High gravity vs. high pressure: ref. Dragon's Egg?

  • #1
165
36
Having re-read "Dragon's Egg" recently, I recall that the cheela, being composed of degenerate matter, would explode if removed from their high-gravity environment and placed in freefall.* (For those who haven't read the story, the environment here is a half-solar mass neutron star with a surface pull of 67 billion gees). One question: would it be possible in principle for the cheela to travel in space by means of (seriously) pressurised tanks instead of using micro-black holes? A parallel sought here is the marine life that inhabits our deep ocean trenches. Or is this idea just a lot of tom-tit. . . that's to say there are fundamental differences between pressure and gravity that make such a workaround impossible? Thanks in advance.

*This fate actually occurs to one unfortunate cheela in the follow-up novel, "Starquake."
 

Answers and Replies

  • #2
There wouldn't be much difference between a cheela and a tank at those pressures. What would keep the tank from exploding? Now that I think of it, a better question is how do the cheela avoid turning into neutrons like the rest of the star? :wideeyed:
 
  • #3
Thanks for pointing that out to me. It's worth mentioning, though, that the cheela can endure far less extreme gravities than that exerted by their neutron star. . . a mere 'several million' gees, if Clear-Thinker's flitter is anything to go by. As for what prompted this post, I've been thinking of trying my hand at writing a short story about the cheela, and as such need something less clunky (and gravitationally disruptive) than portable mini-black holes as a means of conveyance. High-pressure containers might do the trick here. It's just a different kind of pressure, after all. . . omnidirectional rather than straight down, right? I wonder if this is a trick that Robert Forward missed. :rolleyes:
 
  • #4
I've been thinking of trying my hand at writing a short story about the cheela
Be mindful of copyright, @Dr Wu, but reflecting on Dragon's Egg, gravity and pressure are different, and it's not obvious how you would encompass a cheela in a high pressure environment such that they did not explode but could still aspirate, eat, defecate, etc.

As for Dr. Forward missing a trick, that's possible. But it seems more likely that he planned everything to convey the narrative that he did...probably knowing that the entire setup was a MacGuffin, because it's pretty outlandish when you stop to think about it!
 
  • #5
The lightest neutron stars are 1.4 solar masses, the heaviest 1.96 (as I recall).

The surface of a neutron star is made of polymerized iron, not neutrons. It seems to me one of the most hostile-to-life locations in the universe. The bombardment with infalling matter would be fierce. Even a speck of dust would have huge energy. The carbon atmosphere at 2 millimeters thick offers little protection. Radiation would be intense. What's more, if enough hydrogen accumulates it produces a star-wide thermonuclear explosion.

The interior of a neutron star -- the superconductive/superfluid core -- seems a lot more promising. The beings would be made of knotted quantum electromagnetic vorticies substituting for atoms. Such are believed to be both stable and very abundant in the type 1.5 superconductor that is the core. Living in a superfluid, such beings would be quite unaffected by the gravity, rather like our aquatic bretheren. Consumable energy is plentiful in the form of twisted vortex rings. I am not the first to think of this -- Anders Sandberg beat me to it, publishing this fantasy in his Orion's Arm website. The science behind all this is due to a number of people but largely by Egor Babaev, who has had perhaps a hundred articles published in Physical Review and Nature.
 
  • #6
Be mindful of copyright, @Dr Wu, but reflecting on Dragon's Egg, gravity and pressure are different, and it's not obvious how you would encompass a cheela in a high pressure environment such that they did not explode but could still aspirate, eat, defecate, etc.
Regards copyright issues, I'm not a professional - i.e. published - writer, and certainly have no plans as yet of becoming one! The short story idea was always seen as a piece of private amusement. Yes, trying to substitute a high-pressure environment for a gravitational one does, I concede, raises difficulties such as you have outlined. Part of the problem, it seems, is that we're dealing with a fictitional alien lifeform which is truly unearthly. . . that's to say beyond anything we humans have encountered here on Earth itself. The question then centres on how much hand-waving is needed to make the high-pressure idea convincing enough to be believable. Food for thought.

The surface of a neutron star is made of polymerized iron, not neutrons. It seems to me one of the most hostile-to-life locations in the universe. The bombardment with infalling matter would be fierce. Even a speck of dust would have huge energy. The carbon atmosphere at 2 millimeters thick offers little protection. Radiation would be intense. What's more, if enough hydrogen accumulates it produces a star-wide thermonuclear explosion.

Your point about infalling material continually impacting upon the surfaces of neutron stars, and doing so at near-relativistic velocities (0.3c?) is one I fully share. Indeed, quite apart from anything else, given the likely preponderance of dust, micrometeors etc existing throughout much of the interstellar medium, it seems entirely plausible to me that the local environment of any non-pulsing neuton star - that's to say immediately beyond the star's gravitationally tidal 'crush' zone - would be a lethal one in terms of orbiting material for a crewed spacecraft , and in pretty short order too, I should imagine.

The Anders Sandberg fantasy is news to me. The idea of an 'equatic' alien species happily existing within the bowels of a neutron star leaves me literally lost for words. . . ?:)
 
  • Like
Likes Melbourne Guy

Suggested for: High gravity vs. high pressure: ref. Dragon's Egg?

Back
Top