Hypothetical discussion on the effect of magnetic fields on planets

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Discussion Overview

The discussion revolves around the hypothetical effects of disturbances to Earth's magnetic field, particularly in scenarios where the field is significantly altered by external forces or events. Participants explore various implications for life, climate, and technological systems on Earth, as well as historical precedents and theoretical considerations.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants express curiosity about the consequences of a significant disturbance to Earth's magnetic field, questioning what might happen to life and climate under such conditions.
  • Others argue that realistic scenarios where the magnetic field changes drastically at the surface are hard to envision without accompanying catastrophic events.
  • A participant suggests that even without external objects, if the magnetic field were hypothetically morphed, it could have unknown effects on life and climate.
  • Some participants reference historical geomagnetic storms, noting that while they can disrupt technology, they do not appear to harm biological life.
  • There are discussions about the long-term natural processes of magnetic field reversals, with one participant noting that the last reversal was over 800,000 years ago and suggesting that a change is overdue.
  • Questions arise about the potential for human intervention in the magnetic field through artificial means, such as placing a large magnet near Earth, with mixed opinions on the feasibility and impact of such actions.
  • One participant humorously speculates about societal reactions to magnetic field changes, suggesting economic effects rather than biological ones.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of magnetic field disturbances, with multiple competing views and uncertainties remaining throughout the discussion.

Contextual Notes

Some discussions are based on hypothetical scenarios that may not be well-defined, leading to challenges in assessing potential outcomes. The conversation also touches on historical events and their relevance to current understanding, but does not resolve the complexities involved.

Epsilon Eridani
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TL;DR
Discussion on what would happen if the magnetic field of a bio-rich planet like Earth gets disturbed
Ok, so I have long been fascinated with magnetic fields and their mysterious nature. I've been wondering what would happen when the magnetic field of Earth gets bent/disturbed/rippled by some extraneous force. I am aware the extent of effects that magnetic fields have on a planet is great, but I am not really sure what would happen to say Earth, for example, if an alien object would be put in its vicinity, ravaging the magnetic field of the planet. Can someone with a deeper understanding of the topic shed some light on what would happen following such an event?
 
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Epsilon Eridani said:
Summary:: Discussion on what would happen if the magnetic field of a bio-rich planet like Earth gets disturbed

Ok, so I have long been fascinated with magnetic fields and their mysterious nature. I've been wondering what would happen when the magnetic field of Earth gets bent/disturbed/rippled by some extraneous force. I am aware the extent of effects that magnetic fields have on a planet is great, but I am not really sure what would happen to say Earth, for example, if an alien object would be put in its vicinity, ravaging the magnetic field of the planet. Can someone with a deeper understanding of the topic shed some light on what would happen following such an event?
Welcome to the PF. :smile:

It's hard to picture some realistic scenario where the Earth's magnetic field changes by much at the surface of the Earth, without something else big happening. For an object to come close enough to the Earth to change the B-field at the surface, it would probably have other bad effects as well.

You do know that the Earth's B-field does change slowly over time, right? And things seem to survive okay...

https://en.wikipedia.org/wiki/Earth's_magnetic_field

1595946071960.png
 
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For the sake of hypothetical discussion, assume nothing big is happening, no foreign object is present, and not just the surface is changing, but the entire shape of the field is being suddenly thrashed and morphed into something that has no resemblance to how it usually is. What effects would be observed on all life and climate on the planet?
 
Epsilon Eridani said:
For the sake of hypothetical discussion, assume nothing big is happening, no foreign object is present, and not just the surface is changing, but the entire shape of the field is being suddenly thrashed and morphed into something that has no resemblance to how it usually is. What effects would be observed on all life and climate on the planet?
We don't generally start discussions like that. They are ill-defined and generally not productive. Anything that can make those kind of changes to the B-field will most likely have other effects that will probably dominate the B-field secondary effects.

Take the solar wind effects described in the Wikipedia article that I linked. Those have lots of other effects beyond just the small B-field effects at the Earth's surface.
 
Ok, let me phrase the question differently then - what existing systems on Earth that are crucial to the fine balance between biomes and in general the processes that take place in the planet's tectonic layers, atmosphere, and general life-support systems, are entirely dependent on the stability and shape of the magnetic field, and would severely change if that field gets distorted?
 
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How about removal of the magnetic field because the Earth's core ceased generating the field?
Answer: Mars.
https://phys.org/news/2020-05-timeline-ancient-magnetic-field-mars.html

How about a short term major perturbation? Not hypothetical at all...

Answer:severe geomagnetic storm -- it would likely trash satellites and some of the internet, and until we get our act together, severely damage the electric grid. It does not harm life as far as is known. This happened in 1859. Medium sized CME caused a 'the great blackout' in the US Northeast in 1965.

See: https://www.historycentral.com/sixty/Tech/blackout.html

See the Carrington Event, fun read:
https://en.wikipedia.org/wiki/September_1859_geomagnetic_storm

X class CME (coronal mass ejection):
https://en.wikipedia.org/wiki/Coronal_mass_ejection
 
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Epsilon Eridani said:
I've been wondering what would happen when the magnetic field of Earth gets bent/disturbed/rippled by some extraneous force.
That happens every 125,000 years on average when the Earth's magnetic field reverses.
The last change was over 800,000 years ago, so it is now long overdue.
Ask yourself what is expected, or likely to happen when it does flip.
 
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Very interesting stuff. So basically the magnetic field is entirely controlled by the dynamo. Can humans impact that by placing a gigantic magnet near the planet for example? I know this is all very unrealistic but I'm just curious to what extent can humans have an impact on the field.
 
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Epsilon Eridani said:
Can humans impact that by placing a gigantic magnet near the planet for example?
We can add or subtract from the field at the surface by pushing an electric current through loops of conductor, or transmitting radio waves. But the time needed to change the internal field is four times longer than we have had an electric power industry.
(Wikipedia says; “Diffusion in the liquid outer core is on timescales of 500 years or less, while that of the solid inner core is longer, around 3000 years”.)
 
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There wouldn’t be much in the way of biological effects. This has happened many times in the past.

I would expect that there would be some economic effects. People panic buying toilet paper for instance. Tin foil hat companies by the dozens. Shortages of sunscreen, and toxic sunscreens rushed to market. Basically what we are seeing now, but slightly different.
 
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