| Subject: Re: How smart are SETI@homers? |
| From: Joseph Lazio |
| Date: 03/06/2004, 01:11 |
| Newsgroups: sci.astro.seti,alt.sci.seti |
"R" == Rich <someone@somewhere.com> writes:
R> In infinite wisdom Joseph Lazio answered:
I think you want: http://exoplanets.org/msini.html The data is
suggestive, especially considering the sensitivity limits of the
instruments (...). Other investigations, especially the Kepler
mission, will give us much better data on the abundance of lower
mass planets.
R> I'm not at all sure that this simplistic statistical treatment is
R> valid. The dynamics of planet formation are far from know, and many
R> of the gas giants are in highly eccentric orbits, which would
R> disrupt the orbits of any other planets for quite a way in and
R> out. [...]
Please explain how the orbital dynamics of these planets would
affect the measured mass distribution.
R> Orbital resonances with the more massive planets dictate where
R> stable orbits exist.
[...]
R> A gas giant close to a star makes it difficult for stable orbits to
R> exist in the habitable zone.
While true, this is irrelevant to the question at hand. The question
is, How do the orbital dynamics of the known extrasolar planets (which
are almost exclusively Jovian mass) affect their mass estimates?
Nevertheless, the fairly limited assertion that sub-Jupiter mass
planets exist in greater abundance is pretty well supported by
the data on hand (...).
R> Is it? I suggest that this is speculation on the order of the Drake
R> Equation, and as of yet backed by no data.
Whew! Will somebody please explain to me why I continue to post on
this topic? Even better, will somebody please tell me what to say?
How one can look at a mass distribution, taken from the inferred
masses of planets, and claim that it is "backed by no data" is just
incredible.
R> Then show me the data for terresitral mass planets. I'd appreciate
R> it.
You seem fixated on terrestrial planets, even though Christopher
states clearly that he talking about planets with Saturnian and Jovian
masses. Let me try again, Is it reasonable to conclude from the data
that, over the range 0.1 M_J to 10 M_J, less massive planets are more
common that more massive planets?
R> Terrestrial planets may indeed be common, but I don't see any way
R> that can be extrapolated from the data we have, and I doubt any
R> will be found at most of the stars where we have detected gas
R> giants.
Ah, good. Given your statements above, Is it worth looking for
extrasolar terrestrial planets?
R> Is it worth looking for gravity waves? Despite the fact that LIGO
R> has found nothing, physicists think it's a smashing success. And
R> the question remains, what next? Do we build a larger LIGO? And a
R> larger one after that, and keep going until we find something? It's
R> clear that this is what the Physics community would do.
First, LIGO is a bit different in that we have found planets. The
question posed is, Is it worth looking for terrestrial-mass planets
given that Jovian-mass planets have been found?
R> But let's say that you get to pay for part of it, say, it costs
R> every taxpayer $10-20 a year, and $20-30 a year for the next
R> one. And let's say that the money spent is borrowed and
R> inflationary (unreasonable conditions though these may be :-). What
R> are you going to decide?
I've already posted on topics of the US budget and expenditures for
astronomy. Given that you seem inclined to ignore my earlier
comments, I see no reason to repeat them.