"just 12 light-years away" I love the "just". I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-)
let's see if someone will try to upsell the Musk
Two potentially life-friendly planets found orbiting a nearby star
141–150 of 391 posts
Re: Two potentially life-friendly planets found orbiting a nearby star
#142Earlier quoted context omitted.
The birthday paradox works because you are looking for a pair that has the same birthday, regardless of what date that birthday is. It doesn't work in the habitable planet sense because you would be essentially locking the birthday to a fixed date.
Yes. How many people do you need in a room to be confident that one of them has the same birthday as you?
How confident? Even with an even distribution of birthdays it's possible to have a billion people in the room that don't share your birthday. Very unlikely, but as there's only about 20 million people with your birthday, and 7 billion without, it's quite doable.
Re: Two potentially life-friendly planets found orbiting a nearby star
#143Earlier quoted context omitted.
Tidal locking means that the denser side of the lighter body always faces the heavier body, and the less-dense side of the lighter body already faces away from the heavier one. The moon is tidally locked to the Earth, which is why it has a dark side.
There is no dark side in the moon. There is a far side.
You're right, but I'm pretty sure that "The dark side of the Moon" is a proper name at this point.
It's dark like the darknet is dark... Occluded.
Re: Two potentially life-friendly planets found orbiting a nearby star
#144Earlier quoted context omitted.
"However, more recent research is somewhat more optimistic." I am deeply skeptical of that "recent research", which AFAIK is "computer models, where we have zero capability to verify the computer models against even a single data point". The incentives to keep kicking the computer model until it provides something publishable, with no countervailing force provided by real data to be explained by the model, are just t…
well even our deep space observations are largely computed. nobody has "seen" these 2 planets at all ;)
what does seeing mean?
does it have to involve photons?
can gravity work as well?
sensors and computation are always involved, nothing is directly seen.
Re: Two potentially life-friendly planets found orbiting a nearby star
#145"just 12 light-years away" I love the "just". I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-)
I think current technology makes no sense when talking about interstellar travel. I wonder how long it'd take, seen from the perspective of the ship, if we had an engine capable of delivering a constant 1g acceleration. That's the way we'll want to travel, after all.
constant 1g acceleration gets you to speed of light pretty quickly (around 1 year), so still around 12 years.
Re: Two potentially life-friendly planets found orbiting a nearby star
#146Earlier quoted context omitted.
The birthday paradox works because you are looking for a pair that has the same birthday, regardless of what date that birthday is. It doesn't work in the habitable planet sense because you would be essentially locking the birthday to a fixed date.
Yes. How many people do you need in a room to be confident that one of them has the same birthday as you?
Assuming a uniform distribution, the probability is 1/365 for any person#. Those probabilities add up linearly if the people are guaranteed to have different birthdays (union/OR). Otherwise the probability of NOT having someone with the same birthday goes down exponentially as a an exponential power of the fraction 364/365 (intersection of complement/AND NOT)
It’s exactly what you would expect from classical combinatorics with cards with or without replacement. Your term “confident” is vague.
I produced a series called Thinking Mathematically on youtube that makes all of this and other related topics clear for anyone... I recommend checking it out!
https://m.youtube.com/channel/UCuge8p-oYsKSU0rDMy7jJlA
And here are the notes for it
http://magarshak.com/math/numbers.pdf
http://magarshak.com/math/sets.pdf
http://magarshak.com/math/logic.pdf
# if we exclude all people born leap years
Re: Two potentially life-friendly planets found orbiting a nearby star
#147"just 12 light-years away" I love the "just". I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-)
To give a sense of the scales involved - if the sun were an orange and the earth a grain of sand 6 meters away, this star would be a pea about 5000km away.
There would only be another 34 stars / fruit-and-veg within this 10000km wide sphere. It's pretty empty out there!
Re: Two potentially life-friendly planets found orbiting a nearby star
#148Earlier quoted context omitted.
Well, for the journey itself the problem has a simple solution - more shielding. Then of course we have to answer the question of how can we get ships into orbit when they are full of shielding, but that's not insurmountable. The bigger issue is actually living on mars - as romantic as that idea is, human habitation on the surface is really dumb, the radiation level is not insignificant, so anything long term would e…
> And if we are going to build an underground colony....then why not start with one here on Earth? Because if an asteroid hits Earth or if the world superpowers decide to go full nuclear, the underground colony in Mars will survive (unless superpowers decide to nuke that from here as well...)
I'd argue that a colony at the bottom of our own ocean would survive literally any event of any magnitude, maybe except for a direct asteroid strike. In terms of survivability of the human race, that's a better project to start with - and of course then move on to other planets, but underwater/underground colonies would give us lots of insights into living in such environments permanently.
Re: Two potentially life-friendly planets found orbiting a nearby star
#149Stop teasing me, Universe - and show me the aliens already!
The universe may have...
https://www.nytimes.com/2019/05/26/us/politics/ufo-sightings...
Re: Two potentially life-friendly planets found orbiting a nearby star
#150The note that it's an old star makes me worry though. If they're older then us, and habitable, were they inhabited? Our current era is a few hundred years of real, directed technological development. A few thousands years either side of that and who knows what we'd be looking at, but you imagine that - hopefully - the general progression of technology is forward. So if they were inhabited, what happened to them? Are…
> Are they exactly at our level of development?
If so, then at just 12ly away, we could converse with them within (many of) our lifetimes.