The universality of the sky was revealed to me last night.
It started simply enough. Dinner in the valley with my godparents, a typical Saturday evening in August. Given the size of the valley and the small social circles, it's common to run into several friends and families at any given event, and this time was no different. The couples at the table outside, the family at the table next to us and the one next to that, and the neighbors at the table in the far corner, all known to my godparents and after tonight known to me as well. But one of these introductions was to mean more than the others.
The house up the hill from my godparents belongs to a couple who open their home to most of the valley each year when they honor their patriarch. I have vague memories of attending these fetes as a young child and sporadic ones as an adolescent, which came flooding back to me as I was walking into the house for this year's celebration. This particular summer I had come to know two of the three now full grown children in the family so I was especially excited to attend. In between the cocktail chaos and the bustling buffet though, I never came across the third and eldest daughter and her husband...until Saturday night.
As I am introduced to the husband I find myself volunteered and volunteering to set up a telescope for the family, which the aforementioned patriarch has just purchased for their mountain house. I worry a little to myself that my academic qualifications may not translate directly into telescopic proficiency, but being an engineer in a former life and a tinkerer by birth, I can't wait to get my hands on the shiny new toy.
Late Sunday afternoon, I head up the hill to report for duty. Within an hour the hardware is assembled, but due to a lack of batteries, we cannot test the AutoStar function which is where all the fun is - once the telescope is calibrated to a location, it can automatically slew to any number of celestial targets. Instead, I am made an offer that I cannot refuse: drinks and dinner on the porch on a future and hopefully clear night in exchange for returning to help with the remaining set-up. I return home and immediately look up the weather forecast; it's my last week in the valley and I pray that there will be at least one clear night. Tuesday jumps out at me. I check multiple weather websites, and they corroborate the first - Tuesday looks perfect.
Tuesday morning I awake to blue skies and bright sunshine, just the kind of day that makes you never want to leave the valley. As I am going about the online portion of my day, a friend tells me to check out Google's home page - it's familiar logo is composed of telescopes in honor of Galileo Galilei. Unbeknownst to me, it is exactly 400 years to the day after Galileo first unveiled his telescope to Venetian lawmakers. His intention at the time may have been to sell the instrument to merchants for use at sea or in trade, but I have no doubt he had already turned his to the sky. Less than six months later, he would publish his first telescopic astronomical observations in a brief treatise he titled Sidereus Nuncius, or Starry Messenger.
Now across time and space, from a stone patio on the side of a mountain, I find myself looking at the very same sky that Galileo first explored, low those many years ago. The telescope has been calibrated and aligned and it is asking us to choose an object. The Milky Way brilliantly spills across the sky directly overhead with the Summer Triangle practically at the zenith. The Big Dipper is hiding behind the pine trees lining the driveway. An occasional shooting star flashes in and out of view. Unanimously, the dinner party demands a closer look at the exceptionally bright object rising in the southeast from behind the house: Jupiter. Upon acquiring its target, the telescope reveals the exact picture that Galileo once set his sights on. His discovery of four small satellites orbiting Jupiter was what prompted him to question to the principles of Aristotelian Cosmology that required the orbits of all heavenly bodies to be centered on the Earth.
The telescope we are using is not terribly more powerful than Galileo's original one. And the sky has only changed imperceptibly since his time. Standing there with my eye glued to the eyepiece and Jupiter and its four Galilean Moons sliding across my field of view, I feel a sense of connection to Galileo, the Earth, and the cosmos stronger than I've ever felt before. Contrary to many people's reaction to the vastness of space and time, I feel all the more special and privileged to be a part of something universal, in all senses of the word.
Showing posts with label life. Show all posts
Showing posts with label life. Show all posts
Wednesday, 26 August 2009
Tuesday, 25 March 2008
In Memoriam
I was fortunate enough to know and work with G. David Low during my time at Orbital Sciences Corporation. He was and will continue to be an inspiration to me.
Thursday, 14 February 2008
Love From the Universe
The Rosette Nebula is actually a vast cloud of gas and dust about 5,000 light years away from us. It is made up of several smaller nebulae and star clusters known by their more unimaginative names as NGC 2237, 2238, 2239, and 2246. NGC stands for 'New General Catalog'; it was compiled by J. L. E. Dreyer in the 1880's using observations made by William Herschel. It is one of the best known and largest catalogs of deep-space objects of all kinds, i.e. galaxies, nebulae, star clusters, and gas clouds. There are over 8,000 objects with NGC designations. In the center of the nebula's rose lives the open star cluster NGC 2244 which was discovered even earlier in 1690. At 130 light years across, the birth of many hot, young stars has created enough radiation pressure to clear the central region of gas and dust, thereby producing the gorgeous petal visual that we have come to know and love as the Rosette Nebula.
Nice to know we have a standing celestial valentine from the Universe. In my mind it beats anything for sale here on Earth.
Thursday, 17 January 2008
Pale Blue Dot
If you ever have a day like I did yesterday, watching this video will help you put everything in perspective.
Repeat as necessary.
(Movie Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)
Repeat as necessary.
(Movie Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)
Tuesday, 25 December 2007
Christmas in Cambridge
My first Christmas sans family, but never fear, I had a member of my astrophysics family to lean on. My friend Stas and I are keeping misery company as we spend the holidays locked in the Cavendish in front of our respective computers. Our topics actually overlap so we are helping to push each other along up the dreaded and steep hill of completion. (In fact, watch this space for our upcoming publication on the life cycle of black holes!) In the meantime though, we took a brief break to cook an outrageous amount of food and stuff ourselves silly.
Just another day by English weather standards.
The Christmas spread...Yum!
My modest first servings.
Stas's not-so-modest first servings.
Boys have such an unbelievable capacity for food!
Stas post-dinner. He went over capacity.
Attempted Christmas self-portrait of me, Stas and the Christmas tree. (Apparently the camera was more interested in the Eiffel Tower.)
Friday, 21 December 2007
I Miss My Serotonin
The winter solstice comes tonight. The shortest day and the longest night of the year. I, for one, am ready for daylight to make a comeback.
Did you know that the word solstice come from the Latin for sun (sol) and standing still (sistere)? The solstice is when the Sun stands still.
Well...that isn't exactly what happens, but I can see how the ancients might have seen it that way. The Sun actually moves a lot in our sky. In addition to tracing out a path across the sky from sunrise to sunset, the height of the Sun at midday also changes throughout the year. The winter solstice, in the general sense, marks the day when the Sun is the lowest in the sky during midday. However, in astronomical terms, the winter solstice is the exact moment when Earth's axis is tilting farthest away from the sun.
From Astronomy 101, you may remember that our axis is tilted 23.5 degrees from vertical with respect to the plane of the Solar System. You may also be familiar with the North Star, right? Well the North Star got it's name for a reason - it's where our axis appears to point if you were to extend a line straight out into space from the north pole. And that line always points there, regardless of the season. This is because while the Earth rotates on its axis and orbits around the Sun, the tilt of our axis doesn't change. So for the winter solstice, the Earth is at the exact spot in its orbit where the our axis tilts the farthest away from the Sun and for the summer solstice, the axis is tilting towards the Sun.
So from now until June 21st, the Sun will only rise to a higher and higher point during its daily travels. However, right now it's killing me by only getting up to a little over 16.5 degrees above the horizon. Here in Cambridge, I am at 52 degrees latitude. For comparison, back in the states, New York City is around 40 degrees latitude and will see the sun reach 25.7 degrees at its highest. Those 9-ish degrees in latitude may not seem like much, but they translate to 1.5 less hours of daylight for me versus you New Yorkers out there. Given England's penchant for grey skies, I want all the Sun I can get. I may have to overcompensate and move the equator after my tenure here so I can benefit from the Sun wandering back and forth across the zenith. So while the Sun never exactly stands still in our sky, on the solstice it appears to stop at the high or low extreme of its midday elevation. I can see where the ancients where going with that.
These two figures show the range of elevations for the sun at 50 degrees latitude (think England) and 0 degrees latitude (on the Equator). Actually, the illustration for the equator above helps to correct a common misconception. The Sun does not shine directly overhead every day at noon on the equator - it only does so on the vernal and autumnal equinoxes. The equinoxes are the half-way points between the solstices in the spring and fall where the hours of day and night are equal. Don't forget that the equinoxes and solstices are switched below the equator in the southern hemisphere!
Another myth that I would like to dispel is that the Earth is closest to the Sun on the summer solstice and consequently farthest from the Sun this time of year. To that I say: first, props for remembering that Earth's orbit is elliptical - I'm glad you are paying attention, but second, that is unfortunately an incorrect conclusion. Turns out the Earth's distance from the Sun makes less of a difference than the tilt of its axis. When the Earth is at perihelion (its closest point to the sun, peri for close, helio for sun) the heat from the Sun's radiation doesn't differ drastically enough as compared to at apehelion (its farthest point). However, when the northern hemisphere is tilted 23.5 degrees away from the Sun, less radiation strikes the atmosphere in the north and therefore causes the cold temperatures we have come to call winter. The opposite being true for summer.
Lastly, I feel I should warn you about a dangerous trend regarding the winter solstice. It precesses, along with Earth's axis. In fact, one day in the future, Christmas will be in July and Independence Day will be in December...so to speak. My point being that the solstices will be opposite to how they are now, with the shortest day being June 21st and the longest day being December 21st. That will make for quite the change in holiday traditions! Of course, I'm scaring you for no reason, because this won't happen for tens of thousands of years. Breathe easy and go make a snowman.
(N.B. For you those of you who prefer an exact science, the solstice actually occurs on December 22nd at approximately 06:09 UT, also known as Greenwich Mean Time. That's AM here in England. East coasters are 5 hours behind at 1:09 am- West coasters are 8 hours behind at 10:09 pm, back on the 21st.)
(image credits: http://www.physicalgeography.net/fundamentals/6h.html)
Did you know that the word solstice come from the Latin for sun (sol) and standing still (sistere)? The solstice is when the Sun stands still.
Well...that isn't exactly what happens, but I can see how the ancients might have seen it that way. The Sun actually moves a lot in our sky. In addition to tracing out a path across the sky from sunrise to sunset, the height of the Sun at midday also changes throughout the year. The winter solstice, in the general sense, marks the day when the Sun is the lowest in the sky during midday. However, in astronomical terms, the winter solstice is the exact moment when Earth's axis is tilting farthest away from the sun.
From Astronomy 101, you may remember that our axis is tilted 23.5 degrees from vertical with respect to the plane of the Solar System. You may also be familiar with the North Star, right? Well the North Star got it's name for a reason - it's where our axis appears to point if you were to extend a line straight out into space from the north pole. And that line always points there, regardless of the season. This is because while the Earth rotates on its axis and orbits around the Sun, the tilt of our axis doesn't change. So for the winter solstice, the Earth is at the exact spot in its orbit where the our axis tilts the farthest away from the Sun and for the summer solstice, the axis is tilting towards the Sun.
So from now until June 21st, the Sun will only rise to a higher and higher point during its daily travels. However, right now it's killing me by only getting up to a little over 16.5 degrees above the horizon. Here in Cambridge, I am at 52 degrees latitude. For comparison, back in the states, New York City is around 40 degrees latitude and will see the sun reach 25.7 degrees at its highest. Those 9-ish degrees in latitude may not seem like much, but they translate to 1.5 less hours of daylight for me versus you New Yorkers out there. Given England's penchant for grey skies, I want all the Sun I can get. I may have to overcompensate and move the equator after my tenure here so I can benefit from the Sun wandering back and forth across the zenith. So while the Sun never exactly stands still in our sky, on the solstice it appears to stop at the high or low extreme of its midday elevation. I can see where the ancients where going with that.
These two figures show the range of elevations for the sun at 50 degrees latitude (think England) and 0 degrees latitude (on the Equator). Actually, the illustration for the equator above helps to correct a common misconception. The Sun does not shine directly overhead every day at noon on the equator - it only does so on the vernal and autumnal equinoxes. The equinoxes are the half-way points between the solstices in the spring and fall where the hours of day and night are equal. Don't forget that the equinoxes and solstices are switched below the equator in the southern hemisphere!
Another myth that I would like to dispel is that the Earth is closest to the Sun on the summer solstice and consequently farthest from the Sun this time of year. To that I say: first, props for remembering that Earth's orbit is elliptical - I'm glad you are paying attention, but second, that is unfortunately an incorrect conclusion. Turns out the Earth's distance from the Sun makes less of a difference than the tilt of its axis. When the Earth is at perihelion (its closest point to the sun, peri for close, helio for sun) the heat from the Sun's radiation doesn't differ drastically enough as compared to at apehelion (its farthest point). However, when the northern hemisphere is tilted 23.5 degrees away from the Sun, less radiation strikes the atmosphere in the north and therefore causes the cold temperatures we have come to call winter. The opposite being true for summer.
Lastly, I feel I should warn you about a dangerous trend regarding the winter solstice. It precesses, along with Earth's axis. In fact, one day in the future, Christmas will be in July and Independence Day will be in December...so to speak. My point being that the solstices will be opposite to how they are now, with the shortest day being June 21st and the longest day being December 21st. That will make for quite the change in holiday traditions! Of course, I'm scaring you for no reason, because this won't happen for tens of thousands of years. Breathe easy and go make a snowman.
(N.B. For you those of you who prefer an exact science, the solstice actually occurs on December 22nd at approximately 06:09 UT, also known as Greenwich Mean Time. That's AM here in England. East coasters are 5 hours behind at 1:09 am- West coasters are 8 hours behind at 10:09 pm, back on the 21st.)
(image credits: http://www.physicalgeography.net/fundamentals/6h.html)
Monday, 17 December 2007
New York City Star Power
The Washington Post did a feature article in the Science section this weekend about the guy I want to be when I grow up. I've probably already talked the ears off of most of you about him because he is so stellar.
Yes, I'm not ashamed to go there.
His name is Neil de Grasse Tyson and he is the head of the Hayden Planetarium. Now I know when most of you think of a planetarium, you perhaps have flashes of elementary school field trips to a dark, grungy auditorium with tilt back seats where you fell asleep while some boring old guy lectured you on the constellations. Let me assure you, the Hayden smashes all those stereotypes to bits...to bits.
It is housed in the Rose Center for Earth and Space, a wing of the American Museum of Natural History in New York City. If you are anywhere within the radius of a reasonable day trip, this is a must. And it's 'must visit' status is in large part due to Dr. Tyson's overhaul of the Hayden back in 2000. Not only is the building itself fabulous - a cavernous glass atrium housing a massive spherical planetarium known as the Hayden sphere - the museum also offers an endless series of fantastic public programs for every age. And if neither of those get you, Dr. Tyson will. I could wax on and on about it, but instead I'm just going to challenge you to prove me wrong.
Read all about Dr. Tyson and his mad astrophysics skills here through the first link and start planning your visit to the Hayden Planetarium.
And remember all you just read when you come to visit me in New York and I show you my awesome office at the Hayden, down the hall from Dr. Tyson.
Yes, I'm not ashamed to go there.
His name is Neil de Grasse Tyson and he is the head of the Hayden Planetarium. Now I know when most of you think of a planetarium, you perhaps have flashes of elementary school field trips to a dark, grungy auditorium with tilt back seats where you fell asleep while some boring old guy lectured you on the constellations. Let me assure you, the Hayden smashes all those stereotypes to bits...to bits.
It is housed in the Rose Center for Earth and Space, a wing of the American Museum of Natural History in New York City. If you are anywhere within the radius of a reasonable day trip, this is a must. And it's 'must visit' status is in large part due to Dr. Tyson's overhaul of the Hayden back in 2000. Not only is the building itself fabulous - a cavernous glass atrium housing a massive spherical planetarium known as the Hayden sphere - the museum also offers an endless series of fantastic public programs for every age. And if neither of those get you, Dr. Tyson will. I could wax on and on about it, but instead I'm just going to challenge you to prove me wrong.
Read all about Dr. Tyson and his mad astrophysics skills here through the first link and start planning your visit to the Hayden Planetarium.
And remember all you just read when you come to visit me in New York and I show you my awesome office at the Hayden, down the hall from Dr. Tyson.
Sunday, 16 December 2007
Ich bin uberfragt!
Oh, what have I done?!?...While innocently chugging along at work today, I started uncovering error after error. Error might be too strong a word, but there are a myriad of inconsistencies in my database rearing their ugly little heads. Not cool, not cool at all. It's like when I first created the database I was on crack or something! (No offense to any crackheads out there). I am seriously baffled by this and now unsure how to proceed. I only found the mistakes I did by looking further into 22 of my 1908 radio sources. Who's to say that this problem doesn't pervade the whole database? Does this mean I should go over all 1908 entries with a fine tooth comb? Or is that a waste of time? Do I instead just wait until other potential problems rise to the surface? But if that happens enough times in the near future, then wouldn't it have just been better and more time efficient to review the full database now?
Too many questions swirling around my already full postgraduate student head.
Too many questions swirling around my already full postgraduate student head.
Friday, 14 December 2007
Friday Night Lights
Oh my god. I just spent the past four - yes four - hours trying to pair two lists of sources and retain on the ones that didn't match up. I am both ecstatic that I got it to work and defeated that it took this long. Seriously, four hours. I'm just saying.
And the payoff for generating this list of unmatched sources? I now get to pour over all 181 of them to try and figure out why they didn't match up, because they darn well should have. The lights will be on in this office for a bit longer tonight...
And the payoff for generating this list of unmatched sources? I now get to pour over all 181 of them to try and figure out why they didn't match up, because they darn well should have. The lights will be on in this office for a bit longer tonight...
Thursday, 13 December 2007
Hurry Up and Wait
Turns out a lot of an astrophysics Ph.D. can be grunt work. The most frustrating thing is spending 90% of your time writing code and formatting plots for the 10% of the time when you can actually uncover some meaningful scientific result. Apparently that's the way it goes, which I guess makes sense when you think about it; data doesn't exactly organize itself, otherwise breakthroughs would be a dime a dozen.
So 90% of my day today was spent running programs on a catalog of radio sources from the NRAO VLA Sky Survey (NVSS for short). This is a radio survey done at 1.4GHz with the Very Large Array (VLA) in Socorro, New Mexico. For any of you that have seen the movie Contact, this is the telescope she was at in the scene where she sits on the hood of her car with her headphones on - supposedly listening to the telescope signals, but that's a beef for another post. Anyway, the NVSS catalog has 1810672 radio source in it, and by radio sources, I mean galaxies outside our own that emit in the radio part of the spectrum.
I've been sorting these 1.8 million galaxies into files according to how bright they look to us so that I can dig deeper and find out if their brightness correlates to any other parameters - specifically polarization. I have measurements for how polarized each source is and my goal is to make plots galore to see if this correlation exists. Stay tuned for details...
So 90% of my day today was spent running programs on a catalog of radio sources from the NRAO VLA Sky Survey (NVSS for short). This is a radio survey done at 1.4GHz with the Very Large Array (VLA) in Socorro, New Mexico. For any of you that have seen the movie Contact, this is the telescope she was at in the scene where she sits on the hood of her car with her headphones on - supposedly listening to the telescope signals, but that's a beef for another post. Anyway, the NVSS catalog has 1810672 radio source in it, and by radio sources, I mean galaxies outside our own that emit in the radio part of the spectrum.
I've been sorting these 1.8 million galaxies into files according to how bright they look to us so that I can dig deeper and find out if their brightness correlates to any other parameters - specifically polarization. I have measurements for how polarized each source is and my goal is to make plots galore to see if this correlation exists. Stay tuned for details...
Wednesday, 12 December 2007
The Inaugural Post
This is an experiment.
I am in the throes of the end stages of my Ph.D. and I need something creative to maintain my sanity up until the final hour. I figured if I blog (and blag) my way through my thesis, it might stimulate me to produce something to blog (and blag) about. Just a theory.
So gentle readers, of which there are none as I write this (...yet), what follows will be a sequence of reports on my daily progress. I dare say it could bore you to tears but it also might serve to enlighten and perhaps even educate you on the wonderful world of radio astronomy. Of course hard work always comes with a healthy dose of procrastination and digression so there will be plenty of non-sequiturs to keep it interesting. Comments, words of encouragement, and blatant stroking of my ego will be welcome, appreciated and required from time to time, respectively.
I now entreat you to come along for the academic ride of your life...well, at least of mine.
I am in the throes of the end stages of my Ph.D. and I need something creative to maintain my sanity up until the final hour. I figured if I blog (and blag) my way through my thesis, it might stimulate me to produce something to blog (and blag) about. Just a theory.
So gentle readers, of which there are none as I write this (...yet), what follows will be a sequence of reports on my daily progress. I dare say it could bore you to tears but it also might serve to enlighten and perhaps even educate you on the wonderful world of radio astronomy. Of course hard work always comes with a healthy dose of procrastination and digression so there will be plenty of non-sequiturs to keep it interesting. Comments, words of encouragement, and blatant stroking of my ego will be welcome, appreciated and required from time to time, respectively.
I now entreat you to come along for the academic ride of your life...well, at least of mine.
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