Our Galaxy Has at Least 100 Billion Planets, Study Shows
jpl.nasa.gov
jpl.nasa.gov
So we looked in 3 places, found 3 planets and are extrapolating to 100 billion? Surely I would wait for a few more examples?
Edit: Reading the full story, "Of the approximately 40 microlensing events closely monitored, three showed evidence for exoplanets. Using a statistical analysis, the team found that one in six stars hosts a Jupiter-mass planet. What's more, half of the stars have Neptune-mass planets, and two-thirds of the stars have Earth-mass planets. Therefore, low-mass planets are more abundant than their massive counterparts."
I dont get it. Any explanation?
"Unlike other prominent planet-detection techniques, which measure the shadows of planets passing in front of their stars (transit) or measure the wobble of a star due to the gravitational tug of a planet (radial velocity and astrometry), the gravitational-lensing technique is unbiased in the selection of the host star."
To know more, we have to read the story in Nature, which is here:
http://www.nature.com/nature/journal/v481/n7380/full/nature1...
Look at the error bars on their percentages. Super-earths (planets of 5-10x earth mass) are present on "62 +35 -37"% of systems. So, your intuition that the extrapolation was shaky is correct.
However, the actual study costs US$32 so I am not buying it so somewhere in the game of telephone that we just played information could have mutated.
http://www.eso.org/public/archives/releases/sciencepapers/es...
And 50 light years is a long distance to travel even at a tremendous speed like 0.01c, but it isn’t that long to send postcards. If we’d sent out a bunch of reasonably good questions in 1912, we would still be interested in the answers today. (More interesting, I think, is what they would ask us.)
In retrospect, I’m assuming we’re taking a finding-intelligent-life perspective here. But if you’re thinking in terms of human expansion – terraforming and so on – then I agree.
Otherwise it works exactly the same the other way: The chance is that we would be significantly more advanced than them.
In actually chances are we have zero data on the matter and can not calculate chances at all.
The actual reason is that we have invented radio technology only very recently. Because we are so new to the technology, odds are that our communication partner has had radio for much longer than we have (millions of years probably, given the age of the universe), and thus is far more advanced.
This logical step requires a few assumptions. First is that societies don't destroy themselves soon after the advent of nuclear weapons, which would limit them to a very short window of radio capability (measured in hundreds or thousands of years).
The second assumption is that other forms of intelligence progress their technology at a similar rate to that at which we progress ours.
If the former assumption is wrong, it's extremely unlikely that we will ever talk to any intelligence, even with relatively plentiful life in the universe, because it will kill itself too fast. The latter assumption could still be wrong though, particularly if the method used for interstellar radio communication was in any way evolutionarily derived.
This is my understanding of the topic at least.
We have zero data on any kinds of odds for how long anyone else might exist, or if the amount of time we have had radio is considered short or long.
Given how much randomness was involved in our creation as a species, let alone our technological ascendance, it is highly unlikely that other intelligence would develop in exactly the same amount of time elsewhere. It's astronomically unlikely. If they didn't develop at the same time as us, they're either still incapable of radio or have had radio for a long time. A long time in the life of the universe certainly doesn't mean 100 years, it means much longer. Even if it's only 1000 years, if they progress at anything like the rate we do, they'll be massively more advanced than we are.
If a species only has radio for a short period of time (like 200 years) and then disappears or loses it, the odds of overlapping with them are virtually nil (if they die out after getting this far, it says we're much more likely to die out soon too).
And I don't know if they would talk to us before we'd talk to them. Stephen Hawking has a lot to say about why trying to communicate with other civilizations is a bad idea, and they might be smart enough not to try.
"I think with the time scales involved, chances are that anyone communicating with us would be significantly more advanced."
In both my original comment and my clarification I was clearly talking about only aliens who were communicating with us.
The initial poster was talking about a hypothetical question we sent in 1912, meaning we contacted them, and they are communicating with us (they replied). You replied without changing the order of who contacted who.
From Wikipedia: http://en.wikipedia.org/wiki/Star_cluster
Globular clusters, or GC, are roughly spherical groupings of from 10,000 to several million stars packed into regions of from 10 to 30 light years across.
"However, they are not thought to be favorable locations for the survival of planetary systems. Planetary orbits are dynamically unstable within the cores of dense clusters because of the perturbations of passing stars."
So it seems clear that SETI-like efforts will be unlikely to detect any transmissions from civilizations who aren't deliberately trying to talk to us. Only civilizations that occupy the narrow time slice caught between the invention of radio and the widespread adoption of digital computers would be detectable, otherwise.
Compared to what we can wrap our brains around generally, sure, but in the scheme of the universe, not so much.
Sure it'll have a 50 year latency, but we could easily stream all of youtube (or the entire internet really) to them, and so could they. Assuming they're more advanced and their cameras capture the environment in spherical 3D, we could recreate what it's like to stand on their soil pretty accurately from home.
Besides just browsing their extranet would be amazing in itself.
Mind you, seeing another species' civilization's sense of humor would be pretty amazing.
Well Eric Schmidt who's probably in a better position to estimate than most, said that Google estimates the internet is made up of 5 million terabytes.
5 million terabytes / 10gbps = 126.8 years
and I very much doubt 10gbps is even remotely achievable over interstellar distances. I don't what kind of data rates are achievable but I would expect it to be extremely slow relative to Gigabit speeds.
On a related note, the number put forth by the study (at least one planet per star, on average) is roughly consistent with Drake's 1961 estimate that half of all stars will have planets, and stars with planets will have 2 planets capable of developing life.
Except, of course, that Drake estimated an average of >=1 habitable planets per star. Still, it's good to see one of his estimates being corroborated.
As an example, the Kepler mission is a direct result of the Drake equation, designed to resolve the first two parameters - fp and ne.
For some serious geeky pedantry, it's hard to beat the Wikipedia entry for the song (especially the section entitled "Accuracy of figures quoted in the lyrics"):
http://en.wikipedia.org/wiki/Galaxy_Song#Accuracy_of_figures...
Giordano Bruno beat him to the punch by four centuries (if of course one accepts 100,000,000,000 as a reasonable approximation of infinity).
I read that if the "Milky Way" was the size of China, then the the sun and 6 closest planets around together would be the size of one quarter.