《那些古怪又讓人憂心的問題》第139期:中子子彈(3)
The bullet would fall straight through the Earth's crust. On the surface, the vibration would quickly die down. But far below, the bullet would be crushing and vaporizing the mantle in front of it as it fell. It would blast the material out of the way with powerful shockwaves, leaving a trail of superhot plasma behind it. This would be something never before seen in the history of the universe: an underground shooting star.
Eventually, the bullet would come to rest, lodged in the nickel-iron core at the center of the Earth. The energy delivered to the Earth would be massive on a human scale, but the planet would barely notice. The bullet's gravity would affect only the rock within a few dozen feet of it; while it's heavy enough to fall through the crust, its gravity alone wouldn't be strong enough to crush the rock very much.
最終子彈會慢慢停下來，卡在地球中央鐵鎳核心中的某個地方。子彈傳遞給地球的能量在人類看來非常龐大，但對於地球來說就是九牛一毛了。子彈的重力只會影響它周圍十幾米範圍內的岩石。雖然它的重量大到足以讓它穿過地殼，但還是不夠把石頭壓穿。The hole would close up, leaving the bullet forever out of anyone's reach.4 Eventually, the Earth would be consumed by the aging, swollen Sun, and the bullet would reach its final resting place at the Sun's core.
子彈留下的孔會閉合，把子彈永遠掩埋在任何人都不可能挖得到的地方。4最終地球會被年老的太陽吞沒，而這顆子彈最後的安息之所將是太陽的核心之中。
The Sun isn't dense enough to become a neutron star itself. After it swallows the Earth, it will instead go through some phases of expansion and collapse, and will eventually settle down, leaving behind a small white dwarf star with the bullet still lodged in the center. Someday, far in the future-when the universe is thousands of times older than it is today-that white dwarf will cool and fade to black.
太陽本身的質量並不足以使地球變爲中子星。在它吞沒地球后，它會經歷一系列的膨脹和坍縮，最終一切都安寧下來，只留下一顆小小的白矮星，而那顆子彈還留在中央。在遙遠的某一天——當宇宙的年齡變成現在的幾千倍時——那顆白矮星會冷卻成爲黑矮星。That answers the question of what would happen if the bullet were fired into the Earth. But what if we could keep it near the surface?
至此我們回答瞭如果子彈射入地球內部會發生什麼。那麼如果我們設法讓它留在地表呢？
