Comments on: 相對論 http://www.drkhtang.com/2009/02/18/%e7%9b%b8%e5%b0%8d%e8%ab%96/ 你現在是怎樣的心情呢？是歡喜悲傷？還是一點點不知名的愁？如果是，請進來我的世界，稍作停留，在這裡有人陪你歡喜悲傷，陪你愁。 Mon, 16 Jan 2012 05:41:41 +0800 hourly 1 http://wordpress.org/?v=3.3.1 By: drkhtang http://www.drkhtang.com/2009/02/18/%e7%9b%b8%e5%b0%8d%e8%ab%96/comment-page-1/#comment-970 drkhtang Thu, 19 Feb 2009 06:58:35 +0000 http://www.drkhtang.com/?p=486#comment-970 補充一點。衛星上還是有裝一個小型的推進器，用來補助或微調角度。衛星的角度會因為月亮與太陽的引力而有所改變，再加上衛星飛行所在的高度不全然沒有空氣。一丁點的空氣摩擦力最終還是會消耗掉衛星的飛行前進動力。在這些情況下微調就能延長衛星在軌道的時間。根據牛頓定律，它所需要的動力是非常小的，因為它幾乎處于無重力狀態。 推進器的動力一般都是化學動力。所以有爆炸的危險。 補充一點。衛星上還是有裝一個小型的推進器，用來補助或微調角度。衛星的角度會因為月亮與太陽的引力而有所改變，再加上衛星飛行所在的高度不全然沒有空氣。一丁點的空氣摩擦力最終還是會消耗掉衛星的飛行前進動力。在這些情況下微調就能延長衛星在軌道的時間。根據牛頓定律，它所需要的動力是非常小的，因為它幾乎處于無重力狀態。

推進器的動力一般都是化學動力。所以有爆炸的危險。

]]> By: drkhtang http://www.drkhtang.com/2009/02/18/%e7%9b%b8%e5%b0%8d%e8%ab%96/comment-page-1/#comment-968 drkhtang Thu, 19 Feb 2009 03:21:28 +0000 http://www.drkhtang.com/?p=486#comment-968 Yes, the clock brought down from the satellite will show slightly lagging time than the one on earth. That's why the time-travel is possible in theory. Yes, the clock brought down from the satellite will show slightly lagging time than the one on earth. That’s why the time-travel is possible in theory.

]]> By: Ah Hong http://www.drkhtang.com/2009/02/18/%e7%9b%b8%e5%b0%8d%e8%ab%96/comment-page-1/#comment-967 Ah Hong Thu, 19 Feb 2009 02:28:58 +0000 http://www.drkhtang.com/?p=486#comment-967 shiam, U need a lot of power (using rocket/space shuttle) to send the satellite to sky. Need to achieve Escape velocity of 11.186 km/s or abt 4 times faster than speeding bullet to break away from earth's gravity force. However once Satellite is in its outer space orbit, it becomes "weightless" and will continue travelling at high velocity without external force. Most satellite has "wings" to collect solar power to provide the power to communication equiplement or correction of the orbit if needed. shiam,
U need a lot of power (using rocket/space shuttle) to send the satellite to sky. Need to achieve Escape velocity of 11.186 km/s or abt 4 times faster than speeding bullet to break away from earth’s gravity force.
However once Satellite is in its outer space orbit, it becomes “weightless” and will continue travelling at high velocity without external force.
Most satellite has “wings” to collect solar power to provide the power to communication equiplement or correction of the orbit if needed.

]]> By: Ah Hong http://www.drkhtang.com/2009/02/18/%e7%9b%b8%e5%b0%8d%e8%ab%96/comment-page-1/#comment-966 Ah Hong Thu, 19 Feb 2009 02:04:36 +0000 http://www.drkhtang.com/?p=486#comment-966 Imagine I prepare two perfectly synchronous atomic clocks. one put on earth and the other one put in satellite & send to sky. I understand the clock in Satellite will appeared to be slow down relative to the clock or observer on earth. However, after say few months or a year. If I bring down the satellite & compare the two clocks on earth. Will it actually indicate a different time? Imagine I prepare two perfectly synchronous atomic clocks. one put on earth and the other one put in satellite & send to sky.
I understand the clock in Satellite will appeared to be slow down relative to the clock or observer on earth.

However, after say few months or a year. If I bring down the satellite & compare the two clocks on earth. Will it actually indicate a different time?

]]> By: shiam http://www.drkhtang.com/2009/02/18/%e7%9b%b8%e5%b0%8d%e8%ab%96/comment-page-1/#comment-964 shiam Thu, 19 Feb 2009 00:58:28 +0000 http://www.drkhtang.com/?p=486#comment-964 有一點我感到很疑惑 人用什麼能量去讓衛星進行時速幾萬公里的飛行呢？ 又如何補充能量？ 有一點我感到很疑惑
人用什麼能量去讓衛星進行時速幾萬公里的飛行呢？
又如何補充能量？

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