I am in search of another planet in the universe where life exists. I can't see this planet with my naked eyes or even with the most powerful telescopes we currently possess. But I know that it's there. And understanding contradictions that occur in nature will help us find it.
我喺度搵緊其他有生命存在嘅星球 雖然我唔能夠用肉眼睇到呢啲星球 就算用埋最先進嘅望遠鏡 但我知道佢就喺嗰度 而且掌握大自然本身嘅矛盾 可以幫到我哋搵到呢個星球
On our planet, where there's water, there's life. So we look for planets that orbit at just the right distance from their stars. At this distance, shown in blue on this diagram for stars of different temperatures, planets could be warm enough for water to flow on their surfaces as lakes and oceans where life might reside. Some astronomers focus their time and energy on finding planets at these distances from their stars. What I do picks up where their job ends. I model the possible climates of exoplanets. And here's why that's important: there are many factors besides distance from its star that control whether a planet can support life.
響我哋嘅星球 邊度有水,邊度就有生命 所以我哋尋找嗰啲 同恒星保持合適運行距離嘅星球 呢個表入面 藍色係代表咗唔同恒星嘅適居帶 而呢種距離暖到 可以令水喺星球嘅表面流動 形成咗湖同海 而生命就有可能響呢啲地方出現 一啲天文學家集中精神 尋找位於適居帶嘅星球 我嘅任務就係接手佢哋嘅工作 我要推算出系外行星嘅氣候 下面我會講解點解呢樣會咁重要 除咗距離之外 仲有好多其他因素 決定一個星球有生命嘅存在
Take the planet Venus. It's named after the Roman goddess of love and beauty, because of its benign, ethereal appearance in the sky. But spacecraft measurements revealed a different story. The surface temperature is close to 900 degrees Fahrenheit, 500 Celsius. That's hot enough to melt lead. Its thick atmosphere, not its distance from the sun, is the reason. It causes a greenhouse effect on steroids, trapping heat from the sun and scorching the planet's surface. The reality totally contradicted initial perceptions of this planet. From these lessons from our own solar system, we've learned that a planet's atmosphere is crucial to its climate and potential to host life.
就攞金星做例子 佢嘅名代表咗羅馬人 一個象徵愛同美麗嘅女神 正因為佢喺天空 以美善、輕飄嘅姿態出現 但探測器做出嘅測量欲唔係想像中咁靚 金星表面嘅溫度高達華氏 900度 亦即攝氏500度 佢嘅溫度足夠融咗鉛 佢厚厚嘅大氣層 而唔係佢同太陽嘅距離 令大氣層出現溫室效應 太陽嘅熱力被大氣層鎖住 熱力留返喺度,將星球表面加熱 現實同我哋最初對金星嘅想像係倒返轉 從太陽系學到,一個星球嘅大氣 對星球嘅氣候以至生命嘅孕育 係非常之重要
We don't know what the atmospheres of these planets are like because the planets are so small and dim compared to their stars and so far away from us. For example, one of the closest planets that could support surface water -- it's called Gliese 667 Cc -- such a glamorous name, right, nice phone number for a name -- it's 23 light years away. So that's more than 100 trillion miles. Trying to measure the atmospheric composition of an exoplanet passing in front of its host star is hard. It's like trying to see a fruit fly passing in front of a car's headlight. OK, now imagine that car is 100 trillion miles away, and you want to know the precise color of that fly.
我哋唔知道呢啲系外行星嘅大氣係點樣 因為呢啲星球相比起佢哋嘅恒星 實在太細啦,兼且離我哋太遠啦 例如,其中一個 最接近我哋又可以維持地表水嘅星球 叫做 Gliese 667 Cc 真係一個有魅力嘅名 好似個電話號碼咁 佢距離我哋有 23 光年咁遠 超過一兆英里 要響系外行星經過佢哋恒星嗰時 量度佢哋嘅大氣組成 係非常艱難嘅 就好似嘗試望住隻果蠅 飛過一架車嘅前燈 好,你可以想像嗰架車離你一兆英里 而你只想知嗰隻果蠅嘅顏色
So I use computer models to calculate the kind of atmosphere a planet would need to have a suitable climate for water and life.
所以我利用一個電腦模擬程式 去計算星球需要乜嘢大氣層 先至會有合適嘅氣候提供水同孕育生命
Here's an artist's concept of the planet Kepler-62f, with the Earth for reference. It's 1,200 light years away, and just 40 percent larger than Earth. Our NSF-funded work found that it could be warm enough for open water from many types of atmospheres and orientations of its orbit. So I'd like future telescopes to follow up on this planet to look for signs of life.
呢度係畫家對開普勒-62f 概念嘅理解 用地球做參照 佢有 1,200 光年咁遠 比地球大 40% 我哋 NSF 資助嘅項目發現 無論佢嘅大氣同運行軌道嘅方向係咩 佢都夠暖俾到水出現 所以,我想未來嘅望遠鏡 可以追蹤呢個星球 去搵出星球上面嘅生命線索
Ice on a planet's surface is also important for climate. Ice absorbs longer, redder wavelengths of light, and reflects shorter, bluer light. That's why the iceberg in this photo looks so blue. The redder light from the sun is absorbed on its way through the ice. Only the blue light makes it all the way to the bottom. Then it gets reflected back to up to our eyes and we see blue ice. My models show that planets orbiting cooler stars could actually be warmer than planets orbiting hotter stars. There's another contradiction -- that ice absorbs the longer wavelength light from cooler stars, and that light, that energy, heats the ice.
星球表面嘅冰 係另一種決定氣候嘅重要因素 冰吸收長波,偏紅嘅光 反射短波嘅藍光 呢個就係點解呢幅圖嘅冰咁藍 嚟自太陽嘅紅光通過冰塊時就被吸收 剩低藍光穿過底部出返嚟 之後藍光反射到我哋嘅眼 所以我哋見到藍色嘅冰 我嘅模型推算出 星球圍繞溫度較低嘅恒星時 佢嘅溫度 會比圍繞較熱嘅恒星嘅星球更高 下面係第二個矛盾︰ 冰吸收嚟自溫度較低嘅恒星 波長較長嘅光 光,或者能量,令冰嘅溫度上升
Using climate models to explore how these contradictions can affect planetary climate is vital to the search for life elsewhere.
探索呢啲矛盾嘅嘢點樣影響星球氣候 對於尋找外星生命 係非常重要嘅
And it's no surprise that this is my specialty. I'm an African-American female astronomer and a classically trained actor who loves to wear makeup and read fashion magazines, so I am uniquely positioned to appreciate contradictions in nature --
絕對唔係意外,呢個係我鑽研方向 我係非裔女性美國天文學家 亦係一個受過真正訓練嘅演員 鍾意化妝,睇時尚雜誌 所以我好欣賞大自然存在嘅矛盾
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... and how they can inform our search for the next planet where life exists.
呢啲矛盾引領我哋研究 將我哋帶到下一個有生命存在嘅星球
My organization, Rising Stargirls, teaches astronomy to middle-school girls of color, using theater, writing and visual art. That's another contradiction -- science and art don't often go together, but interweaving them can help these girls bring their whole selves to what they learn, and maybe one day join the ranks of astronomers who are full of contradictions, and use their backgrounds to discover, once and for all, that we are truly not alone in the universe.
我嘅組織, Rising Stargirls 通過戲劇表演、寫作同視覺藝術 教授天文學俾唔同膚色嘅中學女生 呢個又係另一個矛盾 科學同藝術好多時唔能夠喺埋一齊 但係將佢哋擺埋一齊 可以令佢哋明白佢哋學嘅嘢 或者有一日 佢哋會加入天文學家嘅行列 呢個充滿矛盾發現嘅職業 利用佢哋嘅背景 探索到我哋唔係宇宙中唯一嘅生物
Thank you.
多謝
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