در دهه هفتاد میلادی، جک سپکاسکی، دیرین‌شناس امریکایی، بعد از ۱۵ سال جمع‌آوری اطلاعات فسیلهای موجودات دریایی موفق شد نقشه تنوع زیستی جانوران دریایی در طی ۵۰۰ میلیون سال گذشته را رسم کند و بر اساس آن موفق شد پنج انقراض دسته جمعی را در تاریخ حیات در کره زمین شناسایی کند. 1-Ordovician Silurian 2-End Devonian 3-End Permian (great dying) 4- End Triassic 5- K-T
در دهه هفتاد میلادی، جک سپکاسکی، دیرین‌شناس امریکایی، بعد از ۱۵ سال جمع‌آوری اطلاعات فسیلهای موجودات دریایی موفق شد نقشه تنوع زیستی جانوران دریایی در طی ۵۰۰ میلیون سال گذشته را رسم کند و بر اساس آن موفق شد پنج انقراض دسته جمعی را در تاریخ حیات در کره زمین شناسایی کند. 1-Ordovician Silurian 2-End Devonian 3-End Permian (great dying) 4- End Triassic 5- K-T
Traders also expressed uncertainty about the situation with China Evergrande, as the indebted property company has not provided clarification about a key interest payment.In economic news, the Commerce Department reported an unexpected increase in U.S. new home sales in August.Crude oil prices climbed Friday and front-month WTI oil futures contracts saw gains for a fifth straight week amid tighter supplies. West Texas Intermediate Crude oil futures for November rose $0.68 or 0.9 percent at 73.98 a barrel. WTI Crude futures gained 2.8 percent for the week.
What Is Bitcoin?
Bitcoin is a decentralized digital currency that you can buy, sell and exchange directly, without an intermediary like a bank. Bitcoin’s creator, Satoshi Nakamoto, originally described the need for “an electronic payment system based on cryptographic proof instead of trust.” Each and every Bitcoin transaction that’s ever been made exists on a public ledger accessible to everyone, making transactions hard to reverse and difficult to fake. That’s by design: Core to their decentralized nature, Bitcoins aren’t backed by the government or any issuing institution, and there’s nothing to guarantee their value besides the proof baked in the heart of the system. “The reason why it’s worth money is simply because we, as people, decided it has value—same as gold,” says Anton Mozgovoy, co-founder & CEO of digital financial service company Holyheld.
