Google doodle celebrates Inge Lehmann

May 13, 2015 • 7:30 am

Today’s animated Google doodle celebrates the 127th birthday of Inge Lehmann. Most of you, like me, won’t know who she is, but Google is trying to bring to our attention accomplished but unsung women scientists. Lehmann (1888-1993; she lived to 104!) should certainly be of note, for she discovered the nature of the Earth’s core. As Wikipedia notes:

Inge Lehmann (ForMemRS; May 13, 1888 – February 21, 1993) was a Danish seismologist and geophysicist who discovered the Earth’s inner core.In 1936, she postulated from existing seismic data the existence of an inner core with physical properties distinct from the outer core’s and that Earth’s core is not a single molten sphere. Seismologists, who had not been able to propose a workable hypothesis for the observation that the P-wave created by earthquakes slowed down when it reached certain areas of the inner Earth, quickly accepted her conclusion.

Inge Lehmann
Inge Lehmann

Vox has a great explanation of how she used fast seismic waves (P waves) to discover that, contrary to what people thought, the Earth wasn’t just a mass of rock surrounding a fully molten core, but that the core itself had a solid inner nucleus:

Over the next few years, she closely analyzed this and other data sets. In the pre-digital age,her cousin later recalled, Lehmann would record the data on pieces of cardboard torn from boxes of oatmeal, and sometimes sat surrounded by them in her garden, puzzling over the numbers. Eventually, she had an idea: a solid inner core inside the soft, molten outer core, which would reflect some P-waves, causing them to end up in the shadow zone.

Her subsequent calculations, published in a 1936 paper simply titled P’ (as P-waves were then called), confirmed that the idea. “I then placed a smaller core inside the first core and let the velocity in it be larger so that a reflection would occur when the rays through the larger core met it,” she wrote, years later. “The existence of a small solid core in the innermost part of the earth was seen to result in waves emerging at distances where it had not been possible to predict their presence.”

And she lived long enough to do this as well:

In her later years, she used seismological data on underground nuclear explosions to discover another, subtler discontinuity in the upper mantle, at roughly 136 miles below the surface. Scientists still don’t fully understand this boundary, now called the Lehmann discontinuity.

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She faced the usual barriers to women in science, and even in the 1950s they wouldn’t appoint her as a professor in Copenhagen. As Time Magazine notes:

Lehmann was educated at a progressive school that valued equal treatment between genders. But when her professional career took off she often faced discrimination for being a woman, once being quoted as saying, “You should know how many incompetent men I had to compete with — in vain.”

Click on the screenshot below to see the animation:

Screen Shot 2015-05-13 at 7.02.35 AM

 

Jesus ‘n’ Mo ‘n’ Cognitive stasis

May 13, 2015 • 7:00 am

The new Jesus and Mo strip, called “Ditto,” reprises some recent research, which I reported about but can’t be arsed to look up. But can their beliefs be any more solid than they are already?

2015-05-13I wonder how many devout Christians—or, for that matter, Muslims—could tell you what observations or incidents would make them give up their faith.

 

Wednesday: Hili dialogue

May 13, 2015 • 4:53 am

Report: Facebook is back, back is improving slowly, and we are being cheated of Spring. Here is our weather through the weekend:

Screen shot 2015-05-13 at 4.42.32 AMIt’s been cold and rainy, and my squirrels are sick of soggy seeds. It is as if winter is reluctant to loosen its talons. Today I have a recorded phone interview with Dan Barker and Annie Laurie Gaylor for their Freethought Radio show, which will be broadcast on May 23rd: book stuff. It’s always a pleasure to talk with Dan and Annie Laurie—heads of the hardest-working secular organization around. Meanwhile in Dobrzyn, Hili is pulling rank as editor of Listy and is cracking the whip:

Hili: I told you that all articles are to be posted before 7 a.m.
A: What’s the difference?
Hili: The readers are waiting.

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In Polish:
Hili: Mówiłam, żeby wszystkie artykuły były publikowane przed siódmą rano.
Ja: A co za różnica?
Hili: Czytelnicy czekają.

 

Evolutionary convergence in swimming fins

May 12, 2015 • 3:15 pm

In this video from the New York Time’s James Gorman, we see an evolutionary convergence: in unrelated creatures that swim with a single undulating fin, the length of the “wave” propagating along that fin is about 20 times longer than the side-to-side displacement of the fin. This ratio has evolved repeatedly. Why is that?

Gorman explains; click on the screenshot below to go to the video:

Screen Shot 2015-05-12 at 2.18.47 PM

Note that Gorman says, “Eight times evolution faced the same physics problem; eight times it got the right answer.”  That shows that there weren’t severe constraints on approaching the “adaptive peak”. That is, when we have some external criteria for judging how close an adaptation gets to “perfection,” in this case (and other cases, such as mimicry), it gets pretty damn close. (Note: you might contemplate what aspects of morphology, physiology, and behavior have to change to get to this ratio.)

Contra Simon Conway Morris, by the way, this kind of convergence is no evidence for God.

h/t: Bill

Reprieve for AstroSam

May 12, 2015 • 1:38 pm

by Matthew Cobb

Our Official Website Astronaut™, Samantha Cristoforetti, has been given a reprieve. She was due to return to Earth from the ISS this week, along with her comrades NASA astronaut Terry Virts and cosmonaut Anton Shkaplerov, after a five-month mission. But because of  the loss of the Russian space agency’s Progress 59 freighter last week, they’ve put a hold on further missions until they’ve worked out what went wrong. There’s no problem for Sam and the others as there are plenty of supplies up there.

Sam is pretty happy about the whole thing, as she announced in this tw**t:

The full ESA announcement about the postponement can be found here, along with this photo of Sam hard at work a few days ago. Any engineering readers got any idea what she’s up to? The caption says “Working with BRIC units. The Biological Research in Canisters (BRIC) is an anodized-aluminum cylinder used to provide passive stowage for investigations studying the effects of space flight on small specimens.” But what exactly is she doing? It’s a high-res pic, so it’ll take a while to load, but here’s a competition: how many bits of kit can readers name (apart from the three computers, although you can get extra marks for saying what operating systems they are running).

One-day special from the TLS: access to a long (and favorable) review of Steve Weinberg’s new book

May 12, 2015 • 1:00 pm

In February I announced the publication of physicist Steven Weinberg’s new book on the history of science, To Explain the World: The Discovery of Modern Science, and included two excerpts he sent us to give an idea of the contents.

Now, for one day only, the Times Literary Supplement is offering a free look at its long (and laudatory) review of Weinberg’s book, a review written by Canadian philosopher John Leslie.

I’m only a few pages into Steve’s book, which is good but not by any means a light read. Do not read it before bedtime, as it demands full attention. Leslie, however, gives it high marks:

To Explain the World, [Weinberg’s] twelfth book, tells of the long, hard struggle to arrive at modern science, which started to take something like its present form only in the sixteenth and seventeenth centuries. The book is a magnificent contribution to the history and philosophy of science.

Leslie’s review is really a mini-lesson in itself in the history of science, and is worth reading just for that. It falls down in only one bit, though, and that bit is about religion. First, Leslie seems to take issue with Weinberg’s famous statement, “The more the universe seems comprehensible, the more it also seems pointless.” That statement, of course, has angered believers, who regularly mistake it as saying that there is no point to life. What Weinberg meant, of course, was that the more we understand about the universe, the less evidence we see for supernatural “design” or any meaning conferred by a deity. I’m sure Weinberg doesn’t see his own life as pointless!

Leslie apparently doesn’t like the pointlessness, and so he has to offer what comfort he can to religious people. Why, oh why, must philosophers regularly affirm, after religion takes a drubbing, “Look, believers, I’ve found you some consolation!” Michael Ruse, for example, regularly engages in this kind of shenanigan. And so Leslie assures worried religious readers that perhaps God lives in the interstices of our understanding, that is, in The Gaps:

Some items, though, in To Explain the World could give comfort to believers. Weinberg is certain that science will never explain every single law of nature. It can explain any one law only by pointing at some other, more fundamental law, as when we show why gases expand when heated: it’s that hotter particles strike their prison walls more violently. Further, he offers no answer to why the cosmos exists. Could God be the reason both for this and for nature’s laws? In the television series Closer to Truth, in episodes initially broadcast in 2008 and 2009, Weinberg stated: “Whatever our final theory of physics, we will be left facing an irreducible mystery. For perhaps there could have been nothing at all. Not even empty space, but just absolutely nothing. If you believe God is the creator, well, why is God that way? The religious person is left with a mystery which is no less than the mystery with which science leaves us”. Some philosophers, however, view the mystery of God as something on which they can throw light.

I don’t see how a believer can find much consolation in that. That would be the case only if you find consolation in the fact that science may never explain everything, as is certainly the case. Then, if you’re a diehard goddist, you can simply declare our igorance as God. As the great atheist Robert G. Ingersoll said, in one of my favorite quotes (which heads a section in Faith vs. Fact):

“No one infers a god from the simple, from the known, from what is understood, but from the complex, from the unknown, and incomprehensible. Our ignorance is God; what we know is science.”

Further, Weinberg raises a question that forever eludes the theist: Why is God that way? (And “where did he/she/it come from?”). For the theist, God is just a label for ignorance, for it has no predictive value at all; if it did, we’d be able to infer evolution from scriptures alone. And different religions would converge on the same understanding of God, which of course they don’t.

Finally, maybe, as Leslie avers, “some philosophers view the mystery of God as something on which they can throw light,” but I don’t know what light has been shed, and believe me, I’ve looked.

And, at the very end, Leslie has a Theistic Alternative to Weinberg’s solution of the mystery of why “dark energy” is so weak:

Why is the dark energy so very weak, a property without which the universe would be utterly hostile to life? Weinberg suggests a solution. It is that “what we call the expanding universe is just a small part of a much larger ‘multiverse,’ containing many expanding parts like the one we observe, and that the constants of nature take different values in different parts of the multiverse”; “only a tiny minority of the subuniverses in the multiverse would have physical constants that allow the evolution of life”, but “of course any scientists will find themselves in a subuniverse belonging to this minority”.

That’s to say, what could be at work is Observational Selection, the fact that nobody can make observations inside subuniverses whose dark energies are too hostile. Still, we might instead be seeing Divine Selection of a life-friendly physical world.

What the bloody hell is “divine selection”? Does Leslie mean “divine creation”? To paraphrase Big Daddy, “Didn’t you notice a powerful and obnoxious odor of the numinous in this room?”

Perhaps it’s unfair to dwell on Leslie’s peroration about religion, which after all is only two paragraphs in a long review, but he chose to end this way, and I think the ending paints not a consoling picture for theists, but a bleak one. If you have to look for your God in science’s ignorance—indeed, to rejoice in that ignorance, as Leslie seems to—you’re in bad shape indeed!

Anyway, you have until tomorrow to read Leslie’s review. (By the way, I’m not sure whether Leslie’s a believer; a few places—one is heresuggest that he’s a pantheist.

h/t: Mark

 

Houston, I have Facebook!

May 12, 2015 • 12:39 pm

Thank Ceiling Cat and some Big Guns who went to bat for me—and on whom I’ll confer anonymity—my Facebook page has returned. Although it’s still listed as “being investigated,” it seems to work fine. I guess I’ll never know why it was taken down.

But I also learned that I have a public Facebook page, or so a reader said. Maybe that’s just the public announcements on my regular Facebook page, but I don’t think so. At any rate, I don’t know where it is, nor did I start it.

Anyway, that’s one First World problem out of the way.