Author Topic: Artificial Gravity - Why Weight?  (Read 30455 times)

Offline llanitedave

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Re: Artificial Gravity - Why Weight?
« Reply #40 on: 05/20/2016 03:07 PM »
Mice on the Moon.  Land a colony there for a few mouse generations, monitor them, and then bring them back for study.  Seems straightforward, and a lot faster and cheaper than a human mission to Mars.
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Offline guckyfan

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Re: Artificial Gravity - Why Weight?
« Reply #41 on: 05/20/2016 04:12 PM »
Mice on the Moon.  Land a colony there for a few mouse generations, monitor them, and then bring them back for study.  Seems straightforward, and a lot faster and cheaper than a human mission to Mars.

On the moon you have the same problem as in orbit. Without humans tending the habitat it will be difficult to maintain it for such a long time.

Plus a habitat with artificial gravity for mice is not that hard, you don't need a large diameter. It would not even be too hard to have two levels with moon and Mars gravity.

Online the_other_Doug

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Re: Artificial Gravity - Why Weight?
« Reply #42 on: 05/20/2016 05:51 PM »
Mice on the Moon.  Land a colony there for a few mouse generations, monitor them, and then bring them back for study.  Seems straightforward, and a lot faster and cheaper than a human mission to Mars.

On the moon you have the same problem as in orbit. Without humans tending the habitat it will be difficult to maintain it for such a long time.

Plus a habitat with artificial gravity for mice is not that hard, you don't need a large diameter. It would not even be too hard to have two levels with moon and Mars gravity.

Well, gee, if you need to send people to tend the thing, well, then, I guess you have to do so.

Since it's a dirty, rotten, thankless job (but somebody has to do it), I would volunteer to go and muck out the rodent stables every day.  I have to go to the Moon to do it?  I can make that sacrifice... :D
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Offline QuantumG

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Re: Artificial Gravity - Why Weight?
« Reply #43 on: 05/20/2016 11:04 PM »
You'll need to get those mice back too. Can't tell much from just remote observation.

It's kinda sad that sending mice to the surface of the Moon and returning them safely to Earth is beyond our capabilities.
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Offline llanitedave

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Re: Artificial Gravity - Why Weight?
« Reply #44 on: 05/21/2016 01:32 AM »
You'll need to get those mice back too. Can't tell much from just remote observation.

It's kinda sad that sending mice to the surface of the Moon and returning them safely to Earth is beyond our capabilities.


Well, I believe this nation should commit itself.
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Offline savuporo

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Re: Artificial Gravity - Why Weight?
« Reply #45 on: 05/21/2016 01:59 AM »
Mice on the Moon.  Land a colony there for a few mouse generations, monitor them, and then bring them back for study.  Seems straightforward, and a lot faster and cheaper than a human mission to Mars.

This would have been enough of a start, without going all the way to lunar surface

https://en.wikipedia.org/wiki/Mars_Gravity_Biosatellite
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Offline llanitedave

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Re: Artificial Gravity - Why Weight?
« Reply #46 on: 05/21/2016 03:35 PM »
Mice on the Moon.  Land a colony there for a few mouse generations, monitor them, and then bring them back for study.  Seems straightforward, and a lot faster and cheaper than a human mission to Mars.

On the moon you have the same problem as in orbit. Without humans tending the habitat it will be difficult to maintain it for such a long time.

Plus a habitat with artificial gravity for mice is not that hard, you don't need a large diameter. It would not even be too hard to have two levels with moon and Mars gravity.


Yeah, that's true.  It would be a good use for a free-flying satellite keeping formation with the ISS.
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Offline WindyCity

Re: Artificial Gravity - Why Weight?
« Reply #47 on: 05/21/2016 04:26 PM »
I am of the firm opinion that artificial gravity on a large scale has no place in such a scenario. We can and should build a base on Mars regardless. That base is the place to find out about long term health, including reproduction. First with animals and then soon with humans.

I understand your point of view, and certainly there would be no lack of volunteers to serve as guinea pigs on Mars. People are willing to accept high risks in order to get involved in a wide variety of activities. Given, however, that artificial gravity studies could be performed on orbit that would show the likely health effects of low-gravity exposure, and further would determine the "sweet spot," the minimal amount of gravity needed to prevent debilitating muscle and bone loss, I think that pursuing them would be prudent and ethical. Contrary to what has been said, according to Schmidth and Goodwin centrifugal studies on orbit would likely be revealing, if not one-hundred percent determinative, of the impact of low gravity on human health. In my opinion, therefore, it would be immoral to send people on a mission involving an unknown risk that could possibly have been lessened or eliminated before launch. The fact there are brave souls who would be willing to jump aboard willy-nilly is beside the point. All of us have a responsibility to protect human life when at all possible. Indeed, it might possibly set back human space flight if early Mars travelers suffered any serious ill consequences from exposure to low gravity. It simply seems to me wise and humane to do the studies first and find out what we can before sending people on a dangerous journey.

Offline scienceguy

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Re: Artificial Gravity - Why Weight?
« Reply #48 on: 05/21/2016 04:40 PM »
What about mice bred in a centrifuge on the ISS?
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Offline nadreck

Re: Artificial Gravity - Why Weight?
« Reply #49 on: 05/21/2016 04:53 PM »
What about mice bred in a centrifuge on the ISS?

The objection read most often here is that running a centrifuge on the ISS will interfere with microgravity experiments/research.  I don't know if I buy that, but it is the objection mentioned most often.

Personally I am a proponent of developing an expandable station with a microgravity section and a spinning section, both with both pressurized and hard vacuum work areas. For a lot of reasons ISS is really not suitable to anything larger than something that might support experiments with small rodents in an AG situation.

But what I do see a need for is the build up of a database of medical information much like what was done with divers over 50 years or more to characterize how humans (animals first if desired) respond to different levels, and different time break downs at these levels, of acceleration.  There are tons of WAGs about how much gravity might mitigate health issues, somewhat less about what a sustainable regime of micro-gravity and acceleration exposure would be both in time mixes and levels for acceleration.  But the one thing is, is that we only have experience with 1 g and greater for any length of time, or microgravity in varying amounts of single exposures more than about 90 seconds before returning to a 1 g regime for a long period of time.  Experience with a daily cycle between microgravity and acceleration would be invaluable as well as experience with different acceleration levels.
It is all well and good to quote those things that made it past your confirmation bias that other people wrote, but this is a discussion board damnit! Let us know what you think! And why!

Offline scienceguy

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Re: Artificial Gravity - Why Weight?
« Reply #50 on: 05/21/2016 05:41 PM »
Will the Bigelow habitat they just installed be big enough to put a mouse centrifuge inside?
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Offline savuporo

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Re: Artificial Gravity - Why Weight?
« Reply #51 on: 05/22/2016 06:40 AM »
What about mice bred in a centrifuge on the ISS?

A free flying centrifuge like Mars Gravity Biosatellite was supposed to be would give much more flexibility. DLRs is going to be launching a very similarly purposed free-flying eu:CROPIS for partial-g plant growth studies soon.

No reason to try and cram it in ISS where it would be difficult to fit a centrifuge and it would likely conflict with micro-g research a lot. However, MGB project plans at some point talked about having a separate experiment in micro-g running in parallel - something that is being done on ISS as we speak.

If ISS were to have any sort of a robotic space tug ( like Jupiter ) then co-orbiting experiments that can be deployed and retrieved would make the most sense.
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Offline WindyCity

Re: Artificial Gravity - Why Weight?
« Reply #52 on: 05/22/2016 05:56 PM »
What about mice bred in a centrifuge on the ISS?

Are we mice or men? Animal studies can help point the way, but their usefulness goes only so far. I should think that human studies will be required to reach a deeper, more reliable understanding of the issue.

Offline The Amazing Catstronaut

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Re: Artificial Gravity - Why Weight?
« Reply #53 on: 05/22/2016 06:44 PM »

Are we mice or men? Animal studies can help point the way, but their usefulness goes only so far. I should think that human studies will be required to reach a deeper, more reliable understanding of the issue.

Pigs would be better, but yet again, pigs require roughly the same life support conditions as humans.
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Offline Robotbeat

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Re: Artificial Gravity - Why Weight?
« Reply #54 on: 05/22/2016 07:03 PM »
What about mice bred in a centrifuge on the ISS?

Are we mice or men? Animal studies can help point the way, but their usefulness goes only so far. I should think that human studies will be required to reach a deeper, more reliable understanding of the issue.
Animal studies are huge. You can't (for several reasons) breed several sequential generations of humans in varying levels of gravity just to see what happens.

Let's do this experiment. And do it with a few different mammals, perhaps even chimps (carefully keeping their welfare in mind).
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Online the_other_Doug

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Re: Artificial Gravity - Why Weight?
« Reply #55 on: 05/23/2016 12:42 AM »
You can't (for several reasons) breed several sequential generations of humans in varying levels of gravity just to see what happens.

Aw, why not?  I will gladly volunteer to spend the rest of my life on the Moon, with as many other volunteers as may arise, to help perform such studies.

Of course, I imagine they would want someone younger than 60 as their starting point... ah, well.  :D  :D  :D
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Offline Robotbeat

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Re: Artificial Gravity - Why Weight?
« Reply #56 on: 05/23/2016 01:03 AM »
You can't (for several reasons) breed several sequential generations of humans in varying levels of gravity just to see what happens.

Aw, why not?  I will gladly volunteer to spend the rest of my life on the Moon, with as many other volunteers as may arise, to help perform such studies.

Of course, I imagine they would want someone younger than 60 as their starting point... ah, well.  :D  :D  :D
1) Cost
2) Unethical study, wouldn't be approved by usual scientific bodies
3) Would take like a century
4) The subjects may decide halfway through not to continue. May revolt. Etc.

These are significant complications. Might as well just solve them as well as you can with animal models and just go for it. After all, if the purpose of these experiments is to reduce risk and cost, the experiment would be just as risky and cost just as much as just trying the real thing and so would be pointless.
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Offline nadreck

Re: Artificial Gravity - Why Weight?
« Reply #57 on: 05/23/2016 01:19 AM »


These are significant complications. Might as well just solve them as well as you can with animal models and just go for it. After all, if the purpose of these experiments is to reduce risk and cost, the experiment would be just as risky and cost just as much as just trying the real thing and so would be pointless.

A mix of both human and animal is what makes sense. Also in LEO on an AG station with many gravity levels. The simplest solution is to do in depth monitoring of all the humans working there logging electronically there time at various G levels and microgravity and recording all their health (including cognitive and emotional) parameters daily with a combination of passive monitoring and more engaging diagnostic processes. The humans aren't controlled as to what time needs to be at different levels of acceleration, but the animals are and their regimes include breeding experiments and even in some cases dissection and vivisection (and lets try not to be too squeamish about this please).  Some of the humans will be involved in the animal research but I see a lot of other research and activity at such a station.
It is all well and good to quote those things that made it past your confirmation bias that other people wrote, but this is a discussion board damnit! Let us know what you think! And why!

Offline RDoc

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Re: Artificial Gravity - Why Weight?
« Reply #58 on: 06/01/2016 06:24 PM »
<snip>
Plus a habitat with artificial gravity for mice is not that hard, you don't need a large diameter. It would not even be too hard to have two levels with moon and Mars gravity.
Why wouldn't you need the same diameter as for humans? Mice are subject to motion sickness and tend to turn their heads a lot faster than humans do I think.

Offline nadreck

Re: Artificial Gravity - Why Weight?
« Reply #59 on: 06/01/2016 06:43 PM »
<snip>
Plus a habitat with artificial gravity for mice is not that hard, you don't need a large diameter. It would not even be too hard to have two levels with moon and Mars gravity.
Why wouldn't you need the same diameter as for humans? Mice are subject to motion sickness and tend to turn their heads a lot faster than humans do I think.
But the gradient over the body height (or even body length if they are climbing) is so much smaller than a human, at a radius of 2 meters for a mouse that is the equivalent of a 40 meter radius for a human if you measure the mouse length wise and more like 100 meters if the mouse is on all fours. That would allow for testing of 1 g at ~20rpm .3 at ~12rpm and .1g at ~6 rpm.
It is all well and good to quote those things that made it past your confirmation bias that other people wrote, but this is a discussion board damnit! Let us know what you think! And why!

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