下載App 希平方
攻其不背
App 開放下載中
下載App 希平方
攻其不背
App 開放下載中
IE版本不足
你的 IE 瀏覽器太舊了 更新 IE 瀏覽器或點選連結下載 Google Chrome 瀏覽器 前往下載

免費註冊
! 這組帳號已經註冊過了
Email 帳號
密碼請填入 6 位數以上密碼
已經有帳號了?
忘記密碼
! 這組帳號已經註冊過了
您的 Email
請輸入您註冊時填寫的 Email,
我們將會寄送設定新密碼的連結給您。
寄信了!請到信箱打開密碼連結信
密碼信已寄至
沒有收到信嗎? 點這裡重寄一次
如果您尚未收到信,請前往垃圾郵件查看,謝謝!

恭喜您註冊成功!

查看會員功能

註冊未完成

《HOPE English 希平方》服務條款關於個人資料收集與使用之規定

隱私權政策
上次更新日期:2014-12-30

希平方 為一英文學習平台,我們每天固定上傳優質且豐富的影片內容,讓您不但能以有趣的方式學習英文,還能增加內涵,豐富知識。我們非常注重您的隱私,以下說明為當您使用我們平台時,我們如何收集、使用、揭露、轉移及儲存你的資料。請您花一些時間熟讀我們的隱私權做法,我們歡迎您的任何疑問或意見,提供我們將產品、服務、內容、廣告做得更好。

本政策涵蓋的內容包括:希平方 如何處理蒐集或收到的個人資料。
本隱私權保護政策只適用於: 希平方 平台,不適用於非 希平方 平台所有或控制的公司,也不適用於非 希平方 僱用或管理之人。

個人資料的收集與使用
當您註冊 希平方 平台時,我們會詢問您姓名、電子郵件、出生日期、職位、行業及個人興趣等資料。在您註冊完 希平方 帳號並登入我們的服務後,我們就能辨認您的身分,讓您使用更完整的服務,或參加相關宣傳、優惠及贈獎活動。希平方 也可能從商業夥伴或其他公司處取得您的個人資料,並將這些資料與 希平方 所擁有的您的個人資料相結合。

我們所收集的個人資料, 將用於通知您有關 希平方 最新產品公告、軟體更新,以及即將發生的事件,也可用以協助改進我們的服務。

我們也可能使用個人資料為內部用途。例如:稽核、資料分析、研究等,以改進 希平方公司 產品、服務及客戶溝通。

瀏覽資料的收集與使用
希平方 自動接收並記錄您電腦和瀏覽器上的資料,包括 IP 位址、希平方 cookie 中的資料、軟體和硬體屬性以及您瀏覽的網頁紀錄。

隱私權政策修訂
我們會不定時修正與變更《隱私權政策》,不會在未經您明確同意的情況下,縮減本《隱私權政策》賦予您的權利。隱私權政策變更時一律會在本頁發佈;如果屬於重大變更,我們會提供更明顯的通知 (包括某些服務會以電子郵件通知隱私權政策的變更)。我們還會將本《隱私權政策》的舊版加以封存,方便您回顧。

服務條款
歡迎您加入看 ”希平方”
上次更新日期:2013-09-09

歡迎您加入看 ”希平方”
感謝您使用我們的產品和服務(以下簡稱「本服務」),本服務是由 希平方 所提供。
本服務條款訂立的目的,是為了保護會員以及所有使用者(以下稱會員)的權益,並構成會員與本服務提供者之間的契約,在使用者完成註冊手續前,應詳細閱讀本服務條款之全部條文,一旦您按下「註冊」按鈕,即表示您已知悉、並完全同意本服務條款的所有約定。如您是法律上之無行為能力人或限制行為能力人(如未滿二十歲之未成年人),則您在加入會員前,請將本服務條款交由您的法定代理人(如父母、輔助人或監護人)閱讀,並得到其同意,您才可註冊及使用 希平方 所提供之會員服務。當您開始使用 希平方 所提供之會員服務時,則表示您的法定代理人(如父母、輔助人或監護人)已經閱讀、了解並同意本服務條款。 我們可能會修改本條款或適用於本服務之任何額外條款,以(例如)反映法律之變更或本服務之變動。您應定期查閱本條款內容。這些條款如有修訂,我們會在本網頁發佈通知。變更不會回溯適用,並將於公布變更起十四天或更長時間後方始生效。不過,針對本服務新功能的變更,或基於法律理由而為之變更,將立即生效。如果您不同意本服務之修訂條款,則請停止使用該本服務。

第三人網站的連結 本服務或協力廠商可能會提供連結至其他網站或網路資源的連結。您可能會因此連結至其他業者經營的網站,但不表示希平方與該等業者有任何關係。其他業者經營的網站均由各該業者自行負責,不屬希平方控制及負責範圍之內。

兒童及青少年之保護 兒童及青少年上網已經成為無可避免之趨勢,使用網際網路獲取知識更可以培養子女的成熟度與競爭能力。然而網路上的確存有不適宜兒童及青少年接受的訊息,例如色情與暴力的訊息,兒童及青少年有可能因此受到心靈與肉體上的傷害。因此,為確保兒童及青少年使用網路的安全,並避免隱私權受到侵犯,家長(或監護人)應先檢閱各該網站是否有保護個人資料的「隱私權政策」,再決定是否同意提出相關的個人資料;並應持續叮嚀兒童及青少年不可洩漏自己或家人的任何資料(包括姓名、地址、電話、電子郵件信箱、照片、信用卡號等)給任何人。

為了維護 希平方 網站安全,我們需要您的協助:

您承諾絕不為任何非法目的或以任何非法方式使用本服務,並承諾遵守中華民國相關法規及一切使用網際網路之國際慣例。您若係中華民國以外之使用者,並同意遵守所屬國家或地域之法令。您同意並保證不得利用本服務從事侵害他人權益或違法之行為,包括但不限於:
A. 侵害他人名譽、隱私權、營業秘密、商標權、著作權、專利權、其他智慧財產權及其他權利;
B. 違反依法律或契約所應負之保密義務;
C. 冒用他人名義使用本服務;
D. 上載、張貼、傳輸或散佈任何含有電腦病毒或任何對電腦軟、硬體產生中斷、破壞或限制功能之程式碼之資料;
E. 干擾或中斷本服務或伺服器或連結本服務之網路,或不遵守連結至本服務之相關需求、程序、政策或規則等,包括但不限於:使用任何設備、軟體或刻意規避看 希平方 - 看 YouTube 學英文 之排除自動搜尋之標頭 (robot exclusion headers);

服務中斷或暫停
本公司將以合理之方式及技術,維護會員服務之正常運作,但有時仍會有無法預期的因素導致服務中斷或故障等現象,可能將造成您使用上的不便、資料喪失、錯誤、遭人篡改或其他經濟上損失等情形。建議您於使用本服務時宜自行採取防護措施。 希平方 對於您因使用(或無法使用)本服務而造成的損害,除故意或重大過失外,不負任何賠償責任。

版權宣告
上次更新日期:2013-09-16

希平方 內所有資料之著作權、所有權與智慧財產權,包括翻譯內容、程式與軟體均為 希平方 所有,須經希平方同意合法才得以使用。
希平方歡迎你分享網站連結、單字、片語、佳句,使用時須標明出處,並遵守下列原則:

  • 禁止用於獲取個人或團體利益,或從事未經 希平方 事前授權的商業行為
  • 禁止用於政黨或政治宣傳,或暗示有支持某位候選人
  • 禁止用於非希平方認可的產品或政策建議
  • 禁止公佈或傳送任何誹謗、侮辱、具威脅性、攻擊性、不雅、猥褻、不實、色情、暴力、違反公共秩序或善良風俗或其他不法之文字、圖片或任何形式的檔案
  • 禁止侵害或毀損希平方或他人名譽、隱私權、營業秘密、商標權、著作權、專利權、其他智慧財產權及其他權利、違反法律或契約所應付支保密義務
  • 嚴禁謊稱希平方辦公室、職員、代理人或發言人的言論背書,或作為募款的用途

網站連結
歡迎您分享 希平方 網站連結,與您的朋友一起學習英文。

抱歉傳送失敗!

不明原因問題造成傳送失敗,請儘速與我們聯繫!
希平方 x ICRT

「Karen J. Meech:'Oumuamua 的故事--來自其他星系的首位訪客」- The Story of 'Oumuamua, the First Visitor from Another Star System


框選或點兩下字幕可以直接查字典喔!

NASA's always on the lookout for possible asteroid collision hazards, so the Pan-STARRS telescope is scanning the sky every night. Each morning, candidate objects are examined by Pan-STARRS staff and usually discovered to be no big deal. But on October 19, 2017, Pan-STARRS spotted an object moving rapidly between the stars, and this time the usual follow-up measurements of position and speed showed something completely different. By October 22nd, we had enough data to realize that this object wasn't from our solar system.

Holy cow. That's when I got the phone call, the phone call that all solar system astronomers are waiting for.

Let me tell you how exciting this was. NASA's been expecting to see an interstellar comet pass through the solar system since the 1970s, but until now, we'd never seen anything. Our own solar system is huge, so even getting a package from the nearest star system 4.4 light years away would take over 50,000 years. So this is a really big deal. The interstellar visitor entered our solar system from above the plane of the planets, coming from the direction of the constellation Lyra, and it passed closest to the Sun on September 9th, passing inside the orbit of Mercury. Now this isn't a particularly close approach or unusual distance. It's just much easier to see objects close by. On October 14th, before we discovered it, it made its closest approach to the Earth, within about 15 million miles. This is really close by astronomical standards.

Now rather than call this by its unwieldy catalog name, we briefly called it "Rama," after the cylindrical spacecraft that passed through the solar system in Arthur C. Clarke's classic science fiction story in 1973. But this wasn't quite right either, so in honor of it being discovered by a telescope in Hawaii, we consulted two experts on Hawaiian culture—a Hawaiian navigator and a linguist—to propose a name. And they suggested "'Oumuamua," which means scout or messenger from the distant past reaching out to us.

Now this discovery was important for many reasons, but to me the most significant is for what 'Oumuamua can tell us about the past of our solar system. The process of the birth of a new solar system and the growth of planets can be a violent and messy business. Leftover icy and rocky debris gets ejected from the new solar system as the giant planets migrate through the dusty disk out of which they're formed.

Now have you ever felt an emotional chill, something that's so exciting that a shiver runs up and down your spine? Or something that's very emotionally moving? Well this was it for me. This was my wow moment. We actually had a piece of material from another solar system coming close enough for us to observe.

So what would you like to know about 'Oumuamua, the very first visitor from another star system? Well, I could think of a million things, but there's what you want and what you can have, and 'Oumuamua was moving away and fading very rapidly. In the span of about a week, it had dropped in brightness by a factor of 100. So this is about all the time we were going to have to study it easily. So we had to distill the process of getting telescope time—normally a very competitive, peer-reviewed proposal process that can take up to months—down to less than a few days. So began a "polite" competition for resources. OK, let me not mince words. It was a fierce battle. We dropped everything, working around the clock, trying to craft perfectly crafted proposal words to send to the observatory directors. Well, good news. We got the time.

Now, from a perfectly selfish point of view, the first thing we might like to know is how massive 'Oumuamua is. Because after all, it passed very close to the Earth, and we didn't know about it until afterwards. How bad would this have been had it not missed the Earth? Well, the impact energy depends on the square of the velocity times its mass, and the mass depends on how big it is and what it's made of. So how big is 'Oumuamua, and what's its shape? Well, we can get this from its brightness. Now, if you don't believe me, think of comparing the brightness of a firefly in your backyard to the navigation lights on a distant airplane. You know the airplane is much brighter—it just appears faint because it's so far away. We're also going to need to know how reflective the surface of 'Oumuamua is, and we don't have any clue, but it's reasonable to assume it's very similar to small asteroids and comets in our solar system, or in technical terms, something between the reflectivity of charcoal and wet sand.

Nowadays, most of the big telescopes are used in what's called a service mode, meaning we have to carefully develop all the instructions and send them to the telescope operator, and then anxiously wait for the data to come back, praying to the weather gods. Now I bet most of you don't have careers that critically depend on whether or not it's cloudy last night. Well, we weren't going to get any second chances here. Because the weather was great, 'Oumuamua decided not to be. Its brightness wasn't constant. Now here we see 'Oumuamua racing between the stars. It's centered in the middle. The stars are trailed out because the telescope is following its motion. It started faint and then it got brighter, fainter, brighter, and fainter again, as sunlight is reflected off of four sides of an oblong object.

The extreme brightness change led us to an unbelievable conclusion about its shape. As shown in this artist's impression, 'Oumuamua is apparently very long and narrow, with an axis ratio of about 10 to one. Assuming it's dark, this means it's about half a mile long. Nothing else in our solar system looks like this. We only have a handful of objects that even have an axis ratio bigger than five to one. So we don't know how this forms, but it may be part of its birth process in its home solar system.

'Oumuamua was varying in brightness every 7.34 hours, or so we thought. As more data started to come in from other teams, they were reporting different numbers. Why is it the more we learn about something, the harder it gets to interpret? Well, it turns out that 'Oumuamua is not rotating in a simple way. It's wobbling like a top. So while it is rotating around its short axis, it's also rolling around the long axis and nodding up and down. This very energetic, excited motion is almost certainly the result of it being violently tossed out of its home solar system. Now how we interpret the shape from its brightness depends very critically on how it's spinning, so now we have to rethink what it may look like, and as shown in this beautiful painting by space artist Bill Hartmann, we think that 'Oumuamua may be more of a flattened oval.

So let's get back to the energetics. What is it made of? Well, ideally we would love to have a piece of 'Oumuamua into the laboratory, so we could study it in detail. But since even private industry can't manage to launch a spacecraft within a week to something like this, astronomers have to rely on remote observations. So astronomers will look at how the light interacts with the surface. Some colors may get absorbed, giving it a chemical fingerprint, whereas other colors may not. On the other hand, some substances may just reflect more blue or red light efficiently. In the case of 'Oumuamua, it reflected more red light, making it look very much like the organic rich surface of the comet recently visited by the Rosetta spacecraft. But not everything that looks reddish has the same composition. In fact, minerals that have tiny little bits of iron in the surface can also look red, as does the dark side of Saturn's moon Iapetus, shown in these images from the Cassini spacecraft. Nickel-iron meteorites, in other words, metal, can also look red. So while we don't know what's on the surface, we know even less about what's on the inside. However, we do know that it must at least be strong enough to not fly apart as it rotates, so it probably has a density similar to that of rocky asteroids; perhaps even denser, like metal.

Well, at the very least, I want to show you one of the beautiful color images that we got from one of the ground-based telescopes. All right, I admit, it's not all that spectacular. We just don't have the resolution.

Even Hubble Space Telescope doesn't present a much better view. But the importance of the Hubble data was not because of the images, but because it extended our observations out to two and a half months from the discovery, meaning we get more positions along the orbit, which will hopefully let us figure out where 'Oumuamua came from.

So what exactly is 'Oumuamua? We firmly believe it's likely to be a leftover archaeological remnant from the process of the birth of another planetary system, some celestial driftwood. Some scientists think that maybe 'Oumuamua formed very close to a star that was much denser than our own, and the star's tidal forces shredded planetary material early in the solar system's history. Still others suggest that maybe this is something that formed during the death throes of a star, perhaps during a supernova explosion, as planetary material got shredded.

Whatever it is, we believe it's a natural object, but we can't actually prove that it's not something artificial. The color, the strange shape, the tumbling motion could all have other explanations. Now while we don't believe this is alien technology, why not do the obvious experiment and search for a radio signal? That's exactly what the Breakthrough Listen project did, but so far, 'Oumuamua has remained completely quiet.

Now could we send a spacecraft to 'Oumuamua and answer this question once and for all? Yes, we do actually have the technology, but it would be a long and expensive voyage, and we would get there so far from the Sun that the final approach trajectory would be very difficult.

So I think 'Oumuamua probably has many more things to teach us, and in fact there might be more surprises in store as scientists such as myself continue to work with the data. More importantly, I think this visitor from afar has really brought home the point that our solar system isn't isolated. We're part of a much larger environment, and in fact, we may even be surrounded by interstellar visitors and not even know it. This unexpected gift has perhaps raised more questions than its provided answers, but we were the first to say hello to a visitor from another solar system. Thank you.

Thanks, Karen. I of course enjoyed that talk very much. Thank you. As I recall, we found it pretty late in its journey towards us. Will future technologies like the Large Synoptic Survey Telescope help us detect these things sooner?

Yeah. We're hoping that we'll start to see a lot of these things, and ideally, you'd love to find one as it's approaching the Sun, because you want to have time to do all the science, or even more ideal, you'd get a spacecraft ready to go, parked somewhere in the L4 or L5 position, somewhere near Earth, so that when something comes by, you can chase it.

Awesome, thanks so much. Let's thank Karen again.

播放本句

登入使用學習功能

使用Email登入

HOPE English 播放器使用小提示

  • 功能簡介

    單句重覆、上一句、下一句:顧名思義,以句子為單位重覆播放,單句重覆鍵顯示橘色時為重覆播放狀態;顯示灰色時為正常播放狀態。按上一句鍵、下一句鍵時就會自動重覆播放該句。
    收錄佳句:點擊可增減想收藏的句子。

    中、英文字幕開關:中、英文字幕按鍵為綠色為開啟,灰色為關閉。鼓勵大家搞懂每一句的內容以後,關上字幕聽聽看,會發現自己好像在聽中文說故事一樣,會很有成就感喔!
    收錄單字:用滑鼠框選英文單字可以收藏不會的單字。
  • 分享
    如果您覺得本篇短片很有趣或很喜歡,在短片結束時有分享連結,可以分享給朋友一同欣賞,一起看YouTube學英文!

    或是您有收錄很優秀的句子時,也可以分享佳句給大家,一同看佳句學英文!