Кислород для подводного царства

О заморных явлениях на водоемах Новосибирской области и мероприятиях по их предотвращению

Новосибирская область располагает одним из самых крупных в России рыбохозяйственных водных фондов. Его площадь составляет около 650 тыс. га. Имеются достаточно крупные водоемы: оз. Чаны — 150 — 200 тыс. га (в зависимости от уровня воды), Новосибирское водохранилище — 107 тыс. га, оз. Убинское — 43 тыс. га, оз. Сартлан — 23 тыс. га. Кроме того, в области более 4 000 небольших озер площадью до 1 000 га.

Farthest Supernova Yet Marked Death of Very Massive Star

Astronomers are reaching ever further back in time, seeking events from the earliest days of the universe. Now, the discovery of the farthest (and thus oldest) supernova ever seen is raising hopes that astronomers will soon detect the explosive deaths of the first stars to form after the universe's birth. These stars forged the first heavy elements, which helped create smaller and longer-lived stars like our own sun.

The earliest stars looked different from modern stars. The big bang produced only three light elements—hydrogen, helium, and a little lithium—but today, stars form in gas clouds that also contain heavier elements such as carbon and oxygen. These elements radiate away enough energy to eventually cool the clouds. When the clouds cool, they fragment into smaller clumps that collapse to spawn a plethora of mostly small stars.

The antediluvian world

Although various ancient traditions refer to a lost antediluvian world, the one that stands out is the tradition in the early chapters of Genesis, because of its geographical detail, its monotheism (which has been shown to predate polytheism) and its historical (rather than epic) style of narration. These chapters describe a world very different from our own, either because the world really was different or because a later pre-scientific culture speculated about it in error. So what source of information did they draw upon?

Moartea și moștenirea stelelor

Ultima fază a ciclului de viaţă al unei stele poate fi tumultuos.

Stelele cu mase mari se dilată sau chiar explodează. De obicei, tot ce rămâne în urma unei stele disipate sunt corpuri ceresti bizare.

Atunci când rezerva de hidrogen din centrul unei stele se epuizează, minimul de energie rezultată duce la scăderea presiunii interne. Miezul stelei se contractă sub propria forţă gravitaţională şi devine mai cald. Dacă nucleul este suficient de fierbinte, heliul se transformă în carbon şi oxigen şi, pentru o vreme, continuă să producă energie.