Comments | mabfan: Lecture: Mike Brown, "How I Killed Pluto and Why It Had It Coming"

mabfan

Lecture: Mike Brown, "How I Killed Pluto and Why It Had It Coming"

Jan 27, 2011 14:32

Last night, thanks to the Boston Skeptics organization, Nomi and I got to meet Mike Brown, the man who discovered Eris and indirectly led to the demotion of Pluto's status as a planet.

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science, space, science-fiction, personal, pluto, astronomy

Comments 20

madknits January 27 2011, 19:37:54 UTC

In my heart, Pluto will always be a planet.

mabfan January 27 2011, 19:38:25 UTC

As in ours.

laurele January 28 2011, 03:40:58 UTC

Pluto IS still a planet in a lot more than just people's hearts. Only four percent of the IAU voted on the controversial demotion, and most are not planetary scientists. Hundreds of professional astronomers led by New Horizons Principal Investigator Dr. Alan Stern signed a formal petition rejecting the IAU definition and the demotion. The New Horizons mission continues to refer to Pluto as a planet. This is an ongoing debate with two equally legitimate views. Brown's is the dynamical planet definition. The alternative is a geophysical planet definition, in which a planet is any non-self luminous spheroidal body orbiting a star. In other words, if the object is large enough to be rounded by its own gravity, a state known as hydrostatic equilibrium, and it orbits a star, it's a planet. By this definition, Ceres is a planet, as are Pluto, Haumea, Makemake, Eris, and any other dwarf planet large enough to be spherical. Dwarf planets are simply a third class of planets in addition to terrestrials and jovians--objects orbiting a star and ( ... )

rikchik January 27 2011, 19:42:27 UTC

It's a shame you couldn't stick around for the Q&A. There were some good questions, and I accidentally triggered a rant by mentioning the "14-planet" definition. "If your definition is 'round things' you have to admit there are about 200 of them!" He was sympathetic to the "4-planet" definition though.

mabfan January 27 2011, 19:45:40 UTC

It would have been nice to stay for the Q&A, but he was very understanding about our reasons for leaving. He has a young daughter, so he knows what it is like for us to need to get home.

I wish I could attend his 4 pm talk today at Boston University, though.

Is the "4-planet" definition the one that defines the solar system as four planets (Jupiter, Saturn, Uranus, and Neptune) plus debris?

rikchik January 27 2011, 19:52:14 UTC

"Debris" is in fact the exact word he used. Apparently in a past class about planetary formation, long before all this, he attempted to get his students to agree to that definition with no luck at all.

mabfan January 27 2011, 20:08:00 UTC

I think Isaac Asimov was one of the first to use that definition, including the word "debris."

Thread 14

be_well_lowell January 28 2011, 14:29:26 UTC

Other than the emotional resonance, what is the importance of the issue? There are no real scientific implications to what's defined as a planet, are there?

laurele January 28 2011, 18:33:44 UTC

Actually, there are real scientific implications. First, it makes no sense to have a "definition" imposed mostly by people who don't study planets at all, an act that was largely politically motivated. At issue is the IAU definition's complete exclusion of geophysics in favor of a dynamical definition. What happens if we discover a Mars-sized object in the Kuiper Belt? We could end up with two identical objects classed differently just because of their locations. It does not make sense to define an object solely by where it is while ignoring what it is. Even Earth wouldn't clear its orbit if put in Pluto's position; this was calculated by Dr. Hal Levison. The IAU definition is inherently biased against planets further from their parent stars because these have progressively larger orbits to clear.

delkytlar January 28 2011, 21:06:34 UTC

Sounds like an interesting evening. Glad you were able to get out for it. Don't you just hate it when your kids force a curfew on you? Children just don't understand. ;)

I recently gave another of my junior high presentations on the subject. I've been tweaking it each time, and seemingly receiving more and more favorable responses from the kids each time. I received some terrific thank you notes this time, with drawings of the solar system, lots of smileys, and a few hearts.

I have to admit that, while I do frame it in terms of the discovery of Pluto and the change in its official status, I've started using that more as a stepping-off point to talking more about how children can influence big science. I need to do a post about the event on my LJ, but have been too busy to get to it. Maybe this weekend.