Evolution tied to Earth movement
December 19, 2007 -
Scientists long have focused on how climate and vegetation allowed human ancestors to evolve in Africa. Now, University of Utah geologists are calling renewed attention to the idea that ground movements formed mountains and valleys, creating environments that favored the emergence of humanity."Tectonics [movement of Earth's crust] was ultimately responsible for the evolution of humankind," Royhan and Nahid Gani of the university's Energy and Geoscience Institute write in the January, 2008, issue of Geotimes, published by the American Geological Institute.They argue that the accelerated uplift of mountains and highlands stretching from Ethiopia to South Africa blocked much ocean moisture, converting lush tropical forests into an arid patchwork of woodlands and savannah grasslands that gradually favored human ancestors who came down from the trees and started walking on two feet - an energy-efficient way to search larger areas for food in an arid environment.In their Geotimes article, the Ganis - a husband-and-wife research team who met in college in their native Bangladesh - describe this 3,700-mile-long stretch of highlands and mountains as "the Wall of Africa." It parallels the famed East African Rift valley, where many fossils of human ancestors were found."Because of the crustal movement or tectonism in East Africa, the landscape drastically changed over the last 7 million years," says Royhan Gani (pronounced rye-hawn Go-knee), a research assistant professor of civil and environmental engineering. "That landscape controlled climate on a local to regional scale. That climate change spurred human ancestors to evolve from apes."Hominins - the new scientific word for humans (Homo) and their ancestors (including Ardipithecus, Paranthropus and Australopithecus) - split from apes on the evolutionary tree roughly 7 million to 4 million years ago. Royhan Gani says the earliest undisputed hominin was Ardipithecus ramidus 4.4 million years ago. The earliest Homo arose 2.5 million years ago, and our species, Homo sapiens, almost 200,000 years ago.Tectonics - movements of Earth's crust, including its ever-shifting tectonic plates and the creation of mountains, valleys and ocean basins - has been discussed since at least 1983 as an influence on human evolution.But Royhan Gani says much previous discussion of how climate affected human evolution involves global climate changes, such as those caused by cyclic changes in Earth's orbit around the sun, and not local and regional climate changes caused by East Africa's rising landscape.A Force from within the EarthThe geological or tectonic forces shaping Africa begin deep in the Earth, where a "superplume" of hot and molten rock has swelled upward for at least the past 45 million years. This superplume and its branching smaller plumes help push apart the African and Arabian tectonic plates of Earth's crust, forming the Red Sea, Gulf of Aden and the Great Rift Valley that stretches from Syria to southern Africa.As part of this process, Africa is being split apart along the East African Rift, a valley bounded by elevated "shoulders" a few tens of miles wide and sitting atop "domes" a few hundreds of miles wide and caused by upward bulging of the plume.The East African Rift runs about 3,700 miles from the Ethiopian Plateau south-southwest to South Africa's Karoo Plateau. It is up to 370 miles wide and includes mountains reaching a maximum elevation of about 19,340 feet at Mount Kilimanjaro.The rift "is characterized by volcanic peaks, plateaus, valleys and large basins and freshwater lakes," including sites where many fossils of early humans and their ancestors have been found, says Nahid Gani (pronounced nah-heed go-knee), a research scientist. There was some uplift in East Africa as early as 40 million years ago, but "most of these topographic features developed between 7 million and 2 million years ago."A Wall Rises and New Species Evolve"Although the Wall of Africa started to form around 30 million years ago, recent studies show most of the uplift occurred between 7 million and 2 million years ago, just about when hominins split off from African apes, developed bipedalism and evolved bigger brains," the Ganis write."Nature built this wall, and then humans could evolve, walk tall and think big," says Royhan Gani. "Is there any characteristic feature of the wall that drove human evolution?"The answer, he believes, is the variable landscape and vegetation resulting from uplift of the Wall of Africa, which created "a topographic barrier to moisture, mostly from the Indian Ocean" and dried the climate. He says that contrary to those who cite global climate cycles, the climate changes in East Africa were local and resulted from the uplift of different parts of the wall at different times.Royhan Gani says the change from forests to a patchwork of woodland and open savannah did not happen everywhere in East Africa at the same time, and the changes also happened in East Africa later than elsewhere in the world.The Ganis studied the roughly 300-mile-by-300-mile Ethiopian Plateau - the most prominent part of the Wall of Africa. Previous research indicated the plateau reached its present average elevation of 8,200 feet 25 million years ago. The Ganis analyzed rates at which the Blue Nile River cut down into the Ethiopian Plateau, creating a canyon that rivals North America's Grand Canyon. They released those findings in the September 2007 issue of GSA Today, published by the Geological Society of America.The conclusion: There were periods of low-to-moderate incision and uplift between 29 million and 10 million years ago, and again between 10 million and 6 million years ago, but the most rapid uplift of the Ethiopian Plateau (by some 3,200 vertical feet) happened 6 million to 3 million years ago.The Geotimes paper says other research has shown the Kenyan part of the wall rose mostly between 7 million and 2 million years ago, mountains in Tanganyika and Malawi were uplifted mainly between 5 million and 2 million years ago, and the wall's southernmost end gained most of its elevation during the past 5 million years."Clearly, the Wall of Africa grew to be a prominent elevated feature over the last 7 million years, thereby playing a prominent role in East African aridification by wringing moisture out of monsoonal air moving across the region," the Ganis write. That period coincides with evolution of human ancestors in the area.Royhan Gani says the earliest undisputed evidence of true bipedalism (as opposed to knuckle-dragging by apes) is 4.1 million years ago in Australopithecus anamensis, but some believe the trait existed as early as 6 million to 7 million years ago.The Ganis speculate that the shaping of varied landscapes by tectonic forces - lake basins, valleys, mountains, grasslands, woodlands - "could also be responsible, at a later stage, for hominins developing a bigger brain as a way to cope with these extremely variable and changing landscapes" in which they had to find food and survive predators.For now, Royhan Gani acknowledges the lack of more precise timeframes makes it difficult to link specific tectonic events to the development of upright walking, bigger brains and other key steps in human evolution."But it all happened within the right time period," he says. "Now we need to nail it down."
- The University of Utah
http://www.brightsurf.com/news/headlines/34875/Evolution_tied_to_Earth_movement.html
Who: The Ganis's - a husband-and-wife along with Students who at The University of Utah
What: Assume that because the ground movements formed mountains and valleys, creating environments that favored the emergence of humanity which is why most ancient artifacts ar descovered upon in ine African Region.
When: December 19th 2007.
Where:
This logic is well thought out and proven pretty well with basic facts. In addition i never even knew where most old artifacts were discoverd. This is a surprise to me along with probally many others . I probally been full of excite,ent if i discovered these. IN addition the Ganis's are probally amused with what they did. Along with many scientsits!
Wednesday, December 19, 2007
Sunday, May 27, 2007
5TH BLOG- IN CLASS RESPONSE
In class on Friday, May 25th we did a lab. This had to be the best lab so far. It was messy though! Our teacher placed corn starch in a beaker then sprinkled a little fod dye inside. Next to the beaker was a smaller one taht contained water. We then poored water into this mixture. It was so hard to stir. The spoon kept getting stuck. Then we were directed to pick up a chunk with our hands. It had teh weirdest feeling. I went first and boy can i say it was interesting!! This gooey substance became hard in an instance jsut by clenching your hand. I realezed if you apply pressure it tightens up. However if you leave it alone, it seems to flow at a fast paste and dangle off your hands. I enjoyed this lab very much. It made a connectionto the mantle of the earth. You see the mantle is flexible.It's made of solid rock and behaves like an extremely viscous liquid so it flows instead of fracturing. Just like the mixture we made.
-http://mediatheek.thinkquest.nl/~ll125/en/mantle.htm
-http://volcano.und.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers6.html
These two websites provide additional detailon the mantle of the earth and how it works and whats inside of it. The connection that i can make from this lab we did in class was to the actual substance inside of the earth's mantle. The gooey like substance would flow until pressure was applied, like a volcano or the substances inside the mantle. This lab helped teach us students what goes on in the mantle. In addition we had fun proforming it. Altough it was a little messy.
Thursday, April 26, 2007
4TH BLOG- CURRENT EVENT
Diminishing dinosaur steps saved by laser and laptop
- The Fumanya site, in the Bergueda region of central Catalonia, is so delicate that experts cannot get physically close enough to the tracks to examine them.In the years since the tracks were discovered they have been exposed to the elements, and as a result are severely weathered and eroding at a rapid rate.To make things even more difficult, the tracks are imprinted into near-vertical rock faces.Palaeontologists feared the tracks could be lost forever - but a permanent and detailed record has now been created using cutting-edge equipment.Using a high-tech laser scanning system called RIEGL, researchers from The School of Earth, Atmospheric and Environmental have produced an interactive 3D model of a quarry face covered in thousands of tracks made by the late Cretaceous dinosaurs, including sauropods and possibly predatory theropod dinosaurs.The portable system, which is powered by a battery, works by rotating and firing laser beams, which reflect off the quarry faces back to a receiver. The device then cross references the reflections with a built-in digital camera and GPS, and feeds the information into an attached laptop. Software is then used to create a detailed and very accurate 3D computer model of the location.This technology has allowed researchers to closely examine and analyse the Spanish quarry tracks from many different angles and even inside out.This information is very important for palaeontologists and dinosaur locomotion experts, because it gives an insight into the way these dinosaurs moved and the environments in which they lived.The on-going project - run in conjunction with Universitat Autonoma de Barcelona - is being led by palaeontologist Dr Phil Manning, who received a grant of Euro 9,000 from the Consorci Ruta Minera to fund the laser scanning.The computer modelling for the project was done by Dr David Hodgetts, a senior lecturer in Reservoir Modelling and Petroleum Geology.Student Karl Bates, who is now carrying out Post Graduate research into dinosaur locomotion, worked on the Fumanya tracks for his MPhil degree project.Karl said: "Due to the fragile environment and the sensitivity of the site we were not permitted direct contact and therefore all measurements had to taken remotely.Dr Manning added: "Laser scanning allowed the rapid, high resolution, 3D digital mapping of an otherwise inaccessible site. The computer-generated trackways we have created preserve important information on the locomotion of dinosaurs, which can be properly accessed for the first time."It took four days for a team from the School of Earth, Atmospheric and Environmental Sciences to collect all the necessary information to create a comprehensive 3D model of the quarry, although some initial results were available within just 15 minutes.The quarry, which lies to the north of Barcelona, was still active until fairly recently, but there are now plans to make it a protected site of special scientific interest.Dr Manning was part of the UNESCO team who initially evaluated the trackway localities in Northern Spain, as part of a pending Iberian Peninsula World Heritage Site application.Although the footprints are imprinted in a vertical cliff face, the surface the dinosaurs travelled across millions of years ago would have been flat.The School of Earth, Atmospheric and Environmental Sciences was the first academic department in the country to acquire the RIEGL scanning equipment.Only one other department in the UK can boast such equipment.The equipment is generally used in oil exploration, but this project is the first time The University has used it to create images of dinosaur tracks.Dr Manning has also extended the use of the scanner to palaeontological investigation in the Creek Formation in the United States, home to the infamous Tyrannosaurs Rex.
University of Manchester
http://brightsurf.com/news/headlines/30453/Diminishing_dinosaur_steps_saved_by_laser_and_laptop.html
who: The Palaeontologists at Manchester university
what: Are looking at whats left of dinosaur fossils with the help of lasers and laptop technology.
when:May 10th 2007
where: At the Manchester University
This is fascinating. Ive always wondered about dinosaurs. They are very interesting creatures and its a shame taht they have vanished. Its good that there are remainders left all over the world from these animals. I hope these Palaeontologists can come through and find additional information describing the fossils.
- The Fumanya site, in the Bergueda region of central Catalonia, is so delicate that experts cannot get physically close enough to the tracks to examine them.In the years since the tracks were discovered they have been exposed to the elements, and as a result are severely weathered and eroding at a rapid rate.To make things even more difficult, the tracks are imprinted into near-vertical rock faces.Palaeontologists feared the tracks could be lost forever - but a permanent and detailed record has now been created using cutting-edge equipment.Using a high-tech laser scanning system called RIEGL, researchers from The School of Earth, Atmospheric and Environmental have produced an interactive 3D model of a quarry face covered in thousands of tracks made by the late Cretaceous dinosaurs, including sauropods and possibly predatory theropod dinosaurs.The portable system, which is powered by a battery, works by rotating and firing laser beams, which reflect off the quarry faces back to a receiver. The device then cross references the reflections with a built-in digital camera and GPS, and feeds the information into an attached laptop. Software is then used to create a detailed and very accurate 3D computer model of the location.This technology has allowed researchers to closely examine and analyse the Spanish quarry tracks from many different angles and even inside out.This information is very important for palaeontologists and dinosaur locomotion experts, because it gives an insight into the way these dinosaurs moved and the environments in which they lived.The on-going project - run in conjunction with Universitat Autonoma de Barcelona - is being led by palaeontologist Dr Phil Manning, who received a grant of Euro 9,000 from the Consorci Ruta Minera to fund the laser scanning.The computer modelling for the project was done by Dr David Hodgetts, a senior lecturer in Reservoir Modelling and Petroleum Geology.Student Karl Bates, who is now carrying out Post Graduate research into dinosaur locomotion, worked on the Fumanya tracks for his MPhil degree project.Karl said: "Due to the fragile environment and the sensitivity of the site we were not permitted direct contact and therefore all measurements had to taken remotely.Dr Manning added: "Laser scanning allowed the rapid, high resolution, 3D digital mapping of an otherwise inaccessible site. The computer-generated trackways we have created preserve important information on the locomotion of dinosaurs, which can be properly accessed for the first time."It took four days for a team from the School of Earth, Atmospheric and Environmental Sciences to collect all the necessary information to create a comprehensive 3D model of the quarry, although some initial results were available within just 15 minutes.The quarry, which lies to the north of Barcelona, was still active until fairly recently, but there are now plans to make it a protected site of special scientific interest.Dr Manning was part of the UNESCO team who initially evaluated the trackway localities in Northern Spain, as part of a pending Iberian Peninsula World Heritage Site application.Although the footprints are imprinted in a vertical cliff face, the surface the dinosaurs travelled across millions of years ago would have been flat.The School of Earth, Atmospheric and Environmental Sciences was the first academic department in the country to acquire the RIEGL scanning equipment.Only one other department in the UK can boast such equipment.The equipment is generally used in oil exploration, but this project is the first time The University has used it to create images of dinosaur tracks.Dr Manning has also extended the use of the scanner to palaeontological investigation in the Creek Formation in the United States, home to the infamous Tyrannosaurs Rex.
University of Manchester
http://brightsurf.com/news/headlines/30453/Diminishing_dinosaur_steps_saved_by_laser_and_laptop.html
who: The Palaeontologists at Manchester university
what: Are looking at whats left of dinosaur fossils with the help of lasers and laptop technology.
when:May 10th 2007
where: At the Manchester University
This is fascinating. Ive always wondered about dinosaurs. They are very interesting creatures and its a shame taht they have vanished. Its good that there are remainders left all over the world from these animals. I hope these Palaeontologists can come through and find additional information describing the fossils.
3RD BLOG -CURRENT EVENT.
-Astronomers find first habitable Earth-like planet April 25, 2007 -
-Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.This exoplanet - as astronomers call planets around a star other than the Sun is the smallest ever found up to now [1] and it completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, given that its host star, the red dwarf Gliese 581 [2], is smaller and colder than the Sun and thus less luminous the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid!"We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid," explains Stphane Udry, from the Geneva Observatory (Switzerland) and lead-author of the paper reporting the result. "Moreover, its radius should be only 1.5 times the Earths radius, and models predict that the planet should be either rocky like our Earth or covered with oceans," he adds."Liquid water is critical to life as we know it," avows Xavier Delfosse, a member of the team from Grenoble University (France). "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."The host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra ("the Scales"). It has a mass of only one third the mass of the Sun. Such red dwarfs are intrinsically at least 50 times fainter than the Sun and are the most common stars in our Galaxy: among the 100 closest stars to the Sun, 80 belong to this class."Red dwarfs are ideal targets for the search for low-mass planets where water could be liquid. Because such dwarfs emit less light, the habitable zone is much closer to them than it is around the Sun," emphasizes Xavier Bonfils, a co-worker from Lisbon University. Planets lying in this zone are then more easily detected with the radial-velocity method [3], the most successful in detecting exoplanets.Two years ago, the same team of astronomers already found a planet around Gliese 581 (see ESO 30/05). With a mass of 15 Earth-masses, i.e. similar to that of Neptune, it orbits its host star in 5.4 days. At the time, the astronomers had already seen hints of another planet. They therefore obtained a new set of measurements and found the new super-Earth, but also clear indications for another one, an 8 Earth-mass planet completing an orbit in 84 days. The planetary system surrounding Gliese 581 contains thus no fewer than 3 planets of 15 Earth masses or less, and as such is a quite remarkable system.The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another Trio of Neptunes (ESO 18/06, see also ESO 22/04).The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs."HARPS is a unique planet hunting machine," says Michel Mayor, from Geneva Observatory, and HARPS Principal Investigator. "Given the incredible precision of HARPS, we have focused our effort on low-mass planets. And we can say without doubt that HARPS has been very successful: out of the 13 known planets with a mass below 20 Earth masses, 11 were discovered with HARPS!"HARPS is also very efficient in finding planetary systems, where tiny signals have to be uncovered. The two systems known to have three low mass planets HD 69830 and Gl 581 were discovered by HARPS."And we are confident that, given the results obtained so far, finding a planet with the mass of the Earth around a red dwarf is within reach," affirms Mayor.
-European Southern Observatory (ESO)
http://brightsurf.com/news/headlines/30140/Astronomers_find_first_habitable_Earth-like_planet.html
Who: A team of Swiss, French and Portuguese scientists
What: Have discovered the most Earth-like planet outside our Solar System
When: April 25th, 2007
Where: At the Geneva Observatory (located in Switzerland)
From my prospective this is very interesting. The people who created the planet hunting machine should be honored. This is something we have been struggling with ofr many many years. And to finally discover another earth-like planet outside of out solar system is shocking. . I find it mind boggling that we have such AMAZING technology. This new discovery has probally triggered other scientits brains. I hope they keep us updated on these type of discoveries because i am very interested in finding out more about whats happening today all around the world.
-Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.This exoplanet - as astronomers call planets around a star other than the Sun is the smallest ever found up to now [1] and it completes a full orbit in 13 days. It is 14 times closer to its star than the Earth is from the Sun. However, given that its host star, the red dwarf Gliese 581 [2], is smaller and colder than the Sun and thus less luminous the planet nevertheless lies in the habitable zone, the region around a star where water could be liquid!"We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid," explains Stphane Udry, from the Geneva Observatory (Switzerland) and lead-author of the paper reporting the result. "Moreover, its radius should be only 1.5 times the Earths radius, and models predict that the planet should be either rocky like our Earth or covered with oceans," he adds."Liquid water is critical to life as we know it," avows Xavier Delfosse, a member of the team from Grenoble University (France). "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X."The host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra ("the Scales"). It has a mass of only one third the mass of the Sun. Such red dwarfs are intrinsically at least 50 times fainter than the Sun and are the most common stars in our Galaxy: among the 100 closest stars to the Sun, 80 belong to this class."Red dwarfs are ideal targets for the search for low-mass planets where water could be liquid. Because such dwarfs emit less light, the habitable zone is much closer to them than it is around the Sun," emphasizes Xavier Bonfils, a co-worker from Lisbon University. Planets lying in this zone are then more easily detected with the radial-velocity method [3], the most successful in detecting exoplanets.Two years ago, the same team of astronomers already found a planet around Gliese 581 (see ESO 30/05). With a mass of 15 Earth-masses, i.e. similar to that of Neptune, it orbits its host star in 5.4 days. At the time, the astronomers had already seen hints of another planet. They therefore obtained a new set of measurements and found the new super-Earth, but also clear indications for another one, an 8 Earth-mass planet completing an orbit in 84 days. The planetary system surrounding Gliese 581 contains thus no fewer than 3 planets of 15 Earth masses or less, and as such is a quite remarkable system.The discovery was made thanks to HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. Located on the ESO 3.6-m telescope at La Silla, Chile, HARPS is able to measure velocities with a precision better than one metre per second (or 3.6 km/h)! HARPS is one of the most successful instruments for detecting exoplanets and holds already several recent records, including the discovery of another Trio of Neptunes (ESO 18/06, see also ESO 22/04).The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs."HARPS is a unique planet hunting machine," says Michel Mayor, from Geneva Observatory, and HARPS Principal Investigator. "Given the incredible precision of HARPS, we have focused our effort on low-mass planets. And we can say without doubt that HARPS has been very successful: out of the 13 known planets with a mass below 20 Earth masses, 11 were discovered with HARPS!"HARPS is also very efficient in finding planetary systems, where tiny signals have to be uncovered. The two systems known to have three low mass planets HD 69830 and Gl 581 were discovered by HARPS."And we are confident that, given the results obtained so far, finding a planet with the mass of the Earth around a red dwarf is within reach," affirms Mayor.
-European Southern Observatory (ESO)
http://brightsurf.com/news/headlines/30140/Astronomers_find_first_habitable_Earth-like_planet.html
Who: A team of Swiss, French and Portuguese scientists
What: Have discovered the most Earth-like planet outside our Solar System
When: April 25th, 2007
Where: At the Geneva Observatory (located in Switzerland)
From my prospective this is very interesting. The people who created the planet hunting machine should be honored. This is something we have been struggling with ofr many many years. And to finally discover another earth-like planet outside of out solar system is shocking. . I find it mind boggling that we have such AMAZING technology. This new discovery has probally triggered other scientits brains. I hope they keep us updated on these type of discoveries because i am very interested in finding out more about whats happening today all around the world.
Saturday, April 14, 2007
2ND BLOG -CURRENT EVET
NASA's Chandra finds black holes are "Green"
-Black holes are the most fuel efficient engines in the Universe, according to a new study using NASA's Chandra X-ray Observatory. By making the first direct estimate of how efficient or "green" black holes are, this work gives insight into how black holes generate energy and affect their environment.The new Chandra finding shows that most of the energy released by matter falling toward a supermassive black hole is in the form of high-energy jets traveling at near the speed of light away from the black hole. This is an important step in understanding how such jets can be launched from magnetized disks of gas near the event horizon of a black hole."Just as with cars, it's critical to know the fuel efficiency of black holes," said lead author Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University, and the Stanford Linear Accelerator Center. "Without this information, we cannot figure out what is going on under the hood, so to speak, or what the engine can do."Allen and his team used Chandra to study nine supermassive black holes at the centers of elliptical galaxies. These black holes are relatively old and generate much less radiation than quasars, rapidly growing supermassive black holes seen in the early Universe. The surprise came when the Chandra results showed that these "quiet" black holes are all producing much more energy in jets of high-energy particles than in visible light or X-rays. These jets create huge bubbles, or cavities, in the hot gas in the galaxies.The efficiency of the black hole energy-production was calculated in two steps: first Chandra images of the inner regions of the galaxies were used to estimate how much fuel is available for the black hole; then Chandra images were used to estimate the power required to produce the cavities."If a car was as fuel-efficient as these black holes, it could theoretically travel over a billion miles on a gallon of gas," said coauthor Christopher Reynolds of the University of Maryland, College Park.New details are given about how black hole engines achieve this extreme efficiency. Some of the gas first attracted to the black holes may be blown away by the energetic activity before it gets too near the black hole, but a significant fraction must eventually approach the event horizon where it is used with high efficiency to power the jets. The study also implies that matter flows towards the black holes at a steady rate for several million years."These black holes are very efficient, but it also takes a very long time to refuel them," said Steve Allen who receives funding from the Office of Science of the Department of Energy.This new study shows that black holes are green in another important way. The energy transferred to the hot gas by the jets should keep hot gas from cooling, thereby preventing billions of new stars from forming. This will place limits on the growth of the largest galaxies, and prevent galactic sprawl from taking over the neighborhood.
-Chandra X-ray Center
Who: NASA's Chandra X-ray Center
What: Have discovered that black holes are green & how black holes function.
When: April 13, 2006
Where: Astrophysics and Cosmology at Stanford University
I think this is very interesting, considering that last year i discovered that black holes are deadly and strech your body like laffy taffy. When you hear the world black hole you would take it literaly. Therefore i was shocked to find out that black holes are green!! Also to find out how black holes generate energy and have an impact on their inviroment was something i never thought about. NASA has created
http://brightsurf.com/news/headlines/24080/NASAs_Chandra_finds_black_holes_are_green.html
-Black holes are the most fuel efficient engines in the Universe, according to a new study using NASA's Chandra X-ray Observatory. By making the first direct estimate of how efficient or "green" black holes are, this work gives insight into how black holes generate energy and affect their environment.The new Chandra finding shows that most of the energy released by matter falling toward a supermassive black hole is in the form of high-energy jets traveling at near the speed of light away from the black hole. This is an important step in understanding how such jets can be launched from magnetized disks of gas near the event horizon of a black hole."Just as with cars, it's critical to know the fuel efficiency of black holes," said lead author Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University, and the Stanford Linear Accelerator Center. "Without this information, we cannot figure out what is going on under the hood, so to speak, or what the engine can do."Allen and his team used Chandra to study nine supermassive black holes at the centers of elliptical galaxies. These black holes are relatively old and generate much less radiation than quasars, rapidly growing supermassive black holes seen in the early Universe. The surprise came when the Chandra results showed that these "quiet" black holes are all producing much more energy in jets of high-energy particles than in visible light or X-rays. These jets create huge bubbles, or cavities, in the hot gas in the galaxies.The efficiency of the black hole energy-production was calculated in two steps: first Chandra images of the inner regions of the galaxies were used to estimate how much fuel is available for the black hole; then Chandra images were used to estimate the power required to produce the cavities."If a car was as fuel-efficient as these black holes, it could theoretically travel over a billion miles on a gallon of gas," said coauthor Christopher Reynolds of the University of Maryland, College Park.New details are given about how black hole engines achieve this extreme efficiency. Some of the gas first attracted to the black holes may be blown away by the energetic activity before it gets too near the black hole, but a significant fraction must eventually approach the event horizon where it is used with high efficiency to power the jets. The study also implies that matter flows towards the black holes at a steady rate for several million years."These black holes are very efficient, but it also takes a very long time to refuel them," said Steve Allen who receives funding from the Office of Science of the Department of Energy.This new study shows that black holes are green in another important way. The energy transferred to the hot gas by the jets should keep hot gas from cooling, thereby preventing billions of new stars from forming. This will place limits on the growth of the largest galaxies, and prevent galactic sprawl from taking over the neighborhood.
-Chandra X-ray Center
Who: NASA's Chandra X-ray Center
What: Have discovered that black holes are green & how black holes function.
When: April 13, 2006
Where: Astrophysics and Cosmology at Stanford University
I think this is very interesting, considering that last year i discovered that black holes are deadly and strech your body like laffy taffy. When you hear the world black hole you would take it literaly. Therefore i was shocked to find out that black holes are green!! Also to find out how black holes generate energy and have an impact on their inviroment was something i never thought about. NASA has created
http://brightsurf.com/news/headlines/24080/NASAs_Chandra_finds_black_holes_are_green.html
Friday, March 30, 2007
1ST BLOG- IN CLASS RESPONSE
"WAVES!"
-Lately during class we have been doing exersises about waves. Waves are caused by vibration. We learned differnt types of waves and even what waves do. Longitudinal and transverse waves are they only two ive learned.I figured out that longitudinal waves move parallel through the medium. While a transverse wave moves at an right angle through the medium(middle point which waves travel through). Some difffernt parts of a transverse waves is the crest-(highest point of the wave) and the trough-( is the lowest point.). In addition the longitudinal wave has two total different parts called compression and rarefraction. Picture a slinky in your head. When the coils are close together is known as compression. When the cils are spaced out it is called rarefraction. In class we did an experiment with sand. sand was placed in a cup and hug 2 feet over 3 sheets of paper and was swung in a back and forth motion while the paper was slowly slid. We then traced our wave and labeled parts of it.
-http://www.gmi.edu/~drussell/Demos/waves/wavemotion.html/
-http://hyperphysics.phy-astr.gsu.edu/hbase/sound/tralon.html
From these sites i leraned exactly how waves move. It gave great examples and the exersises we did in science was a great help. I also leraned waves are all around you. These are the most two common waves.From the second website i discovered that transverse waves cannot propagate in a gas or a liquid because there is no mechanism for driving motion. This is goingt o be interesting to find out more facts!
-Lately during class we have been doing exersises about waves. Waves are caused by vibration. We learned differnt types of waves and even what waves do. Longitudinal and transverse waves are they only two ive learned.I figured out that longitudinal waves move parallel through the medium. While a transverse wave moves at an right angle through the medium(middle point which waves travel through). Some difffernt parts of a transverse waves is the crest-(highest point of the wave) and the trough-( is the lowest point.). In addition the longitudinal wave has two total different parts called compression and rarefraction. Picture a slinky in your head. When the coils are close together is known as compression. When the cils are spaced out it is called rarefraction. In class we did an experiment with sand. sand was placed in a cup and hug 2 feet over 3 sheets of paper and was swung in a back and forth motion while the paper was slowly slid. We then traced our wave and labeled parts of it.
-http://www.gmi.edu/~drussell/Demos/waves/wavemotion.html/
-http://hyperphysics.phy-astr.gsu.edu/hbase/sound/tralon.html
From these sites i leraned exactly how waves move. It gave great examples and the exersises we did in science was a great help. I also leraned waves are all around you. These are the most two common waves.From the second website i discovered that transverse waves cannot propagate in a gas or a liquid because there is no mechanism for driving motion. This is goingt o be interesting to find out more facts!
Wednesday, February 28, 2007
"Meiosis Square Dance!!"
Topic: Meosis
Facts:http://genetics.gsk.com/chromosomes.htm
-Your body is made up of trillions of cells.
- The process of meiosis begins with a single cell containing 46 chromosomes
Other Facts:www.bbc.co.uk/.../celldivisionrev3.shtml
-For each of the 23 pairs there is a 50-50 chance as to which pole the paternal or maternal pair of chromatids go.
-There are over 8 million possiblities for variation.
-A human body cell contains 23 pairs of chromosones to begin with.
My thoughs:
During science we wathced a movie called "Meiosis Square Dance." This was an interesting movie. This movies was easy to learn form. I learned how exactly the process of meiosis goes. It sems like a very complex procedure. I find it amusing that a human body cell conatins 23 chromosones....that is alot. I wonder how this process was discovered?
Facts:http://genetics.gsk.com/chromosomes.htm
-Your body is made up of trillions of cells.
- The process of meiosis begins with a single cell containing 46 chromosomes
Other Facts:www.bbc.co.uk/.../celldivisionrev3.shtml
-For each of the 23 pairs there is a 50-50 chance as to which pole the paternal or maternal pair of chromatids go.
-There are over 8 million possiblities for variation.
-A human body cell contains 23 pairs of chromosones to begin with.
My thoughs:
During science we wathced a movie called "Meiosis Square Dance." This was an interesting movie. This movies was easy to learn form. I learned how exactly the process of meiosis goes. It sems like a very complex procedure. I find it amusing that a human body cell conatins 23 chromosones....that is alot. I wonder how this process was discovered?
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