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Our Solar System Isn't Normal

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Re: Our Solar System Isn't Normal

#41

Post by yolesaber »

Shivetya wrote: post #28

Being a long time fan of 4x games, well of space games in general, this article makes me smile. I remember reading game forums where one subject that always arose was galaxy and system formations. So many of our concepts are strictly based on the very little observable data we have. Its great to live in a time when many assumptions are proven to be just that. Now the question that remains is, which configurations are…

A bit off-topic, but can you recommend any recent space 4x games to check out? The last one I played was Galactic Civilizations II and I enjoyed it immensely.

Re: Our Solar System Isn't Normal

#42

Post by kpierre »

pekk wrote: post #40
kpierre wrote: post #32

Earlier quoted context omitted.

> But by no means is our solar system special in any light: it's only special in that its particular conditions produced lifeforms able to observe it. sorry, but i don't understand what's the logic here? it's not special, but it's only very special in sustaining/producing life? isn't that more than enough to call it special? :-)

Not in the requisite sense. Suppose that our existence depended on a purely random roll of a six-sided die coming up as 1. If the roll had come up anything else, we would not be here to reflect on it. But if it did come up as 1, that does not mean a mystical force guaranteed that it came up as 1. Our existence (whether likely or not) does not constitute evidence that our existence was guaranteed or predetermined. Low…

it seems like you, and the top comment are interpreting this news story as some attack on atheism? i don't see how that's even related. is that your preemptive strike against non-atheistic interpretation?

Re: Our Solar System Isn't Normal

#43

Post by calinet6 »

kpierre wrote: post #32
calinet6 wrote: post #22

"We have to figure out why our solar system turned out different from all the others." Not entirely—we have to understand statistics and the anthropic principle, which states "observations of the physical Universe must be compatible with the conscious life that observes it." (Wikipedia: http://en.wikipedia.org/wiki/Anthropic_principle ). In other words, our situation appears "perfect" because it was one of the many r…

> But by no means is our solar system special in any light: it's only special in that its particular conditions produced lifeforms able to observe it. sorry, but i don't understand what's the logic here? it's not special, but it's only very special in sustaining/producing life? isn't that more than enough to call it special? :-)

It's special from our perspective, certainly. It's just not special in a cosmic sense: it just happened, and the universe produced something that could observe it. It could have happened anywhere, but it happened to happen on Earth. To me, that's the special part, and I find it fascinating and mind-blowing to think about.

Re: Our Solar System Isn't Normal

#44

Post by teamonkey »

gweinberg wrote: post #31

I think the author has the "frost zone" theory backwards. It's not that it's too cold for rocky planets to form outside the frost zone (after all, there are some planet-sized moons out there) but rather that inside the frost zone it is too hot for planets to hold on to hydrogen, so you don't get gas giants. I would think that a gassy planet close to a star would have to have a really big solid or liquid core of heavy…

The frost line is the point at which ice crystals can form of the major planetary gasses. The theory was that outside the frost line these crystals would add to the density of particulates in the region, therefore larger planets would form outside the frost line and they would have a greater proportion of gasses than the inner planets.

Re: Our Solar System Isn't Normal

#45

Post by calinet6 »

ajross wrote: post #36
calinet6 wrote: post #22

"We have to figure out why our solar system turned out different from all the others." Not entirely—we have to understand statistics and the anthropic principle, which states "observations of the physical Universe must be compatible with the conscious life that observes it." (Wikipedia: http://en.wikipedia.org/wiki/Anthropic_principle ). In other words, our situation appears "perfect" because it was one of the many r…

You misinterpreted. The point of the article isn't to explore the epistemology of why or how we perceive ourselves to be "special". The point was that a few years ago we had a solid, broadly-agreed-upon scientific theory of planetary formation. And it was wrong. That's interesting for scientific reasons, not philosophical ones.

In most articles investigating how our solar system or planet is different from the others, they take a pop-sci tone (which I may be reading too much into, for sure) about scientists studying why our special planet got this way.

That is absolutely true to some degree—we want to find out what conditions support life, and why the Earth did end up how it did, and resulted in conditions stable enough and correct enough to allow life to evolve for millions of years essentially uninterrupted.

It's the tone that I read into, and I have a tendency to look out for the earth-centric perspective, mainly because I find the alternative way to look at it basically mind-blowing and fascinating. That doesn't make study of the development of our solar system any less important, any more than the study of evolution makes biology less important. The study of planetary formation, the solar system, geology and every other related field are all extremely important to broadening and deepening our understanding of how the universe works. Understanding statistics and the anthropic principle just gives us a framework in which to view that knowledge that is even more true and complete, in my opinion.

Re: Our Solar System Isn't Normal

#46

Post by stephenhuey »

calinet6 wrote: post #39
stephenhuey wrote: post #30

Earlier quoted context omitted.

Unlike a cash lottery for which we intend there to be a winner, winners of a cosmic lottery do not "necessarily" exist--a winner like us is not guaranteed, I mean.

Not guaranteed, no, but it has been verified experimentally.

An experiment has verified that there is a cosmic lottery, and that the winner of a cosmic lottery gets a planet like ours?

Re: Our Solar System Isn't Normal

#47

Post by madaxe »

saalweachter wrote: post #17
madaxe wrote: post #9

Earlier quoted context omitted.

Yeah, that was my first thought too. Sample bias all the way. 1) Things which orbit rapidly are easy to spot as we get lots of observations from occlusion and wobble. You can identify a planet over the course of a few weeks if it has a period measured in days. 2) Things which are massive are easy to detect using wobble methods. The closer in they are, the more wobble there is. GMm/r^2 and all that. 3) Massive close-i…

I think sampling bias is definitely the most likely reason we haven't seen any solar systems like ours, but... Even with sampling bias, we could still be seeing something legitimately weird. We expect to detect some certain number of exo-planets with a certain range of characteristics with our current technology. We don't think this set of exo-planets is necessarily representative of the average exo-planet in the gal…

Yeah, but the other possibility is that our tech hasn't lived up to our expectations, and therefore we haven't made the observations and measurements we might have hoped for, which I'd wager is far more likely.

"Hot Jupiter" type planets aren't as much of a revelation as one might expect, however, given the prevalence of binary systems, many of which have very, very short periods (J0106-1000 has one of 39 minutes) - and there's still nothing to say that those same systems don't have rocky worlds tucked away that we can't see due to the overwhelming noise from the massive inliers.

Re: Our Solar System Isn't Normal

#48

Post by kpierre »

calinet6 wrote: post #43
kpierre wrote: post #32

Earlier quoted context omitted.

> But by no means is our solar system special in any light: it's only special in that its particular conditions produced lifeforms able to observe it. sorry, but i don't understand what's the logic here? it's not special, but it's only very special in sustaining/producing life? isn't that more than enough to call it special? :-)

It's special from our perspective, certainly. It's just not special in a cosmic sense: it just happened, and the universe produced something that could observe it. It could have happened anywhere, but it happened to happen on Earth. To me, that's the special part, and I find it fascinating and mind-blowing to think about.

i see your point, but i just find that 'not special in a cosmic sense' is scientifically meaningless and therefore irrelevant here

Re: Our Solar System Isn't Normal

#49

Post by calinet6 »

kpierre wrote: post #42
pekk wrote: post #40

Earlier quoted context omitted.

Not in the requisite sense. Suppose that our existence depended on a purely random roll of a six-sided die coming up as 1. If the roll had come up anything else, we would not be here to reflect on it. But if it did come up as 1, that does not mean a mystical force guaranteed that it came up as 1. Our existence (whether likely or not) does not constitute evidence that our existence was guaranteed or predetermined. Low…

it seems like you, and the top comment are interpreting this news story as some attack on atheism? i don't see how that's even related. is that your preemptive strike against non-atheistic interpretation?

Absolutely not. My intention was to broaden the point by introducing the mind-blowing anthropic principle and a new perspective on the conditions leading to life, nothing more.

Re: Our Solar System Isn't Normal

#50

Post by calinet6 »

stephenhuey wrote: post #46
calinet6 wrote: post #39

Earlier quoted context omitted.

Not guaranteed, no, but it has been verified experimentally.

An experiment has verified that there is a cosmic lottery, and that the winner of a cosmic lottery gets a planet like ours?

Humor is lost on HN. No, our existence has been verified, and therefore a planet on which we can exist does exist. I hope we don't need to go further with this line of inquiry.
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