Author Topic: Episode 36: Space Megastructures with Mur Lafferty  (Read 4216 times)

Offline bn

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Episode 36: Space Megastructures with Mur Lafferty
« on: September 01, 2013, 02:56:52 PM »
Hey everyone.
this episode was fun. it's about building giant things in space: specifically why we would bother.

I meant to release it in august, but i've been pretty busy with moving and trying to find a job and stuff.
too busy to even poke my head in around here and make sure that things are still working.
but.. quite soon, routine will return to my life.
Titanium Physicists has a pro-bee-analogy agenda. That's certainly no secret.

Offline CthulhuKid

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #1 on: September 04, 2013, 10:20:41 AM »
Good luck with the job hunt, Ben.  I've been looking for 2 or 3 months now to no avail, but I'm sure "podcast host" on a resume opens lots of doors. :P

Now to the episode...I understood everything, except for that last loopy structure you were talking about.  I get space elevators, I get sky hooks and rotating weights, but I just couldn't picture that last bit for the life of me.  Anyone out there have a good picture or something I could wrap my brain around?

Offline scikopas

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #2 on: September 05, 2013, 10:38:01 AM »
haha I didn't understand the last slingshot on a string thing either... I couldn't really visualize it during the show...

I also really laughed when you dubbed over "KEVLAR". Its really great Ben, the amount of work you put into editing and cutting the show so that its coherent and accurate and not ramble-y.

The show was good!  These megastructures are just ridiculous though, it seems like whats leftover of  Smalley's group is all about working up press buzz with only short-term goals in mind.  Its great for funding in the next couple years, but when scientists hype up things like nanotubes without considering their macroscale properties, and then when there isn't a space elevator in Ecuador in ten years people begin to lose faith in science, or at least that area. If people are more modest about their claims its more likely that long term funding will be available for steady incremental advancements that will finally lead to the "breakthrough" they need, instead of a glut of funding at the beginning and then everything drying up.  I think researchers in superconductors, Buckyballs, fuel cells, and solar have all been guilty of the same thing in the recent history.... 


PhD student in Materials Science at Arizona State University currently working on high-temperature superconductors and quantum computers or something.
my (materials) science podcast: LASER (Let's Agree Science and Engineering are Rad!) twitter @scikopas

Offline bobmath

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #3 on: September 05, 2013, 12:32:55 PM »
http://en.wikipedia.org/wiki/Launch_loop

Imagine you have a huge gun that fires a bullet in a high arc. At the place where it comes back to the ground, you have Bugs Bunny holding a piece of pipe bent into a U. The bullet goes in one end and out the other, so it's headed along the same arc back at the gun. But before it hits, Daffy Duck moves the gun aside and holds up another U-shaped pipe. Bugs and Daffy proceed to juggle the bullet back and forth between them. Now imagine a machine gun firing a steady stream of bullets. Finally, imagine that the bullets are links of a chain.

Yeah, this stuff isn't just pie-in-the-sky, it's a whole bakery.

Offline scikopas

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #4 on: September 05, 2013, 01:19:50 PM »

Thats totally ridiculous.
PhD student in Materials Science at Arizona State University currently working on high-temperature superconductors and quantum computers or something.
my (materials) science podcast: LASER (Let's Agree Science and Engineering are Rad!) twitter @scikopas

Offline bn

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #5 on: September 05, 2013, 07:58:11 PM »
hi peeps.
sorry i haven't been around much. *guh*
at the last minute i got  a job teaching at a university in kelowna, bc.
suffice to say, my life is very busy, but the commute is very lovely.
there is a big lake in our backyard.

so yeah, bobmath. that was a great explanation. pretty much what i was imagining in my head. good work everyone.
Titanium Physicists has a pro-bee-analogy agenda. That's certainly no secret.

Offline bn

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #6 on: September 05, 2013, 08:07:33 PM »
If people are more modest about their claims its more likely that long term funding will be available for steady incremental advancements that will finally lead to the "breakthrough" they need, instead of a glut of funding at the beginning and then everything drying up.  I think researchers in superconductors, Buckyballs, fuel cells, and solar have all been guilty of the same thing in the recent history....

I don't disagree, but I think the main problem is that the public doesn't appreciate the romance of science. People will pay through the nose to support the purchase of big awesome sophisticated jets that no one will use... because everyone understands the romance of war.

part of the reason for my show is that I want to demonstrate to other science outrechians that there's genuine entertainment value in hearing elegant explanations of complicated phenomena. That we shouldn't waste our time talking about chasing down "the next scientific breakthrough", because often the information will be wrong, and because there's enough fascinating stuff out there that has already been verified.

there's more to physics than string theory, just as there is more to medicine than finding a cure for aids. Focusing on the big sexy chase stories are exhausting . :p
Titanium Physicists has a pro-bee-analogy agenda. That's certainly no secret.

Offline CthulhuKid

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #7 on: September 06, 2013, 06:56:00 AM »
From the Wiki:

Lofstrom estimates that an initial loop costing roughly $10 billion with a one-year payback could launch 40,000 metric tons per year, and cut launch costs to $300/kg. For $30 billion, with a larger power generation capacity, the loop would be capable of launching 6 million metric tons per year, and given a five-year payback period, the costs for accessing space with a launch loop could be as low as $3/kg.[5]

^ Launch Loop slides for the ISDC2002 conference

This doesn't seem to be an economically ridiculous at all.  Where's the kickstarter?

Offline bn

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #8 on: September 06, 2013, 09:05:06 AM »
I think jocelyn might have been right when she described the reason we're not really doing it right now.

also, there's kessler syndrom. which we didn't talk about... but i think we should probably get our kalamari together before we go TOO crazy sending stuff into orbit.
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Offline keith_nyc

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #9 on: September 06, 2013, 03:12:48 PM »
Can someone explain why Dyson Spheres are unstable?  I'm not a professional, but here's my thought experiment:

If I were to lower myself into a mine, I would continue to feel gravity pulling me towards the center of the earth, less and less, until presumably, I reached the center of the earth and I had equal amounts of mass on all sides of me.  It seems that the earth "wants" me at its center (or equivalently that I want the earth all around me!)  This feels like a stable system.  So why wouldn't a Dyson Sphere want the star to stay at the center?

Thanks in advance
Keith

Offline Cosmodot

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #10 on: September 06, 2013, 03:36:57 PM »
Inside of a perfect spherical bubble of matter, there is no net gravitational attraction in any direction.

Offline bobmath

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #11 on: September 06, 2013, 06:44:19 PM »
If you hollowed out a big spherical chamber at the center of the Earth, you'd be weightless everywhere in the chamber.

Offline beans

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #12 on: September 09, 2013, 06:46:47 PM »
Great episode, as usual.
Space printers would be pretty cool - http://www.dezeen.com/2013/08/30/nasa-develops-3d-printing-factory-in-space/

Offline bn

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Re: Episode 36: Space Megastructures with Mur Lafferty
« Reply #13 on: September 09, 2013, 08:15:14 PM »
oh thanks!
Titanium Physicists has a pro-bee-analogy agenda. That's certainly no secret.