《那些古怪又讓人憂心的問題》第108期:地球擴張(1)

EXPANDing EARTH

地球擴張

Q. How long would it take for people to notice their weight gain if the mean radius of the world expanded by 1cm every second? (Assuming the average composition of rock were maintained.)

Q．如果地球半徑現在開始以每秒1釐米的速度擴大，要花多久人們才能意識到他們自己變重了？（假設岩石的平均構成不變。）

-Dennis O'Donnell

——丹尼斯•奧唐奈

A. THE EARTH IS NOT, currently, expanding.

A．地球目前並不在擴張。

People have long suggested that it might be. Before the continential drift hypothesis was confirmed in the 1960s,1 people had noticed that the continents fit together. Various ideas were put forward to explain this, including the idea that the ocean basins were rifts that opened in the surface of a previously smooth Earth as it expanded. This theory was never very widespread,although it still periodically makes the rounds on YouTube.

一直有人主張說地球也許在擴張。在20世紀60年代1板塊漂移學說被證實之前，人們就已經發現了不同大陸的海岸線能夠互相吻合。於是人們想出很多個解釋方法，其中有一個認爲，地球本是一個十分光滑圓整的球，而海洋盆地則是地球不斷擴張產生的裂縫。這個理論從未變得十分流行，但它的身影不時在YouTube上出現。

To avoid the problem of rifts in the ground, let's imagine all the matter in the Earth, from the crust to the core, starts expanding uniformly. To avoid another drain-the-oceans scenario, we'll assume the ocean expands, human structures will stay.

爲了避免出現大地裂痕，我們不妨假設地球上從地殼到地核的所有物質都會均勻擴張。爲了不讓之前發生的“榨乾海洋”慘劇再度發生，我們假定海洋也會擴張。所有人類建築都會保持原樣。

t = 1 second

1秒後

As the Earth started expanding, you'd feel a slight jolt, and might even lose your balance for a moment. This would be very brief. Since you're moving steadily upward at 1 cm/s, you woudn't feel any kind of ongoing acceleration. For the rest of the day, you wouldn't notice much of anything.

當地球剛開始擴張時，你可能會感覺到一些顫動，甚至會暫時失去平衡。不過別擔心，這隻會持續很短一段時間。因爲你是以每秒1釐米的速度勻速上升，你不會感受到任何由此產生的加速度。在這一天剩下的時間裏，你什麼也不會注意到。

t = 1 day

1天后

After the first day, the Earth would have expanded by 864 meters.

1天后，地球已經變胖了864米。

Gravity would take a long time to increase noticeably. If you weighed 70 kil-ograms when the expansion started, you'd weigh 70.01 at the end of the first day.

重力增長得非常慢。如果你在擴張伊始是70千克，那麼第一天結束時你將是70.01千克。