Rare Earth

I tend to pay way too much attention to theories on the formation of planetary systems than is strictly good for me. :)

But the whole thing is tied up with things like the Great Filter and "where are all the aliens" and other questions that bother me. So I keeping poking around and finding things like the Grand Tack, which is a simply fascinating theory about the origin of the Solar System where a resonance between Jupiter and Saturn kept Jupiter from spiraling in and becoming one of those "hot Jupiters" that we see so frequently in other planetary systems. And once a Jupiter-sized object has crashed its way into a close orbit, the chances of putting together an Earth-like planet fall abruptly, I suspect.

All of this leaves open the question of why the terrestrial planets of the system are, well, terrestrial. There should be plenty of hydrogen-rich material to accrete to make one of those "super-Earths" that we see in other planetary systems. Where did all of the hydrogen and all of the extra mass go?

And it turns out that there's a theory for that.

According to this article, the Grand Tack would have bombarded any super-Earths that had formed in the system with planetesimals, destroyed them, and driven most of the mass into the Sun. The terrestrial planets formed out of the hydrogen-depleted leftovers.

Well, that would explain a lot.

We are apparently a very rare Earth.

The Grand Tack: is there anything it can't do? :)

XML Hell Redux

I have been frantically coding this week to try to fix a problem with formula translation as we move from the old account numbering regime to an account naming regime, because a function that I had hacked together that depended on the specific format of the old account numbers no longer worked. I had been trying to produce a solution that would require reverse parsing the byte stream that results from parsing the formula text, but that became increasingly unwieldy -- actually, it was more just a matter of it was a lot of work -- so I set that aside and went to a simpler solution using the parser with a flag setting that told it to correct the formula text on the fly so I could store the fixed version.

I think that works, but something went wrong when I tried to test it. So I pulled up the trusty audit dialog in the Excel add-in version of our product to see what the formula was in the debugger.

It immediately failed.

What the--?

A bit of debugging later, I discovered that this time they had remembered to encode the string with the quotation marks on the way in, but not to decode it on the way out from the XML format.

To quote the late Casey Stengel, "Can't anybody here play this game?"

I have now coded the XML retrieval to use one of my utility functions that automatically decodes the string output. I had to write a new version of the function, because the one that I had used boost::shared_ptr, while the function I was working with had used std::auto_ptr, but that was a quick substitution.

I don't really care which one we use, but it would be nice if we made up our minds...

Now to see if this damned thing works...