life still being around without it.

Im not sure what PEMF means, so I can't say on that.
 
Drakkith said:
I'd say that shielding us from solar winds and such is helpful, but I'd bet on life still being around without it.

Perhaps, but not human-type life on such an exposed surface.
Unless underground, of course.
 
pallidin said:
Perhaps, but not human-type life on such an exposed surface.
Unless underground, of course.
The Earth's field reverses every million years or so - during which time the field at large bits of the surface must be close to zero for long periods of time. Life seems to have survived so far
 
Pemf -pulsed electromagnetic field
 
dysond said:
2. do astronauts need pemf in their capsules or space staions?

The ISS and therefore the shuttle remain largely inside the Earth's magnetic field. There is largely no need for additional shielding. Astronauts are considered radiation workers under US law and therefore are allowed a certain amount of radiation dose as part of their duties.

When we partnered with the Russians for the International Space Station (ISS), the orbital inclination of the ISS was adjusted to allow for easier access from their higher latitude launches. This causes the ISS to drift through the South Atlantic Anamoly (SAA), which is a region of the Earth's magnetic field in the south Atlantic somewhere off the coast of Brazil where the trapped particles (typically called the Van Allen Belt radiation) in the Earth's magnetic field come down much further. The short period spent in the SAA accounts for a large fraction of the radiation dose received by an astronaut on the ISS.

The only radiation shielding used on the ISS or the Shuttle is bulk material shielding. There is no active shielding deployed currently. In fact, when you start looking at the specifics of active radiation shielding for space flight, most of it is bad science usually coupled with impossible engineering. You can read through this paper: "ieeexplore.ieee.org/iel5/10432/33126/01559364.pdf"[/URL]
 
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NobodySpecial said:
The Earth's field reverses every million years or so - during which time the field at large bits of the surface must be close to zero for long periods of time. Life seems to have survived so far

I have no evidence, but my opinion is that when the Earth's magnetic field reverses, that the "zero" field does not exist or, if so, for a very short time; seconds or minutes.
Again, I have no evidence.
 
  • #10
pallidin said:
I have no evidence, but my opinion is that when the Earth's magnetic field reverses, that the "zero" field does not exist or, if so, for a very short time; seconds or minutes.
Fortunately we do have evidence and it takes 10,000s years for the poles to reverse during which the field drops to very low levels
 
  • #11
dysond said:
Hi I have two questions.
1. is all life on Earth reliant on energy from the Earth's magnetic field- Iknow it protects us from solar winds.
2. do astronauts need pemf in their capsules or space staions?

Perhaps life 'as we know it today' would have impacted to a degree, without a magnetosphere. (i.e.) one would have to wonder about the stability of highly complex DNA (over time) and the state of a delicate atmosphere. A steady dose of highly charged particles, cyclical CMEs, etc. - could have altered the evolution of complex DNA.

PEMF - Astronauts working in space today are relatively safe, w.r.t. solar wind pressure / high energy radiation - considering the periods spent in space -today. A trip to Mars and beyond may present different challenges.

If such a vessel had a PEMF, capable of clear deflection of solar-wind pressure, I'd be curious to know design/integration of the its power source, method for generating the EMF, and how long it could be sustained.
 

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