Wednesday, April 28, 2010

My Lineage

Today I was rewriting a talk I've been giving lately about a peculiar class of planets known as "hot Jupiters": gas giant planets with period of only a few days. In past talks I would say that based on the example of our Solar System---with its giant planets in very wide, long-period orbits---"no one could have expected these hot, close-in Jupiters!"

Well, this isn't entirely true. There was a person who predicted the existence of hot Jupiters well before the first exoplanet was found around a normal star in 1995. I wanted to change my introduction to give proper credit where it is due, but I couldn't remember the intrepid astronomer who made this bold prediction. So I sent an email to Geoff Marcy:

On Apr 28, 2010, at 2:34 PM, John Johnson wrote:

Hi Geoff,

I recall you mentioning an old paper from the 60's in which the author noted that there was no reason not to expect Jupiters in few-day orbits. Can you point me to that paper or remind me of the author?




Geoff wrote back right away with the name, reference, and one other really cool bit of trivia:

Hi John,

In October 1952, the famous Berkeley professor, Otto Struve, published a paper, published in "The Observatory" about "high-precision stellar radial velocity work". At the top of the second page he wrote,

"But there seems to be no compelling reason why the hypothetical stellar planets should not, in some instances, be much closer to their parent star than is the case in the solar system. It would be of interest to test whether there are any such objects." In the next paragraph he explicitly computes the RV signal of a planet with a period of 1.0 day, predicting a reflex velocity of 0.2 km/s!

I've attached a scan of the article below. Note the quote at the top of the second page. Also note that at the end it is signed, "Berkeley Astronomical Department, University of California, 1952 July 24." Otto Struve was the mentor of George Herbig, who in turn was my mentor at UC Santa Cruz.

Thus, you are Otto Struve's great grandchild.



How cool is that?!

[Click images to enlarge to more readable versions:]

While I was at Hawaii, I got to "talk shop" with George Herbig frequently, and he gave me a lot of good advice while I was a postdoc there. He is 90 years old, works every single day, and always has data on his computer screen. One of my favorite moments was sitting in the audience with George when a 19-year-old undergraduate student gave a talk about Herbig AeBe stars. He sat there with the slightest of grins on his face while the student talked on with apparently no idea that Dr. Herbig himself was right there in the room!

You've seen this right? Hubble Gotchu!

Man, I love being in a field of science that produces data that can get a late night show audience to cheer. It gives me that warm, well-funded feeling.

Sunday, April 25, 2010

The last thing I miss about Mac Mail

Gmail now has drag-drop email attachments (with Chrome and Firefox 3.6).

I am now fully converted...

So how was the TMT/Discover panel discussion?

Well, let's just say it went better than this panel discussion:

In The Know: Situation In Nigeria Seems Pretty Complex

Sunday, April 11, 2010

Friday, April 9, 2010

My academic big sister

Here's a video from last year's NSF, TMT & Discover panel, on the topic of "Mysteries of the Universe."

Mike Brown is one of my colleagues at Caltech, and his daughter is in Owen's class (the Beavers) at the Caltech Children's Center. The moderator Phil Plait is the author of a great blog called Bad Astronomy. I'm really looking forward to meeting him in person.

The woman with the awesome red socks is Debra Fischer, my friend, close collaborator and newly minted full professor of astrophysics at Yale (previously a prof. at San Francisco State). Debra and I are both former students of Geoff Marcy, so I consider her my academic big sister. She taught me how to use a telescope, plan an observing run, give a good science talk, and, most importantly, how to be a good scientist. I owe a great deal of my success to the lessons I learned from Debra late at night at Lick Observatory using the CAT to search for planets.

As if being a Yale professor isn't enough, she's also currently a Fellow at the Radcliffe Institute for Advanced Study, and was recently on the subject of the cover story in their magazine. You can read more about my big sis' and her search for planets around the Sun's closest neighbors here:

Thursday, April 8, 2010

Timescales and aliens

This morning I had a teleconference with the good folks running the upcoming Discover Magazine/TMT discussion panel (see the flyer in the last post). After going over the details about the format and subject matter, I'm really excited. It's going to be a lot of fun answering questions from the public about exoplanets and the prospects of finding another Earth around a star other than our own.

The discussion this morning, and the webcast of last year's event, got me thinking about what types of questions I'll likely hear. One question that I think I can count on is, "Do you think there is life out there?" This question was asked in at least two forms in last year's panel discussion, and the subject matter wasn't focused exclusively on Earth-like planets like it will be this year. And when people find out that I study exoplanets, this is usually one of their first questions.

My answer is usually in two parts. First, yes, I believe there is life out there. This belief is based on the relative ease and speed with which life sprang up here on Earth. Indeed, the more places we look for life on Earth, the more it is becoming clear that life doesn't have overly stringent requirements. Given a decent energy source, life seems to happen quite readily.

One example was recently in the news. Researchers drilling beneath the Polar ice cap were surprised to find a 3-inch long shrimp hanging out 600 feet below the ice and 12 miles away from open water. The shrimp seemed quite happy in its cold, dark environment. What is especially striking is that the researchers weren't looking for life, yet there it was. And the life form was macroscopic, implying there was ample food for it down there, which probably means tons of additional, smaller lifeforms down where no one expected it. Life has been found deep underground, thriving around volcanic vents at the bottom of the ocean, and nearly anywhere else you can think to look. Why not beneath the ice on Europa, or on the shores of the methane seas on Titan, or on a blue planet orbiting another G-type star?

The second part of my answer to the question about extraterrestrial life is that, while I think there is life out there on other planets, I don't think it is very likely at all that there is intelligent life. And I suspect that this is what most people want to know about: where's ET? To understand why I think intelligent life is rare, you need to come to terms with the extreme age of the Earth, and how recently intelligent life came onto the scene.

The best way to think about geological (and astronomical) time scales is to imagine a time-lapse movie of the Earth's history, played back such that the whole movie takes only 24 hours. Here's the Earth's history on a 24-hour clock (midnight straight up, noon straight down):

If we start the movie at midnight, we wouldn't see any life until about 3am, when the first single-cell organisms show up. Then you have to wait another 12 hours until the first multi-cell organisms start swimming around. Land dwelling planets appear at around 9:20PM. Dinosaurs arrive on the scene at 10:45PM!

The first human-like apes join the party extremely late, knocking at the door at 11:57PM. Homo sapiens wake up at 23:59:56.9PM. The first known civilization starts up at 23:59:59.9PM. Finally, the Industrial Revolution fires up 1 millisecond before midnight.

So, if an alien living on Earth II orbiting Alpha Centauri A picked a random time in the Earth's history to start searching for life, it wouldn't be very likely that the alien would pick a time when humans are doing their thing--all broadcasting radio waves, blasting off into space, altering the atmosphere. Similarly, it's not very likely that we'll find an Earth-like planet with intelligent beings waving back at us (under the assumption that intelligent life unfolds elsewhere at the same rate it does here on Earth).

However, just because something is unlikely doesn't mean we shouldn't look around. There are about 300 billion stars in the Galaxy, and in the Solar neighborhood alone about 20% have planets of some sort or another.

So where's ET? Stay tuned. The Kepler Mission will likely find the first habitable Earth sometime in the next 2-3 years. SETI is diligently scanning the skies, looking for radio waves and laser pulses carrying messages from a distant civilization--all with the desktop computers of ordinary Earthlings. And my collaborators and I are about to submit a proposal to the National Science Foundation for funding that would help us build the next generation Earth-hunting instruments. If life is out there, we intend to find where it lives, and soon!

Upcoming Event!

Click for a larger view.

Wednesday, April 7, 2010

easter 2010 & the weirdest day ever

we did a little easter egg dying last week and i learned how much better it is to make your own dye using vinegar, hot water and food coloring. those little dissolving tablets they sell just don't even come close!

also, it was so fun to have the johnson cousins over for some easter egg hunting action. aren't the facial expressions are priceless in these group shots? they were all so annoyed with the photo session because it was keeping them from stuffing their faces with candy!

we had an amazing day last sunday at hermosa beach. shockingly enough, this was our first beach trip since the move last august. it was mighty windy and chilly, especially compared to our beach trips past. but, the chilly weather gave us plenty of time for beach football and a nice stroll up the strand so i could look into the windows of all the schmancy beachfront homes :)

about halfway into our visit & seeing other kids splashing in the waves, owen decided he wanted to get in the water. he had fun dipping his feet in, but soon found himself declaring "this is the weirdest day ever! beaches are not supposed to be so cold!" mar made the most of the day by devouring an entire bag of honey pretzel sticks and snuggling close to mama.

My professorship at Hogwarts

TO: Faculty

FROM: Dean of Students

DATE: April 7, 2010

SUBJECT: Senior Ditch Day 2010

As it has every year since 1921, Senior Ditch Day will take place sometime this term. Ditch Day is officially recognized as a holiday by the faculty (see the Faculty Handbook, Chapter 9, page 6), but the date is kept secret by the seniors. With great care and ingenuity, the seniors set up systems of puzzles and tasks, known as "stacks", for the underclassmen to work on. Stacks take a variety of forms, and many provide themed t-shirts to the undergraduate participants.

It has been customary for instructors to make allowances for the fact that not only seniors, but all undergraduates can be expected to devote the entire day to some creative and often bizarre enterprises. Because Ditch Day can fall on any day of the week, I encourage you to plan your courses so that one lecture may be missed or rescheduled. Please postpone the due dates for work originally due on Ditch Day for the day after. In addition, since underclass students do not know when Ditch Day is, it is reasonable to give these students an extra day to complete assignments that were due on the day after Ditch day. All students should also have the opportunity to make up labs.

If you ask seniors when Ditch Day will be, they always answer "tomorrow." Caltech is proud of the ingenuity often shown by our students in carrying this tradition and hope that you will join in participating, at least as a spectator. Faculty are welcome to take an informal tour of the houses on Ditch Day.

Thanks for your support of this activity.

Scum River Bridge

Astoria Scum River Bridge from Jason Eppink on Vimeo.

h/t Andrew Sullivan, as usual :)

Friday, April 2, 2010

Computer issues

Also, I think the new xkcd interface was an April Fool's joke, but it remains pretty awes:

Up-arrow works!

h/t Kelle

Sean responds, Sam counters, Sean doubles down

Fellow Caltech scientist Sean Carroll over at Cosmic Variance disputes the notion of the objective morality advocated by Sam Harris in his TED talk. Sam explains position in greater detail. Sean is not impressed. Meanwhile, I wonder how they get any work done...while I spend my afternoon reading their posts...

Now what was I doing? Ah, yes, SCIENCE!

Oh, she'll know what to do with the internets...

...if she knows what's good for her

From Andrew Sullivan, as with about half of the cool things I read about these days.

Thursday, April 1, 2010

More on Moral Browsing

I'm very excited by the huge turn out in the comments section after my recent post on the subject of morality. Thanks to everyone who participated in the discussion.

I wanted to highlight two links people shared in the comments section. The first is to a post by a former atheist who turned to Christianity named Jennifer, from her blog Conversion Diary (hat-tip to Blissful_e). A couple of quotes:
As I studied Christianity, I found that this religion claimed to offer objective truth about life and the world, including matters of what is right and what is wrong.
Without God -- or, to phrase it another way, without objective truth -- we are sailors without a compass, trying to rely on gut instinct to navigate troubled waters.
Andrew Howard shared a related link to a recent TED talk by author Sam Harris (It's 20 minutes long, but it's much better than what's on TV right now, I guarantee you!). I include a few key quotes after the embedded video.

Now, it's often said that science can not give us a foundation for morality and human values because science deals with facts. And facts and values seem to belong to different spheres. It's often thought that there is no description of the way the world is that can tell us how the world ought to be. But I think this is quite clearly untrue. Values are a certain kind of fact. They are facts about the well-being of conscious creatures.
It's interesting that the Christian blogger and scientific skeptic agree on one point: There are objective facts about morality. Where they differ is in what/who they see as the source of these objective facts. Jennifer sees her god as the source of truth. Sam believes that we humans can work out these truths for ourselves, without the help of a god.

It's probably not surprising that my personal beliefs are closer aligned with those of Sam. I believe in my own ability to seek out the answers to the questions of morality. Furthermore, I strongly disagree with Jennifer's assertion that her god is the (only) source of truths relating to morality. I don't go so far as to think that my own belief system is necessarily the only way or the best way. And I certainly don't think my moral code is either novel or foolproof. But I do strongly believe that the way in which I have built my moral code is inescapable and universal: We all have to browse around for morals that fit and discard those that don't (I was going to say that we're all moral hermit crabs, but I thought that would be too silly :)). Both Jennifer and Sam have to do this on a daily basis, no matter how dogmatically they hold to their faith or lack thereof.

I'm going to think more on the similarities and contrasts between the two points of view presented above and I hope to come back soon with a longer post. In the mean time, let me know what you think of the two views.