作者介紹 4大疑團 不要緊，中國的諾貝爾物理 學家李政道曾說：「求學問，先求 問，再求學。」每事問才會有好學 問，以下問題就緊纏我腦中！ 1. 我聽說當太空人要長期受訓練， 其中體能方面的要求特別高，是 真的嗎？ 2. 上次中國航天科技國際交流中心 的周岫彬主任來我校探訪時，他 說過中國首名太空人楊利偉，在 起飛時差點要死，那是甚麼一回 事？周主任說那是因為「共振」， 拿破崙也遇過共振，甚麼叫「共 振」？還有網上流傳楊利偉回地 球時嘴角有血，是受了內傷嗎？ 3. 我看見每次太空人返回地球，總 是一大堆救護車衝過去迎接他 們，有那麼危險嗎？只是降落傘 着陸而已。還有，都要人扶他們 坐下來，連站也站不起來，是降 落艙太小，令他們血液不循環 嗎？ 4. 疫情期間，我看見網上說太空人 返回地球後，要隔離14天，太空 也有新冠病毒嗎？ 其實，只是起飛和降落已有一 大堆問題要解決，我們真是要向中 國航天人員致敬！ 如何成為太空人 根據中國載人航天工程辦公室 的資料，要成為太空人必須「過五 關，斬六將」！申請者至少要有碩 士學歷，年齡介乎25至35歲避免培 訓後會超齡；除了要有強健體格， 更要檢查家族病史；另外，「打鼻 鼾」的人因為在睡眠時會有窒息風 險，故不能入選。 準太空人之後還要接受一系列 體能訓練，包括離心機及電動鞦韆 等，亦要具有數學、天文和工程學 等知識。 極限訓練 據媒體報道，準太空人有「5大 極限訓練」： 1. 超重耐力訓練︰在高速旋轉的離 心機，承受相當於8個自己的重 量，進行訓練； 2. 模擬失重訓練︰身穿160多公斤 的訓練服，持續在水底訓練； 3. 飛行程序訓練︰熟記上百萬字的 飛行手冊、上千條指令及數百項 操作； 4. 頭低位卧床訓練︰進入太空時， 血液會因為失重而向頭部轉移， 因此他們必須在負6度，即「頭 低、腳高」卧姿下進行飲食及工 作訓練，亦會利用轉床變換體位 令血液重新分布； 5. 抗疲勞抗寂寞考驗︰由於在狹小 密閉的隔離艙內連續工作72小 時，故須提高心理承受能力。 經過訓練後，太空人可隨時調 節生理時鐘，調整心跳速度，在失 重下無暈車感，並準確判斷方位。 受傷風險 楊利偉在自傳《天地九重》中提 到，他在「神舟五號」爬升到距離地 面30公里時，船體由於物理作用下 發生抖動，更引起劇烈的共振，雖 然只持續26秒，但足以令他極度不 適，甚至有「瀕臨死亡」的感覺。 物理學上，「共振」是兩個振動 頻率相同的物體，當一個發生振動 時，會引起另一個物體振動的現 象。共振是常見的現象，為何受過 專業訓練的楊利偉也難以承受？因 為共振是有分等級的，低於20赫茲 以下的振動，稱為「低頻共振」，正 正是楊利偉遇到的，對人體傷害性 極高。至於嘴角有血，楊利偉指不 是受到內傷，而是飛船與大氣層摩 擦產生巨大的衝擊力，令他的嘴角 被頭盔的麥克風刮傷。 其實當返回艙高速進入大氣層 時，外面溫度可高達數千度，對太 空人構成極大威脅。1971年6月30 日，前蘇聯「聯盟11號」進入大氣層 時，便因壓力閥門被震開，令空氣 洩漏引致內部迅速減壓，3名太空 人急性缺氧而死亡。因此當返回艙 降落時，你會看見大批搜救隊一湧 而上，目的是希望能及時協助太空 人安全離開返回艙。 至於太空人被醫務人員抬着走 或坐到椅子上，是因為他們長時間 在無重力的環境下，影響了身體機 能和肌肉的運動力，強行站立或行 走會出現摔倒或骨折的情況。 「復常」過程 太空的物質極其稀薄，加上宇 宙射線、太陽光和太陽風離子都非 常強烈，細菌或病毒難有生存的機 會。不過太空人要回復「正常」生 活，必須經歷約5個月的3個階段︰ 1. 醫學隔離期︰太空人首先要進行 最少14天醫學隔離，除了讓他們 重新適應地球環境及微生物外， 也讓身體器官慢慢恢復正常運 作。另外，太空人受過宇宙射線 的照射，不排除身上的微生物發 生基因變異而造成對其他生物不 利的異變，所以他們需要待在專 門的空間內。 2. 醫學療養期︰經歷隔離期後，太 空人便進入為期約30天的療養 期，進行有氧運動及相關的身體 檢查，以便了解及減少他們受到 在太空的潛在傷害。 3. 恢復療養期︰太空人最後要 進入約3個月的恢復療養 期，他們的活動範圍 更大，運動量也會增 加，更會進行某些高 強度的專項訓練，讓 他們的生理參數恢復 到出發前的水準。 香港科學館總館長李為君曾 指，太空人上太空及返回地面時是 最危險的。中國載人航天工程取得 豐碩成果，背後有賴很多人員付出 及努力，希望年輕一代對航天科技 感到興趣，日後更作出貢獻！ 小思考，大智慧 1. 共振現象在日常生活中相當普 遍，但是否對於我們百害而無一 利？ 2. 太空人抵達太空之後，為甚麼臉 會變得浮腫，出現所謂的「月亮 臉」？ 參考答案 1. 共振在工程中是可怕的，但是在 生活中也能帶來一定好處。例如 我們用的微波爐，就是利用微波 頻率使食物自身的分子活動，從 而達到加熱效果；另外，磁力共 振是一種完全非侵入性的醫學檢 查，它使用磁場和無線電波創造 身體部位的影像，不像X光輻射 對人體有負面影響。 2. 正如上文提及是跟太空的微重力 環境有關。地球上人類受地心吸 力影響，體液會傾向流到下肢。 不過太空人抵達太空後，血液及 體液會重新分布，上身及面部的體 液也會變多，情況跟倒立有 點像，令人看起來 變得浮腫。 當我知道中國4名太空人︰劉伯 明、王亞平、陳冬和張陸會在2023 年11月28日訪港4天，我真的興奮難 耐，更走到民政諮詢中心排隊，希望 拿到29日大匯演的門票，可惜派完 了⋯⋯我整晚輾轉難眠，腦中還產生 了一大堆問題，我快要瘋了！ 星島教室 航天與天文 蔡世鴻 鄭俊傑 中華基督教會協和小學 （長沙灣）校長、 教育評議會主席 中華基督教會協和小學 （長沙灣）副校長 讀社論學 英文 The Macau Jockey Club (MJC), which has been operating at a loss, decided to terminate its concession contract with the Macau government ahead of schedule, while there would not be a new public tender for any further concession. This is both good and bad news for the Hong Kong Jockey Club (HKJC). The loss of one competitor is good, while the cessations of horse racing in the region mean that the business environment is becoming more difficult. Hopefully, the authorities can effectively crack down on illegal and offshore bookmakers to keep the horse racing industry sustainable. Generation with more gambling options The MJC franchise was originally scheduled to expire in August 2042, but last year it applied for an early termination on the grounds of operational difficulties and inability to meet current social needs. Considering the diminishing appeal of horse racing, the government accepted the application with effect from April 1. The 44-year-old MJC used to hold races three days a week with 14 events on each racing day at its peak, but today it has to struggle for survival with only four events on each of the two racing days per week. The decline of horse racing in Macau is related to the over-reliance on Hong Kong and overseas patrons. The MJC and HKJC are rivals and partners. The former initially engaged in harness racing. It later changed to horse racing and accepted bets in Hong Kong, causing the unhappy HKJC to exert pressure on the government, which in May 2002 amended the law to prohibit anyone in Hong Kong from placing bets on any offshore betting activities. Over 70 percent of MJC bets were from Hong Kong, while Singapore and Australia subsequently adopted similar measures to protect their own interests. It seriously affected the total amount of MJC bets steadily dropping from the peak of about 9.1 billion patacas in 2003 to 140 million last year. With the loss of bets from Hong Kong, the MJC has relied only on local fans and inbound tourists, but they constitute the minority. Macau having l iberal ized the gaming franchise, a large number of beautiful Las Vegas-style luxury casinos sprang up offering youngsters and tourists more choices. As a result, racecourse visits dropped from the peak of about 370,000 in 2003 to 29,000 last year with a drastic fall in race-goers and turnover, leading to an accumulated loss of 2.5 billion patacas since 2005. The cessation is only a microcosm of the global horse racing industry. As early as last June, the Singapore Turf Club, which has a history of more than 180 years, announced that it would close down in October this year and return the 120 hectares of land at the racecourse to the government. This, together with smaller racecourse closures in Europe and the US, is a warning on the industry. The decline in the appeal of horse racing is linked to the aging of racing fans. The public rarely has the experience of contacting horses while keeping a horse is regarded as a rich man's game. In addition, it is much more difficult to learn about horse racing compared to other sports and gambling. For example, studying the bloodline or condition of a horse during training and on the track is far less accessible than football. So, young people go for football betting instead. Although the Macau government has tried to diversify the gambling industry by including provisions for more non-gaming investment during licence renewal, it is still unable to reverse the fate of certain diminishing gambling sectors. The MJC sees that horse racing cannot be self-supporting and it is unable to turn the tide even after operating riding schools, amusement parks, hotels and shopping malls. So instead of continuing to sink into an abyss, it cuts loss. Ban illegal bookmakers, cut betting duty The popularity and profitability of horse racing have declined in many regions, but the HKJC is one of the few operators still making a profit. Last year's betting turnover was $304.8 bi l l ion, a year-on-year increase of 5.1 per cent. The amount of money given back to the community even hit a record high of $35.9 billion. Nevertheless, the HKJC, like its peers, faces many challenges including global recession as well as fierce competition from illegal bookmakers. However, to address the fiscal deficit, the government imposes an annual "special betting duty" of $2.4 billion on the HKJC only to weaken its competitiveness and undermine its contribution to charitable trust funds. Therefore, apart from stepping up efforts to combat illegal bookmakers, the authorities should seriously look into reduction of betting duty, especially that on horse racing which is as high as 75 per cent - almost double Japan's 40 per cent. As profitability grows, so will the amount of money that can be given back to the community. 翻譯自1月16日《星島日報》社論 （http://std.stheadline.com/） cessation (n) —— 中止 franchise (n) —— 特許經銷權 liberalize (v) —— 放寬 gaming (n) —— 賭博 casino (n) —— 賭場 race-goer (n) —— 觀賽馬者 microcosm (n) —— 縮影 bloodline (n) —— 血統 concession contract —— 特許經營權合約 public tender —— 公開招標 offshore bookmaker —— 境外莊家 harness racing —— 賽馬車 The Secretary for Administration and Justice, Cheong Weng Chon, acknowledged the MJC's 40-year history but said that the club had lost its appeal to residents and visitors. He noted that the MJC had been severely impacted by the economy and three-year-long pandemic and that it showed no signs of being able to operate effectively. 1. The word _____ in the first paragraph is the opposite of "partner". 2. The appeal of horse racing has been _____. 3. In the passage, the word _____ means "a very deep hole". 4. The HKJC gives money back to the _____. 5. According to the last paragraph, the government's stepping up efforts to combat _____ bookmakers is not enough. Answers 1. competitor 2. diminishing 3. abyss 4. community 5. illegal Vocabulary Useful Terms Did you know? MJC closure & illegal bookmaking sound alarm 翻譯︰George & Q A D6 侷芎 10.25.2024 星期五
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