Sunday, February 27, 2011

Dark Matter: Interperating Data Can Be a Very Hard Task for Scientists Including Galileo And Kepler

I just finished  with Galileo's Sidereal Messenger/ Kepler's Dioptics for the umpteenth time and I marvel at the discoveries made in those first few years after the invention of the telescope. Galileo got so many things right with his observations but the genius Galileo got a slew of things wrong too. Johannes Kepler  the wunderkind that came up Kepler's three Laws of Planetary Motion, got his share of stuff wrong. Some cases in point with these two giants are...
Galileo was trying to figure out why the edge of the moons disk appeared smooth and the rest of the Moon was littered with mountains and valleys.  Galileo wrote:  To this explanation may be added another, namely, that there is round the body of the Moon, just as round the Earth, an envelope of some substance denser than the rest of the ether, which is sufficient to receive and reflect the Sun s rays, although it does not possess so much opaqueness as to be able to prevent our seeing through it—especially when it is not illuminated. That envelope, when illuminated by the Sun's rays, renders the body of the Moon apparently larger than it really is, and would be able to stop our sight from penetrating to the solid body of the Moon, if its thickness were greater; now, it is of greater thickness about the circumference of the Moon, greater, I mean, not in actual thickness, but with reference to our sight-rays, which cut it obliquely; and so it may stop our vision, especially when it is in a state of brightness, and may conceal the true circumference of the Moon on the side towards the Sun. This may be understood more clearly from the adjoining figure, in which the body of the Moon, A B c. is surrounded by an enveloping atmosphere, D E G. An eye at f penetrates to the middle parts of the Moon, as at a, through a thickness, dia, of the atmosphere; but towards the extreme parts a mass of atmosphere of greater depth, E B, shuts out its boundary from our sight. Galileo, using the data he had acquired,  was way off base with this solution. Galileo also originally and erroneously thought  Saturn was a triple system with two smaller planets on either side of the planet.
This is from the preface of Kepler's Dioptics. : For if the earth were banished from the centre of the universe, some fear lest the water should leave the orb of the earth and flow to the centre of the universe ; and yet we see that in the moon, as well as in the earth, there is a quantity of moisture occupying the sunken hollows of that globe ; and although this orb revolves actually in the ether, and outside the centres not merely of the universe, but even of our earth, yet the mass of water in the moon is not at all hindered from cleaving invariably to the orb of the moon, and tending to the centre of the body to which it belongs. So Kepler thought that the Moon had water on it lots of water. Hmmm The Moon does have water but not where he said and not how much he said.

That is the problem with RAW data. The interpretations are as varied as the Universe itself. That might be a little over the top but you definitely get my meaning. They can be varied using the same science available to any thinking human being. This is where Dark Matter /Dark energy comes in. Can it be explained by just baryonic sources such as Brown dwarfs, black holes  and the like.  Or just maybe it is non baryonic in nature?  So if it is non baryonic,  is it cold,  warm or hot  Dark matter? If it is one of those three, could the particles be neutrinos super-neutrinos or even neutralinos. or maybe weakly interacting massive particles etc. or how about theoretical partcles yet to be found? By the way it could be a combination of some or all of the above... or none of it.

It could be one of several gravity theories floating out there (paradox intended) Modified Newtonian dynamics ie  MOND, TeVes, MOG NGT and back reaction theory etc. each one might include the some quantity of Dark Matter to shore up it's point. The latest MOG theory is stand alone in nature. there are many others out there clamoring to stay off the trash pile of dis-proven theories.

I have seen mandates that call for a solution in the next two years or science will have to reevaluate the whole Dark "stuff" scene. I have seen the Ether come up  to explain some of this circa 2006? Are you kidding me?  Do I have a favorite theory? Well, yes I do but my vote hardly counts. What does count  is the hard working scientist of this age striving to make sense out of the many Terra-bites of information continuing to be gathered by oh so many sources. Two years is a short time to sort out all of this.One thing is for certain these next couple of years are sure to be exciting! For the many theories that will go by the way side just remember you are in some very good company.

Until next time

Keep looking up!

Steve T

Monday, February 21, 2011

A World Record Length For Cosmic Yardstick!!!

Continent-wide telescope extends cosmic 'yardstick' three times farther into universe

Now just looking at the title you have to giggle a little bit because three feet (yardstick) is well... three feet and hardly a world record. It is when we pull out the Cosmic Yardstick that things start to get real long  like 450 million light years long and yes folks that is a direct measurement!Using the super-sharp radio "vision" of astronomy's most precise telescope, scientists have extended a directly-measured "yardstick" three times farther into the cosmos than ever before.This has some very important implications for the hottest fields right now namely Determining the nature of Dark Energy and extrasolar planet searches. The continent-wide Very Long Baseline Array (VLBA) also is redrawing the map of our home galaxy as I type and is on the precipice of delivering big  in these two fields and more.The VLBA provides the greatest ability to see fine detail, called resolving power, of any telescope in the world. It can produce images hundreds of times more detailed than those from the Hubble Space Telescope.  This power allows astronomers to make precise cosmic measurements with far-ranging implications for research within our own Galaxy and far beyond.

Via  the NRAO: New measurements with the VLBA have placed a galaxy called NGC 6264 at a distance of 450 million light-years from Earth, with an uncertainty of no more than 9 percent. This is the farthest distance ever directly measured, surpassing a measurement of 160 million light-years to another galaxy in 2009. Previously, distances beyond our own Galaxy have been estimated through indirect methods. "Our direct, geometric measurements are independent of the assumptions and complications inherent in other techniques," said James Braatz, of the National Radio Astronomy Observatory (NRAO), who worked with Cheng-Yu Kuo, of the University of Virginia and NRAO. Fine-tuning the measurement of ever-greater distances is vital to determining the expansion rate of the Universe, which helps theorists narrow down possible explanations for the nature of Dark Energy. Different models of Dark Energy predict different values for the expansion rate, known as the Hubble Constant.
"Solving the Dark Energy problem requires advancing the precision of cosmic distance measurements, and we are working to refine our observations and extend our methods to more galaxies," Braatz said. Measuring more-distant galaxies is vital, because the farther a galaxy is, the more of its motion is due to the expansion of the Universe rather than to random motions.

Another ongoing project uses the VLBA to redraw the map of our own home Galaxy. Recent work has added dozens of new measurements to star-forming regions in the Milky Way, The direct VLBA measurements improve on earlier estimates by as much as a factor of two.
This improvement significantly aids in understanding the physics of the young stars and their environments. It also has changed the map of the Milky Way, indicating that our galaxy has four spiral arms, not two, as previously thought.
"Because we sit inside our galaxy, it's difficult to actually map it. These precision distance measurements are our most effective tool for learning about the structure of the Milky Way," said Mark Reid, of the Harvard-Smithsonian Center for Astrophysics.
Earlier work by Reid and his colleagues showed that the Milky Way is rotating faster than previous estimates had indicated. That measurement in turn showed our galaxy to be more massive, equaling our neighbor, the Andromeda Galaxy, in mass.
Reid's team also is observing the Andromeda Galaxy in a long-term project to determine the direction and speed of its movement through space. "The standard prediction is that the Milky Way and Andromeda will collide in a few billion years. By measuring Andromeda's actual motion, we can determine with much greater accuracy if and when that will happen," Reid said.

A long-term, sensitive search of 30 stars seeks to find the subtle gravitational tug that will reveal planets orbiting those stars. The VLBA's precision can reveal a "wobble" in the star's motion through space caused by the planet's gravity. A four-year program, started in 2007, is nearing its completion.
"This study tracks stars smaller than our Sun, seeking evidence of planets the size of Jupiter or smaller," said Geoffrey Bower, of the University of California, Berkeley. "We want to learn how common it is for these low-mass stars to have planets orbiting them at relatively large distances," he added.
The project uses the VLBA along with NRAO's Green Bank Telescope in West Virginia, the largest fully-steerable dish antenna in the world. Together, these telescopes can detect the faint radio emission from the stars to track their motion over time.
Early results have ruled out any companions the size of brown dwarfs for three of the stars, and the astronomers are analyzing their data as the observations continue.
Astronomers reported on the new measurements and ongoing projects at the American Association for the Advancement of Science meeting in Washington, D.C.
The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

So what have we got here? a possible new way to find  extrasolar planets , A much bigger Milky Way Galaxy than previously thought and narrowing down the solution to the Dark Energy problem ... Not bad VLBA not bad at all . I may have a new hero!

Sunday, February 13, 2011

On The Horizon What Is The Next Big Thing?

The decadal survey for where astrophysics and astronomy is headed for the next ten years has been here for a few months now. The dust has settled; our course is set and we are full speed ahead. 23 scientists headed by Roger Blandford, a Stanford professor put their heads together and came up with a list of needs that focus on Extra solar planet searching, researching supernovae, defining dark matter and the origin of the universe within a tight budget. Now that is quite the tall order. Blandford , notes that astronomers are watching their budget: "The program of research that we recommend will optimize the science return for future ground-based projects and space missions in a time of constrained budgets and limited resources," he says. Astrophysics on a shoestring budget. To do this,  missions for the next decade need to be multiple pronged in their data collection. This will involve some great planning and innovation for these future projects to be successful. Ten years ago little if anyone had heard of dark matter. Now the race is on to pin DM down and make it give up it's secrets.  
artist's conception

The tools needed for this decade long push come in the form of the Wide-Field Infrared Survey Telescope (WFIRST), previously known as the Joint Dark Energy Mission. The new $1 billion-plus space telescope will enable researchers to study dark energy, find Earthlike exos , and survey multiple galaxies, including the Milky Way. 

The second front of exploration will be earth based and is named the Large Synoptic Survey Telescope (LSST), a massive wide-field optical scope that will also help investigate dark energy. Scientist are looking to broaden their understanding of how the first stars, galaxies and black holes formed; to unravel the physics that drive these processes, including gravity and to find the closest habitable Earth-like exoplanets so scientists can study them in greater detail.Would you believe it both top-priority telescopes are already under way.The date of operation for this wonderful scope is 2015 so far...

Ten years have gone by and we are still waiting for the James Webb Space Telescope (JWST) to get off the ground (launch)The  JWST is a large, infrared-optimized space telescope, scheduled for launch in 2014/2015. JWST will find the first galaxies that formed in the early Universe, connecting the Big Bang to our own Milky Way Galaxy. JWST will peer through dusty clouds to see stars forming planetary systems, connecting the Milky Way to our own Solar System. JWST's instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range.
The James Webb Space Telescope has a 6.5-meter primary mirror. and will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of
our Universe, ranging from the first luminous glows after the Big Bang to the formation of solar systems capable of supporting life on planets like Earth. The evolution of our own Solar System will also be in the wheelhouse of this big space scope. JWST was formerly known as the "Next Generation Space Telescope" (NGST). JWST was renamed in Sept. 2002 after a former NASA administrator, James Webb.  The next ten years will see three new telescopes. The Webb is a very big drain in the exploration column of NASA's budget. That may hinder funneling money into the other two projects  right away. 

I am excited for the next ten years tight budget or not. If history is any indicator;  the economy will rebound and budgets will increase. We have so much data to crunch right now from all of the many space telescopes and ground base scope doing research  that we have a lot to look forward to these next few years. I parallel these time to the times of Galileo. The discoveries made with the new technology of the day (the Telescope) turned the science world on its ear and out of it modern astronomy was born. We are finding so much so fast in these hi-tech days and truly it is amazing to watch and take in. It is fun to wonder what the next ten years will uncover and wonder I will.
until the next time,

Keep looking up!

Steve T

Sunday, February 6, 2011

Students (Yes Students) Discover Pulsars and More

Alexander Snider and Hannah Mabry in GBT Control Room,
Casey Thompson on-screen, during confirmation observation.
Astronomical discoveries have no loyalties to scientist with PHDs. Anyone with a mind  can  discover the grandest of things out in the universe. Never has that point been more true than with the recent discovery of a rapidly spinning pulsar (30 times a second) by three high school students from Virginia and Kentucky. This rare pulsar located in Ophiuchus and above the Milky way disk was discovered by  Alexander Snider, Casey Thompson and Hannah Mabry as they sifted through data gathered by the Robert C. Byrd Green Bank Telescope (GBT). These students are a part of the Pulsar Search Collaboratory (PSC) project, run by the National Radio Astronomy Observatory (NRAO) in Green Bank, WV, and West Virginia University (WVU). 
Basics of a Pulsar

From the NRAO press release:
The pulsar, which may be a rare kind of neutron star called a recycled pulsar, was discovered independently by Virginia students Alexander Snider and Casey Thompson, on January 20, and a day later by Kentucky student Hannah Mabry. "Every day, I told myself, 'I have to find a pulsar. I better find a pulsar before this class ends,'" said Mabry.When she actually made the discovery, she could barely contain her excitement. "I started screaming and jumping up and down."
Thompson was similarly expressive. "After three years of searching, I hadn't found a single thing," he said, "but when I did, I threw my hands up in the air and said, 'Yes!'." Snider said, "It actually feels really neat to be the first person to ever see something like that. It's an uplifting feeling."

As part of the PSC, the students analyze real data from NRAO's Robert C. Byrd Green Bank Telescope (GBT) to find pulsars. The students' teachers -- Debra Edwards of Sherando High School, Leah Lorton of James River High School, and Jennifer Carter of Rowan County Senior High School -- all introduced the PSC in their classes, and interested students formed teams to continue the work.Even before the discovery, Mabry simply enjoyed the search. "It just feels like you're actually doing something," she said. "It's a good feeling."

Once the pulsar candidate was reported to NRAO, Project Director Rachel Rosen took a look and agreed with the young scientists. A followup observing session was scheduled on the GBT. Snider and Mabry traveled to West Virginia to assist in the follow-up observations, and Thompson joined online.
"Observing with the students is very exciting. It gives the students a chance to learn about radio telescopes and pulsar observing in a very hands-on way, and it is extra fun when we find a pulsar," said Rosen.Snider, on the other hand, said, "I got very, very nervous. I expected when I went there that I would just be watching other people do things, and then I actually go to sit down at the controls. I definitely didn't want to mess something up."Everything went well, and the observations confirmed that the students had found an exotic pulsar. "I learned more in the two hours in the control room than I would have in school the whole day," Mabry said.

Discoveries by High school students are growing. The PSC has netted three discoveries by high school students in recent years. In 2009, Shay Bloxton of Summersville, WV, discovered a pulsar that spins once every four seconds, and Lucas Bolyard of Clarksburg, WV, discovered a rapidly rotating radio transient, which astronomers believe is a pulsar that emits radio waves in bursts. But there are other programs out there that have students doing the discovering as well as students independently discovering new objects

In 1994, two students used images from the Leuschner Telescope in Berkeley, Calif., to record the first sighting of SN 1994I, a supernova in the Whirlpool Galaxy.  These images of SN 1994I were obtained before its discovery was reported. High school students Heather Tartara and Melody Spence requested observations of the Whirlpool Galaxy on March 29 and 31, 1994. Their request was made through the Hands-On Universe program, which allows elementary and high school students to request observations on automated telescopes. Their images captured the Whirlpool Galaxy just before and after SN 1994I began to brighten, and are some of the earliest data recorded for a supernova.The two girls wanted to take pictures of galaxy M51, or Messier 51, to try to capture a picture of the galaxy's black hole. What they ended up finding,  was the supernova.
In November 2008 Warwick Valley High School junior Caroline Moore  a freshman, was catapulted into International fame following the discovery in her backyard observatory of what has now been named Supernova 2008ha in galaxy UGC 12682. She became the youngest person in the history of astronomy to discover a supernova. This discovery earned her the 2010 Jack Horkheimer/Parker Award for exceptional service in astronomy.

I can go on  and on but the important thing here is that students are engaging science  and that my fiends is a wonderful thing. More importantly teachers are teaching hands on science be it in the class room or after school in a club setting .  The opportunities for amateur discoveries abound.  Hobby  Space is a great website listing a huge number of organizations using Students and amateurs alike to do real science.  We are talking real, hands on make a difference science. If you are a teacher,  take a look and get involved. Shaping the minds of tomorrow's scientists  is just about as noble an endeavor as one can have.

Keep looking up!

Steve T