Reading about cosmology, I am immediately drawn into the big questions it attempts to answer about from the very start of the universe, how it was created, and ultimately, how matter and life exists at all. After all, what we learn in a variety of subjects always has pertinence, but I was infinitely more curious to the creation, to how we live and how nature conspired to allow our own conception and the universe’s creation.

What is fascinating news about the topic of cosmology that Carroll and Ostile have written about is the fundamental difference between how what many of us were taught as children was a hotly debated topic as to the cosmological creation of the universe. With the study of the cosmic microwave background and its proven existence by blackbody radiation and microwaves existent in the atmosphere, the theory of a steady-state universe was proven false. The steady-state universe theory really drew me due to its idealization of the universe as constant and never-changing, never created and with no beginning or time with the tying of time to the infinite scale, and more due to the fact that it seems like a foreign theory. As children, we were never taught about the steady-state universe and were immediately drawn towards the Big Bang, which is now the standard theory of choice, but it is interesting to look into alternate theories.

Cosmic microwave background

The cosmic microwave background shown here is something that is common practice when describing the start of the universe. However, its fascinating nature and description only continues to be exacerbated when one considers the fact that this energy released from the Big Bang was expected to have nuclear reactions, and with the light elements in the universe, that Big Bang nucleosynthesis occurred to ensure that reactions continued occurring to create the universe from the very dense point of spacetime. Further, this picture is also shown to see what we from Earth can see as the last traces of scattering from the photons that were not scattered by free electrons, leading to an expansion and also revealing what areas are more energy dense.

It is absolutely baffling to consider how much work goes into the consideration and theories that shape our conceptions of the modern world and of the science-fiction world in which we have curved spacetime, meaning relativistic cosmology and creation, as well as traveling towards these sources to see what they mean. However, when one considers it, this is the fundamental question that behooves us all as people to understand, to see and discover more about our own creation.

The applications of physics generally do not interest me in terms of engineering or practicality. They function well and are definitely necessary and provide infinite cool feats that show what the human mind, with the aid of some technology, can accomplish; however, these ultimately are not something I find worth reading about, thinking about, or really delving into. The world of application in terms of space and the more abstract features, such as time travel, quantum mechanics, and space travel all interest me greatly, though.

Particularly, if we look at time travel, the ideas that science fiction provide give us a fairly inaccurate picture about how the world works and are a fascination as to how we want it to work – science becomes something we can control for our own benefit, or as in many time travel movies, for ill-guided ideas that inevitably lead to our own destruction. Time travel in particular, as it’s described with wormholes and the bending of the time-space continuum, provide infinite layers of fascination at something that could be possible but manages to elude us in our approach to light speed. Many physicists have exclaimed and discussed its theoretical possibility, particularly into the future as we approach light speed that time begins to slow down, but in terms of development of the energy sources required for approaching this speed and ensuring some sort of safety, time scales estimate even 6 years just to approach the speed, with no specified energy source nor money source.

This summer, I attended a conference called Icarus Interstellar Conference mostly focused on interstellar travel, with many discussions and panels on the theoretical possibility of not just short-range interstellar flights, but long-term flights as well as flights that allowed for such forward motion by utilizing planetary gravity, black hole gravity, and a variety of sources to generate the gravitational force and relativity speed necessary to allow us to jump forward in time. Most often, it seems that for the time being, this is the more plausible ability that we have rather than the ability to travel backwards in time through wormholes, which changes the plausibility for scenarios where we can change history, but is inspiring to the idea that we may be able to accelerate towards the future with life being entirely different from how we left it. Wormholes also have never been observed, with modifies the perspective of the possibility of time travel backwards, and many scientists seem to reject it on principle.

The possibility of these ideas pose much interest, and, as the first article in the article so eloquently puts, “for many scientists, it is the principle that counts, not the practical engineering.” So ultimately, it rests in the known possibility to travel to the future and the ramifications of what it means and how it affects us as a human, global civilization as well as individuals. The question does remain to be asked about the possibility towards going backwards in time, but for the time being, I think there are enough discussions and thoughts to have to the current state of forward travel that will keep us questioning further and further.

Sources:

http://www.cnn.com/2013/05/13/opinion/opinion-time-travel-paul-davies/

http://www.huffingtonpost.com/2013/09/13/time-travel-possible-physicist-machine-future-only_n_3921944.html

What is interesting about this picture is that this is the artist’s rendition of what the artist believes Sedna looks like (1). Recently, another small world like Sedna was found to have similar properties, known only as VP 2113. Sedna reaches an interesting part of discussion because although it is not the largest object in the Kuiper Belt, a region of area outside of Neptune’s orbit from 30-50 AU, it easily has the largest period, reaching 12,300 years (2). What is fascinating about the new discovery of VP 2113 is that it similarly is a large body that is left relatively unexplained by many theories and structures of the solar system (1).

While Sedna was found in 2003, it was identified as a trans-Neptunian object, objects outside of Neptune’s own orbit. However, most bodies tended to fit within the Kuiper Belt, a belt defined outside of Neptune’s semimajor axis as being between 30-50 AU and thus defining a moment. However, Sedna defied many of the similarities in the area, and does not match much data with its other Kuiper Belt Objects, many of which have shorter periods, semimajor axes, and eccentricities (2). Now, with the discovery of VP 2113, a neighbor and another trans-Neptunian object, another match is found to relate its data and study further what these bodies should be classified as. Sedna itself has an orbit reaching to 76 AU and reaching out to 1000 AU, unheard of in comparison to the Kuiper belt, and similarly, VP 2113 reaches from 80 AU to 452 AU, with a smaller maximum range but still at a very significantly large semimajor axis. This discovery has led to others questioning these objects and speculating at their further existence, as one astronomer Megan Schwamb wrote that, “something else earlier on in the history of the solar system had to put them on these orbits.” (1)

What this discovery and many like it always reveal is the fascinating nature of science – as we learn more and discover more, there only becomes more to discover, question, and study. I’m excited to find a career or a life where I can always be making more discoveries and realizations and always be ever more curious to search for more.

Sources:

Klotz, Irene – http://news.discovery.com/space/astronomy/small-world-discovered-beyond-pluto-140326.htm

Carroll, Ostlie – Introduction to Modern Astrophysics

Read a report about a rare meteorological phenomenon that is beautiful and fascinating: Rime ice.  The report is the work of Dave Whiteman, Research Professor at the University of Utah and Rolando Garibotti, an expert on the mountains of Patagonia.

Specific conditions are necessary for the formation of rime.  Supercooled water droplets must be suspended in the atmosphere, (water that is liquid below 0C).  This occurs during rapid topographic uplifting of wet, maritime airmasses downwind of water.  They must not cool much below -10c because then the water tends to freeze independent of a surface to stick to.  The rock surface of a mountain must be below freezing, and rime collides with it during high winds, and is accreted in layers.  Above is a photo of Cerro Torre, a mountain in Argentine Patagonia.  Conditions are conducive to rime formation for much of the year, and the formations can grow to huge proportions. Here is Dave Whiteman’s formula for the mass growth of rime ice:

dM/dt=awUA [kg/s]       where w is the supercooled liquid water content of the passing cloud, U is the wind velocity in m/s, A is the area of the obstacle perpendicular to the wind, and a is the droplet-obstacle collision efficiency, between 0 and 1.

Throughout the course of a year wet weather deposits rime steadily on the faces of exposed, windswept ridges and summits.  In the photo above, these ‘mushrooms’ can grow to thicknesses of over 30m.

It is hard for the human to comprehend how small the planets are in comparison with the sun. If you shrunk the sun from its radius of 6.96E8 m down to the size of a beach ball with a radius of 20 cm, and then shrunk all the planet’s radii by the same factor, our earth would have a radius of 1.8 mm, like a large grain of sand. The largest planet jupiter would have a radius of only 2 cm, the size of marble. This is simply calculated by using a ratio, if you wanted to calculate the rest of the planet’s relative size you could use the relation, r=(0.2m/6.96E8m)R where R is the actual radius of the planet and r is the relative size in our scheme. It puts into perspective why to the early astronomers, and the uninformed observer, the planet’s simply look like stars in the night sky. We see our sun to be an actual circle in the sky, because not only is it very large compared to the planet’s, but also very close compared to the next closest stars. The planet’s appear so small, because they are actually much smaller than the sun. In addition, they are relatively the same distance from earth as the sun, when we consider how much farther it is to any object outside our solar system; the closest visible object is the next closest star, Proxima Centauri, which is 4.2 light years away, 272,000 AU (the distance from earth to sun), or 4E16 m.

Actual stars then are all much farther away from the earth than the planets, and as any person knows, things look smaller as they get farther away. This effect is simply perspective. If one changes their line of sight looking at the object its distance from you can be calculated based of the change in apparent angle of the star. More simply, this change in apparent angle is how fast you perceive the object to move. A perfect example is if you are in a car looking out the side window, you will notice that the houses right next the road move faster than the houses farther away from the road. This is how astronomers first calculated the distance to the stars: They would measure the apparent location of a star and then wait 6 months for the earth to orbit half-way and move 2 AU (2x the distance between the sun and earth) from its initial position, and then measure again, and find out the angular difference. When you take into account this effect of distance, and try to calculate the radius of these far off objects, you realize all the stars on average are about the same size as our sun, or bigger. Thus, the human eye sees stars and planet’s to be about the same size in the night sky, but in reality, only the planets are actually ‘small’ when compared with the sun. Most stars are just so much farther away they appear to be so small.

Another great example of this effect of perspective on the perceived size of an object is the sun and moon. To the average observer of the sky, it is pretty easy to notice that the only actual ‘circular’ objects and not ‘point’ objects, (I’m considering anything that has a angular width of less than a minute of a degree to be a ‘point’) are the sun and the moon. What is even more amazing is that the sun has an angular width of about 31.6′ and the moon has about 29.3′ of width: almost exactly the same! The result of this coincidence is that we are able to have total solar eclipses. If either was smaller or bigger in angular width, our solar eclipses wouldn’t completely cover the sun, or would completely block out the sun. The lunar width depends on the size of the moon and its distance from earth, and the solar width depends on the size of the sun and its distance from earth. In the case of the lunar width, the moon is actually smaller in radius than the earth, about 27% the radius of earth, but its about .0025 AU from the earth, or about 0.25% the distance from the earth to the sun, thus it appears to be large in the sky because it is so much closer. Whereas the sun has a radius about 110 times the size of earth, but is 400 times farther away, thus giving comparably the same angular width by total coincidence. I find this coincidence very puzzling, but beautiful at the same time.  Before astronomers could reason the distances to the sun and moon and their sizes, our perspective made us believe the sun and the moon were the same size (not to mention many thought the moon was a perfect sphere!). In reality however, the sun is a massive ball of hot gas/plasma much farther away that humans will never be able to step foot on. Conversely, the moon is a small, cold rock, that is so close to us, it only took humans 300 years after learning the laws of gravity to build a spaceship to travel to it in just 3 days and have a few humans walk around on it.

sources cited

http://en.wikipedia.org/wiki/Solar_eclipse

Bradley W. Carroll and Dale A. Ostlie. An Introduction to Modern Astrophysics. 2nd Edition http://en.wikipedia.org/wiki/Angular_diameter

The universe is oddly uniform. This may seem unimportant to the casual observer, but to Physicists this fact is very odd. The universe is (almost) the same temperature throughout, despite being larger in diameter in light years than the universe is old in years. What does this mean? It means that there is no way that one side of the universe could have interacted with the other. There is simply not enough time for the universe to cool as evenly as it has, which creates a bit of a problem, as Dennis Overbye states in his New York Times Article, it is as if you were to look one mile in every direction and see a cup of coffee that has cooled to the exact temperature. Of course, Physicists haven’t just been been sitting waiting for the solution to drop out the sky(although in some ways that’s how most discoveries in Cosmology take place). The leading theory for this was “inflation” a mysterious force that caused the universe to violently (or less violently depending on which flavor of inflation you prefer) expand at “speeds” faster than the speed of light, giving us the giant, uniform, expanding universe we have today. This model produced telltale signs of its truth in the form of gravitational waves, ripples in space time produced from the chaotic expansion that would still conceivably be lapping on the shores of distant galaxies to this day. There was only one problem, most people thought that the waves would be far too faint to ever be detected. That was all until about a week ago, when scientists operating the the BICEP2 telescope located near the South Pole announced that they had detected what they believed to be those pesky gravitational waves. It is important to note that nothing is every truly confirmed in science, and this is very far from being effectively confirmed. The data has not undergone peer review, that process that separates real science from any Joe writing whatever he wanted on a blog and calling it truth, but if confirmed this discovery will be monumental. According to inflationary theory, Gravitational Waves are the telltale signs of Gravitons, the much doubted and sought after particle that relates Einsteins eloquent theory of Gravitation with Quantum Theory. What does all of this mean for Physics and the future of Physics? Well until now, scientist were pretty good at explaining the nature of 3 out 4 of the Forces in Nature. According to Quantum theory, each force has a particle attached to it that serves as it’s actor. To those who don’t know the 4 fundamental forces are the 2 Nuclear forces, the Strong and the Weak, Electromagnetism, and Gravity. To the layman, Gravity would seem the most familiar. We know that it is what keeps us on the Earth, what keeps the Earth(and all the other Planets) in orbit with the Sun, and what holds Galaxies together. However to the Physicist, gravity has long been the misunderstood. The Standard Model explained the other forces marvelously, but when it came it was a bit stuck. Gravitons were thought to exist but there was no experimental evidence, and what more this theory of Gravity contradicted with Einsteins Theory of General Relativity. According to Einstein gravity was not a force but was a curvature of spacetime. This troubled Physicists, since their is loads of experimental evidence that supports Einstein. However, with the detection of Gravitational Waves there is renewed hope that the two seemingly far apart models may be married. It would seem with this discovery that their is evidence that Gravity may be based off the roll of dice just as everything else in the universe has proved to be. Einstein might be rolling in his grave but this announcement also sets the framework for a New Look Physics that introduces the possibility of discovering some of the nagging questions that have dogged Physicists for sometime, including Dark Matter and Energy, as well as the ultimate fate of our giant, uniform, expanding home that is the Universe.

Links:  http://www.nytimes.com/2014/03/25/science/space/ripples-from-the-big-bang.html?ref=science&_r=0

http://www.nature.com/news/gravitational-wave-finding-causes-spring-cleaning-in-physics-1.14910

http://www.nytimes.com/2014/03/18/science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html?action=click&module=Search&region=searchResults%230&version=&url=http%3A%2F%2Fquery.nytimes.com%2Fsearch%2Fsitesearch%2F%3Faction%3Dclick%26region%3DMasthead%26pgtype%3DSectionFront%26module%3DSearchSubmit%26contentCollection%3Dscience%26t%3Dqry425%23%2FSouth%2BPole%2Fsince1851%2Fallresults%2F1%2Fallauthors%2Fnewest%2F

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For the next month or so I will be posting here for my PC 357 Astrophysics class, mainly about science, but also about life and things.

My classmates’ blogs are at thomasbraine.wordpress.com, and samuelhuestis.wordpress.com

One of the sections in our assigned reading tonight covered extrasolar planets. It reminded me about HD 189733b, an extrasolar planet I researched during first block, and one of the wildest things I’ve learned about at any level of physics.

Image Source: Wikimedia Commons

HD 189733b was discovered in 2005, orbiting its host star about 63 light years away from Earth. Using the Hubble Space Telescope to conduct spectroscopy on the exoplanet, researchers determined the planet to be blue, since a drop in blue light was detected whenever HD 189733b would pass in front of the host star. Naturally, a blue planet draws comparisons to Earth, but nothing else about the two planets are remotely comparable.

Image Source: http://chandra.harvard.edu/photo/2013/hd189733/

For starters, the blue color comes not from water, but from a high concentration of silicate in the atmosphere. Furthermore, HD 189733b does not spin about its axis, so there is no day and night. The side facing the host star cooks perpetually at a temperature around 1800°F, baking the silicate into a molten glass cloud straight out of a sci-fi movie. Since the dark side never receives any heat, the vast temperature differences result in incomprehensible wind speeds exceeding 4000 MPH, whipping the molten glass across the planet’s surface

It is safe to say that HD 189733b does not support the alien life that many humans are obsessively searching for. However, the detail to which astronomers have been able to discern the activity on the surface of this planet should be encouraging to anyone interested in the exploration of outer space.

Sources and Further Reading:

http://www.nasa.gov/content/nasa-hubble-finds-a-true-blue-planet/#.UzI7EYVTry0

http://en.wikipedia.org/wiki/HD_189733_b

http://www.space.com/22614-blue-alien-planet-glass-rain.html