221–230 of 307 posts
Things like this boosts my thoughts of life out there living alone, discovering/inventing everything from scratch over and over. While we pride ourselves on passing the knowledge generation by generation to be where we are now, imagine if we could learn/share it beyond our planet, solar system, galaxies.... Long way to go!!
I wonder if we'll abide the prime directive when the day comes ;)
The significance is this: it's very likely that there are a lot more such planets a lot nearer to us. This is because Kepler can only detect planets which lie in the same plane as earth and the star so the planet occults the star. Assuming random distribution, there's probably thousand fold amount of off plane planets. There are 259 stars within about 30 light years. Communication could be conceivable with such dista…
So what's the current fraction of stars that have habitable zone planets? (i.e. how many stars were surveyed?) That would get us an estimate of how many of those 259 might contain Earth-like planets: we use the fraction of orbital those planets that Kepler detects to estimate the total fraction of planets per star, and multiply that by 259.
"Kepler has observed over 156,000 stars simultaneously and near continuously to search for planets that periodically pass in front of their host star (transit)"
From the article:
"The confirmation of Kepler-452b brings the total number of confirmed planets to 1,030." — and I have verified that this refers specifically to planets confirmed by Kepler, not just planets in total.
From Wikipedia[2]:
"four, including Kepler-296f, were less than 2 1/2 the size of Earth and were in habitable zones where surface temperatures are suitable for liquid water."
These figures give us an approximate sense of the number of planets that occult their host star, as a proportion of the number of stars surveyed.
TRIGGER WARNING: SKETCHY BACK-OF-THE-ENVELOPE MATH
259 stars within 30 light years
1030 / 156000 = 0.00660256410256 (fraction of Kepler-surveyed stars possessing Kepler-confirmed planets that transit)
4 / 1030 = 0.00388349514563 (fraction of significantly Earth-like Kepler-surveyed planets)
259 * 0.00660256410256 * 0.00388349514563 = 0.00664102564102 or 0.66% (chance of a transiting Earth-like within 30 light years)
And that's not even factoring in planets that do not transit their host star.
[1] http://ntrs.nasa.gov/search.jsp?R=20100030619 [2] https://en.wikipedia.org/wiki/List_of_exoplanets_discovered_...
Earlier quoted context omitted.
Imagine if all the great Scottish scientists were referred to as 'the English'. That might piss some people off.
I'm sure some people track these sort of tribal affiliations between inhabitants of the British isles over the course of a millenium, too, but again I'd consider it a silly thing to get riled up about.
Hence the 'weaker' nation feels deprived of its history when its proudest moments are appropriated away.
Earlier quoted context omitted.
Imagine if all the great Scottish scientists were referred to as 'the English'. That might piss some people off.
I'm sure some people track these sort of tribal affiliations between inhabitants of the British isles over the course of a millenium, too, but again I'd consider it a silly thing to get riled up about.
Earlier quoted context omitted.
There's an implicit assumption running through most of this thread that if there's a civilization there, it's enjoyed 2 billion years of continuity. I suspect that's unlikely, even if there were advanced life there for 2 billion years.
> I suspect that's unlikely, even if there were advanced life there for 2 billion years. Why do you think so? "Continuity" doesn't have to be having the same government or the same political structure, or even the same physical form (the article itself talks about uploads and nanomachines). It just means continuity of technological development. It doesn't have to mean steady progress either; our civilization hasn't h…
Earlier quoted context omitted.
There's an implicit assumption running through most of this thread that if there's a civilization there, it's enjoyed 2 billion years of continuity. I suspect that's unlikely, even if there were advanced life there for 2 billion years.
> I suspect that's unlikely, even if there were advanced life there for 2 billion years. Why do you think so? "Continuity" doesn't have to be having the same government or the same political structure, or even the same physical form (the article itself talks about uploads and nanomachines). It just means continuity of technological development. It doesn't have to mean steady progress either; our civilization hasn't h…
The significance is this: it's very likely that there are a lot more such planets a lot nearer to us. This is because Kepler can only detect planets which lie in the same plane as earth and the star so the planet occults the star. Assuming random distribution, there's probably thousand fold amount of off plane planets. There are 259 stars within about 30 light years. Communication could be conceivable with such dista…
For a star like ours with a single Earth-size planet at 1AU, the odds of observing a transit are 0.47%. There is a page devoted to this question which gives some idea of the variables involved: http://certificate.ulo.ucl.ac.uk/modules/year_one/NASA_Keple...
Earlier quoted context omitted.
My favorite thought is that they've sent probes millions of years ago and we could send a request to watch some HD surveillance of dinosaurs roaming the Earth. It'll just take ~3k years to receive the requested footage.
Not if you board a spaceship and travel to them at close to light speed! Then you, personally, would just wait a few hours.
Assuming an acceleration of 10 m/s^2 (similar to Earth's gravity), it will takes roughly one year to accelerate to a speed close to the speed of light were relativistic effects occurs, and you will need one more year to decelerate.