Forget about Florida. Have you ever considered vacationing in space? Thanks to Virgin Galactic, we are getting closer and closer to this possibility. Last year, Virgin Galactic SpaceShipTwo crashed in the southwest desert, killing a pilot and completely destroying the aircraft. However, Virgin is getting ready to launch a second SpaceShipTwo this month in Mojave, California for its’ first test flight.
Known for his radical ideas and sense of adventure, Sir Richard Branson launched the Virgin Galactic project in 2004, with the sole hopes of making space travel available to the public. The concept is for passengers to be carried by another aircraft until they reach 50,000 feet, when the two aircrafts will disconnect and the SpaceShip will continue its’ journey up. Passengers will be able to experience zero gravity.
Some hopeful passengers have already put down $250,000 to reserve a spot on Virgin Galactic when it actually comes out, which could be several years. After going through extensive testing, the aircraft must be certified and licensed by the FAA, which is not an easy task in this field. There are several other companies trying to send people to space, including Jeff Bezos’ Blue Origin. It will be exciting to see this actually happen in the near future!
If you spend an entire day at the beach, it is pretty obvious to notice that the tide changes throughout the day. Sometimes it comes up all the way to your feet while you lay in your beach chair, while other times the tide can be so low it seems like the water is a mile away from you. Why you ask? The answer is somewhat simple: it has to do with the moon and gravity.
As the moon orbits the Earth, the strength of gravity between the two objects increases and decreases. The force of attraction that the moon has on Earth changes depending where you are on Earth. In places where the force of attraction is strongest, the tides will be highest as the gravity from the moon is literally trying to pull Earth apart. Technically this force of attraction effects all of Earth, but you can only really notice it through tides as the force is not strong enough to move land.
Because of the variance of the force of attraction that the moon has on Earth depending on where you are, the tide fluctuates different amounts around the globe. Factors like latitude, the direction the coastline faces, and the shape of the land around the water all impact the variance of the tides.
Check out these cool pictures of high tide and low tide at the abbey of Mont-Saint-Michel, France
Do you ever wonder how we know what we do about stars? The closest stars besides our sun (Alpha Centauri) are 4.4 lightyears away which may not seem far away, but they aren’t the only stars we have data for. We know all about stars that are farther away. And even if distance weren’t an issue, our technological limitations would be. We can’t just stick a thermometer in a star to read its temperature. So how do we know things like distance, luminosity and temperature?
The answer is in the picture above and others like it. This is the absorption line spectrum of the Sun. From this, we can determine the temperature and using that temperature we can find total energy emitted (and therefore Luminosity– total energy(W/m^2) x area (m^2)).
There are two relevant equations and they both apply to Blackbody Radiation. An object is a blackbody if:
It’s opaque and at thermal equilibrium
No net transfer of heat occurs
Blackbodies have the following radiation properties:
They emit light at all wavelengths
Emit more light at all wavelengths as they get hotter
Thank you for taking the time to come to my blog post. It was another very exciting week in Astronomy 2110, making my job today easy. First and foremost, we must comment on Dr. G’s style choice on Thursday. My dad, who sat in on the class, cannot stop telling family and friends how proud he is to send his son to “a school where an Astronomy Professor can wear Rhinestones to class and fit right in.” It was awesome, Dr. G.
There were a few activities that we did in class this week that stood out, but first I’d like to discuss our abnormal class on Thursday. In somewhat lucky fashion, the breaking news of the first ever detection of gravitational waves was released. Walking into class, I figured we would spend a minute or two discussing the news before moving on to the planned agenda. Clearly, Dr. G had other plans. We spent over half of the class discussing the recent findings and went into great depth on the groundbreaking subject. Do you guys think that was a good decision by Dr. G considering the fact we have a test next week? Contrasting our discussion last week about the importance of science history, what do you all think about the importance of current events in science? Do they help us understand what we are learning or distract us from the actual content of our course?
Furthermore, like we discussed two weeks ago, I must mention the use of visuals and activities in our astronomy class. On Tuesday, we did the spacetime simulation using a latex glove and metal balls, and on Thursday we watched YouTube videos on the gravitational wave discovery and the impact that our universe has on tides on Earth. We also did a light refraction grading experiment. Is Dr. G’s use of visuals and experiments worth the amount of time that they take to do? I think they are, but I also have a tough time understanding astronomy conceptually. Would you change anything about the way these concepts were presented to us?
I hope these questions get everyone thinking in a direction you wouldn’t normally think in! I know this stuff is all new to me. Hope you all are having a fun weekend. Look forward to reading your responses and discussing further on Tuesday.
Doesn’t necessarily stay in space. Humans have been traveling to space since the first orbits about the Earth in the 1960s, we’ve gone to the Moon, but what keeps us from going further out into our solar system or even beyond it? Well, the obvious answers would include our technological limitations and how we can’t travel anywhere fast enough, but another limiting factor is the effects that space has on the human body and how quickly they occur.
A postmenopausal woman will lose 1-1.5 percent of the mass of her hip bone in a year if she isn’t being treated for bone loss-it only takes an astronaut 1 month to lose the same amount. If it take 260 days to get to Mars (approx. 9 months), an astronaut would lose as much as 13.5 percent of their bone mass!
And bone loss isn’t the only problem. Astronauts also lose blood (as a reaction to the bodily fluids moving towards the head- which also results in swollen faces and skinny legs), when the are under the influence of gravity again, this decrease in volume of blood can lead to a decrease in blood pressure and cause them to pass out.
How fluid travels in the Human Body in space (Wikipedia )
Space also has effects on the immune system that cause dysregulation and depressed function.
While reading the textbook, I found it very disappointing just how close the Greeks were to figuring out that Earth was not the center of the universe. Had they not been fooled by looking for parallax, they would have been led to the right conclusion that the Earth orbits the sun, rather than that everything orbits the Earth. I then set out to look into the history of the heliocentric model a bit more, hoping to find some kind of ancient civilization which successfully concluded that the Earth revolved around the sun before Copernicus.
Although I was unable to find one, I found that the first notion of a heliocentric model of the solar system dated back to 9th Century BCE, credited to an Indian philosopher by the name of Yajnavalkya. Unfortunately, just as was the case with the Greeks, supporters of this model were in the minority and the model was not widely accepted until much later.
Credit for the first heliocentric models successful at predicting the positions of celestial bodies goes to the Indians as well. In his magnum opus Aryabhatiya, Aryabhata (476-550) created a planetary model in which Earth was taken to be spinning on its axis and the planets revolved around the sun. Later, Nilakantha Somayaji (1444 – 1544) proposed a heliocentric model that was even more accurate at predicting the orbits of the planets than was both the Tychonic and Copernican models. It fell short of predicting the movement of the rest of the universe, but many of the astronomers in India seemed to have accepted his planetary model. Despite this, like many things in astronomy, the European model later took over instead.
We talked a bit in class on Tuesday about what would happen to someone’s body if he were to spend too long in space. His bones would start deteriorating, his muscles would get weaker, and his body would produce less blood as he adjusts to zero G. I was reminded while we were talking about this in class of a book I read by Isaac Asimov, The Gods Themselves. The book took place at a time when mankind had already colonized the moon. However, although people born on Earth could easily travel to the moon and back, people who were born on the moon could not. They would just crumple up and die, their bodies too unaccustomed to the Earth’s gravity. I thought it would be interesting to do some research on the topic and what I found was that no one really knows what would happen.
However, I did find a diagram which showed the rate of bone loss per part of body for every month that someone spends in zero G gravity. Assuming that a baby born on the moon would not just immediately perish, it seems as if the baby would be born with an immensely low bone density compared to a human on Earth, just because it wouldn’t need as much to support its own body. If the human were one day introduced to Earth gravity all of a sudden, it is easy to see that the shock of experiencing a constant gravity of 6x greater than normal would cause it to shut down, especially considering that the heart would probably not be strong enough to pump blood up to the brain any more.
2. Nicholas Copernicus (1473-1543) was important to astronomy because he served as a pioneer in drifting away from the geocentric model of the universe. He dove tediously into the tables and mathematics of the previous, geocentric model of the universe and found enlightenment in geometry. He thereby successfully determined the distances between planets and the Sun, as well as their relative orbits around our home star. Though he was not able to perfectly model our universe, he was courageous enough to eventually publish a book on his findings—one that helped future scientists slough their way through tedious trial and error necessary to the knowledge we have today.
The Spanish Conquest began shortly after Christopher Columbus’s discovery of America(s) when he sailed the ocean blue in 1492. Hernan Cortes and Francisco Pizarro were two famous conquistadors from the era, both vital to the destruction of the Aztec and Inca civilizations.
2nd Event: Ferdinand and Isabella unite to become the ‘Catholic Monarchs of Spain’ (1479):
Ferdinand of Aragon and Isabella of Castile, “royal cousins,” were married in 1469 in an effort to unite Spain during a time of war and turmoil. It wasn’t until 1479 that the two were officially announced King and Queen of Aragon and Castile, thanks to the Treaty of Alcáçovas, and began restoring the country’s political destruction and royal authority.
B. Niccolò Machiavelli was a pioneer in modern day political science and humanitarian thinking. Born in May of 1469 (and died June 1527), the Italian published an agelessly famous work, “The Prince,” assessing that “the ends justify the means.” His progressive thought challenged the Roman Catholic Church’s most fundamental doctrines and authority. Though he was not an astronomer, his audacity in “The Prince” shook the Church’s near perfect foundation and foreshadowed further changes (i.e. transition from the accepted geocentric model to heliocentric).
4. First, I always think it’s interesting to look at other events happening around the world when learning about history—which is why I enjoyed question #3B in particular. On first glance, Machiavelli’s book seems totally irrelevant to astronomy (after all, he was a thinker, a philosopher, NOT an astronomer). However, looking at the succession of events, starting with the Catholic Church’s banning of “The Prince” on the basis of challenged authority, we can see the beginning of the crumbling that eventually lead to confrontations with the Church in the early 1600’s and its slow transition to the heliocentric model of the universe. Second, it’s fascinating to see the differences that cultures make in science. While Copernicus was tucked away in Europe busily tacking away at geometric models of orbital paths and distances from various planets to the Sun, things were heating up in the Americas as entire civilizations crumbled. The context leavens our understanding of just how significant and advanced thoughts like Copernicus’s truly were.
Works Consulted:
“A Timeline of Contemporary European Events, 1400 to 1550.” Illuminating the Renaissance. British Library Board, n.d. Web. 09 Feb. 2016.
Bennett, Jeffrey O. “The Copernican Revolution.” The Cosmic Perspective: Solar System. 7th ed. Boston: Pearson, 2014. 64. Print.
“Historical/Cultural Timeline – 1500.” Historical/Cultural Timeline – 1500. College of Education, University of Houston, n.d. Web. 09 Feb. 2016.
Let’s talk about Galileo [February 15th, 1564 – January 8th, 1642]. Not only was he a champion of the Copernican heliocentric view of the cosmos; he also discovered four of Jupiter’s moons with his telescope – giving less and less credence to a critics of the heliocentric model because it showed that small objects could orbit a moving object. He also demonstrated the phases of Venus – a phenomenon that could only be possible if it orbited the Sun instead of Earth. For that he is considered by many, among many other things, the father of modern science, the father of physics, and the father of observational astronomy.
Galileo’s lifetime was a formative period in Europe. One important thing that strikes me is the publication of the first novel in the form as we understand it in 1605, Don Quixote of La Mancha by Miguel de Cervantes, arguably one of the most influential literary works and the formative work for modern Western literature. Another major event that happens is the establishment of Jamestown, Virginia in 1607, which is the first permanent English settlement in America, marking the beginnings of the British Empire.
Let’s put this further in context. William Shakespeare [birth date unknown | baptized April 26th, 1564 – April 23rd, 1616] considered by many to be the greatest figure and dramatist in English literature, was his contemporary. His works continue to have a marked influence on the way we study and interact with literature.
It’s always very enlightening to ground our knowledge in a historical basis. I feel like – especially in a liberal arts college environment – we are inundated with knowledge about many different fields, but it can rarely ever occur to us how this knowledge came about in history. It’s especially interesting to see what kinds of historical figures were contemporaries of each other – and hence, what kind of intellectual epoch humanity was in at a particular time in history. It’s fascinating that hallmark events in astronomy and literature (here specifically) were happening within a person’s lifetime.
Nicholas Copernicus- February 19, 1473 to May 24, 1543
Nicholas Copernicus’ greatest contribution to science was the idea that the Sun was the center of our solar system rather than the Earth. In other words, a heliocentric model rather than a geocentric model. This was a major step forward in determining that the Earth is nothing special in this universe full of other planets, solar systems, and galaxies. Copernicus Source
3a. In 1492, Christopher Columbus sailed to what we now know as the Americas, and became the first non native to discover the land.
3b. King Henry VIII of England also lived during the time of Copernicus. He is a notable king for his erratic behavior and being responsible for separating the English government with the Roman Catholic Church. Significance of King Henry VIII
4. I think it is more than interesting to get a little bit of context when discussing the history of astronomy. I did not realize how closely together these 5 influential figures lived, and as a result they must have relied on each other’s work greatly. Furthermore, they lived during a time of great exploration, much of which relied on celestial navigation. Could there be a connection between the huge advances we made in Astronomy during this period and the need for astronomy in order to travel by sea?
