Archive for the ‘Uncategorized’ Category

Votes from Space!

Friday, November 7th, 2008 by William Reynolds

And to think some people can’t be bothered because “There wasn’t any parking at my polling place…” Actual quote.  Sigh…. Let me see if I got this straight, astronauts circling in orbit can cast their votes in the general election, but 1 parking spot too few is enough to delay your civic duty 4 more years?

I’m not trying to spin up some indignant rhetoric around patriotic duty and whatnot, but considering how many people have given their lives to obtain and protect the freedoms we enjoy – not the least of these being the right and privilege to determine our leadership through general elections – it seems a tad remiss to take a pass on casting a ballot because of a lack of convenience.

[Slashdot] [Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

Galaxy Having a Major Baby Boom

Monday, October 27th, 2008 by Bellatrix

Astronomers have discovered a distant galaxy making stars at an amazing rate. It is creating stars at a rate more than a thousand times that of the Milky Way, but the remarkable thing about it is its extreme distance. This galaxy may call into question the current theory of how galaxies form.

The galaxy, nicknamed the baby boom galaxy, is making stars at a rate of about 4000 per year, compared to the Milky Way, which makes only 10 stars per year. This galaxy is also located very far from us, 12.3 billion light years. We have observed other starburst galaxies before, but none this far away, or similarly this old. This galaxy is a very young galaxy, since it is so far, we are looking at it as it was almost 12 billions years ago. That gives this galaxy the record for furthest (or youngest) starburst galaxy ever observed. The furthest before this one was 11.7 billion light years from us.

Now this galaxy calls into question the current most popular model for how galaxies are believed to form, called the hierarchal model. This model states that galaxies form slowly by consuming other smaller galaxies and star clusters, thus the stars in the galaxies should all have different birthdays. However, with this new galaxy all the stars will have very similar birthdays, meaning formation of around the same time. So the question now is whether this case is the norm or the exception. With this kind of star formation we may be witnessing the birth of one of the most massive elliptical galaxies in the universe.

The discovery of this was only possible through combined use of several different telescopes. Measurements in the radio wavelengths were made with the National Science Foundation’s Very Large Array in New Mexico. Infrared data was used from both the Spitzer space telescope and the James Clerk Maxwell Telescope on Mauna Kea Hawaii. Visible light images were used from both the Hubble Space Telescope and Japan’s Subaru Telescope also atop Mauna Kea. The identification of this galaxy and its properties would not have been possible without observations in the full range of the light spectrum. So its discovery is a fine example of the combination of different available technologies, from different sponsoring organizations. Now that we know how to find them, i.e. using data from across the electromagnetic spectrum, hopefully we can find out if galaxy baby booms were common in the distant universe, and if not, what is special about this case.

[Slashdot] [Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

Schopenhauer was right: Part 5 – A Departure From Kant

Friday, October 10th, 2008 by William Reynolds

Having been away from my Schopenhauer series for nearly 2 months, I’ve felt the longing pangs of unfinished business in my gulliver.  So it is with renewed vim and vigor that I return to the dais for yet another installment.

When I think back on my earliest encounter with philosophy, it is not dissimilar from my first brush with theology.  During the spring of my freshman year at the University of Minnesota, I became enamored of theology largely on account of dating an inordinately religious woman named S____.  My enamored fancy fell up Saint Thomas Aquinas via a medieval history course, and I soon found myself reading Summa Theologica at Coffman Union between classes.

Q:  Is there a more wearisome, and austere scholarly contribution than Summa Theologica?
A:  Not likely.

I find a it little amusing that my first forays into philosophy and theology resulted in overmatched efforts involving the aforementioned.  One might deem Socrates and CS Lewis a bit more age appropriate if not efficacious.

Immanuel Kant’s contribution to modern philosophy is well known for synthesizing empiricism and continental rationalism.  Where empiricists contended that knowledge arises from experience, and rationalists asserted that reason alone provides the basis of knowledge, Kant – in his own estimation – created a compromise between the two by presenting knowledge as function of comprehension involving 2 actors:  Concepts of the mind and phenomena.  Concepts (categories) of the mind are 4 fold with 3 aspects each – quantity (unity, plurality, totality), quality (reality, negation, limitation), relation (substance, cause, community) and modality (possibility, existence, necessity).  These concepts are universals; we cannot process phenomena (experience) without them.  For example, we cannot look at 2 apples on a table without immediately apprehending plurality.  Kant went on to refer to these categories as filters through which knowledge is made possible.

There remains in Kant the problem of things – in – themselves.  If knowledge is obtained by applying filters to phenomena arriving via our senses, then how can we ever say with certainty “That which I perceive exists as I perceive it”? On this point, Schopenhauer departs from Kant and is correct in doing so.  For Schopenhauer, the problem of knowing things – in – themselves is even deeper than Kant implied for it is not enough to merely enumerate the filters through which knowledge is made manifest without acknowledging the obvious conclusion:  That so long as filters lie between our senses and our reason, the extension of our knowledge cannot lie beyond our senses i.e. we do not know a sun “but only an eye that sees the sun…”

But we do know our bodies….

To be continued…

[Slashdot] [Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

Little Stars with Jets

Monday, September 29th, 2008 by Bellatrix

There are many objects in the universe that have jets of material exploding from them. A few examples are neutron stars, black holes, quasars, and protostars. Well now we can add brown dwarfs to that list. One wonders what causes these jets and if brown dwarfs can have them what’s next?

A brown dwarf is like a failed star. It’s cool and small, with a mass range of between 10 to 90 Jupiter masses. These objects are not massive enough to start nuclear burning like normal stars. They can be hard to observe since they are so small and don’t give off nearly as much light as a normal star. There is some debate about how to distinguish a brown dwarf from a giant planet like Jupiter. There are some differences; they all have about the same radii so if the mass is higher than about 10 Jupiter masses, they have a higher density and are usually not considered a planet. Also with brown dwarfs water is always found in a gaseous state where in giant planets it condenses to ice; also planets usually have ammonia in their atmospheres while brown dwarfs do not.

Now the brown dwarf called 2MASS1207-3932 has a mass of about 24 Jupiter masses with a companion planet of about 5 Jupiter masses. This brown dwarf also has a disk around it like that seen in young stars. This is the smallest object ever observed to have a jet. The jet is moving at a speed of a few kilometers per second and stretches about 1 billion kilometers; it is also much smaller and less bright than jets seen in regular stars. Astronomers had observed jets from one other brown dwarf, so with this new discovery a pattern is emerging. Its discovery suggests that these brown dwarfs form in a similar manner to normal stars but also that outflows are driven out by objects as massive as hundreds of millions of solar masses down to Jupiter-sized objects.

Astronomers were not able to observe the jets directly. Astronomers had to use the powerful Very Large Telescope (VLT) , and only an instrument called UVES could provide the sensitivity and resolution required to “see” the jet. The results highlight the incredible level of quality of instruments available today. With ever more powerful and sensitive instruments we are observing more of these faint objects and are able to learn much more about brown dwarfs, their properties, and how they develop.

This discovery tells us more about the development of brown dwarfs, but also raises some new questions. Does this mean that giant planets also have jets that we haven’t detected yet? If not, why not? What is the cut off threshold between the two? Also, what role exactly do these jets play in the life of the brown dwarf? If not all brown dwarfs have jets, what are the resulting differences between ones that do and ones that don’t? Hopefully, as we are able to observe more of these objects with our better instruments we will learn the answers to these questions.

[Slashdot] [Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

Our Undiscovered Universe Blog is proudly powered by WordPress
Entries (RSS) and Comments (RSS).