Kategorie: Allgemein

A team of UK, French and German astronomers have discovered that the majority of the most distant galaxies so far identified are very young, undergoing their first extremely vigorous bursts of star formation. This discovery allows the astronomers to study the first important stages in the formation of the kind of galaxies we see in the Universe today. One of the scientists involved in the study, Dr. Malcolm Bremer of the University of Bristol, presented the team’s findings at the Royal Astronomical Society National Astronomy Meeting in Preston/UK.
Caught In The Act: Forming Galaxies Captured In The Young Universe

Physicists can rest easy – the Standard Model of Particle Physics is still in effect. More than 100 MIT students and professors jammed into Room 35-225 on Wednesday, April 11, 2007, to hear the long-anticipated results of a particle detection experiment designed to produce evidence that would confirm or reject the model, which outlines the elements of particle physics. MIT postdoctoral associate Jocelyn Monroe, who worked on the experiment, revealed the results about half an hour into her talk: the experiment confirms the model’s prediction that there are only three types of neutrinos.
https://news.mit.edu/2007/neutrino

Early results from a NASA mission designed to test two key predictions of Albert Einstein show the great man was right about at least one of them. It will take another eight months to determine whether he got the other correct, say scientists analysing data from NASA’s Gravity Probe B satellite. The spacecraft was launched into orbit from Vandenberg Air Force Base, California, on April 20, 2004. Gravity Probe B uses four ultra-precise gyroscopes to measure two effects of Einstein’s general relativity theory. One of these effects is called the geodetic effect, the other is called frame dragging. The mission’s principal investigator, Professor Francis Everitt from Stanford University, discussed preliminary results at the American Physical Society meeting in Jacksonville, Florida. The data from Gravity Probe B’s gyroscopes clearly confirm Einstein’s geodetic effect to a precision of better than 1%.
Stanford University – Gravity Probe B

NASA – Gravity Probe B: The Relativity Mission

A remarkable eclipse of a supermassive black hole and the hot gas disk around it has been observed with NASA’s Chandra X-ray Observatory. This eclipse has allowed two key predictions about the effects of supermassive black holes to be tested.
https://chandra.harvard.edu/photo/2007/ngc1365/

Geophysicists have probed deep into Earth’s childhood and recorded the earliest measurement yet of the magnetic field that protects the planet from devastation by the solar wind. The finding provides new insight into Earth’s early years and could even reveal more about when life began. The history of Earth’s geomagnetic field plays a key role in scientists‘ understanding of the development of our planet’s deep interior, its atmosphere, and even the early evolution of terrestrial life. But scientists have had a hard time pinning down how long ago the magnetosphere first formed. Now, geophysicist John Tarduno at the University of Rochester in New York, and colleagues, have made the earliest direct measurement of Earth’s magnetic field. They discovered that the magnetosphere was already in existence 3.2 billion years ago, 500 million years earlier than previously believed. The researchers extracted minimally disturbed bits of feldspar and quartz from 3.2 billion-year-old rocks in the Archaean Kaapvaal craton in South Africa.
Abstract (PDF): Rory D. Cottrell, John A. Tarduno and Michael K. Watkeys
„Examining the strength of Earth’s early magnetic field“

NASA and ESA have released some absolutely amazing new images of the surface of the Sun, taken by the Japanese Hinode spacecraft (formerly known as Solar-B). For the first time, astronomers are able to see how tiny granules of hot gas rise and fall, caught up in the Sun’s magnetic atmosphere. They’re able to watch how magnetic variations start out, and then spread across the surface.
The photographs are beautiful, but what will really blow your mind are the videos.

A Falcon 1 rocket lifted off late Tuesday on a test flight that the rocket’s developer, SpaceX, declared a success even though the rocket failed to reach orbit. The Falcon 1 lifted off from Omelek Island, part of Kwajalein Atoll in the Pacific Ocean, at 9:10 p.m. EDT Tuesday carrying a test payload. The launch initially went well, but telemetry from the rocket was lost about five minutes into flight. Company officials said that the rocket experienced a roll control anomaly during the second stage burn which apparently kept the rocket from achieving orbit, although it did fly to an altitude of approximately 300 kilometers. While the root cause of the problem isn’t known, SpaceX believes it can be fixed relatively easily and that the flight overall retired 90 percent of the risk associated with the vehicle, including operation of the first stage, stage separation, and payload fairing separation. Tuesday’s launch took place about an hour after a previous launch attempt was aborted at T-0 seconds when sensors detected a low chamber pressure in the main engine, caused by colder-than-normal kerosene fuel. SpaceX, which developed the small launch vehicle privately, is not planning to perform another test flight before its first operational mission, the launch of the TacSat 1 experimental satellite for the Defense Department, later this year.

SpaceX’s Second Falcon 1 Rocket Fails to Reach Orbit

Some 40 years after the release of the classic science fiction movie „Fantastic Voyage“, researchers in the NanoRobotics Laboratory of École Polytechnique de Montréal’s Department of Computer Engineering and Institute of Biomedical Engineering have achieved a major technological breakthrough in the field of medical robotics. They have succeeded for the first time in guiding, in vivo and via computer control, a microdevice inside an artery, at a speed of 10 centimetres a second.
Article @ École Polytechnique de Montréal

A new image of the Crab Nebula supernova remnant taken using the Prime Focus Camera on the Subaru telescope highlights the beauty of stellar debris expanding away from the site of this ancient blast. The high-resolution image captures details of an elongated tendril of gas rushing out at roughly 1.500 kilometers per second. While the nebula has been observed many times using both ground- and space-based telescopes, the new image is giving astronomers another opportunity to study the mechanics of the expanding gas in much greater detail.
https://www.subarutelescope.org/Pressrelease/2007/03/12/index.html

A modified ink-jet printer can be used to directly print layer upon layer of artificial bone for quick-fix grafts used in reconstructive surgery.
Jake Barralet of the Faculty of Dentistry at the McGill University in Montréal, Québec, and Uwe Gbureck of the Department for Functional Materials in Medicine and Dentistry at the University of Würzburg, Bavaria, and their team describe a method for „printing“ artificial bone from the same chemical components as living bone and including biomolecules that trigger blood vessel growth to bring the bone to life after it is implanted in the body. The McGill-Würzburg team uses the minerals brushite and hydroxyapatite instead of conventional „ink“ in their printer. By printing one layer on top of another they can build up a highly porous 3D bioceramic material resembling bone at room temperature.
Printing better bones