This picture, taken and scanned in 1972, caught the attention of scientists of the analysis group in Aachen, Germany, and word of it soon spread across the entire collaboration. The neutrino, which leaves no track because it has no electric charge, entered the bubble chamber from the bottom of this image and hit an electron.
Space shuttle Endeavour lights up the night sky as it lifts off from Launch Pad 39A at NASA's Kennedy Space Center in Florida. The primary payload for the STS-130 mission to the International Space Station is the Tranquility node, a pressurized module that will provide additional room for crew members and many of the station's life support and environmental control systems. Attached to one end of Tranquility is a cupola, a unique work area with six windows on its sides and one on top. The cupola resembles a circular bay window and will provide a vastly improved view of the station's exterior. The multi-directional view will allow the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects. The module was built in Turin, Italy, by Thales Alenia Space for the European Space Agency.
اگر لیزر را داخل یک سیال کانونی کنیم به طوریکه دمای آن قسمت را به بالاتر از نقطه جوش سیال افزایش دهد، یک حباب به وجود میآید. به خاطر تقارن مسئله و کمینه کردن کشش سطحی، این حباب به شکل کروی است.
اما میتوان به این حبابها شکل دلخواه داد. تنها کافی است که شکل ناحیهای که لیزر در آن کانونی میشود را کنترل کرد تا بتوان حبابهایی به شکل V و یا حتی مکعب درست کرد.
This composite color infrared image of the center of our Milky Way galaxy reveals a new population of massive stars and new details in complex structures in the hot ionized gas swirling around the central 300 light-years. This sweeping panorama is the sharpest infrared picture ever made of the Galactic core and offers a laboratory for how massive stars form and influence their environment in the often violent nuclear regions of other galaxies.
This view combines the sharp imaging of the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) with color imagery from a previous Spitzer Space Telescope survey done with its Infrared Astronomy Camera (IRAC). The Galactic core is obscured in visible light by intervening dust clouds, but infrared light penetrates the dust.
NICMOS shows a large number of these massive stars distributed throughout the region. A new finding is that astronomers now see that the massive stars are not confined to one of the three known clusters of massive stars in the Galactic Center, known as the Central cluster, the Arches cluster, and the Quintuplet cluster. These three clusters are easily seen as tight concentrations of bright, massive stars in the NICMOS image. The distributed stars may have formed in isolation, or they may have originated in clusters that have been disrupted by strong gravitational tidal forces. The winds and radiation from these stars form the complex structures seen in the core, and in some cases, they may be triggering new generations of stars.
The NICMOS mosaic required 144 Hubble orbits to make 2,304 science exposures from Feb. 22 and June 5, 2008.
Image Credits: Hubble: NASA, ESA, and Q.D. Wang (University of Massachusetts, Amherst); Spitzer: NASA, Jet Propulsion Laboratory, and S. Stolovy (Spitzer Science Center/Caltech)
دانشمندان براى آشكار شدن خصوصيات و ساختارهاى احتمالى يك نظريه نهايى در جست وجوى نقض اصول فيزيكى اينشتين هستند؛ «كه زمانى مقدس بود »
نسبيت در قلب مهم ترين نظريات بنيادين فيزيك قرار گرفته است. نسبيت آنگونه كه اينشتين آن را در ۱۹۰۵ فرمول بندى كرد بر اين ايده كليدى بنا شده كه قوانين فيزيك از نگاه تمام مشاهده گرهاى لخت (اينرسى) (مشاهده گرهايى كه از ديد يك مشاهده گر داراى جهت دلخواه و سرعت ثابت هستند) يكسان است. اين نظريه يك دسته از آثار شناخته شده را پيش بينى مى كند كه از ميان آنها مى توان به ثابت بودن سرعت نور براى تمام مشاهده گرها، كند شدن ساعت هاى در حال حركت، كوتاه شدن طول اجسام متحرك و هم ارزى جرم و انرژى E=mc2 اشاره كرد. آزمايش هاى بسيار دقيق اين نتايج را تائيد مى كنند. نسبيت اكنون يك پايه و ابزار مهم و روزمره براى فيزيكدانان تجربى است: برخورد دهنده هاى ذرات از مزاياى افزايش جرم و طول عمر ذرات پرسرعت به خوبى بهره مى برند و آزمايش با ايزوتوپ هاى راديواكتيو نشان دهنده تبديل جرم به انرژى است.
