Thursday, December 18, 2008
Aliens
I believe that aliens can exist in our universe and I think that they do. It seems a little odd that out of how many galaxies we are the only planet that has life on it. Experts don't think that aliens exist because we haven't ever communicated with them, but maybe they don't know we are here. If they do or don't, they might not have any desire to interact with us of to find anything out there like them. We might not ever be able to reach a distant planet that could support life just like earth, but that doesn't change the possibility that something might be out there. Another side that no one has considered is what if there is another form of humans out there that doesn't need the same elements to survive that we do. When we explore Mars, we look for water or things like that but there might be another form of people that don't need things like that.
The Big Bang
I agree with the big bang theory in some ways. The science and math that back it up can't be ignored, but the religious side of me also doesn't agree. It seems amazing that the universe began and then within not even a second it cooled down a lot. It also seems weird that it could cool down so quickly, and then it took billions of years to cool more and more.
I think that the big bang and the religious side of it can exist together. In the bible it says that God created the earth. That can be true.. the big bang put everything into place and then God evolved everything from that.
I think that the big bang and the religious side of it can exist together. In the bible it says that God created the earth. That can be true.. the big bang put everything into place and then God evolved everything from that.
Monday, December 15, 2008
Exploring Hubble Deep Field
I never realized that the universe is so big. Somehow even though I have learned differently, I assumed that our galaxy was one of a kind and there isn't another one like it. I know that there are billions upon billions of galaxies in the universe, and there is a good possibility that life could exist in any one of those galaxies.
The Hubble Deep Field picture made me realize that even though I might stare at a black spot in the sky and think there can't be anything there, there are actually billions of galaxies in every black or empty spot in the sky. There are different types of galaxies also; ellipticals, spirals, and irregulars. Each of them are unique in their own way.
I learned that you need to have a larger sample size so your measures of central tendency are closer. Astronomers suggest a sample size between 35-45 for best results. Also when you have a larger sample size, your range decreases. I found out that humans are often biased when it comes to picking galaxies and such. Even when we close out eyes and point to one, we are still being biased when we open out eyes and say which our finger is pointing to. It's better to use the computer to select a sample group. The computer is very unbiased and you often get the best results with it. When you use a computer you become much closer to the astronomers results also.
An important thing that I learned it that the number of galaxies (elliptical, spiral, irregular) are near the same in the Hubble Deep Field North and the Hubble Deep Field South. From this we can say that the universe looks the same in these two directions. I think that I learned many things that I didn't know or expect from this activity. I also knew that the universe was big, but I never realized just how big it really is.
Tuesday, December 2, 2008
My Passion
My passion would be to help animals. I would love to let people know everything about them, and show them that some of the most dangerous animals aren't all that terrifying. It would be amazing to work at a zoo. Being around animals all day would be the best job in the world. I would love to go on the ship that is trying to stop the Japanese from whaling. I think that it is cruel and there is no good explanation to put those animals in extreme danger. I would love to devote my whole life to helping animals survive and educating people about them.
Black Holes
1. Distinguishes between an event horizon and an accretion zone of a black hole.
The accretion zone has matter that is just floating around, the event horizon is the place that if matter passes into this it will be sucked in and lost forever.
2. Defines escape velocity, black hole, and the speed of light.
Escape Velocity- The speed needed to break free from a gravitational field.
Black Hole- An area that is so compact that when you get too close, the speed of light isn't fast enough to escape.
Speed of Light- The speed of (2.99793 X 108 m/s, or 186,000 miles/s). It is a constant in empty space.
3. Explains the relationship between escape velocity, black hole, and the speed of light.
The speed of light isn't fast enough to escape a black hole, which is composed of escape velocity.
4. Identifies more than one single type of black hole.
Stellar Black holes- When a massive star super novas.
Super Massive Black holes- At the center of galaxies.
Quasars- When 2 black holes combine and energy is driven off.
5. List evidence that our understanding of black holes has changed.
A black hole cannot be viewed directly because light cannot escape it. Effects on the matter that surrounds it infer its presence. Matter swirling around a black hole heats up and emits radiation that can be detected. Around a stellar black hole this matter is composed of gas and dust. Around a supermassive black hole in the center of a galaxy the swirling disk is made of not only gas but also stars. An instrument aboard the Hubble Space Telescope, called the Space Telescope Imaging Spectrograph (STIS), was installed in February 1997. STIS is the space telescope's main "black hole hunter." A spectrograph uses prisms or diffraction gratings to split the incoming light into its rainbow pattern. The position and strength of the line in a spectrum gives scientists valuable information. STIS spans ultraviolet, visible, and near-infrared wavelengths. This instrument can take a spectrum of many places at once across the center of a galaxy. Each spectrum tells scientists how fast the stars and gas are swirling at that location. With that information, the central mass that the stars are orbiting can be calculated. The faster the stars go, the more massive the central object must be.(site from blog)
7. List at least 2 myths about black holes that are discredited.
The volume of a black hole approaches zero. As volume decreases, density increases. Density is the relationship of mass per unit of volume (Density = Mass/Volume). The density of a black hole affects the escape velocity of an object — even light.
Black holes have a broad range of masses — from the smallest (miniature) to the largest (supermassive).
The accretion zone has matter that is just floating around, the event horizon is the place that if matter passes into this it will be sucked in and lost forever.
2. Defines escape velocity, black hole, and the speed of light.
Escape Velocity- The speed needed to break free from a gravitational field.
Black Hole- An area that is so compact that when you get too close, the speed of light isn't fast enough to escape.
Speed of Light- The speed of (2.99793 X 108 m/s, or 186,000 miles/s). It is a constant in empty space.
3. Explains the relationship between escape velocity, black hole, and the speed of light.
The speed of light isn't fast enough to escape a black hole, which is composed of escape velocity.
4. Identifies more than one single type of black hole.
Stellar Black holes- When a massive star super novas.
Super Massive Black holes- At the center of galaxies.
Quasars- When 2 black holes combine and energy is driven off.
5. List evidence that our understanding of black holes has changed.
Astronomers have found convincing evidence for a supermassive black hole in the center of the giant elliptical galaxy M87, as well as in several other galaxies. The discovery is based on velocity measurements of a whirlpool of hot gas orbiting the black hole. In 1994, Hubble Space Telescope data produced an unprecedented measurement of the mass of an unseen object at the center of M87. Based on the kinetic energy of the material whirling about the center (as in Wheeler's dance, see Question 4 above), the object is about 3 billion times the mass of our Sun and appears to be concentrated into a space smaller than our solar system.
For many years x-ray emission from the double-star system Cygnus X-1 convinced many astronomers that the system contains a black hole. With more precise measurements available recently, the evidence for a black hole in Cygnus X-1 is very strong.(site from the blog) It shows that we haven't known everything. The Hubble telescope discovered a lot for us.
A black hole cannot be viewed directly because light cannot escape it. Effects on the matter that surrounds it infer its presence. Matter swirling around a black hole heats up and emits radiation that can be detected. Around a stellar black hole this matter is composed of gas and dust. Around a supermassive black hole in the center of a galaxy the swirling disk is made of not only gas but also stars. An instrument aboard the Hubble Space Telescope, called the Space Telescope Imaging Spectrograph (STIS), was installed in February 1997. STIS is the space telescope's main "black hole hunter." A spectrograph uses prisms or diffraction gratings to split the incoming light into its rainbow pattern. The position and strength of the line in a spectrum gives scientists valuable information. STIS spans ultraviolet, visible, and near-infrared wavelengths. This instrument can take a spectrum of many places at once across the center of a galaxy. Each spectrum tells scientists how fast the stars and gas are swirling at that location. With that information, the central mass that the stars are orbiting can be calculated. The faster the stars go, the more massive the central object must be.(site from blog)
7. List at least 2 myths about black holes that are discredited.
The volume of a black hole approaches zero. As volume decreases, density increases. Density is the relationship of mass per unit of volume (Density = Mass/Volume). The density of a black hole affects the escape velocity of an object — even light.
Black holes have a broad range of masses — from the smallest (miniature) to the largest (supermassive).
Thursday, November 13, 2008
The End of the World...
I agree with the article that nothing bad is going to happen to us. The Mayans simply just didn't design a calendar that went past the date 2012. They weren't able to calculate dates after 2012. As for solar flares and such, there is no HARD evidence that tells us that we will be destroyed by one. It's like Mrs. Powell said the sun doesn't have enough energy to push a solar flare all the way to Earth. People who study the Mayan calendar aren't all that sure if it doesn't just start back over at 0.0.0.0.0 after 13.0.0.0.0, or whether the calendar simply continues to 20.0.0.0. I am the type of person that needs to see something to believe it and there just isn't enough evidence out there to convince me that we are all going to die on December 21, 2012.
Space Weather and Asteroids
I don't believe that we have to be worried about getting hit by an asteroid. This should not be a big concern to us. What we call Near Earth Objects, sometimes are not all that close. NASA says that anything within 1.3 AU of the sun is considered this. This is still a great distance from Earth. We haven't been hit by an asteroid recently, so the threat of them getting close to us shouldn't be a grave concern now.
Most objects that come close to Earth aren't anything that could do damage to us. NASA says that only a relatively small number of the hazardous objects are large enough for us to worry about. They also say that because of the gravitational pull, these objects could come into Earth's path. The closest that an object has been recently was .01LD, but it was only 4m in size. If people are worried about another Tunguska happening, we aren't 100% sure what it was that hit. Most of the asteroids are located in the asteroid belt and that is a ways from Earth. There are only a few that regularly travel by us.
I think that most anything that comes close to us is going to be relatively small and nothing that we should have to worry about. We shouldn't be scared for the time being.
Most objects that come close to Earth aren't anything that could do damage to us. NASA says that only a relatively small number of the hazardous objects are large enough for us to worry about. They also say that because of the gravitational pull, these objects could come into Earth's path. The closest that an object has been recently was .01LD, but it was only 4m in size. If people are worried about another Tunguska happening, we aren't 100% sure what it was that hit. Most of the asteroids are located in the asteroid belt and that is a ways from Earth. There are only a few that regularly travel by us.
I think that most anything that comes close to us is going to be relatively small and nothing that we should have to worry about. We shouldn't be scared for the time being.
Subscribe to:
Posts (Atom)
