سر النفاثات الكونية.. منطقة ملتهبة قرب ثقب أسود تكشف الآلية
كيف يلتهم ثقب أسود هائل المادة بشراهة، ثم يطلق في الوقت نفسه نفاثات تقترب من سرعة الضوء؟ رصد جديد كشف منطقة خفية قد تحمل مفتاح هذا التناقض الكوني المحير.
Science
Two Saudi scientists among six Arab researchers honored by L’Oréal-UNESCO program
Two Saudi scientists among six Arab researchers honored by L’Oréal-UNESCO program
Science
Nearly all coral reefs risk collapse in 50 years: IUCN
Nearly all of the world's shallow-water coral reefs face an "extremely high risk" of collapse by 2075 due to climate change, the International Union for Conservation of Nature (IUCN) warned Thursday. In the first global assessment of its kind, the world authority on threatened wildlife classified 96 percent of the planet's coral reef systems as "critically endangered" -- its highest risk category.
Science
An Affinity for Warm Climes has Helped Crocs Thrive for Eons
Crocodilians — today's crocodiles, alligators, caimans and gharials and their many extinct relatives — have been a roaring success since debuting more than 240 million years ago. And new research identifies one important factor in their success — stubbornly keeping to warm climates throughout their history. In fact, the researchers said, this trait may help explain why crocs as a group survived the asteroid strike 66 million years ago that doomed the dinosaurs, along with certain physiological characteristics that make them one tough bunch of reptiles.