Space Elevator (The Epic Tower) (Page 16)

Zereous Excentris: I guess I am right about Gravity having a roll to play in wind changes.. hmmm.. but.. who cares about me gitting something right.. OMFG though boy do they cry when I make mistakes!

Corwin: Huh?

You suggested that the tidal pull of the Moon causes wind changes... this is not correct.
Although there is such a thing as "atmospheric tides", the effect that the Moon's gravitational pull has on the atmosphere as the Earth rotates every 24 hours is barely measurable, and is more pronounced in the upper rarefied atmospheric layers.
This tiny effect is insignificant, especially in comparison the how much the heat of the Sun affects the atmosphere every 24 hours.
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@ Aura - Yes, the stratosphere does rotate slightly slower than the atmosphere at lower altitudes which match the rotation of the Earth. But as the atmosphere is very thin at those high altitudes, I don't think it will have too much of an impact on our hypothetical 36,000km tall skyscraper.

Zereous Excentris: if that atmosphere shifts to gravity.. and pulls with the moon you think that does not effect wind.. thats absurd to beleive that all of the atmosphere being pulled like the tide does not effect wind.. because it effects jet current under water..

Corwin: The lunar tides have a much more pronounced effect on the oceans, due to the fact that ocean density does not change with depth, whereas the air density changes drastically with altitude.
And as I said, it's only the upper rarefied atmospheric layers that are measurably affected... this effect is translated into a minuscule increase in heat...
... an increase that is a THOUSAND times smaller than how much the Sun heats the atmosphere in 24 hour cycles.

The lunar atmospheric tides have such a tiny impact on the atmosphere that it's hardly worth mentioning.

Zereous Excentris: Woow.. It is still a damn effect.. I am sure shit would get fucked up with the atmosphere without the moon effecting it.. Especialy the water equating into it aswell. seeing as it rises the water and lowers it.. ALSO effecting the Atmosphere Genius!

Aura: Cor, can I just point out that meteors mostly start 'burning' in the mesosphere, which is above the stratosphere and thinner still, yet thick enough to heat those ice rocks to form streaks of light. Yes, I know, speed helps a lot in that. But I wasn't saying the heat generated by the tower would set it aglow, I just said there would be enough heat to create a problem. Along with static charge which builds up.

Corwin: Meteors are typically traveling at over 10 times the speed of a spacecraft on reentry - about 70kms/second on average. Whatever air currents would buffet our imaginary space-tower shouldn't be much of a problem regarding friction.

Now, electric current, on the other hand, would be tremendous... but not because of friction or static charge, but rather because of the current that exists within the magnetic lines of the Earth's magnetic field, and charged by the solar wind. A 36,000km tall tower would set up a tremendous amount of current.. but the tower would be grounded, so the current would flow down to the Earth. If anything, this current could be harnessed and utilized as a bonus freebie power source, as long as we could properly conduct it downwards. (a room temperature superconductor would be helpful).

Some years back, the Space Shuttle tried a "tether" experiment, and sent out a probe attached to the shuttle with about 2 km of wire... as a result of the above mentioned current, the thing ZAPPED and vaporized the tether... not a very useful experiment.

Corwin: Aura's mention of the "centrifugal pull" concept reminded me of Arther C. Clarke' idea of how a space-elevator could work:

A giant space-station (or spacecraft) with a cable lowered down and attached to the ground, and an elevator platform that rode the cable up and down... he used this idea in his sci-fi novel The Songs of Distant Earth... I found this idea preposterous, although not as preposterous as a 36,000km tall skyscraper (Clarke used the space-skyscraper idea in his sci-fi novel 3001: A Final Odyssey).

Okay... the cable idea... in theory, yes, this is imaginable:
The space-station would orbit geosynchronously, but at a higher altitude with a greater than orbital velocity to achieve tension on the cable as a result of centrifugal force.

The space-station would need to be very massive... massive enough to counter the weight of the cable, plus countering the full-weight at ground level of the largest mass you would want to lift.
Now the cable itself will "weigh" much less than it's mass... at 36,000km the cable matter weighs 0% of it's mass, and at ground level the cable matter weighs 100% of it's mass under one G. The weight of the cable material decreases with altitude in proportion to [a] it's centrifugal velocity, and [b] the weakening gravitational pull in regards to the distance squared... to calculate the overall weight of the cable requires Calculus (dammit) that is beyond my abilities (and an internet search was of NO help at all)...
... so let's just say that the cable will weigh "a fraction" of it's mass, and move on.

The "tension" required of the cable, and the extra distance and extra-orbital velocity needed of the massive space-station will be a matter of "how much" mass you want to lift from ground-level. Although the mass will lighten increasingly as it rises, it will put it's full weight on the cable as it first rises... so... how much mass we can burden this cable with depends on how much tension we can put on it... in other words - how frickin' STRONG is this hypothetical cable we're talking about?? And how thick would it need to be? (It's thickness will also determine how massive the cable will be, adding to the needed tension factor to support the weight of the cable itself).

Now, as I mentioned, I'm no good at Calculus, but I believe Mr. Clarke came up with some rough figures... and this 36,000km (plus) "cable" would need to be constructed out of a material with three very special properties:
[1] Lightweight
[2] Be almost indestructible with super-tensile strength
[3] Have superconductive properties

In regards to weight, if it's strength-to-weight factor isn't great enough, the thickness of the cable to achieve the required tension keeps increasing... the thicker the cable the more heavy it is, and the more tension you need to put on it, etc, etc,... a curve that approaches infinity... or in other words, if it's not light and strong enough this entire endeavor is impossible. I seem to remember that Clarke's imaginary cable was about as light as aluminium and about 10cm in diameter.
In regards to superconductivity... as I mentioned before, a cable that long will pass through the highly charged electromagnetic lines of the Earth's magnetic field and Van Allen Radiation Belts, setting up a current of perhaps billions of watts. Any electrical resistance whatsoever would fry that cable into vapour in a millisecond, so nothing less than superconductivity would be required... and I don't see how super-cooling tens of thousands of kms of cable would be possible, so we need "room-temperature" superconductivity.

So... no problem... we just invent some magical new metal or material that's lightweight, almost indestructible with super-tensile strength, and is a room temperature superconductor...
... no problem.

This all went through my head when I first heard Clarke describe his space elevator idea, and why I found the idea preposterous. This is easy to do in a Science Fiction novel; you just say the material exists, and Bob's your uncle... but then why not just say that anti-gravity generators exist, or Warp Drive, or Superluminal Interplanetary Teleportation?

I know, I know... because Clarke's idea works with just ONE bit of new technology... simply an indestructible superlight superstrong superconductor material.
To be honest, I think if we could develop a material like that, we could also develop awesome new spacecraft that have no trouble lifting into orbit from the ground... why muck about with space-elevators or mega-skyscrapers?

Aura: "why muck about with space-elevators or mega-skyscrapers?"
Traffic congestion? It's not about getting them from the ground into orbit only, it's getting them from orbit to the ground as well.
They main difference though, it that we consider Warp drive and teleporters mathematically and physically impossible. The elevator is merely unlikely.

Corwin: Good point, Aura.

Our present method of "air-braking" with reentry is very damaging to any craft we intend to use over again. The space shuttle ended up being a very bad idea in the long run. The newest "workhorse" command-module/reentry vehicle that NASA has in the works, named Orion, is based on the "single-use" Apollo craft, historically their most reliable design ever, although sadly disposable.

But if we had some kind of new and amazing form of propulsion, that didn't require such a bulky fuel source like our primitive chemical rockets, we could use the engines to slow the craft down BEFORE we entered the atmosphere... then just glide down like a conventional aircraft without the heat of reentry.

The concept of Fusion propulsion was tossed around in Sci-Fi novels as far back as the 1950s from writers like Asimov and Heinlein... but we haven't gone very far in that direction, and even Deuterium isn't the most compact fuel imaginable.

The REAL pie-in-the-sky fuel would be Anti-matter... our present understanding of physics knows of no more a powerful reaction than that. I once read that an amount of Anti-matter the size of a shirt-button would unleash the equivalent power they used to put a Saturn V rocket into space.
But I imagine that mucking about with Anti-matter would be a very dangerous endeavor... a sizable enough amount of anti-matter to propel a craft to relativistic speeds would also likely be enough to vaporize the planet. We'd do well to do that kind of experimenting our around the orbit of Neptune.

A quote from Arther C. Clarke -- "Some of the supernova we observe may possibly be industrial accidents."

Zereous Excentris: Imagine this Construct made out of an asteroid.. Using mirror to bounce light into a central complex orbiting the Star of sol.. Using light to Forge asteroids from the asteroid belt into seamless Bladed sword ships!

Corwin: You kind of lost me on this one, Zereon.

Zereous Excentris: Its a Star foundry! pumping out epic Sword Bladed star ships! Using light to heat up Iron.. from the asteroid belt.. and.. carbon and aluminum and some silica is added to the iron to make carbon spring steel..

kittybobo34: I think steel would be a bad choice for ships, Carbon fiber on the other hand, light weight, very strong.. I like the idea of hollowing out ice asteroids, using the power of the sun to melt the interior and redeposit it out on the surface. Once re-enforced it could be spun to simulate gravity on the inside.

kittybobo34: Corwin,, I think Zereous has read one too many Sci Fi novels,, but somehow missed basic physics.

Corwin: I'm not sure if he read a lot of Sci Fi. I think he thought he was living one.

I often wonder what happened to that guy. He's been AWOL for at least 5 years. Just stopped posting one day.
He mentions his "Love quest" on an earlier page. I know a bit more about that from other convos... he apparently shared some kind of "psychic link" with an extraterrestrial soul-mate from an advanced race in another galaxy. I saw a picture he drew of her -- some kind of half-horse half-humanoid woman, but was also some kind of royalty, like a princess or something.

Ah yes, here she is -- Princess Starlight zereous excentris's Picture

He made a Wireclub account for her too, I think perhaps either to make her seem more "real", or perhaps in hopes that she might actually find a way to log into it from that other galaxy, and they could share a more tangible link than merely a psychic one. Hey, I'm not one to judge. But talk about "long-distance" relationships. That's a doozie.

And I believed him. I mean, I didn't believe that he had an alien girlfriend in another galaxy, but I believed that he believed it. So I didn't bust his balls about it.
As I understood it, a large part of his "Love quest" was to enlighten humanity to the point where we could actually build those Sword Ships of his, and he could then fly out to that distant galaxy and be with her. (awww)
Save humanity, and as a bonus be with his true love. You can't deny his good intentions.

Zereous was nothing if not interesting, and not the usual tin-hat that you see on Wire. I liked the guy, and kind of miss him.

Hey... you never know... maybe 5 years ago his Princess found a way to transport him to her galaxy without Sword Ships, and that's why we haven't heard from him.
They say truth is stranger than fiction.

Well, here's to Zereous, whichever galaxy he may reside in now.

Corwin: But, putting that aside for now... this discussion fizzled out 5 years ago, so I've readdressed this concept of the "Space Elevator" and given it further thought.

I STILL say that a mega-skyscraper reaching all the way to geosynchronous orbit is preposterous. A.C. Clarke's idea of a 36,000 km cable reaching to a giant space-station, although more plausible, also preposterous.

And when you get right down to the crux of the matter, what exactly is it we would be trying to gain from a "net" standpoint? Efficiency. Nothing more.
Whether using rockets, or some magical elevator, we can't escape the laws of physics... Work = Mass x Distance, so any way you slice it, lifting a large mass up 36,000 km (or propelling it to orbital velocity) will require a tremendous amount of energy.
An elevator would be more efficient in energy consumption than rocket tech... but at what COST??


There have been a few developments since we last had this discussion, and Elon Musk came to the rescue.
When NASA designed a "reusable" space vehicle (the shuttle), they were thinking "ass-backwards" and addressing the problem from the wrong end. Back in the Apollo days, it wasn't the disposable Apollo Command Module that was the big expense -- it was that behemoth disposable Saturn V first-stage booster that was breaking the bank.

That Saturn V booster WAS the "Space Elevator" that did most of the work to get all that mass up there (then perform a roll and get the mass on it's way to orbital velocity), and the much smaller second-stage took over from there and did the rest of the work to propel the remaining mass to achieve orbital velocity.
So THAT FIRST STAGE is what we needed to make reusable, NOT the relatively tiny spacecraft/reentry-vehicle.

Good ol' Elon -- thinkin' outside the box -- he DID it, and it WORKS.
A giant first-stage booster that does the lion's share of the work, separates from the second-stage, does NOT have to withstand destructive reentry velocities, and flies itself back down to Earth, and lands itself gently back onto the launch-pad where it departed. BRILLIANT.

There's your "Space Elevator", folks.
Mark my words -- Elon Musk will go down in history as the man who truly paved the way to space.
Makes the Wright Brothers look like a couple of bicycle mechanics who strapped an engine to a glorified box-kite... oh... because that's what they were.



Next up? .... A new "wonder-fuel" in the works -- Metallic Hydrogen.
Stay tuned, folks.

kittybobo34: Yes,, that was very impressive, the way the 1st stage landed on a barge at sea. Hopefully we will not be at the whim of the Russians to get into space anymore.

Corwin: Oh... you haven't been keeping your ear to the ground, Kitty.

That barge thing was just an earlier experimental test-flight. Ancient history.

Elon has already sent two crews to the ISS with his Space X Dragon spacecraft. The first mission was a crewed preliminary run, and they didn't stay long, but his second mission (that docked with ISS a few days ago) plans to stay 6 months up there.

And the Space X first-stage booster doesn't land on some barge... it lands back at Kennedy.


Here's the Space X site link so you can stay up to date ---> https://www.spacex.com/


And just LOOK at that Dragon spacecraft (especially the tech inside)... it looks like frickin' Star Trek, man.
It makes the Apollo craft look like something slapped together with primitive 1960s tech, that merely got the job done... well... because that's what it was.

Corwin: Elon's original plan was for the Dragon spacecraft to ALSO land back at Kennedy under it's own power at mission's end, but it was decided that that was too much too soon (too ambitious ), and too risky. So they opted for the old parachute and splashdown method for now.

Manned spaceflight is finally taking off again in huge leaps... it's kind of sad that the general public isn't showing that much interest in it.

Corwin: OH... and check out Elon's spacesuits.

He didn't just design them for pure functionality like those ugly NASA suits of the past -- he hired some Hollywood guys to make them look slick and cool as well.
Elon's using his noggin', man... if you want to get a new generation of youth excited about "real" space-travel, you gotta compete with Hollywood's fictional dazzle... so... get them on the payroll.

If it isn't obvious, Elon Musk is my frickin' hero these days.

Corwin: In case you missed that first historic manned Space X flight to the ISS back in May, here's the video link from their site. It's over 4 hours, but you can skip around to the good bits.



How about those badass Teslas they use to ferry the astronauts out to the launchpad.

I stand corrected though... the first-stage lands on a ship. I guess booster landings at Kennedy are still in the works.

But you gotta admit, this is NOT the space program of the old Apollo days. The future is now.

kittybobo34: You got that right, this isn't grandpa's space program !

Corwin: THAT'S the metaphor I was looking for!

I spent a few hours yesterday browsing the Space X website, and watching more videos.

Apparently, Elon's Falcon rocket and Dragon spacecraft have gotten FAA certification for commercial flight. So we're talking a whole new level of reliability and safety here.
The road is now truly paved for space tourism.

And for the first time in a very long time, I can see us going to Mars in my lifetime. Well, maybe not Kitty and I, but somebody.
Going back to the Moon right now would be a walk in the park.

Corwin: Oh, and I wasn't mistaken about Falcon boosters landing back at Kennedy, but they only do that when launching the Falcon Heavy, which is three Falcon 9s strapped side-by-side.The outer two separate during ascent and land back at Kennedy, while the third lands downrange on the drone-ship.