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Old 2nd July 2021, 09:57 AM   #41
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Originally Posted by Ziggurat View Post
It can (and will) if the base is to the side of the equator.

Putting the base at the equator is the simplest option because it makes the cable vertical. But it isn't strictly required. Consider the most extreme case: but the base at the pole, and have the cable start out running horizontal. It's obviously much harder to do that way, but the cable wouldn't come near the equator.

I don't think that's right. It's a tension structure (not a compression one), the COG of which is at geostationary (or areostationary) orbit. If the base is not at the equator the orbit described by the COG is going to criss cross the equator (as do all orbits that are not exactly equatorial).

You absolutely cannot build one at the pole, it just doesn't work that way.

(as ever, I might be missing something)
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Old 2nd July 2021, 10:02 AM   #42
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The orbit of the COG isn't dependent on where the base is. The COG has to be in synchronous orbit or the length of the cable has to constantly change, which I assume is not what Ziggurat has in mind. You're not on the equator now right? But you have a (theoretical) "view" of satellites in GEO that are not changing their distance from or orientation to you. A fixed length cable can theoretically run from any point on the surface to any satellite in equatorial synchronous orbit that it can see.

ETA: And note that the more reasonable case that Ziggurat started with, just a few degrees off the equator, actually includes the possibility that the COG and any counter weight could be in off equatorial plane orbits.

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Old 2nd July 2021, 10:08 AM   #43
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Originally Posted by RecoveringYuppy View Post
The orbit of the COG isn't dependent on where the base is. The COG has to be in synchronous orbit or the length of the cable has to constantly change, which I assume is not what Ziggurat has in mind. You're not on the equator now right? But you have a (theoretical) "view" of satellites in GEO that are not changing their distance from or orientation to you. A fixed length cable can theoretically run from any point on the surface to any satellite in equatorial synchronous orbit that it can see.
I think the additional strain on the structure from having to go sideways while maintaining structural integrity would be, putting it very mildly, a problem.
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Old 2nd July 2021, 10:12 AM   #44
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Originally Posted by 3point14 View Post
I think the additional strain on the structure from having to go sideways while maintaining structural integrity would be, putting it very mildly, a problem.
Virtually, all space elevator concepts have ridiculous practical problems at the moment.
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Old 2nd July 2021, 10:18 AM   #45
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Originally Posted by 3point14 View Post
I don't think that's right. It's a tension structure (not a compression one), the COG of which is at geostationary (or areostationary) orbit. If the base is not at the equator the orbit described by the COG is going to criss cross the equator (as do all orbits that are not exactly equatorial).

You absolutely cannot build one at the pole, it just doesn't work that way.

(as ever, I might be missing something)
Yes, you missed something, which is that the cable is not vertical both at the base AND at the orbit of your end point. So the cable will exert a lateral force component which will allow the path to remain off equator.

And you COULD build one at the pole. It's a bad idea to, but assuming sufficiently strong materials and launch capabilities (both harder than an equatorial cable), there's nothing that makes it impossible.
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Old 2nd July 2021, 10:19 AM   #46
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Originally Posted by 3point14 View Post
I think the additional strain on the structure from having to go sideways while maintaining structural integrity would be, putting it very mildly, a problem.
Oh, absolutely. It's a very bad idea. But (again, assuming sufficiently strong materials and launch capabilities) not an impossible idea.
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Old 2nd July 2021, 10:22 AM   #47
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Originally Posted by Ziggurat View Post
Yes, you missed something, which is that the cable is not vertical both at the base AND at the orbit of your end point. So the cable will exert a lateral force component which will allow the path to remain off equator.
I'm still missing it.

The counterweight sits at a synchronous orbit and the cable leaves it at an angle?


Quote:
And you COULD build one at the pole. It's a bad idea to, but assuming sufficiently strong materials and launch capabilities (both harder than an equatorial cable), there's nothing that makes it impossible.
I see I misread. I thought you meant at the pole going straight up. You didn't, I think, you mean at the pole running up at an angle to the counterweight, I think.

I'm far from an expert, but I think the concept it way less viable than the already pretty unrealistic space elevator that's all at the equator.

Again, I could be misunderstanding you entirely.
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Old 2nd July 2021, 10:50 AM   #48
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Originally Posted by RecoveringYuppy View Post
The orbit of the COG isn't dependent on where the base is.
That's not quite true. If the base is not equatorial, then the tilt of the cable means there's a lateral force component being applied by the cable. So there has to be a counteracting lateral force component from gravity. Which means your "orbital" plane is actually going to be offset from the equatorial plane, not tilted.

Have you ever seen the TV show Final Space? The logo for the Infinity Guard has a planet with two rings:



It looks nice, but obviously isn't physical for free-floating planetary rings. But the lateral force from an off-equator would pull the center of gravity into an orbit offset like one of those rings. Such a cable isn't free floating. It's constrained.
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Old 2nd July 2021, 10:55 AM   #49
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Originally Posted by 3point14 View Post
I'm still missing it.

The counterweight sits at a synchronous orbit and the cable leaves it at an angle?
The counterweight has to be farther out than synchronous orbit, in order to hold up the weight of the cable. In other words, if you release the counterweight, it has to go flying away, not stay in that same orbit.

If the base is not equatorial, then the counterweight will be pulled off the equatorial plane. At the counterweight's position, the cable will be angled slightly off from straight down.

I'll see if I can make a drawing to illustrate.
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Old 2nd July 2021, 11:09 AM   #50
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Here's a really crude diagram.


The circle is your planet. On the right side, a space elevator at the equator. The force of gravity and the tension in the cable both pull in the same direction, and the counterweight travels in a circular path in the equatorial plane.

On the left side is a space elevator with a non-equatorial base. The cable (black line) pulls downward (relative to our viewing of the diagram) and to the right, parallel to its length. Gravity pulls upward and to the right (dashed red line). The net force is horizontal and to the right. So the counterweight travels in a circular path, in a plane parallel to but offset from the equatorial plane.
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Old 2nd July 2021, 11:15 AM   #51
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Originally Posted by Ziggurat View Post
Here's a really crude diagram.
http://www.internationalskeptics.com...f5540de155.png

The circle is your planet. On the right side, a space elevator at the equator. The force of gravity and the tension in the cable both pull in the same direction, and the counterweight travels in a circular path in the equatorial plane.

On the left side is a space elevator with a non-equatorial base. The cable (black line) pulls downward (relative to our viewing of the diagram) and to the right, parallel to its length. Gravity pulls upward and to the right (dashed red line). The net force is horizontal and to the right. So the counterweight travels in a circular path, in a plane parallel to but offset from the equatorial plane.
Okay, thank you, I see what you're saying now. It does make an impossible engineering feat even more imposisble, but yes.

I wonder how much more strength you'd need from the unobtanium over an equatorially based one.
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Old 2nd July 2021, 11:18 AM   #52
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Originally Posted by Ziggurat View Post
That's not quite true. If the base is not equatorial, then the tilt of the cable means there's a lateral force component being applied by the cable.
Yep, agreed. Thanks for your additions. I realized I wasn't being complete but thought there was risk of opening a can of worms that would be off topic for this thread.
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Old 2nd July 2021, 11:26 AM   #53
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Originally Posted by 3point14 View Post
Okay, thank you, I see what you're saying now. It does make an impossible engineering feat even more imposisble, but yes.

I wonder how much more strength you'd need from the unobtanium over an equatorially based one.
Depends on how far off the equator you are. Phobos is pretty small and orbits pretty much right in the equatorial plane, so you might not need to be far off to miss it. Might not actually make that much difference.

Not that we're going to be building space elevators on Mars any time soon. They'll come after our interdimensional portals.
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Old 2nd July 2021, 11:35 AM   #54
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Originally Posted by Bikewer View Post
Hopefully, no Muzak on the way up.....
...and there's always some jerkweed who thinks it's funny to press all the buttons.
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Old 2nd July 2021, 11:38 AM   #55
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Originally Posted by 3point14 View Post
I wonder how much more strength you'd need from the unobtanium over an equatorially based one.

Note that if you've built one you can "just" build a second one. If you want the base to off the equator but the COG to be over the equator you "just" build a second base on the opposite side of the equator attached to the same COG.
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Old 21st November 2022, 07:23 PM   #56
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It's been a while. Here's something that I thought was a bit interesting.

A fungus growing naturally on roots is found to detoxify mercury in soil and water

There's a bunch more to the story, of course, but that makes for an okay summary. The burning of fossil fuels has increased environmental levels of mercury, with detrimental effects all around, but it's one of the many issues that doesn't get much attention. Good to have some better means available to help counter the damage.

Elsewhere...

An entire genome is made from scratch to support a new genetic code; the result is a living organism


One that might be immune to pretty much all current viruses, for that matter.
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Old 22nd November 2022, 02:33 AM   #57
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Originally Posted by Aridas View Post
It's been a while. Here's something that I thought was a bit interesting.

A fungus growing naturally on roots is found to detoxify mercury in soil and water

There's a bunch more to the story, of course, but that makes for an okay summary. The burning of fossil fuels has increased environmental levels of mercury, with detrimental effects all around, but it's one of the many issues that doesn't get much attention. Good to have some better means available to help counter the damage.
Interesting indeed!
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Old 23rd November 2022, 01:59 PM   #58
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Originally Posted by Aridas View Post
It's been a while. Here's something that I thought was a bit interesting.

A fungus growing naturally on roots is found to detoxify mercury in soil and water

There's a bunch more to the story, of course, but that makes for an okay summary. The burning of fossil fuels has increased environmental levels of mercury, with detrimental effects all around, but it's one of the many issues that doesn't get much attention. Good to have some better means available to help counter the damage.

Elsewhere...

An entire genome is made from scratch to support a new genetic code; the result is a living organism


One that might be immune to pretty much all current viruses, for that matter.
Along similar lines.

This genetically engineered houseplant does the air-purifying work of 30 plants

Quote:
To program the pothos vine to scrub the air, the team had to go where no lab had gone before. Most bioengineers start with a lab-friendly model organism, like Arabidopsis thaliana or Nicotiana benthamiana, whose genomes are mapped and annotated six ways to Sunday.

But the Neoplants team had to map the entire pothos genome themselves, and then determine which genes to target for maximum VOC filtration. “It’s like trying to build a plane while flying,” Torbey says.

The process took four years of near-constant work, but in the end, the engineers managed to create a plant that can metabolize four major indoor air pollutants, including formaldehyde and toluene. The customized flora can even absorb certain VOCs, like the carcinogen benzene, that are present in wildfire smoke.

But the real breakthrough came from modifying the microorganisms living in the plant’s roots. The team inserted genes from extremophile bacteria, which thrive in inhospitable environments by eating toxic chemicals, into these symbiotic microbes. This tweak in turn boosted the plant’s pollutant-metabolizing capacity.

And to ensure that they comply with FDA standards, the engineers were careful to avoid sections of the genome that could enhance the plant’s survival in the wild. “We don’t give a selective advantage to the plant. We don’t make it grow faster, we don’t increase its resistance to pesticides,” Torbey explains. “We’re not touching any of that.”
It's a bit expensive. A single Neo P1 costs $179
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Old 23rd November 2022, 02:02 PM   #59
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Dupe post.
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Old 23rd November 2022, 02:09 PM   #60
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Originally Posted by Gord_in_Toronto View Post
It's a bit expensive. A single Neo P1 costs $179
Yeah, that is a bit pricey. Even so, if its functionality is actually 30 times as good, the equivalent other plants would need to be about $6 each for similar functionality. That's probably far less than the usual price for them. Also, space and care issues are probably of some note in such a situation. How well it compares to other forms of purification is of relevance, but I can easily see a niche for them even at $179. A caveat, of course, is that those living in situations where it would be most useful are much less likely to have the money available to spend on it.
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Old 23rd November 2022, 03:36 PM   #61
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Originally Posted by Aridas View Post
Yeah, that is a bit pricey. Even so, if its functionality is actually 30 times as good, the equivalent other plants would need to be about $6 each for similar functionality. That's probably far less than the usual price for them. Also, space and care issues are probably of some note in such a situation. How well it compares to other forms of purification is of relevance, but I can easily see a niche for them even at $179. A caveat, of course, is that those living in situations where it would be most useful are much less likely to have the money available to spend on it.
I'm just wondering if you could grow some cuttings from your original purchase. Maybe, given a bit of time, you could have a greenhouse full!
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