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Why this forum is fun!

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Why this forum is fun!
Post by DDHvi   » Mon Jan 25, 2016 10:47 pm

DDHvi
Captain (Junior Grade)

Posts: 365
Joined: Mon Dec 15, 2014 8:16 pm

Many of the posters are obviously also technical nerds - see how often there is discussion on possible technical or strategy improvements.

BTW, in Honorverse there was a thread re contragravity. At that time I'd not figured out the way to start new topics. I noted that the purpose of contragravity was to produce vertical height and mentioned a canadian patent, which discusses a way to make a twenty mile tall launch tower for spacecraft. The math says that except for toppling problems, it would work. Basically, it is a giant bubble, with air pressure holding up the walls and top. You need to slant the walls enough for the central pressure to hold them up, and the walls can be tubes with a higher pressure holding the main platform up.

The real problem is that a large expensive artificial mountain like that would be a major target for the lie, steal, kill, and destroy crowds.
:(
Douglas Hvistendahl
Retired technical nerd
ddhviste@drtel.net

Dumb mistakes are very irritating.
Smart mistakes go on forever
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Re: Why this forum is fun!
Post by cthia   » Tue Jan 26, 2016 7:55 am

cthia
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Posts: 14951
Joined: Thu Jan 23, 2014 1:10 pm

DDHvi wrote:Many of the posters are obviously also technical nerds - see how often there is discussion on possible technical or strategy improvements.

BTW, in Honorverse there was a thread re contragravity. At that time I'd not figured out the way to start new topics. I noted that the purpose of contragravity was to produce vertical height and mentioned a canadian patent, which discusses a way to make a twenty mile tall launch tower for spacecraft. The math says that except for toppling problems, it would work. Basically, it is a giant bubble, with air pressure holding up the walls and top. You need to slant the walls enough for the central pressure to hold them up, and the walls can be tubes with a higher pressure holding the main platform up.

The real problem is that a large expensive artificial mountain like that would be a major target for the lie, steal, kill, and destroy crowds.
:(

Aren't 99.999 % of Sci-Fyers also technical nerds - with the remaining .001 % simply lost or kindred spirits who stumbled, or were forced or coerced into the realm? :lol:

I didn't get the memo. Has our maker released the restriction on building that high? What, considering a tower that high is beginning to make me babel? Can you hear me now? :D

The project would almost certainly be threatened by religious zealots as well, who would most likely think that such a construction project would be blasphemous - in recreating the Tower of Babel. Every group has its crack pots.

Seriously, this reminds me of the space elevator...

A space elevator is a proposed type of space transportation system. The main component would be a cable (also called a tether) anchored to the surface and extending into space. The design would permit vehicles to travel along the cable from a planetary surface, such as the Earth's, directly into space or orbit, without the use of large rockets. An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit (35,800 km altitude). The competing forces of gravity, which is stronger at the lower end, and the outward/upward centrifugal force, which is stronger at the upper end, would result in the cable being held up, under tension, and stationary over a single position on Earth. With the tether deployed, climbers could repeatedly climb the tether to space by mechanical means, releasing their cargo to orbit. Climbers could also descend the tether to return cargo to the surface from orbit.

The concept of a space elevator was first published in 1895 by Konstantin Tsiolkovsky. His proposal was for a free-standing tower reaching from the surface of Earth to the height of geostationary orbit. Like all buildings, Tsiolkovsky's structure would be under compression, supporting its weight from below. Since 1959, most ideas for space elevators have focused on purely tensile structures, with the weight of the system held up from above by centrifugal forces. In the tensile concepts, a space tether reaches from a large mass (the counterweight) beyond geostationary orbit to the ground. This structure is held in tension between Earth and the counterweight like an upside-down plumb bob.

To construct a space elevator on Earth the cable material would need to be both stronger and lighter (have greater specific strength) than any known material. Development of new materials which could meet the demanding specific strength requirement is required for designs to progress beyond discussion stage. Carbon nanotubes (CNTs) have been identified as possibly being able to meet the specific strength requirements for an Earth space elevator.[4][2] Other materials considered have been boron nitride nanotubes, and diamond nanothreads which were first constructed in 2014.

The concept is applicable to other planets and celestial bodies. For locations in the solar system with weaker gravity than Earth's (such as the Moon or Mars), the strength-to-density requirements for tether materials are not as problematic. Currently available materials (such as Kevlar) are strong and light enough that they could be used as the tether material for elevators there.

...

https://en.wikipedia.org/wiki/Space_elevator

Son, your mother says I have to hang you. Personally I don't think this is a capital offense. But if I don't hang you, she's gonna hang me and frankly, I'm not the one in trouble. —cthia's father. Incident in ? Axiom of Common Sense
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Re: Why this forum is fun!
Post by DDHvi   » Tue Jan 26, 2016 7:13 pm

DDHvi
Captain (Junior Grade)

Posts: 365
Joined: Mon Dec 15, 2014 8:16 pm

cthia wrote:
snip

Seriously, this reminds me of the space elevator...

snip

https://en.wikipedia.org/wiki/Space_elevator


It reminds me of the space elevator also. However, that is tension, and if broken in the middle (Meteor? Nuke?) would wrap around a major portion of the earth - at very high energies. Sorry, Ecuador, we didn't mean to destroy so much of your country. This "bubble" elevator could only destroy nearby countryside.

I don't think it will be built. What gives me the thrill (as with the space elevator) is that it is even theoretically possible. Perhaps because I've been reading SF since I snuck up the back stairway at the library and found Astounding in the adult stacks with "Mission of Gravity" in it, at about 12 years old.

Re Babel: did you notice they were building with water resistant materials and the stated purpose of NOT spreading across the earth again? The geological strata have been laid down over stretches of hundreds of miles. If the former mountains, etc. weren't chewed up (cavitation?) where did the material come from? The average sedimentary depth is around five miles, and once a given stretch of ground has been covered with sediment, how can the rock under it erode? OTOH, if the sediments have been moved around to expose more rock over the ages, why are there so few gullies in the subsurface strata?

They didn't believe the promise that such a flood would never happen again.
:?:
Douglas Hvistendahl
Retired technical nerd
ddhviste@drtel.net

Dumb mistakes are very irritating.
Smart mistakes go on forever
Unless you test your assumptions!
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Re: Why this forum is fun!
Post by cthia   » Thu Feb 04, 2016 2:07 pm

cthia
Fleet Admiral

Posts: 14951
Joined: Thu Jan 23, 2014 1:10 pm

Hyperloop
From Wikipedia, the free encyclopedia

The Hyperloop is a conceptual high-speed transportation system originally put forward by entrepreneur Elon Musk, incorporating reduced-pressure tubes in which pressurized capsules ride on an air cushion driven by linear induction motors and air compressors.
The outline of the original Hyperloop concept was made public by the release of a preliminary design document in August 2013, which included a notional route running from the Los Angeles region to the San Francisco Bay Area, paralleling the Interstate 5 corridor for most of its length. Preliminary analysis indicated that such a route might obtain an expected journey time of 35 minutes, meaning that passengers would traverse the 354-mile (570 km) route at an average speed of around 598 mph (962 km/h), with a top speed of 760 mph (1,220 km/h). Preliminary cost estimates for the LA–SF notional route were included in the white paper—US$6 billion for a passenger-only version, and US$7.5 billion for a somewhat larger-diameter version transporting passengers and vehicles —although transportation analysts doubted that the system could be constructed on that budget.

Hyperloop technology has been explicitly open-sourced by Musk and SpaceX, and others have been encouraged to take the ideas and further develop them. To that end, several companies have been formed, and tens of interdisciplinary student-led teams are working to advance the technology.
Designs for test tracks and capsules are currently being developed, with construction of a full-scale prototype 5-mile (8 km)-track scheduled to start in 2016. In addition, a subscale pod design competition on a very short, 1 mile (2 km), test track is underway, with test runs expected later in 2016.

... ...
https://en.wikipedia.org/wiki/Hyperloop


http://hyperlooptech.com/

They really do do things big in Texas don't they?...
http://www.bing.com/videos/search?q=Hyp ... ORM=VRDGAR

Son, your mother says I have to hang you. Personally I don't think this is a capital offense. But if I don't hang you, she's gonna hang me and frankly, I'm not the one in trouble. —cthia's father. Incident in ? Axiom of Common Sense
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