Posts tagged ‘science’


“All Ravens are Black” — a meta-investigation

Technique 1

Observe a sufficiently large number of ravens, and determine whether any are non-black.

Examples 1

Raven 1 – black
Raven 2 – black
Raven 3 – black
. . .
Raven N – black

Technique 2

Observe a sufficiently large number of non-black entities, and determine whether any are ravens.

Examples 2

White Snowball 1 – not a raven
Red Pepper 1 – not a raven
Brown Bag 1 – not a raven
White Snowball 2 – not a raven
. . .
Yellow Yield Sign N – not a raven


It may be necessary to make significantly more observations in technique 2 for the same degree of confidence.

On the other hand, it will be significantly easier to find appropriate entities for observation in technique 2.

When stating the results of technique 2, it is good practice (although not strictly required) to observe a single raven*.  If this is not done, the statement of results should include, for clarity of communication, the statement that the observations made do not establish that any ravens in fact exist.

* Note that it is not necessary to observe the color of the raven in this case.

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Extra-solar pond slime

So today I went to a talk by Lee Billings, author of Five Billion Years of Solitude (which, note, I haven’t read yet, although I now have a signed copy; I’ve just heard the talk).

He is all about how incredibly cool it would be to find out that there is life on some planet outside the solar system (by deducing, say, a particular unstable mixture of gasses in its atmosphere that we can’t account for except by life), and that we are not investing nearly enough resources (money) in building the just-now-becoming-possible huge honking telescopes that would help us find such planets.

Or alternately, he says, it would also be extremely important in some way to discover that there isn’t life on any extra-solar planets that we can find, and that therefore we are even Specialer than maybe we thought.

There has recently been an Enormous Boom in the finding of planets outside the Solar System, apparently; an inneresting fact that I hadn’t known. Significant numbers of them are sort of vaguely Earth-like in various ways; also inneresting.

Extra-solar planets

But, as I said during the Q-and-A period (for which I may appear on the YouTube at some point in the future!) I’m not sure how interesting it would really be to know that there is, say, probably pond-slime on Kepler 22b.

The two reasons the speaker gave for the importance of looking for extra-solar planets with life (besides raw coolness, which I don’t think is a good reason to spend billions of dollars, really) were (1) having more places for humans to live by the time the Sun swells up and eats the Earth or whatever, and (2) knowing whether or not We Are Alone In The Universe (hence the title of the book).

In terms of having more places to live, I think that by the time the Sun swells up (a few hundred million years), and even by the time we’re conveniently able to go in large numbers to other solar systems, we’ll long since have just remade ourselves so that we don’t need certain sorts of planets with particular chemistries to live on, so that particular issue will be moot.

And in terms of knowing whether or not we are alone, I think it’s far more important to know whether there’s anyone sentient out there than it is to know whether there’s any carbon-oxygen-based life out there. Given a few dozen billion dollars and the choice between looking for photosynthesis, and looking for intelligent signals, I’m going for the latter.

The extra-solar pond slime is just going to have to wait…


Happy Christmas to All!

A Happy Christmas and greetings of the Season to all of my good Readers! The Queen’s Message has just finished, and we are sitting by the Tree, listening to Traditional Carols being played upon the stereo-phonic system, with a pie crust heating in the oven for Chocolate Silk Pie in the French mode later on, with the Ham Dinner.

This year I have received Gifts that spring from the Profligate Bosom of Technology! M has given me a bound copy of Robert Hooke’s “Micrographia”, as published by the Royal Society in September to General Acclaim. It is quite an astonishing volume; I admit I have been “looking at the pictures” primarily, rather than reading the text, but it is clear just how revolutionary a piece of work this is, opening whole new worlds to human examination, and whole new channels in the human psyche.

From the Little Daughter, a selection of knit “sweaters”, including two open ones in the style of the Earl of Cardigan, that she assures me are popular with the “hipsters” in her set. I am wearing one now, and if I say so myself it is both agreeable to the eye, and significantly Warming.

In my “Christmas stocking”, I also found an Eight Gigabyte USB Key, in the style of Swiss Army Knives (from Victorinox, the Original Makers). This offers enough “memory”, I should think, to contain a detailed narrative of my own Life, and for that matter most of the History of the Universe. Quite an amazing bauble for one’s key-ring!

And less Technologicially, I also have a new Messenger Bag for carrying things in, and a Quantity of Chocolate, as is traditional. :)

As it says in Clement Moore’s verse, which also in accord with Tradition I read aloud to the family last night (notwithstanding the eye rolls of the teen-agers): Happy Christmas to all!

(And to all, after Dinner, a Good Night!)