Nomad

...
拜託,先讀讀沙文那條Link

此外,只要有中三的物理常識已經知道
用電腦『推算』出地球曾經停止轉動已經是天下笑話。

Nomad

不單是科學根據的問題
而是在現時的力學理論中
就算地球真的停止過,或者時間除了以色列的部份以外停止過
也不可能用軌道計算測出來 - 一個有中三力學知識的人都應該知道原因。

Nomad

不是那麼簡單的數學都要我慢慢解釋吧...(苦笑)

Nomad

OK既然沙文老大說到
我也沒辦法了(大苦笑)

首先,星系軌跡作為天文現象,幾乎完全是經典物理性的
唯一的分別是星系間的重力影響必須以低於光速的速度傳送(相對論限制)
然後,地星圍繞太陽的轉動基本上是一個三星體重力運動(地球,月球,太陽)
其餘行星本身距離相對於地球的質量太遠,所以對於本星的軌道影響極低。
將這個模型再約化為地球和太陽之間兩個質量的運動
就是中四時最簡單不過的衛星軌道問題。
這情況下假定已知所有影響力(重力源(質量),其他力源(電磁力源等)和可能撞擊的物體)
只要拿出牛頓重力定律和牛頓三運動定律
就可以利用現在所知的質量,位置和動量計算出未來的位置和動量。
但是只是照著牛頓公式是無法得知過去的情況
因為在數學上,任何物理活動是可以以無限種方式照著牛頓公式達到現今的位置
比方說你現在看到一個物體繞著地球轉
它可以(數學上)是由無限遠的時間開始就一直繞著地球轉
也可以像慧星一樣向地球方向衝來,然後撞上一個本來正在更低的軌道上公轉的物體
然後兩者粘在一起形成現時的軌道
更可以是由地球射上去,然後用火箭改變運動方向,再利用重力形成公轉

在數學上,地球有停頓與否都可以存在一個當時條件的假設照著牛頓公式演變成今日的形態

當然,由於牛頓公式數學上仍然是所謂的"time-symmetric"的關係
你可以假設地球的軌道沒有受現在找到天體以外的影響,然後估計地球和各天體在某個時間之前的位置
但是唯一知道這個估計是對與否的方法,是知道當時這些天體的位置。
問題是約書亞的長日發生在超過2000年前,那時沒有望遠鏡等等的工具
不可能有準確的天體位置記錄


要是說地球公轉停頓過的證據,唯一的大概就只有所有地球上的物體曾經被拋上宇宙
因為地球公轉速度太快了(印象中是音速百倍,有數據者請指正)

Nomad

I'm in my computer lab in school so I can't type Chinese right now...
Please reply me with Chinese if you are comfortable with it, though.
But in any event
The answer to that is yes, and no.
You can "predict" when did past astronomical events occur by assuming that there are no major disruptions in the orbits (in fact, even a physically crazy initial condition that the earth had stopped for a day and resume moving in full speed will most likely have very little effect on its orbit). That's how they predicted roughly when major astronomical phenomena like a double sun rise (as you have quote) had occured.
Also have to remember that this assumption is quite scientific since if earth's orbit had been majorly disrupted in human history, no one will survive.

As for Zheng He's fleets' positions that's actually not a major issue, since some of the Zheng He's reference stars can be millions of lightyears away from earth, they will have to be moving in speed comparable to speed of light to create a major change in what we see in the sky. Moreover, Zheng He's navigation is used to obtain the position of the Zheng's fleet on earth by knowing how angles at which we see the stars derivates, not the other way round. The change of angle moving from, say, Beijing to Hong Kong will inflict a considerable change in the angle at which we gaze one of the stars that will neglect much of the minor change in the star's own movement - leave alone earth's gravitational wave that may never reach the star until the end of the human race XD.

Nomad

But again, Sherman, you are right on that if you provide the EXACT DAY, or even exact hour of an eclipse, then you may have a quite good check of the orbit of earth, but that is not quite possible 2000 years ago...

... leave alone the fact that we couldn't even manage to find the "great city of Jerusalem" as in the old testament (we might have dug a small village out of the same position...)