What, in this context (and most likely all), does outside our solar system actually mean?
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Extreme supersonic winds measured on a planet outside our solar system
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Re: Extreme supersonic winds measured on a planet outside our solar system
#22Not an original thought, but I wonder if the answer - or part of it - to the Fermi paradox is that we don't know all the ways it's possible for a planet in the Goldilocks Zone to be otherwise hostile to life. Liquid water and.. chemistry leading to an ambient pH of 2 or 12. Liquid water and.. radiation environment such that proto-RNA strands get immediately smashed to bits by high-energy rays. Liquid water and.. bomb…
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see. The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth. I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
IMO the dark forest hypothesis leads to fun books but makes little sense. If a civilization is capable of the unimaginable feat of interstellar travel, surely their basic needs are well met and they aren't driven by base animal instincts anymore. They can probably engineer their own psyche. We humans will soon hit a population peak too, no exponental growth on the horizon.
Also, I don't think the timescales make sense at all. It took 200 years for industrial civilization to develop, maybe 200 more for us to travel the stars, but it takes billions of years for intelligent life to develop. I don't think there could ever be two comparable civilizations emerging at the same time, close enough to one another to compete for resources. Either the aliens found Earth millions of years ago and prevent us from ever existing, or there aren't any aliens closeby.
If you want an optimistic outlook on the far future which I think more plausible, read "Diaspora" by Greg Egan.
Re: Extreme supersonic winds measured on a planet outside our solar system
#23there is a good chance that the "measurement" is recording some other phenominon, as this can only be an interpretation of albedo changes, and could be the signal from say, low orbiting small moons
or a planetary ring,atmospheric electrical discharges
in any case, it is most definitly not an actual wind speed measurement, plus strictly speaking "wind" can only happen in air, and this, again, can only be something else, with the use of the term "supersonic" not even remotly applicable, unless of course its of the football field per second type of calculation standard
Re: Extreme supersonic winds measured on a planet outside our solar system
#24Woah how’s that even possible? How does the fluid pick up so much kinetic energy? I’m not saying they’re wrong, I’m just fascinated.
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Re: Extreme supersonic winds measured on a planet outside our solar system
#25Woah how’s that even possible? How does the fluid pick up so much kinetic energy? I’m not saying they’re wrong, I’m just fascinated.
It's twenty times closer to its star than the Earth; the intensity of its starlight is hundreds of times brighter. Hot enough (1,400 K) to melt gold.
I don't understand the details, but in some sense it has to be an atmospheric heat engine between the day and night side of this planet. (Its rotation is tidally locked, so they are permanently distinct sides).
Re: Extreme supersonic winds measured on a planet outside our solar system
#26As with black holes, in my lifetime exoplanets have gone from being conjectural-but-likely to scientifically rich observable phenomena. I love it.
I have memories of asking adults how many planets in the universe we know of at a time when the answer was 10 because we had just discovered the first exoplanet (and Pluto was still considered a planet) and laughing when they would give answers in the thousands or millions.
Re: Extreme supersonic winds measured on a planet outside our solar system
#27Earlier quoted context omitted.
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see. The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth. I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
IMO the dark forest hypothesis leads to fun books but makes little sense. If a civilization is capable of the unimaginable feat of interstellar travel, surely their basic needs are well met and they aren't driven by base animal instincts anymore. They can probably engineer their own psyche. We humans will soon hit a population peak too, no exponental growth on the horizon. Also, I don't think the timescales make sens…
> If a civilization is capable of the unimaginable feat of interstellar travel, surely their basic needs are well met and they aren't driven by base animal instincts anymore.
That is a bit like saying a human isn't driven by base instincts because we are so large and advanced compared to amoeba. We have concerns and options that are so far beyond the amoeba's comprehension that it makes no sense to even talk about an amoeba comprehending. And yet we are still driven by the same basic resource-acquisition logic as any microbe. Being more advanced again is unlikely to change that.
Although I do agree that the Dark Forest hypothesis seems unlikely. It seems more reasonable to suggest that gravity wells and interstellar distances are a barrier that cannot be economically overcome, so intelligent life is bound to its own rock and eventually dies there. Then the odds just favour us not detecting life out there in whatever time period we've been looking.
Re: Extreme supersonic winds measured on a planet outside our solar system
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Re: Extreme supersonic winds measured on a planet outside our solar system
#29Earlier quoted context omitted.
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see. The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth. I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
> I'm coming around to the Dark Forest theory, personally, as terrifying as it is. If you're silent with the intent of remaining hidden, then that behavior must have been learned. Either you evolved from a prey type of species, or a non-apex predator. It would be strange of humanity is the only apex-ish predator intelligent-ish life form in the universe that blasts signals into space without consideration of who migh…
We don't have telescopes capable of receiving accidental emissions from Earth (say television) at interstellar distances. It seems reasonable that you could use the gravitational lens of a star to do so if you could launch a probe to 800 au for each and every star system you want to monitor.
As we transition to digital technology, our transmissions look more like broadband noise as opposed to having a strong carrier wave, cellular communications in 2025 are far less visible than, say, television broadcasts of 1975.
Deliberate attempts to communicate with other intelligent life are quite forlorn. This message was sent to a globular cluster 25,000 light years away
https://en.wikipedia.org/wiki/Arecibo_message
There a few 100,000 stars there, somebody there would have to be looking at our sun in particular at the right time, then it would take at least 25,000 years to get a message back to us, in which case it is likely that we'll be extinct, collapsed back to hunter-gatherers, or maybe advanced but forgotten that we sent the message or don't care anymore.
Re: Extreme supersonic winds measured on a planet outside our solar system
#30Earlier quoted context omitted.
But there are also 7500 known exoplanets within a few tens of thousands of light years of Earth. There are almost certainly multiples more than that we cannot see. The "Goldilocks Zone" is also highly anthropomorphised: there are extremophiles that live in all sorts of crazy environments on Earth. I'm coming around to the Dark Forest theory, personally, as terrifying as it is.
IMO the dark forest hypothesis leads to fun books but makes little sense. If a civilization is capable of the unimaginable feat of interstellar travel, surely their basic needs are well met and they aren't driven by base animal instincts anymore. They can probably engineer their own psyche. We humans will soon hit a population peak too, no exponental growth on the horizon. Also, I don't think the timescales make sens…
There's the question of motivation. It seems possible that an advanced civilization could gravitationally disrupt a small planet like mercury, turn it into solar collectors and particle accelerators and create multiple-ton quantities of antimatter and use that for interstellar travel, but they would likely choose to do something else with those resources.
People have a hard time thinking on a timescale of half a lifetime, never mind a lifetime or several lifetimes. The realistic version of the Bussard ramjet is not that you aim for c=0.1 or more, but rather with D-D fusion you can make hops of 1,000-10,000 au to Oort cloud bodies, you could possible gravitationally disrupt an object like Pluto and turn it into little ringworlds or other colonies. It might take people like that 10,000 years to make it to the next star but if they can make a comfortable lifestyle along the way why would they bother? And why would we even care enough to send them out on such a quest?
Even colonizing Mars is problematic in the sense that it's inconceivable that you could bring anything back from Mars that would give us flatlanders any economic incentive to do it. It might be a gift to a population of a billion or so people that will live there, but profitable to us? No way.
So even if you could colonize the galaxy with Von Neuman probes, it won't happen in your lifetime, your children's lifetime, etc. Our civilization might not be there to get the data from the first probes to reach other stars and the more steps removed the more the probability drops. Still there's just that tiny probability of a 'dark forest' scenario where somebody finds one of those things and decides to do something about it.