Friday, September 28, 2007
Tuesday, September 25, 2007
This weekend, while the Professor was mourning the apparent desire of Penn State's offense to spot Michigan 14 points, summer officially came to an end in the northern hemisphere. As seen from the Earth, the sun moved south of the equator, heralding the start of autumn and the bleak winter now only 13 weeks away.
You probably have noticed the days getting shorter. It is now dark when my alarm clock goes off, and the sun is setting as I head home; it seems just a few weeks ago that the sun was high in the sky when I awoke and light until late at night.
Many people who get interested in astronomy think that they need to buy a big telescope and then try and find extremely faint objects, then they get disappointed when they can't. It would be like an average person deciding to take up jogging as a hobby and being disappointed at not being able to run a marathon on their first time jogging, or someone who takes up carpentry and tries to build a house as a first project. Such an approach to amateur astronomy is only bound to lead to frustration.
But this is a great time of year to begin the hobby of astronomy. If you happen to wake up before sunrise or are getting home right about sunset, pay attention to where on the horizon the sun is rising or setting. Then, a couple days later, stand at the same spot and watch again. I bet you will be shocked to see how much the sun's rising or setting point has moved.
Since many of us are now still active when it is getting dark, it's also a great time to pay attention to the moon. In the next few days, a nearly-full moon will be rising just about sunset. If you just spend a few minutes over a few days, pay attention to the phase of the moon -- can you see the moon's phase start to wane from completely full on Wednesday night to more partial phases over the weekend. You'll also be able to notice that the moon is rising a little later each night (by about 30 minutes to an hour). And, if you pay attention to the stars around the moon, you'll easily see that the moon moves a large distance relative to the stars in just one day's time.
Ten years ago, I lived in Munich, Germany for a year and had an apartment that looked west across the city. Because of this, I had a great view of sunset every night. And although I was studying astronomy, I was amazed at how much the sun's setting point moved from one day to the next. It was not a subtle effect -- the sun would change its setting point by more than its own diameter, especially around the beginning of fall and the beginning of spring.
By watching this motion, I for once felt more connected to the larger Universe around me -- I was able to experience Earth's motion around the sun and the changing of the seasons without needing to stare at a computer screen or thinking very hard about orbital physics. The evidence was right there in front of me, very plain to see.
I think that, in our modern technological world, we often lose sight of the big picture. Clocks, cars, and computers dominate our lives, and the seasons only serve to tell us what to wear and, maybe, that the peaches in the supermarket came from our own state instead of being shipped in from Central America. Just a few minutes a day of looking at the sun, moon and stars, and even those of us with minimal astronomy knowledge can begin to see the daily, monthly, and yearly dance of the Earth, moon and sun, and begin to reconnect us with something a bit larger than ourselves.
Monday, September 24, 2007
Universities love press releases. Any news story containing the name of an institution that gets even the least bit of (positive) media attention is highly prized by university public outreach departments. And if that story is sure to grasp media headlines (something like "Broccoli Found to Increase Cancer Risk," "Pretzels: Solution to World Hunger?" or "Newly Discovered Poisonous Sludge Worm Named After Famous Politician," to make up a few) will have the university PR folks banging down an office door. Press coverage means increased prestige which means increased money.
In an environment like this, shakey or bad science is often presented as proven fact because a paper is published on it. For this reason, many scientists naturally shy away from press releases.
It also doesn't help that the press often garbles the science. I remember reading an article several years ago that claimed a newly-discovered planet outside our Solar System was "45 million light-years away." That would be an astounding feat, as 45 million light years would put the planet well outside our local neighborhood of galaxies! The true number was 45 light years, which puts the new planet around a nearby star in our own Milky Way galaxy.
Yet press releases are important, because they are one of the few means to get new science in the public eye. We astronomers want you to know what we are up to, and what cool things we are finding across the Universe. But, often, what we announce in a press release is later found to be slightly (or greatly) incorrect. That is science. We can observe the universe and try and describe what we are seeing, only to later find that we mis-interpreted things. Or we make predictions based on a new theory, and those predictions are found to be wrong. And, sometimes we are right. But often we don't know for certain that we are right until many years down the road, and we want you to share in our excitement now.
I was thinking about these things this weekend when I read a couple of news stories on new science coming out of Mars. The first story talks about how Mars may not have as much water as we thought. But, wait, didn't we just read stories about Mars having LOTS of water? This is a story that, every few months, you see a new headline. Some scientists think Mars has a lot of water hidden under its surface, others disagree strongly. But, since we are talking about Mars and possible life on Mars, the PR firms are out in force, pushing scientists to make press releases on tentative evidence. And so, you get conflicting pictures in the press. The long and short of the story is this: there are features on Mars that some scientists think were caused by water and others think could have been caused by other things. Until we get a probe on the ground near these areas and find (or don't find) large lakes of ice under the surface, this controversy will rage on. So, the next time you see a headline about water (or lack thereof) on Mars, take it with a grain of salt.
The other story was about possible caves on Mars discovered from new pictures. And you may remember a similar story coming out several months ago on Martian caves being discovered (somewhere else). What is new about this story? Not too much -- more caves, and some discoveries on the temperatures of the caves (the temps are found to vary a lot, unlike caves on Earth). But, since caves might hold Martian life, it makes a good story! So, even though a similar story has been released previously, this one gets out, too.
The point of this is not to disparage the scientists working on these questions. Their work is important, and they want to share what they are doing. But once their science gets through the hype of public relations, the true new science is often the first casualty of the story. So, when you hear about a new scientific discovery on the news, whether in astronomy, physics, biology, or any other science, be a little sceptical. In time, the science may or may not hold up to scrutiny. This isn't to say you shouldn't believe a word of what you hear, but try to ferret out the grains of truth from the oceans of hype. It's not an easy task to do that, but that's one reason I'm here!
Friday, September 21, 2007
I survived my trip to the East Coast to serve on the telescope time allocation committee. It was a surprisingly interesting meeting, though exhausting. But I learned a lot about areas of astronomy where I knew little before, I learned a lot about the entire process of proposing to use telescopes, and I even saw some friends I hadn't seen for a long time.
As I said before, I can't talk very much about what happened. All of my notes and copies of proposals were left behind to be destroyed; all proposed ideas are secret, as are the titles of the proposals and even the other people on the review panel. So, there's not much I can say.
But I can report that I am happy with the professional way in which the entire job is handled. Often, scientists get accused of not even listening to ideas that differ from their own, yet I saw nothing approaching that at this meeting. If we were good friends, co-workers, or die-hard enemies of the author of a proposal, we had to leave the room while it was discussed. That way nobody would even be tempted (or unwittingly) prop up a mediocre proposal or to shoot down an otherwise good proposal.
The only bad thing about the week (and it didn't impact us, just the organizers), was how many astronomers were asked to attend and refused to do so. Sitting on these panels is a bit like jury duty -- it is a community responsibility, but few people really like to do it. Four days of my time went into this (two for travel), and none of my other work got done during that time. Many of those asked are probably legitimately busy -- teaching classes they can't get out of, or at the telescope, or at workshops. But many don't want to do the work, because it can be tedious, boring, and it takes time that could be put to more interesting uses. But, all in all, I had a very good experience. Would I do it again? Almost certainly. But I won't make panel reviews my career.
Monday, September 17, 2007
This morning, I'm sitting at the Austin airport, off to the Time Allocation Committee meeting I've been asked to participate in. For the next two days, I'll be sitting in a room with 5 or 6 other people, trying to decide whose projects are worthy of telescope time and whose miss the cut. As I've been reading, some projects seem pretty obviously good or bad; it's the big middle that will be hard.
Unfortunately, I won't be able to say much more than generic comments about it. I've had to sign various nondisclosure agreements (NASA's legal staff), but, even outside of that, it is considered bad form to talk too much. If other scientists hear the ideas that are being proposed, they may try and steal somebody else's project (usually it would not be purposeful; someone might say, "oh, that's a good idea, I could do that," and then go off and do it before the original scientist could.
In other news, if you didn't hear, as part of their Lunar X Prize, Google is letting members of the public submit electronic photos and messages that, for a $10 fee, will be carried to the moon by robots that will be landing on the moon. These photos will be in electronic form, and presumably the money is going to help fund the lunar prize purse. If you are interested in reading more, here is the Lunar Legacy website with details on the program. I'm not sure yet if I will participate in this or not; I have a feeling that I would be the only person ever to see the photo I would submit to go to the moon. But, as you might be interested in such a thing, I though I'd mention it.
Friday, September 14, 2007
A few days ago, a colleague and I were working on some data we had published in a paper several months ago. But something wasn't adding up right. After some research, I found that I had made a mistake in analyzing the original data -- in matching two sets of data on the same galaxies, things got shuffled. Luckily, it only affected one of the twelve objects we were looking at, but it also meant that one group of galaxies we claimed to have discovered actually doesn't exist. Oops.
We find small errors in our work all the time. Most typos are just allowed to exist -- they don't hurt anybody. But if a typo messes up an equation, or if the publisher mixes up the figures, or if we claim to find something that doesn't exist, we have to do something about it.
For this case, I wrote a short article called an "erratum." This article just says that we made a mistake, details what the mistake was, and what changes need to be made to the conclusions because of the mistake. Thankfully, although my mistake was, in some ways, a pretty dumb one, it didn't change our conclusions much. In short, an erratum says, "Oops -- we messed up, here's the right answer."
If my mistake had been much more serious (like it had affected all twelve of the objects we talked about in our original paper), an erratum would not be enough. In a case like that, we would need to print a retraction, a short blurb saying, "Completely ignore this paper, we screwed up big time." Retractions look bad, but they do happen.
Admitting mistakes is an important part of science, as I discussed a few entries ago. Everyone makes mistakes, even in science. And, hopefully, people will forgive me for messing up here. You can bet I will be a bit more careful in the future to avoid the stupid error!
Wednesday, September 12, 2007
Early this morning, I was taking my sister to the airport, and I noticed the planet Venus up pretty high in the pre-dawn sky. I was a little surprised by this, since the planet Venus was high in the evening sky just a couple months ago.
I should not have been surprised. First, all the stars appear to move from the evening sky to the morning sky, though takes place on longer timescales (a few months). And, while I'm often up and peering at the evening sky, I rarely am awake enough to see the dawn sky (unless I'm at the telescope).
But Venus's rapid appearance in the morning sky is also due to Venus's orbit in the Solar System. Venus is closer to the sun than the Earth, so it moves faster than the Earth due to a stronger pull of gravity. It also has a smaller orbit, and so can get around that much faster.
When we see in the evening sky, it is getting ready to pass the Earth. As it catches up to the Earth, Venus seems to hang lazily in the evening sky, but really it is hurtling closer to us, preparing to pass on the inside curve. When it gets close to Earth, it appears to zoom past, quickly moving from the evening to the morning, and then it hangs lazily in the morning sky as it races away from us. It is much like watching a faster car come up on you on the interstate. In your rearview mirror (which is our evening sky), you see the car coming -- you can see it getting bigger (as you could with Venus if you used a telescope), but the car appears to remain in about the same place in your mirror until it gets close. Then the car zips by, appears out your front windshield, and pulls away, all the while appearing smaller, but not changing position much. Likewise with Venus -- once it is in the morning sky, if you watch it with a telescope, it will rapidly decrease in size, although it appears to hang in about the same spot in the sky. So, as the nights are getting longer, if you happen to get up before sunrise, look toward the east. That bright "star" you will see there for the rest of the year is the planet Venus, leaving the Earth yet another lap behind in our race around the sun.
But don't worry about getting lapped by our sister planet. In December, we'll pass inside of Mars, and any Martians will just have to watch us pass them by.
Thursday, September 06, 2007
Let's start with a review of what I'm going to call idealized science. In an idealized science, a scientist (call him Alfred) develops a hypothesis (say that the mass of a certain type of star should be 1.5 times the mass of the sun). Alfred then devises an experiment to measure the mass of the star, and he measures that the star is indeed 1.5 times the mass of the sun. Alfred then writes a paper detailing his hypothesis, his experiment, and his results confirming his hypothesis. Now, scientists Betty, Charlie, and Dana read Alfred's paper. They check his work by repeating Alfred's experiment, and they get the same answer. Maybe Dana has another experiment that can also determine the mass of the star. She runs that experiment and gets 1.5 times the mass of the sun. Alfred's experiment is confirmed, and his idea gets credit. (Or, perhaps on repeating his experiment, Betty, Charlie and Dana all measure 1.1 times the mass of the sun; this would suggest Alfred made an error. Or maybe they all get Alfred's measurement using his experiment, but Dana's second experiment gets a different answer; this would suggest that further investigation needs to be done.)
In idealized science, it doesn't matter whether Alfred is famous or unknown, young or old, a student or a professor. And, if Alfred then goes to work on a different hypothesis, his success or failure on this first hypothesis doesn't matter -- the new result should stand on its own.
Now, in real life, this is not what happens; let's look at what I'll call real science. In real science, the same basic method as above is followed. I'll outline a few scenarios and mention what I suspect would happen.
- In the first scenario, Alfred makes a mistake (maybe he errs in a math calculation). Alfred's mistake is uncovered by Betty, Charlie and Dana. He publishes a retraction or an "erratum" admitting his mistake. When he does another experiment later, Alfred's second (and third and fourth) experiments are confirmed by further testing. In this scenario, most people will forgive Alfred's first error. When Alfred does a fifth experiment, most scientists will tend to believe the results, because Alfred has been right quite often. Yes, the results should be (and probably will be) checked, but many people will believe him before further testing, since Alfred is such a careful scientist.
- In a second scenario, Alfred is just a sloppy guy, and makes mistakes in several different experiments. Later experiments show Alfred made errors, Alfred admits to the errors, but he continues to be sloppy. When Alfred does later experiments, other scientists will be very sceptical at first. Yes, later testing may prove Alfred right, but until that testing is done, few will believe Alfred.
- In a third scenario, Alfred is a new scientist, and Dana is a well-respected scientist people tend to believe. If Dana contradicts Alfred, Alfred's results are in trouble, even if it is Dana who made the mistake. Alfred can still be vindicated, but he will have to do a lot of work to show why Dana is wrong to criticize Alfred. This is a very tricky scenario. If Alfred's work is actually wrong yet he insists that he is right, his reputation will suffer. If Alfred is right but, in proving Dana wrong makes her angry (maybe by a poor choice of words in a paper), Alfred is not helping himself, and his future work will be viewed with scepticism.
I can think of many other scenarios in real science -- maybe Charlie and Alfred had an argument long ago and Charlie tries to sabotage Alfred's career by spreading rumors that Alfred's work isn't reliable. Maybe Alfred is making up his data to bolster his points. In all of these scenarios, there are two major differences from idealized science. First, people are involved, meaning that human error and emotions play a role, even if unconsciously. Second, scientists in real science have memories. They use past performance to gauge future success.
And I think that real science has advantages and disadvantages when compared to idealized science. That memory factor is both an advantage and disadvantage. I I know that Alfred is constantly sloppy or occasionally invents data, then I have every reason to be wary of his new work. If Alfred is not acting in the good faith that idealized science requires, then it is wasteful of time and resources to be constantly following up his shoddy work. And if Alfred is a tremendously careful scientist, then it is wasteful of time and resources for many people to be checking on every detail of his every experiment (assuming, of course, that these are not situations of life and death). If the careful Alfred does make a mistake, it likely will be caught, maybe even by Alfred himself. And if the sloppy Alfred does happen to produce some good work, then the fact that others may disbelieve it is a result of Alfred's own actions, not necessarily bad science on the part of other people.
My opinion is that we cannot (and should not) remove the human element from real science. When awarding resources (such as telescope time), people who do careful research and important research should get those resources; sloppy researchers should not. Maybe the sloppy researchers can do good work if given resources, but if they don't have a good track record, then it is reasonable to expect that they will not suddenly reform. So, in short, I don't think we can and should neglect a person's record when considering new ideas from them.
Real science does have drawbacks. Like everyone, scientists have friends and enemies, hold grudges, and have things they feel passionate about and things they find boring. These human traits do work their way into science, into how resources and money are allocated, into whether somebody's work is believed or rejected. And that is very non-scientific and can be counter-productive. But then, competition spurs people to work harder, and friends help each other out on tricky problems. So, like in the non-scientific world, society has advantages and disadvantages.
In short, scientists do have memories and biases. These biases can be both good and bad in the cause of advancing science. It would be great to minimize the bad biases, and, in theory, to dispose of all biases. But as long as people are involved in science, these biases will undoubtedly be present.
Tuesday, September 04, 2007
Astronomers are not just freely given nights at a telescope or time on orbiting satellites. There is a well-defined process to getting this time. It starts by the astronomer developing a project to do on the telescope. Then she/he writes the project down in a few-page summary we call a proposal.
The proposals from all astronomers interested in using a telescope in a given time period (usually 6 months or a year are dealt with at a time) are collected and given to a committee, the Time Allocation Committee, or TAC. This committee is made of astronomers who are familiar with either the science and/or the telescope in the proposal. The committee reads all of the proposals, talks about how important the science is, whether the science can be done on a given telescope, and whether a project represents the best use of a given telescope.
For example, one proposal may have the best science, but is not technologically feasible. Another proposal may be good science but requires 95% of the telescope for the next year. Another proposal may be okay science but could be done with a smaller telescope. And another proposal may be poorly written. So time goes to the remaining dozen proposals that do reasonable science in a reasonable amount of time.
I've been asked to be a member on a TAC that meets later this month. I have a few dozen proposals I need to read through, and a handful that I need to read in detail so I can lead the discussion about those particular proposals. The assignments (which proposals I have to read and which ones I have to lead discussion on) were made by other people, so I have a wide mix of things to read, some of which I know a lot about, some of which I don't know much about. And I will get to spend two full days talking about all of these proposals with the rest of the committee, which doesn't sound like a lot of fun. But it is an vital bit of community service, so I'm willing to do my share.
This is the first time I've been on a TAC, so it is a bit nerve-wracking. I want to make sure to do all the preparations I need to and make sure I give each proposal the consideration it deserves. At least it will keep me out of trouble for the next few weeks!