- Vote on Hubble's Next Target! Normally, astronomers get to choose where to point the Hubble Space Telescope. It's a long, difficult, frustrating process, but it does insure that the best science gets done. Alas, that best science doesn't always result in the prettiest pictures. For that reason, for the last decade the Hubble Heritage project has used Hubble to take pretty pictures of some of the most photogenic planets, stars, nebulae, and galaxies in the sky. And these pictures are not just pretty, but they've been used for some groundbreaking science, too! Now, NASA is asking for your opinion on which object Hubble should target next. Go here to learn more and register your vote! You might even win a prize.
- Global warming that puts our puny human efforts to shame. Astronomers looking at a known planet around another star were able to see the planet warm up from 1000 degrees Fahrenheit to 2200 degrees Fahrenheit in just 6 hours. The planet, about 4.5 times the mass of Jupiter, has a very elliptical orbit around its parent star, going from a distance of about 85 million miles to just a couple million miles above its parent star and back again every 111 days. The press release has a link to a movie of a computer simulation of the planet heating up.
- Mars Spirit Rover is acting weird. NASA's Spirit Rover, which has been exploring Mars's Gusev Crater for just over five years, has been acting funny for the last couple of days. Diagnostics are ongoing, and this probably doesn't mean the end of the line for Spirit. If you watch documentaries on the Mars rovers, Spirit has always been the problem child, but she has always come through. Some day, alas, we will lose both rovers.
Thursday, January 29, 2009
Image Credit: IAU / IYA 2009
The Galileoscope is an inexpensive (I believe $15) kit that allows people to build their own telescopes of the same size as Galileo's pioneering telescope. But it is better than Galileo's version, because it uses modern optical components. With the telescope, you can see Jupiter's moons, Saturn's rings, mountains and craters on the moon, the phases of Venus, and even many extra stars in some star clusters like the Pleiades or the Beehive. These were all major discoveries that Galileo made 400 years ago. One of my colleagues was able to look through a Galileoscope last week, and said that the quality is amazing, especially considering the small size and small price of each kit.
Anyone will be able to buy the kit, but it is really ideal for educators. With the inexpensive cost and the build-it-yourself nature of the kit, we hope that teachers at all grade levels will be able to buy one or more kits for their science classes. Some tested Galileo-oriented teaching activities will be available, that not only allow students to learn about optics and astronomy, but also fulfill many other state-mandated science teaching goals.
I think that efforts will be made to try and provide some financial assistance for needy classrooms, both in the U.S. and abroad. You should contact the Galileoscope project to get further information.
And, if you don't want or need a Galileoscope of your own, but would like to help this project and other astronomy outreach projects of the International Year of Astronomy, please consider donating a little money. Budgets are tight, and our goal as astronomers is to get every human on the Earth to think about astronomy at least once this year!
Finally, if you'd like to use the Galileoscope with your classes to look at the phases of Venus, be sure to order one soon. Venus will be visible in the early evening sky only until about the start of April. From May through the rest of the 2009, Venus will be up only in the pre-dawn sky (good luck at trying to get school children out of bed early for that!)
Wednesday, January 28, 2009
Image Credit: NASA
This morning dawned cold and icy here in Austin, TX. As I drove to the commuter Park and Ride, I was tailgated by a driver who was talking on a cell phone and swerving back and forth within the lane, seemingly oblivious to the numerous shiny icy patches that were covering the roadway. Thankfully, I only had to go a mile to the bus depot; hopefully the careless driver did not cause any accidents on the rest of her commute.
23 years ago today, January 28, 1986, was another cold, icy morning in the southern US. I lived in Pennsylvania at the time and had a snow day home from school. There was supposed to be a space shuttle launch that morning, and I was nuts about space travel at the time. But I spent the morning sledding in the backyard.
At Kennedy Space Center, the ice and cold worried numerous engineers, but those worries were not communicated to the people at mission control who made the final launch decision. The results were disastrous, resulting in the loss of seven lives.
Back up north, I was getting ready to have some lunch when the phone rang. My mom was calling from her office to tell me that she heard something on the radio about the space shuttle landing in the Atlantic. It was only then that I turned on the TV to learn what had transpired, and it was hours before I could pull myself away from the coverage. All these years later, my memories of that day are still vivid and clear.
For information, pictures, video, and numerous reports on the Challenger accident, poke around on NASA's history site.
Tuesday, January 27, 2009
Image Credits: Sony Pictures Home Entertainment / Wikipedia
(This post is not in response to any particular news story, but the rant has been building up for a while.)
Metaphors are a powerful figure of speech, and are quite common in the English language. Metaphors are quite useful in astronomy, because of their ability to link abstract or difficult astronomical discoveries and theories to everyday occurrences that most people can understand. I use metaphors and analogies quite a lot, as anyone who has read many of my postings knows. So, in general, I have no problem with the use of metaphoric imagery in the dissemination of astronomical news.
But there are a handful of often-inappropriate metaphors that continually pop up in astronomical news. Most often I see these in press releases, which often means that the press, and not the astronomers, are the guilty party. But I've seen them in published professional papers, too, where the astronomers definitely are at fault. Most likely, I've used these metaphors myself from time to time. Yet now I think it is time to stop, because these metaphors are overused and misused. Here's my current list of metaphorical pet peeves:
- Holy Grail: When an important discovery is made (or is thought to have been made), it will often be called a "Holy Grail." Various Holy Grails have been found or searched for over the years, including the Cosmic Microwave Background, variations in the Cosmic Microwave Background, extrasolar planets, smaller extrasolar planets, pictures of extrasolar planets, etc. An irreverent discussion of Holy Grails in astronomy can be found here. Nonetheless, the "real" Holy Grail is a mythical object that nonetheless has been hunted relentlessly by many people for millennia, to no avail (claims by by Henry Jones, Jr., notwithstanding). So, properly, an astronomical Holy Grail would be a discovery that (a) will never happen, because it is mythical, and (b) will nonetheless consume many people's careers. Frankly, I don't want any of my research to fall into that category.
- Rosetta Stone: The real Rosetta Stone is a portion of a priestly decree written in three languages: Egyptian hieroglyphics, Demotic (another Egyptian language), and Ancient Greek. Since the same thing is written three times, this stone permitted the translation of ancient Egyptian hieroglyphics. So, metaphorically, any discovery that allows us to understand an otherwise completely mysterious thing could be called a "Rosetta Stone." But all too often it is used to describe discoveries that are just another piece of the puzzle (to use another metaphor).
An example: For three decades, the causes of gamma ray bursts were unknown, though many theories existed. In 1998, a supernova in a nearby galaxy coincided with a gamma ray burst in the same direction. This was truly a Rosetta Stone that allowed us to finally understand many of the gamma ray bursts. Five years later, another gamma ray burst was anointed the "Rosetta Stone" for the same finding. Granted, the later burst was very important for further confirming the hypothesis of the connection between gamma ray bursts and the deaths of massive stars, and it was an important finding. But I'd hesitate to call it the Rosetta Stone.
I've also seen "Rosetta Stone" used to describe events that could also be (inappropriately) described as "Holy Grails," astronomical discoveries of important and rare objects. Just because something is rare or new or involved a lot of luck doesn't mean it is a Rosetta Stone or a Holy Grail!
- Smoking Gun: The term "smoking gun" is used to refer to a piece of evidence that is the conclusive proof of something. For example, the Smoking Gun Tape was a recording of Richard Nixon that proved that he was trying to cover up the Watergate scandal illegally. In astronomy, "smoking gun" often refers to discoveries that hint (or even strongly hint) at proof of a theory, but often these findings are still controversial. Just Google dark matter smoking gun and you'll get a list of lots of discoveries that were all claimed to be the smoking gun of dark matter.
I am pretty sure that dark matter exists. There's a ton of evidence for it. But none of those individual pieces of evidence is a "smoking gun." If the existence of dark matter were put up to a criminal trial, it would be a case relying on many pieces of strong circumstantial evidence, and the DA would get a conviction from an astronomical jury. But the true "smoking gun" for dark matter will be laboratory detection of dark matter particles. Only then will there be no room for doubt about its existence.
In short, I would claim that at least 75% of astronomy articles claiming to have found either a "Holy Grail," "Rosetta Stone," or "Smoking Gun" have really found no such thing. So, if you are an astronomer, please don't use these terms unless you are certain that you're using the metaphor properly! If you ever see me using one of these terms from now on, please stop by my office and beat me silly with a copy of Strunk and White. And, if you are reading an article and come across one of these terms, just mentally replace it with "really neat discovery." Most of the time, you won't be losing any real meaning.
Monday, January 26, 2009
Image Credit: Pew Research Center
Due to the poor economy, this year is turning out to be a very tough year for those of us who want to find faculty positions. With a lot of states suffering from large budget deficits and a lot of endowments (donated money that has been invested, with the profits used to fund the school) having lost a large fraction of their values, many schools cannot afford to hire new faculty right now. Many other schools are worried that if they hire someone, budget cuts next year might lead to a need for pay cuts or layoffs, and so they are not hiring either. In short, there are fewer faculty jobs than normal being offered, and several jobs that were advertised have since been withdrawn.
For those of us hoping to get faculty jobs, the smaller number of them makes this year's hunt all the more nerve-wracking. And since many of the people in the faculty job market are my age, I know a lot of them. I don't imagine myself in competition with my friends and colleagues; I hope we all get good faculty jobs. But there are far more people on the market than there are faculty positions, which means that there will be some good astronomers who either have to wait or have to move to the private sector. And that is why many of us are nervously hanging on every rumor and nuance that comes down the pike.
P.S. If you look at the sun with a telescope like the observer in the cartoon above is, you'll never get a faculty job in astronomy. You'll also be lucky if you can still see anything.
A couple of weeks ago, I put up a new poll on the top right of this page. If you haven't already, feel free to vote! The poll was based on my musings in this post.
Also, due to a couple of minor recent incidents, I've made some minor changes to the comments policy. The policy used to say that I reserved the right to edit posts for clarity or to keep out questionable matters, but it turns out that Blogger won't let me edit comments. So I changed it to specify that I may delete comments that are far off-topic, rude, have foul language, or contain advertising (alas, I've had all of those in the past few weeks).
I also added a brief blurb mentioning that all comments on posts more than 7 days old are moderated, since about 80% of those comments are spam. So, feel free to comment on old posts, but please be patient when waiting for them to appear.
Wednesday, January 21, 2009
So, I asked my friend and colleague, Marcel Agüeros, to be a guest author. Marcel, in addition to astronomy research, works on diversity-related issues. Reading his post, I am all the happier that I didn't try and write anything myself. Here is Marcel's piece:
When I hear the word diversity...
When Kurtis asked me to blog about diversity, I'm guessing he thought I would write about how un-diverse our field is and go on to describe some of the programs I'm involved in that try to address this situation. When I agreed, I thought that's what I'd do too. But somewhere between thinking about MLK, Jr over the weekend and being swept up by inauguration energy my thoughts got more personal.
So, very briefly: Minority astronomers are a factor of 10 rarer in our profession than they are in society at large; every year, one African American receives a PhD in astronomy--nation-wide--and that number hasn't changed in 20 years. With a number of like-minded astronomers, some minority, many not, I've been working to change these facts. Programs I'm involved in or rooting for include: the Pre-Major in Astronomy Program at the University of Washington, the Fisk-Vanderbilt Masters-PhD Bridge Program, and Columbia's new Bridge to Ph.D. Program in the Natural Sciences, of which I am the Associate Director.
Now, what I decided to talk about...
When I hear the word diversity, I think of my dad. Papi is 74 now, but he looks a decade younger--not that it matters; he doesn't know how old he is anymore. He's in what I routinely describe as the middle stages of Alzheimer's disease, as though that's a clearly defined place. In his case this means that his short-term memory is mostly gone, although occasionally he'll surprise us with a joke that shows he's remembering something recent. Sadly, his longer-term memory is also evaporating--at least that part not dedicated to music or poetry.
Papi grew up in East Harlem, the only child of two lightly educated Puerto Ricans who came to New York separately at the tail end of the (last?) Great Depression. There was nothing in our family history that suggested he'd ever become an intellectual; if anything, Abuelo worried that his son's interest in books was going to turn him into a sissy. How he went from there to Brooklyn College, the first cohort of National Urban Fellows, the directorship of El Museo del Barrio for much of my childhood, and eventually to being a full-time poet/writer is a long story and not one that readers of an astronomy blog may care for...
...but I swear it's relevant. It's Papi's story that keeps me focused on my own work as an astronomer--and specifically as an astronomer working to increase the diversity of the field.
As a high school student, Papi did particularly well in Biology, and commuted for a while to Brooklyn Tech, one of NYC's traditional powerhouses. He hated it there and came back to the Barrio... and gave up on science until he more-or-less accidentally enlisted in the early 1950s in the Air Force (the most progressive of the four branches of the military at the time, not that he knew that), where he turned into a guided-missile instructor. The apocryphal story my mom tells is that when he was asked to reenlist he was told that if he did he would go to Florida to work on big rockets.
Instead, because he'd had enough of taking orders, he decided he wanted an engineering degree, and enrolled at Brooklyn College via the GI Bill and a graveyard shift at the General Post Office... In an English class taught by Prof. Bernard Grebanier--whose name he most certainly has not forgotten, forty years on--he fell in love with Shakespeare, and there went engineering.
So, the relevance?
One possible way of looking at Papi's life is that talent comes from unlikely places, may struggle to find its way, and will eventually end far from where anyone would have expected. There's nothing original about this narrative, of course; in one form or another it is the heart of the classic American tales we are familiar with... and which yesterday's inauguration only reinforces.
There is a less charitable view, of course, that points a finger at the systemic discrimination that has poisoned our society seemingly forever, and against which Papi and his generation fought tooth and nail--sometimes winning, often losing. I'm sure my father's regrets are not those that I have for him, but it seems to me that better opportunities and less time spent fighting would have made it easier for him to find his place, perhaps even in science.
Regardless, I was freer than he ever was to imagine a world beyond the confines of my own barrio--and even to come around (slowly) to the idea of being a professional astronomer, an improbable career for a kid born and raised in Manhattan. And, in gratitude, I try to make the improbable less so for others.
The very least I owe Papi is not to forget his history, even as he does.
Tuesday, January 20, 2009
Back when I was a kid, a gum company ran a successful series of ads, claiming that 4 out of 5 dentists recommended their brand of gum. The concept is that dentists are smart, caring people who should know if it is safe for your teeth to chew gum. And I think that most of us would agree that dentists are indeed very intelligent and know a lot about teeth and gums.
Now, suppose you go to your dentist, and she says there is a problem with a spot on your gums, perhaps due to an infection in a tooth, so she's referring you to an oral surgeon. You go to the oral surgeon, who says that the spot looks like cancer. The oral surgeon asks you if you chew tobacco, and you honestly reply that you do. The surgeon says that the cancer was probably caused by chewing tobacco, that he can do surgery that should get rid of the cancer, and that you need to stop chewing tobacco.
On hearing this bad news, you decide that you need a second opinion. After all, your dentist thought it was an infection. And, since you want a representative sample of oral surgeons, you ask another 99 opinions. In total, 97 of the 100 orals surgeons you go to say that you likely have cancer, and that it was likely caused by chewing tobacco.
Not satisfied, you go and get the opinion of 100 dentists. 90 of those 100 say, yes, you likely have cancer, and 82 of them think that chewing tobacco caused it. (That would be 4 out of 5 dentists, and remember how we always joked that there was something wrong with the fifth dentist?)
Next, you ask 100 dental hygienists about your problem. Most of them will claim they don't have the proper training, but if you force them to give an answer, 62 of them say that you could well have cancer, and that the tobacco caused it.
Lastly, you ask 100 Tobacco Institute scientists, and only 47 of them think that you have cancer that was caused by their product. (Still, that's more Tobacco Institute scientists who ever would have claimed that lung cancer was caused by smoking.)
So, now, who would you believe? Frankly, I'd go with the oral surgeons. Yes, everyone you've asked has had extensive training in teeth and gums and related diseases. Some (like the Tobacco Institute scientists) clearly have ulterior motives not to tell you the truth. Others, like the dental hygienists, certainly have lots of training and mean well, but oral cancer and the scientific evidence behind the causes are not the focus of that training. And if 97 of 100 oral surgeons said "You have cancer, and chewing tobacco caused it," would you believe them? I think most people, after some introspection, probably would. The consequences of not believing them are a matter of life and death.
So, that whole story was a hypothetical preparation for the real thing. A news story was released today that have the results of a survey asking several groups of people: Have global temperatures increased over pre-18th century averages? Is human activity a primary factor in that change? Let's look at the results:
- Among climatologists, scientists who actively study the climate through observations, theory, and computer models, 97% of them agree that temperatures are increasing, and that humans are the primary cause. 97%.
- Among scientists in general, 90% believe global warming is occurring, and 82% believe that humans are the primary cause ("4 out of 5 scientists agree...")
- In what surprised me at first, only 64% of meteorologists believe that humans are the primary cause of global warming. However, on further thought (and through prompting in the article), meteorologists are scientists whose job is to produce and convey short-term forecasts. Most meteorologists do not work daily in global climate studies. And the report on the study doesn't make it clear what constitutes a meteorologist; would a television weatherman count? Most TV weathermen are well-trained, but not all of them are, and many do not actively participate in ongoing scientific research (one thing I've learned in astronomy, is that not doing research in a specific area means that one quickly falls behind on the current state of the science).
- And, not surprisingly, only 47% of petroleum geologists (scientists who look for oil) believe in human-caused global warming. Many of these are paid by petroleum companies, and so have reasons not to believe in man-made global warming. Further, geologists typically get little training in climatology, and petroleum geologists certainly are not active researchers in climatology.
So, who are you going to believe? I defer to the climatologists. They are the most knowledgeable, are on the cutting edge of climate research, and they have no motive to misconstrue the data. And of that group, 97% believe that humans cause global warming. That's 97 out of every 100 climatologists, way beyond 4 out of 5. It's hard to get 97 out of 100 people to agree on what color a wall is painted or even what day of the week it is. But 97% of them are certain that the Earth is warming up and that humans are the primary cause of that warming.
So, the next time someone tells you that we don't even know if the Earth is warming, let alone why, remember that 97 out of every 100 trained climate researchers strongly disagree with both of those points. Ask yourself who is more likely to be right. The answer could have a profound impact on your life and the lives of your descendants. Me, I'm going to side with the climatologists.
Friday, January 16, 2009
Image Credit: Todd Carlson / Environmental Health Perspectives
Humans are primarily diurnal creatures. This means we like light. We wake up when the sun is up, we get tired and sleep when the sun has set. We feel groggy on gray days. We are afraid of the dark, often even when we know there is nothing to be worried about. We don't see as well in the dark as during the day.
Our preference for light is encoded in our genes. It's the result of millions of years of evolution. Our ancestors hunted and gathered by day. At night, they stayed huddled together, lest they be eaten by lions and tigers and bears (oh my!). So it is natural that, now that we have the power to make artificial light, we want to flood the places where we live with light. We feel safer. We can move about more freely and with less danger.
But now we are discovering that our proclivity to shine light into every dark corner is not necessarily a good thing. I don't have the space to illuminate (ha!) each of the following topics, but clicking on the links will give you further information:
- Much of our lighting (especially outdoor lighting) is wasteful.
- It uses a lot of energy.
- Half of the light goes out into space instead of down on the ground where we need it.
- Often the design is such that the lighting doesn't really help us see better.
- Excess lighting is bad for the environment
- Excess lighting is even bad for our health(!).
- Excess lighting prohibits us from seeing the wonders of the night sky
This is why excess lighting is often referred to as light pollution. It's wasteful, harmful, and it looks bad. Just look at the picture above, taken in Toronto during and after an electrical blackout.
The great thing is that we know how to fix all of these problems, and the cost isn't, umm, astronomical. Yes, we could just turn off all lights, but I realize that is a silly suggestion that will never happen. However, more reasonable solutions exist, including using more carefully-designed light fixtures, energy-efficient light bulbs, and turning lights off where they aren't needed. Most, if not all, costs of solving light pollution are recouped quickly through energy savings. The environmental benefits and renewed views of the sky from the cleaning up of light pollution are added bonuses.
As part of the International Year of Astronomy, we are sponsoring a Dark Skies Awareness campaign. We're not trying to get people to stop using lights; we're trying to get people to use lights more intelligently. It saves money, saves energy, helps the ecosystem, makes us healthier, and it re-opens the city skies to stargazing. Learn more here or from the International Dark Sky Association!
Wednesday, January 14, 2009
It's a well known law of research science, known as the "Professor Astronomy Law," that the last person to discover something new gets the credit. Today has seen two examples of that.
The first is from today's 365 Days of Astronomy podcast, which features the story of Thomas Harriot. Harriot was a British gentleman who lived in the early 1600s. New research works has shown that Harriot likely was the first person to make maps of the moon through a telescope, beating Galileo by at least a few months. Harriot didn't make a big deal out of his findings (the podcaster, Oxford historian of astronomy Allan Chapman, speculates that Harriot was well off and didn't want to get into any trouble), so Galileo gets the credit. And, most likely, other people also looked at the moon through the spyglasses around the same time as Galileo. But since Galileo was the most successful at publicizing his findings, he gets the credit.
The other story is much more modern. I was surprised to see a press release today claiming that astronomers have made the first ever ground-based detection of the atmosphere of an exoplanet (a planet around another star). It surprised me because Seth Redfield, one of my colleagues and friends, announced such a finding 13 months ago.
I don't know the astronomers involved in the more recent discovery, but they are quoted as saying "Others have tried to detect planetary atmospheres from Earth, but to no avail." Perhaps they were misquoted. Perhaps they weren't aware of Seth's work. Perhaps they don't believe his detection. It's hard to get scientific details from the press release, but I suspect that what this team (along with a Dutch team also mentioned in the same article) has done is to view the planet's atmosphere in infrared light, whereas Seth's team detected it in optical light. There is a lot more atmospheric work that can be done in the infrared than in the optical (molecules like carbon dioxide and water are common in the infrared), so this is an important find. But it's not the first detection of an exoplanet atmosphere from the ground.
This is a problem with press releases; sometimes the science gets garbled, sometimes claims are made that are not quite right. That's why we astronomers (and most scientists) prefer to use papers published in our official professional journals to findings announced in press releases. The journal articles are longer, more complete, and more technical. I haven't seen the paper on the new exoplanet find yet, but it should be out very soon, and I'll let you know what I find.
Update: As I kind of suspected, there was some subtle nuance to the wording of the press release that was lost in the Space.com article. Universe Today's article on the discovery gives the all-important nuanced wording: "For the first time, astronomers have measured light emitted from extrasolar planets around sun-like stars using ground-based telescopes." (emphasis mine). The two studies found infrared light emitted from the hot atmosphere of the planet, whereas Redfield's team measured light from the star absorbed by the planet. It's an important distinction, but in both Redfield's case and the newly-announced data, the teams are detecting the atmosphere of the planet.
Image Credit: United States European Command
I know nothing about General Gration other than what is stated in the article. It worries me somewhat (well, a fair amount) that he has very little prior experience with NASA, but that doesn't mean he is unqualified for the job, and he may well do a super job as NASA's chief administrator. The job is much more than just deciding whether we should go to the moon, send a robot to Mars, or build a new space telescope. It's a bureaucratically intensive position, with NASA centers spread across the nation, each with their own pieces of turf they like to defend. That requires skills no astronomy or aerospace engineering course will ever teach someone.
Perhaps I should be more concerned, but at the moment, I think the government's hands are full with economic, political, and international crises. So far (as evidenced by his campaign), Obama and his advisers have done a pretty good job of filling positions with excellent people, so I'm going to trust their judgement. Time will tell if this is a good choice.
In spite of the flack he's taken, I'd like to thank outgoing NASA administrator Michael Griffin for his efforts and vision over the past four years. I may not have agreed with everything he said or with his extended vision for the space agency, but he did work hard to advance NASA's case, he got the agency started on major new projects -- beyond just giving lip service to some nebulous new idea, he got the ball rolling on the Constellation program, to the point where hardware is being produced and tested. That's hard to do in just four years!
Tuesday, January 13, 2009
Image Credit: David Levene / The Guardian
Yesterday, I was asked a simple-sounding question, "What do you think has been the biggest discovery in astronomy or physics of the last 100 years?" With no time to think hard about an answer, I dove in and gave the answer below. But, the more I think about it, the more I like my answer, despite the fact that it was, in some ways, a cop-out.
A lot of big discoveries have been made in the past 100 years. At the start of 1909, we knew about Einstein's theory of special relativity, but general relativity was still 7 years away. We knew that we were just one star in a larger galaxy, but we didn't know how large. We didn't even know that other galaxies existed. The Bohr model of the atom (where electrons went around a nucleus but could only be in very specific orbits) was still four years away; the quantum physics that underlies most all modern physics would not appear for 15 years. We didn't know that the Universe was expanding, and we certainly didn't know how old it was. Dark matter and dark energy hadn't even entered the minds of people yet. So, which of these do I think was the most important discovery?
My answer is that no single astronomical or physics discovery of the past century was most important. Many of the discoveries were intricately interwoven. I think it is the sum total of many of these discoveries, which led to what is virtually a second Copernican Revolution (¡Viva la Revolución!).
The Copernican revolution was many things, primarily the realization that the Earth was not the center of the Universe, but was one of the planets orbiting the sun. Philosophically, the Copernican revolution removed humans from being the center of everything, and reduced us to co-inhabitants of just another planet. Since we all live in a time when this is accepted, it's hard to realize the enormous impact of this discovery on not just science, but society.
At the start of the 20th century, we realized that not only was the Earth just one of many planets, but we also knew that the sun was just one of many stars. But our universe was still a kinda small place. Our Universe was a collection of stars and nebulae, probably no more than a few thousand light-years across, and our sun seemed to be relatively near the center of that.
Today, thanks to the contributions of many astronomers, physicists, and through rapidly evolving technology, we realize that we live on the outskirts of the Milky Way galaxy, which itself is only one of billions of galaxies in an expanding and evolving Universe that is at least 14 billion light-years across, and perhaps far bigger. Instead of being near the center of a small universe, we humans have been relegated once again to just being a tiny, typical part of something much vaster than we can comprehend.
So, I would claim that this realization, that we live in a gargantuan and dynamic Universe, is the most important discovery of astronomy in the past 100 years. This discovery was not made by any one person, but has emerged from the discoveries of many astronomers and physicists. This realization has not just required looking through telescopes at distant things, but also rests on our understanding of subatomic particles and the structures and interactions of atoms.
Like a 10,000 piece jigsaw puzzle, it is not until we put all the pieces in place that we start to see the whole picture. And that is why I think no one scientific discovery is bigger than all the rest. In order to understand our home Universe, we have to fit lots of pieces, some big, some small, together. The fact that we've been able to piece this together in only 100 years is quite astounding.
Now, I wonder what the next 100 years will hold...
Monday, January 12, 2009
Some months, the life of the astronomer is more glamorous than others. Gone are the days of the astronomer looking through the eyepiece night after night at a lonely mountaintop observatory. We don't even get to spend all day, every day working on pretty pictures on a computer.
This week, I am starting the new year by filling out reports for last year. I have expense reports from last week's American Astronomical Society meeting, progress reports on Hubble Telescope research, final reports on National Science Foundation-funded research, and even reports on research I may want to do ten years from now.
It's all incredibly boring and mind-numbing, but this paperwork is all quite essential. Expense reports and final reports help to ensure that I've spent research money wisely, and since most of that money comes from you, the taxpayers, we're simply being accountable. So, while I find the reports excruciating to write, I understand their importance.
Likewise, the report on future research is part of a once-every-10-years planning cycle in astronomy, where a select panel of astronomers solicits works within the astronomical community to develop a report on where we see the science headed, and what large missions and projects we would like to prioritize in terms of funding. That process is also an arduous and gargantuan task, but the report from this panel is used by Congress and funding agencies to help guide decisions over the next 10 years. Given the importance placed on this "decadal survey," I figure that it's my responsibility to help out.
At any rate, all of these reports are sucking the creative juices out of me, so I've precious little that's interesting to say today!
Thursday, January 08, 2009
I've written a few posts chronicling Texas's adventures in revising its state science standards: last September I introduced the issue, and in December I wrote about what science is and why that matters for state science standards, and why religion doesn't belong in the science classroom.
Why does this matter to you if you are not in Texas? Because Texas is the second-largest buyer of textbooks in the nation, so many publishers edit their textbooks to follow Texas state standards. What happens in Texas doesn't stay in Texas.
First, the good news. The final draft on science standards sticks to science. It does not try and inject religion (which, I would argue, can be freely taught in houses of worship and, as one commenter on my post mentioned, can also be covered in comparative religion courses in public schools). The standards are not antagonistic to religion, either. They simply cover science, which is all they should do.
Second, the bad news. Texas has a history (from last year!) of ignoring the recommendations and substituting their own standards, without opportunity for discussion or public input, at the last minute. Given nearly half of the Texas State School Board are on the record as favoring the teaching of some flavor of creationism in science classes. It would, alas, not be surprising if the school board tried to pull the same sort of stunt.
Such a move should be viewed as wrong, no matter what your religious inclinations. What is to stop some future school board from using such a move as precedence for adding or cutting other topics? What's to stop the school board from recommending that grade 6th students use Playboy as reading for English class? Or to stop them from deciding not to teach addition or subtraction?
I'm stretching things beyond what would probably happen, but it is to make a point. We demand that our government be open and not make decisions without at least considering the will of the people. For that reason, government committees such as the state school board set up expert panels, request reports, and hold public comment sessions before a decision is made. It would be wrong of the Texas school board to ignore this process just because they don't like the results of the process. I'm hoping that they don't go down that road again.
In short, this week we've dodged two bullets: a gamma-ray burst mass extinction and a science education meltdown. But we're not out of the woods yet. Alas, I'm infinitely more confident in my safety from gamma rays than I am in the science standards fight.
Image Credit: UC Berkeley / Keck Observatory
Last year, I blogged about the "Pinwheel Star", a pair of massive stars that looked like they might one day (in the next few million years) explode as gamma-ray bursts, bathing the Earth with a lethal dose of radiation and killing all life. Based on results from a new study, it looks like we will all live to see another day.
The study was presented by astronomer Grant Hill of Keck Observatory, who is also quite a fine fellow and has helped me out of many sticky spots while I've been observing at Keck. I also really like the findings because they are quite simple, which makes them all the easier to believe.
The idea behind the deadliness of the Pinwheel was that we seemed to be looking straight down on top of the two stars, and that gamma ray bursts tend to come out the tops of stars. What Grant discovered is that we are not looking straight down the barrel, but are actually quite a ways off to one side.
Grant measured this be measuring how fast the stars are moving toward and away from the Earth. The two stars orbit each other in a flat disk. Think of a vinyl LP (or a compact disc or a frisbee) spinning around. Now, pretend you are looking down on the top of the spinning disk. While you can see the spinning motion, no part of the disk is moving toward you or away from you. It's just going around in a circle, always at the same distance away. Now, think of looking at the spinning disk from its edge. Now, parts of the disk are getting closer to you, and parts are moving away.
In the case of the Pinwheel system, if we are looking straight down on the orbits of the stars, then, just like with the face-on spinning disk, we shouldn't measure any movement toward or away from us. We'll still see the stars moving around each other, but they aren't changing how far away they are from us.
Grant Hill's measurements found that the stars are actually moving toward and away from us. This means we aren't looking straight down on them. Grant's analysis suggests that we are actually seeing the orbits from about a 45 degree angle (halfway between edge-on and face-on). Should the stars blow up and send a gamma ray burst out along their poles (tops and bottoms), it won't be coming toward us. We're safe!
Well, maybe. Perhaps the poles of the stars are not aligned with their orbit. For the Earth, it's pole is 23 degrees away from the pole of its orbit. There's no reason that the stars can't be misaligned. In this case, there is still a very tiny chance that if one of the stars explodes, it could send a gamma ray burst toward us. But there are also reasons to think that the poles of the stars should be close to that of the orbit, in which case our viewing angle is far enough away that we are safe.
As always, we'll need to study more. But now we Earthlings can breathe a tiny bit easier!
Wednesday, January 07, 2009
Image Credit: Interstellar Studios
Last night, the International Year of Astronomy had it's US opening ceremony at the Long Beach Convention Center here in sunny southern California. The ceremony featured a sing-a-long with George Hrab, composer and performer of the 365 Days of Astronomy podcast theme song. We got to sample a special brew from Sierra Nevada called "Galileo's Astronomical Ale." And we got to watch the world premier of the new hi-def documentary on the history of the telescope called "400 Years of the Telescope" (which will premier on PBS April 10 at 10pm Eastern/Pacific; set your DVR now!).
The documentary itself is well-made, presents a coherent story, and conveys both history and science. The on-location shots at worldwide observatories are spectacular in HD, and the computer animation, while not Pixar quality, surpasses the vast majority of documentary animation I've seen recently. Best of all, the studio is teaming up with planetariums, Celestron telescopes, and the National Science Foundation to bring a roving planetarium show to many regions in the nation over the next year.
The premier was also an interesting juxtaposition of Hollywood and academic cultures. Hollywood would throw a gala black-tie bash for the premier of "Gilbert Godfried Reads the Alphabet Forwards and Backwards," while if Albert Einstein and Isaac Newton were to rise from their graves and come on stage to give a talk on a new unified theory of gravity, astronomers would give them a polite but perfunctory round of applause before starting to mutter about how Albert ignored the paper they had published in 1995 on a similar-sounding but completely unrelated topic. So, I hope that the production team of the documentary realizes that the polite applause they received, along with the lack of questions in the Q&A session after the premier, actually meant that most of us were extremely happy with the documentary.
Meanwhile, last night we also opened a Second Life island, complete with virtual fireworks and some internet sluggishness due to the popularity of the opening. The Cincinnati Observatory, the oldest public telescope still in use in the United States, was crowded with well-wishers as they tried to show live pictures of the Pleiades. (Since the Pleiades is about 400 light-years away, light from those stars reaching us last night left the stars when Galileo was building his first telescope.) Alas, clouds happen, and the overcast winter skies of southwestern Ohio prevented those observations.
Tuesday, January 06, 2009
While you are at it, why not listen or subscribe to the 365 Days of Astronomy daily podcast?
Join in the fun tonight, no matter where in the world you are! We all live under the same big sky.
Sunday, January 04, 2009
Image Credit: City of Long Beach
Friday evening, I arrived in Long Beach, CA for the winter meeting of the American Astronomical Society. Several thousand astronomers are descending upon this unsuspecting city for a big bash to share news, renew friendships, and learn more about the vast Universe of which we are a part.
I find these meetings both draining and invigorating. By the end of the week, I will be dog tired, and barely able to function. But I also find the meetings intellectually stimulating. Seeing a wide variety of interesting science results just rekindles my love for the science of astronomy. There are so many interesting things to study!
I am starting off the week with a meeting of the National Science Foundation Astronomy and Astrophysics Postdoctoral Fellows, a group of young astronomers with a passion not just for science, but for astronomy outreach and education. During this meeting, we give short talks on our research, on our education activities, and discussions on important issues facing all of us (like job searches or new outreach opportunities or future funding outlooks). Yesterday alone, we heard about studies of dark matter, searches for planets, a student-built radio telescope, and rooftop astronomy on 120th Street in New York City. Today promises just as many fascinating subjects!
Friday, January 02, 2009
Image Credit: American Astronomical Society
For many astronomers, the first full week of January means one thing: the annual winter meeting of the American Astronomical Society. This meeting is one of the largest regular meetings of astronomers,surpassed only by the International Astronomical Union meetings, held every three years. A few thousand astronomers are descending on Long Beach, California for next week's meeting.
In addition to our normal slew of too-short research talks, this winter's meeting will also feature opening ceremonies for the International Year of Astronomy, special lectures from winners of several astronomical awards, and discussions of the future of astronomy in the US , as it is time for our once-a-decade review of the science and our priorities as a community for the next decade.
In short, it will be a busy week. I'll let you know any interesting results I hear; you are also likely to see many news stories in the next several days on astronomical discoveries.
Thursday, January 01, 2009
The most recent SOHO spacecraft picture of the Sun
Image Credit: SOHO/ ESA/ NASA
As I mentioned in my last post, today is the first day of the International Year of Astronomy. The IYA is starting with an effort called "Dawn of the International Year of Astronomy." The point is for as many people as possible to look safely at the sun at noon today. At some places, astronomers will have special telescopes or other projectors to give all passers-by a safe view of the sun. (Simply looking with your eyes is dangerous and will permanently damage your eyes!) If it is cloudy where you live, or if you missed it, or if it was cloudy, you can look here at pictures taken by NASA's STEREO spacecraft, which are looking at the sun from two different angles.
The sun is the ultimate source of the energy most life on Earth needs to survive. Even when you are using coal or oil or gasoline to survive, the chemicals you are burning were made with the help of energy from sunlight by plants millions of years ago. Storms on the sun affect our life on Earth, causing electrical blackouts, communications failures, airplane route diversions, and the aurorae. (For more, see "space weather" websites such as SpaceWeather.com)
Though you may think of astronomy as a science that happens just at night, when we can see the stars, the sun is a crucial part of astronomy. The sun is the closest star to the Earth, and we can study and probe the sun in ways that we cannot probe other stars. We also think that our best chance of finding life in the Universe is by looking around sun-like stars, because we know that life can exist around such stars!
All astronomy therefore really starts with the sun. So it is only appropriate that the Year of Astronomy start with the sun.
Image Credit: IAU/UNESCO
Four hundred years ago this year, the Italian scientist Galileo Galilei turned his spotting scope on the heavens and reported on his findings. He saw spots on the sun, craters and mountains on the Moon, moons circling Jupiter, and funny bulges on the sides of Saturn. He saw the planet Venus go through phases, just like our Moon does. He saw that the other planets were not tiny points of light like the stars, but were actually spheres like the Earth, Moon and Sun. He even became the first human to see the planet Neptune, though he did not recognize it for what it was. From these observations, Galileo was able to confirm that the Copernican view of the Solar System (that the Earth orbits the sun, as do all the other planets). Due to Galileo's findings, society was forever changed.
To celebrate the 400th anniversary of Galileo's first use of the telescope, the International Astronomical Union and the United Nations Educational, Scientific and Cultural Organization (UNESCO) have teamed together to declare 2009 the "International Year of Astronomy" (IYA). All year long there will be world-wide events celebrating the IYA, with the ultimate goal of getting every human on the planet to think about astronomy at least once during the year.
Even if you just think that telescope pictures are pretty and do not understand anything about them, you can help to celebrate this year and help us to reach our goal of touching every human this year. Most importantly, take advantage of at least one of the opportunities to learn more about astronomy that the IYA will be bringing forth. Next, if you think it worthwhile, help us to spread the word about the IYA. Get your friends and family to participate with you, even if it is just a night spent looking at the stars. Consider contributing money to some of our efforts to spread astronomy education to the developing world. Or just talk about how pretty the moon was last night.
For you Internet-savvy folks, here are a few ways to keep in touch with the IYA this year (besides reading my blog, of course!). First, check out Cosmic Diary, a collection of blog postings by professional astronomers who will be talking about their research. Second, listen to daily podcasts (audio posts) about astronomy at the 365 Days of Astronomy website. You can even subscribe via iTunes (assuming your MP3 player isn't frozen). Third, poke around on some of the blogs and links I have listed off on the right-hand side of this page. See what other people are talking about. Read about future events. Participate in discussion forums. Comment on astronomy blogs. In short, keep your eyes and ears and mind open, and have some fun learning about space and astronomy!
I hope you enjoy the International Year of Astronomy. Stay tuned!
Happy New Year everybody! After a leap year and second, the Earth began another trip around the sun. The Earth has already completed roughly 4.55 billion such trips, and still has at least another 5 or 6 billion to go.
There is no magic gatepost in space that says that today should mark the start or end of Earth's orbit. Earth's orbit is, after all, a nearly perfect circle. The date of the new year was set in the Roman Senate in 153 BC (no word if the Roman Senate was influenced by a powerful or rich Janus-worshipping lobby).
By sheer coincidence, the date of January 1 in our modern calendar is only a few days different from the Earth's closest approach to the sun (January 4 at 9am EST this year). More on that in a few days.
This year starts off busy. It is the International Year of Astronomy (see my next post), and the winter meeting of the American Astronomical Society starts Sunday in Long Beach, California, preceded by a meeting of my fellow National Science Foundation Astronomy and Astrophysics fellows. I'll be bringing news from there as time allows.
At any rate, like many of you, I am happy to have a fairly bleak 2008 behind me and a fresh new year ahead. I am, at heart, an incurable optimist, though I often disguise it with a thick layer of sarcasm. So, although I'd never admit it, I believe that our best days lie ahead. So, I might as well get started on that bright future today.