Nombre total de pages vues
10/05/2024
SANTé/MEDECINE - Anti-inflamatoires naturels - L'écorce de saule blanc : une aspirine végétale
ASTRONOMY - Simulation: Two Black Holes Merge
2024 May 10
Simulation Credit: Simulating eXtreme Spacetimes Project
Explanation: Relax and watch two black holes merge. Inspired by the first direct detection of gravitational waves in 2015, this simulation plays in slow motion but would take about one third of a second if run in real time. Set on a cosmic stage, the black holes are posed in front of stars, gas, and dust. Their extreme gravity lenses the light from behind them into Einstein rings as they spiral closer and finally merge into one. The otherwise invisible gravitational waves generated as the massive objects rapidly coalesce cause the visible image to ripple and slosh both inside and outside the Einstein rings even after the black holes have merged. Dubbed GW150914, the gravitational waves detected by LIGO are consistent with the merger of 36 and 31 solar mass black holes at a distance of 1.3 billion light-years. The final, single black hole has 63 times the mass of the Sun, with the remaining 3 solar masses converted into energy radiated in gravitational waves.
09/05/2024
SANTé/MEDECINE - Homme ou animal qui est le plus fort ? - Apnée
SANTé/MEDECINE - Anti-inflamatoires naturels Le basilic : un anti-inflammatoire digestif
ASTRONOMY - The Galaxy, the Jet, and a Famous Black Hole
2024 May 9
Image Credit: NASA, JPL-Caltech, Event Horizon Telescope Collaboration
Explanation: Bright elliptical galaxy Messier 87 (M87) is home to the supermassive black hole captured in 2017 by planet Earth's Event Horizon Telescope in the first ever image of a black hole. Giant of the Virgo galaxy cluster about 55 million light-years away, M87 is rendered in blue hues in this infrared image from the Spitzer Space telescope. Though M87 appears mostly featureless and cloud-like, the Spitzer image does record details of relativistic jets blasting from the galaxy's central region. Shown in the inset at top right, the jets themselves span thousands of light-years. The brighter jet seen on the right is approaching and close to our line of sight. Opposite, the shock created by the otherwise unseen receding jet lights up a fainter arc of material. Inset at bottom right, the historic black hole image is shown in context at the center of giant galaxy, between the relativistic jets. Completely unresolved in the Spitzer image, the supermassive black hole surrounded by infalling material is the source of enormous energy driving the relativistic jets from the center of active galaxy M87. The Event Horizon Telescope image of M87 has been enhanced to reveal a sharper view of the famous supermassive black hole.
08/05/2024
SANTé/MEDECINE - Homme ou animal qui est le plus fort ? - Vitesse de nage
ASTRONOMY - Visualization: A Black Hole Accretion Disk
2024 May 8
Visualization Credit: NASA’s Goddard Space Flight Center, Jeremy Schnittman
Explanation: What would it look like to circle a black hole? If the black hole was surrounded by a swirling disk of glowing and accreting gas, then the great gravity of the black hole would deflect light emitted by the disk to make it look very unusual. The featured animated video gives a visualization. The video starts with you, the observer, looking toward the black hole from just above the plane of the accretion disk. Surrounding the central black hole is a thin circular image of the orbiting disk that marks the position of the photon sphere -- inside of which lies the black hole's event horizon. Toward the left, parts of the large main image of the disk appear brighter as they move toward you. As the video continues, you loop over the black hole, soon looking down from the top, then passing through the disk plane on the far side, then returning to your original vantage point. The accretion disk does some interesting image inversions -- but never appears flat. Visualizations such as this are particularly relevant today as black holes are being imaged in unprecedented detail by the Event Horizon Telescope.
07/05/2024
SANTé/MEDECINE - Anti-inflamatoires naturels - La gaulthérie pour soulager les tendinites
SANTé/MEDECINE - Homme ou animal qui est le plus fort ? - Haltérophilie
ASTRONOMY - Black Hole Accreting with Jet
2024 May 7
Illustration Credit: NASA, Swift, Aurore Simonnet (Sonoma State U.)
Explanation: What happens when a black hole devours a star? Many details remain unknown, but observations are providing new clues. In 2014, a powerful explosion was recorded by the ground-based robotic telescopes of the All Sky Automated Survey for SuperNovae (Project ASAS-SN), with followed-up observations by instruments including NASA's Earth-orbiting Swift satellite. Computer modeling of these emissions fit a star being ripped apart by a distant supermassive black hole. The results of such a collision are portrayed in the featured artistic illustration. The black hole itself is a depicted as a tiny black dot in the center. As matter falls toward the hole, it collides with other matter and heats up. Surrounding the black hole is an accretion disk of hot matter that used to be the star, with a jet emanating from the black hole's spin axis.
SANTé/MEDECINE - A la découverte de l'oreille - Anatomie de l'oreille
L' oreille externe comprend le pavillon qui entoure le canal qui mène au tympan . Dans l' oreille moyenne se trouvent les osselets...
-
2021 May 11 Lightning and Orion Beyond Uluru Image Credit & Copyright: Park Liu Explanation: What's happening behind Uluru? A Un...
-
2021 January 3 A Phoenix Aurora over Iceland Image Credit & Copyright: Hallgrimur P. Helgason ; Rollover Annotation: Judy Schmidt Ex...