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> According to NASA Planetary Science Division director Jim Green, a powerful magnetic dipole positioned at the Mars L1 Lagrange Point could potentially deflect

> According to NASA Planetary Science Division director Jim Green, a powerful magnetic dipole positioned at the Mars L1 Lagrange Point could potentially deflect the solar wind like a natural magnetic field. https://www.extremetech.com/extreme/245369-nasa-proposes-building-artificial-magnetic-field-restore-mars-atmosphere https://www.extremetech.com/extreme/245369-nasa-proposes-bui...

londons_explore 3y ago
Such a project would see no tangible benefits for tens of thousands of years. Unfortunately, humans tend not to put much effort into anything that has no benefits within ~100 years. "If neither me nor my children will benefit from something, I don't want to invest my time/money."
- yincrash 3y ago
  Wouldn't it still protect humans who visit (or stay on) Mars from the solar radiation?
- Levitz 3y ago
  That makes sense though. I can hardly imagine any effort put 10.000 years ago that would be valuable now, with the technological difference.
  - reactordev 3y ago
    Yeah humans can measure progress afterwards but are terrible planners for anything beyond ourselves and next of kin.
    - bobthepanda 3y ago
      I mean, how would you even do maintenance over 10,000 years? At some point your descendants will be too far to remember the reason but not far enough to need it and they’ll stop wasting resources on a nothing activity.
      - withinboredom 3y ago
        People still do some maintenance on the 8k year old Afghanistan water system (underground aqueducts) because they are still used today. I’m failing to find some good sources, but when I was there in 2008, it was something the Army Core of Engineers was investigating on my base.
        bobthepanda 3y ago
        That solves an immediate need though, not a once in a few ten thousand year disaster.
        kaz-inc 3y ago
        this[1] places them at 3k years old: https://en.m.wikipedia.org/wiki/Qanat https://en.m.wikipedia.org/wiki/Qanat
        withinboredom 3y ago
        That sounds more right to me than a memory of some random conversations from nearly 20 years ago.
      - SV_BubbleTime 3y ago
        You could write exactly what this is and what you’re supposed to do with it on a big stone plate outside… Then in 10,000 years, find that an entire religion, culture, and wars were built around the simple maintenance instructions.
        bobthepanda 3y ago
        Outside, on Mars. So we have to assume we will maintain the ability for human Mars travel in ten thousand years, that anyone can read English or whatever in ten thousand years, and that the supporting religion didn’t lose any of its wars. To put this in perspective our first evidence of any human agriculture was 12,000 years ago.
        hattmall 3y ago
  - blamestross 3y ago
    Progress is exponential until "surprise it is a sigmoid!" I'd argue we are there already, but even if we aren't planting seeds is rarely a waste in the long term.
  - dehrmann 3y ago
    Only 5,000, but look at the pyramids. They're cool to look at, and the construction is fun to think about, but they're utterly useless. For any sort of 10,000 year space project, there's little (1%) harm in having a 100-year cool-off period to see if it still makes sense and how far technology has come.
  - pchristensen 3y ago
    Road networks in cities are probably the most durable creations.
- fnordpiglet 3y ago
  I’m not sure I understand why you think this would take 10’s of thousands of years to yield benefit. The most important benefit is shielding the planet surface from solar radiation and cosmic rays. This would be immediately beneficial to anyone living on the surface and would be essential in any terraforming effort of any duration, long or short. There are proposals that terraform mars in the span of a few generations (orbital solar powered large lasers evaporating the iron oxide and melting the ice for instance). But even without terraforming making the surface less hostile has immediate benefits.
  - Loughla 3y ago
    All of the terraforming business always seems like just digging around in your belly button. We can't even fix the problems on our first planet. How (and why) can we even begin to think about another one?
    - wiseowise 3y ago
      There’s a lot why’s to do that. How is the question.
    - c22 3y ago
      I guess if we do develop terraforming technologies I'd rather we test them on Mars first.
    - mortehu 3y ago
      We have solved countless problems on our planet. What are "the problems" you are thinking of?
      - sgu999 3y ago
        Green house gases emissions and the collapse of biodiversity are two reasonably conservative examples
        simondotau 3y ago
- thejackgoode 3y ago
  A hundred years? I feel like 90% of what happens is done because of election cycles and quarterly reports
  - londons_explore 3y ago
    People build bridges today that are expected to still be standing in 100 years. They could have made it a bit weaker, not bothered with paint or inspection hatches, and saved a little money, and had it only last 25 years... The time-value of money says that any benefit 25+ years from now is almost worthless, so it probably wasn't worth spending anything on those things to make the bridge last longer. Yet in most cases we still tend to build it to last 100 years, despite the economist saying it isn't worth it.
    - moffkalast 3y ago
      Probably not the best example since once a bridge is built you can immediately use it, the benefits don't only start rolling in after a 100 years. Making sure something lasts is correlated with natural disaster safety margins anyway so if it has to be built to survive near term extremes it'll generally also survive a while as a side effect. Older constructions also seemingly last longer through survivorship bias and the lack of computer modelling at the time meant that safety margins had to be higher. A better example are maybe tree avenues that take decades to grow into anything useful, or maybe long term river redirection projects or reactors. ITER's still in construction after 16 years. But there's just about nothing we do that would take more than a few decades to start showing returns.
    - elliotto 3y ago
      I'm not sure what the rules are in the US but in Australia the infrastructure service life is set by regulation. It's not an economic / financial argument or even a benevolence / moral argument that causes this, it's a legal requirement. There are significant real world advantages of having a bridge last more than 25 years that are not reflected by a financial return on investment.
    - ozim 3y ago
- Elucalidavah 3y ago
  To fix that, we need humans that actually expect to live for tens of thousands of years.
Yizahi 3y ago
As soon as that technology level is reached, humanity need not to worry about restoring dead ecosystems, but about preventing total destruction of the existing ones, including Earth. Throwing space rocks will be trivial for any terrorist cell, so any fragile single points of failure will be demolished first (like this magnetic shield, or possible Earth solar shade(because carbon capture doesn't work so far)). Then orbital stations will go, then pressurized domes, then planet surfaces in general. I think we have no chance at the large space structures, and current age will be considered a fluke of the insufficient lifting capabilities.
- aeternum 3y ago
  Seems like redundancy could solve this. Instead of a single huge magnet you create a constellation of smaller magnets with aligned fields that orbit the LaGrange point. We're decent at tracking large space rocks, and small space rocks will likely have to be dealt with anyway since some occur randomly. It's somewhat interesting that terrorism already isn't such a problem for huge skyscrapers. Skyscrapers can be destroyed with just a small fraction of the explosive energy required to launch an orbital rocket yet it rarely happens.
  - natpalmer1776 3y ago
    Your last paragraph is an excellent point that highlights the likely risk factor by using existing infrastructure as an example.
  - Yizahi 3y ago
    Skyscraper are not a good or a primary target. Why bother with a tower if the same number of people can be hit easier on a surface - a demonstration, Sunday market, transportation hub etc. Also I suspect that a lot of conventional explosives is needed to topple one, and it also requires to have a specific faults. You need at least half a ton of explosives to maybe do something (basing on the amounts russia uses in their ballistic missiles against cities), and that is not guaranteed.
- slibhb 3y ago
  If throwing space rocks is trivial (which I'm not sure I buy), surely knocking them off course will also be trivial.
HideousKojima 3y ago
I've seen this idea before, and someone did the math showing that while it would be possible it would take an exceptionally large amount of energy to keep the magnetic field running. Not impossible, but I recall it being equivalent to some significant fraction of the energy produced by all power plants on Earth or something like that. Have any advances been made to lower the energy needs for something like this?

londons_explore 3y ago

Such a project would see no tangible benefits for tens of thousands of years. Unfortunately, humans tend not to put much effort into anything that has no benefits within ~100 years. "If neither me nor my children will benefit from something, I don't want to invest my time/money."

yincrash 3y ago
Wouldn't it still protect humans who visit (or stay on) Mars from the solar radiation?
Levitz 3y ago
That makes sense though. I can hardly imagine any effort put 10.000 years ago that would be valuable now, with the technological difference.
- reactordev 3y ago
  Yeah humans can measure progress afterwards but are terrible planners for anything beyond ourselves and next of kin.
  - bobthepanda 3y ago
    I mean, how would you even do maintenance over 10,000 years? At some point your descendants will be too far to remember the reason but not far enough to need it and they’ll stop wasting resources on a nothing activity.
    - withinboredom 3y ago
      People still do some maintenance on the 8k year old Afghanistan water system (underground aqueducts) because they are still used today. I’m failing to find some good sources, but when I was there in 2008, it was something the Army Core of Engineers was investigating on my base.
      - bobthepanda 3y ago
        That solves an immediate need though, not a once in a few ten thousand year disaster.
      - kaz-inc 3y ago
        this[1] places them at 3k years old: https://en.m.wikipedia.org/wiki/Qanat https://en.m.wikipedia.org/wiki/Qanat
        withinboredom 3y ago
        That sounds more right to me than a memory of some random conversations from nearly 20 years ago.
    - SV_BubbleTime 3y ago
      You could write exactly what this is and what you’re supposed to do with it on a big stone plate outside… Then in 10,000 years, find that an entire religion, culture, and wars were built around the simple maintenance instructions.
      - bobthepanda 3y ago
        Outside, on Mars. So we have to assume we will maintain the ability for human Mars travel in ten thousand years, that anyone can read English or whatever in ten thousand years, and that the supporting religion didn’t lose any of its wars. To put this in perspective our first evidence of any human agriculture was 12,000 years ago.
      - hattmall 3y ago
- blamestross 3y ago
  Progress is exponential until "surprise it is a sigmoid!" I'd argue we are there already, but even if we aren't planting seeds is rarely a waste in the long term.
- dehrmann 3y ago
  Only 5,000, but look at the pyramids. They're cool to look at, and the construction is fun to think about, but they're utterly useless. For any sort of 10,000 year space project, there's little (1%) harm in having a 100-year cool-off period to see if it still makes sense and how far technology has come.
- pchristensen 3y ago
  Road networks in cities are probably the most durable creations.
fnordpiglet 3y ago
I’m not sure I understand why you think this would take 10’s of thousands of years to yield benefit. The most important benefit is shielding the planet surface from solar radiation and cosmic rays. This would be immediately beneficial to anyone living on the surface and would be essential in any terraforming effort of any duration, long or short. There are proposals that terraform mars in the span of a few generations (orbital solar powered large lasers evaporating the iron oxide and melting the ice for instance). But even without terraforming making the surface less hostile has immediate benefits.
- Loughla 3y ago
  All of the terraforming business always seems like just digging around in your belly button. We can't even fix the problems on our first planet. How (and why) can we even begin to think about another one?
  - wiseowise 3y ago
    There’s a lot why’s to do that. How is the question.
  - c22 3y ago
    I guess if we do develop terraforming technologies I'd rather we test them on Mars first.
  - mortehu 3y ago
    We have solved countless problems on our planet. What are "the problems" you are thinking of?
    - sgu999 3y ago
      Green house gases emissions and the collapse of biodiversity are two reasonably conservative examples
      - simondotau 3y ago
thejackgoode 3y ago
A hundred years? I feel like 90% of what happens is done because of election cycles and quarterly reports
- londons_explore 3y ago
  People build bridges today that are expected to still be standing in 100 years. They could have made it a bit weaker, not bothered with paint or inspection hatches, and saved a little money, and had it only last 25 years... The time-value of money says that any benefit 25+ years from now is almost worthless, so it probably wasn't worth spending anything on those things to make the bridge last longer. Yet in most cases we still tend to build it to last 100 years, despite the economist saying it isn't worth it.
  - moffkalast 3y ago
    Probably not the best example since once a bridge is built you can immediately use it, the benefits don't only start rolling in after a 100 years. Making sure something lasts is correlated with natural disaster safety margins anyway so if it has to be built to survive near term extremes it'll generally also survive a while as a side effect. Older constructions also seemingly last longer through survivorship bias and the lack of computer modelling at the time meant that safety margins had to be higher. A better example are maybe tree avenues that take decades to grow into anything useful, or maybe long term river redirection projects or reactors. ITER's still in construction after 16 years. But there's just about nothing we do that would take more than a few decades to start showing returns.
  - elliotto 3y ago
    I'm not sure what the rules are in the US but in Australia the infrastructure service life is set by regulation. It's not an economic / financial argument or even a benevolence / moral argument that causes this, it's a legal requirement. There are significant real world advantages of having a bridge last more than 25 years that are not reflected by a financial return on investment.
  - ozim 3y ago
Elucalidavah 3y ago
To fix that, we need humans that actually expect to live for tens of thousands of years.

Yizahi 3y ago

As soon as that technology level is reached, humanity need not to worry about restoring dead ecosystems, but about preventing total destruction of the existing ones, including Earth. Throwing space rocks will be trivial for any terrorist cell, so any fragile single points of failure will be demolished first (like this magnetic shield, or possible Earth solar shade(because carbon capture doesn't work so far)). Then orbital stations will go, then pressurized domes, then planet surfaces in general. I think we have no chance at the large space structures, and current age will be considered a fluke of the insufficient lifting capabilities.

aeternum 3y ago
Seems like redundancy could solve this. Instead of a single huge magnet you create a constellation of smaller magnets with aligned fields that orbit the LaGrange point. We're decent at tracking large space rocks, and small space rocks will likely have to be dealt with anyway since some occur randomly. It's somewhat interesting that terrorism already isn't such a problem for huge skyscrapers. Skyscrapers can be destroyed with just a small fraction of the explosive energy required to launch an orbital rocket yet it rarely happens.
- natpalmer1776 3y ago
  Your last paragraph is an excellent point that highlights the likely risk factor by using existing infrastructure as an example.
- Yizahi 3y ago
  Skyscraper are not a good or a primary target. Why bother with a tower if the same number of people can be hit easier on a surface - a demonstration, Sunday market, transportation hub etc. Also I suspect that a lot of conventional explosives is needed to topple one, and it also requires to have a specific faults. You need at least half a ton of explosives to maybe do something (basing on the amounts russia uses in their ballistic missiles against cities), and that is not guaranteed.
slibhb 3y ago
If throwing space rocks is trivial (which I'm not sure I buy), surely knocking them off course will also be trivial.

HideousKojima 3y ago

I've seen this idea before, and someone did the math showing that while it would be possible it would take an exceptionally large amount of energy to keep the magnetic field running. Not impossible, but I recall it being equivalent to some significant fraction of the energy produced by all power plants on Earth or something like that. Have any advances been made to lower the energy needs for something like this?