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1 Markets I: The Ecosystem and Exchange-Traded Markets市场在线 2 Markets II: Rates, FX and Credit市场在线 3 Markets III: Commodities, Energy and Crypto市场在线 4 Quantitative Methods方法在线 5 Derivatives and Volatility衍生品在线 6 Rates, Credit, XVA and Risk利率、信用与风险在线 7 Research Craft: Predictors, Backtests, Measurement, Portfolios研究在线 8 Strategies I: Equities and Futures策略在线 9 Strategies II: Volatility, Relative Value, Macro and the Bank Desks策略在线 10 Microstructure and Execution交易执行在线 11 Market Making and High-Frequency Trading做市在线 12 Machine Learning for Markets机器学习在线 13 Low-Latency Software技术在线 14 Networks, Hardware and Trading Infrastructure技术在线 15 Research, Data and Risk Platforms技术在线 16 The Desk and the Firm公司运营在线 17 The Industry: Firms, Roles and Careers职业发展在线 18 Interviews I: Maths, Probability and Speed职业发展在线 19 Interviews II: Markets, Trading Games and the Final Round职业发展在线 20 Interviews III: Code职业发展在线

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Earth and Space Sciences · 术语表

什么是 Faint young Sun problem？

Definition 26.4 High School Earth and Space Sciences · 第 26 章 — The Early Earth and Its Atmosphere

The faint young Sun problem is the contradiction between the dimmer Sun of the Earth’s first billions of years, under which the Earth with today’s atmosphere would have frozen, and the rocks, which show that liquid water was present.

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Definition 18.12 University Earth and Space Sciences — Year 2 · 第 18 章 — The Precambrian Earth

The faint young Sun problem is the contradiction between the models of the Sun, which make it 25 to $30\,\%$ fainter $4\,\mathrm{Ga}$ ago, and the rocks, which show liquid water and an active water cycle through the Archean: with today’s atmosphere and albedo the early Earth should have been frozen.

示例

Example 18.13 (The greenhouse of the young Earth)

To keep $288\,\mathrm{K}$ under the Sun of $4\,\mathrm{Ga}$ ago with today’s albedo, the absorbed sunlight is $0.741\times340.25\times0.706 = 178.0\,\mathrm{W}\,\mathrm{m}^{-2}$ , so the effective emissivity must fall to $178.0/(\sigma\times288^4) = 0.456$ , against 0.616 today: the share of the surface’s emission trapped by the greenhouse must rise from 0.384 to 0.544.

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