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Can a Living Creature Be as Big as a Galaxy?

nautil.us

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Re: Can a Living Creature Be as Big as a Galaxy?

#131

Post by alextheparrot »

Koshkin wrote: post #94
alextheparrot wrote: post #85

Earlier quoted context omitted.

No, it isn't. Imagine a hypothetical sterile human that was single celled - suddenly we've reached the same conclusion without the sub-organism reproduction issue. Making reproduction a core premise of being alive really drives to the idea of mortality, as reproduction is a way of overcoming our mortal coils. Yet, it is truly reasonable to classify reproduction as the only way? It also assumes a lineage, which is not…

Somehow I am having hard time imagining a single-celled, synthetically created, non-water-based, sterile human being... I am not sure I understand the drive to redefine life beyond the life as we know it (i.e. what it actually is, as a fact), the drive that leaves one in what can only be seen as the domain of fiction at best (and pseudo-science at worst).

The drive was that I don't believe the original question, "Can a living creature be as big as a galaxy" is reasonable for organisms we are familiar with. If we hope to answer such big hypothetical questions, we may need to find ourselves in foreign lands as well.

Re: Can a Living Creature Be as Big as a Galaxy?

#132

Post by olegkikin »

Swizec wrote: post #66
olegkikin wrote: post #46

Earlier quoted context omitted.

In terms of definitions, generally cosmos contains everything. Universe is our local observable space-time with the earliest event we can detect being the big bang.

> Universe is our local observable space-time So if we observe something beyond what is currently observable, would that not become observable and thus part of the universe?

You're in a room. You give it label "room". Then you find a door, you go outside of the room, you don't call everything outside "room", you give new things new names.

For now we're stuck in our universe, we know it's expanding (in something, potentially). So we preemptively give the name "cosmos" to EVERYTHING. It's entirely possible that cosmos is equal to universe. But it's also possible there are other universes out there, or something entirely different.

Re: Can a Living Creature Be as Big as a Galaxy?

#133

Post by jfoutz »

So this requires a few things,

First off, single organisms can have pretty advanced local processing of control. An octopus has a nerve cluster for each tentacle that can operate independently of the main brain [1]. So in at least one case, biological brains delegate work out to another region of the body. An argonaut octopus actually detaches part of it body, which as far as i can tell, keeps living for a while. it's kind of creepy. The only thing i can't find an example of, is remote control. A detachable body part, with a nerve cluster, that responds to light or sound seems like what would be needed for the base creature. Evolution hasn't stumbled on that trifecta here on earth. But it sure seems like something that could have come about.

The latency argument isn't compelling. If i can send one message, i can send another hundred billion messages along with it. So, sure only a few thousand round trips, but a fabulous amount of information transferred. There's no actual biological equivalent to a semi autonomous drone, so i'm not sure what that would look like before the creature took to the stars.

There's also no real obvious way for this lone detatched tentacle to consume the resources of a planet. But whatever. I think one entity with those three features might have a chance.

Also, is the creature smart? Does it get to genetically engineer itself? do cyborgs count? That greatly simplifies things as well. The detachable parts could have detachable parts, and recurse down to whatever arbitrary degree is useful.

Alternatively if you admit superorganisms, then everything is much easier.

So anyway, you don't really need to send many messages when the message is "here are the latest designs for industrial architecture to dismantle a solar system and send the resources back" It's up to the billions of lone tenticles and their machines to execute the will of the super brain.

On the other hand, yeah, there's not going to be a galaxy sized amoeba or panther or anything like that. maybe an incredibly fine mist of fungus or mold, but i think it'd be too hard to keep a system like that from collapsing in on itself from too much mass. a galaxy sized ring of spider silk orbiting a black hole sounds like great science fiction. but i can't imagine that working.

[1] https://en.wikipedia.org/wiki/Octopus#Nervous_system_and_sen... [2] https://en.wikipedia.org/wiki/Argonaut_(animal)#Sexual_dimor... [3] https://en.wikipedia.org/wiki/Superorganism

Re: Can a Living Creature Be as Big as a Galaxy?

#134

Post by qbrass »

dogma1138 wrote: post #56
samstave wrote: post #24

Earlier quoted context omitted.

What if quantum entanglement is simple an indicator that there is another way to send information - but we haven't discovered that function of that mechanism to do so yet?

Possibly, but then it would break relativity and potentially a lot of other things.

That's the point. Relativity is a barrier and we want a way to break through it.

Re: Can a Living Creature Be as Big as a Galaxy?

#135

Post by yladiz »

chongli wrote: post #126
knome wrote: post #120

Earlier quoted context omitted.

The only part of the flesh which is "you" is the nervous system. Everything else can be hacked off or replaced without a loss of identity.

So if somebody has a limb amputation, losing a lot of nerves, are they a different person? Is somebody a different person when they're drunk? I've heard both of these thrown around colloquially. It's not obvious or straightforward to answer. You could imagine a Ship of Theseus style replacement of all the neurons in your head with artificial ones. At what point would you stop being you?

My thoughts are that 'you' as a person change constantly, year to year, and who you are now is not the same as 5, 10, more years ago. I don't think it's so much that you are a different person because you lost a limb or are drunk, it's the change in personality and mind that accompany those that makes that person different. You could absolutely lose a limb and be 'the same' person, but you could also change significantly.

Re: Can a Living Creature Be as Big as a Galaxy?

#136

Post by bitJericho »

delecti wrote: post #118
Consultant32452 wrote: post #117

Earlier quoted context omitted.

There are more bacterial cells in your body than there are human cells. Where exactly do you draw the line between what constitutes "you."

A zoo is still a zoo if there aren't any animals in it, but it wouldn't stay in business very long. No matter how important the animals are to the long-term viability of the zoo, they are not the zoo. My gut bacteria may be vital to my survival, but they are not me. I don't find placing that line to be difficult at all.

Interestingly, the makeup of your gut biome con dramatically affect personality.

https://www.theatlantic.com/health/archive/2015/06/gut-bacte...

Parasites can also alter your personality. Perhaps they can even turn you into a cat lady/man.

http://abcnews.go.com/blogs/health/2013/09/19/cat-lady-paras...

Re: Can a Living Creature Be as Big as a Galaxy?

#137

Post by andars »

olegkikin wrote: post #124
andars wrote: post #63

Earlier quoted context omitted.

You have some misunderstandings about the expansion of the universe. I would recommend reading http://www.preposterousuniverse.com/blog/2015/10/13/the-univ...

No, it's you who gets incorrect information from some random blogs. The size of the observable universe: ~93 billion light-years Time since the big bang: ~13.7 billion years. http://curious.astro.cornell.edu/about-us/104-the-universe/c... https://phys.org/news/2015-02-fast-universe.html

The author of that random blog is Sean Carroll, professor of physics at Caltech specializing in cosmology and GR.

That doesn't mean he must be right, but I feel pretty comfortable citing him.

Re: Can a Living Creature Be as Big as a Galaxy?

#138

Post by meric »

jfoutz wrote: post #114
Taek wrote: post #45

Earlier quoted context omitted.

If we assume that the big bang was actually the conception event of some other cosmic entity, the universe could very easily be a living organism that's the equivalent of a few microsecond old fertilized zygote. So yes, a universe sized lifeform could not have evolved randomly since the big bang, but you can only be confident about that if you assume that nothing exists outside the spacetime bubble we call the univer…

or it could be the big bang is the relaxing of a muscle cell is some cosmic monster. Or perhaps the big bang was kinda like enzymes, breaking something hard to eat into a nice easily digestible heat bath. or it could be an edge transition of one wire of some cosmic computer. It's fun to kick around crazy ideas on Saturday afternoon. It could be anything. Sadly, there's no way i'll ever know. But the idle speculation…

Or, you can write a science fiction short story and make it true in a fictional world you invent.

Re: Can a Living Creature Be as Big as a Galaxy?

#139

Post by ZenoArrow »

banachtarski wrote: post #7
bitL wrote: post #2

We still don't know if the Universe itself isn't a living organism with us playing the role of tiny viruses that require intelligence/consciousness to fulfill certain tasks, like what gut bacteria does for us.

We do. If you bothered to read the article, it makes a point that the communication speed between the components would be slow enough (even at light speed signaling) that the age of the universe would not have permitted sufficient time for such an organism to evolve and do anything.

We don't. How do we know that the big bang wasn't part of the internal activity of another organism? There are just some things we will never know.

Re: Can a Living Creature Be as Big as a Galaxy?

#140

Post by sriku »

"Exhalation" by Ted Chiang is, I think, a great literary exploration of this topic and brings the essence of what is required for life, though it doesn't get into what life is as opposed to other phenomena. For those who've not read it, I may be giving off too much if I said anything more.

It is certainly more insightful (again imho) than this article.

http://www.nightshadebooks.com/Downloads/Exhalation%20-%20Te...

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