Houston, it's a bit warm up here.
太空可能極度寒冷,也可能熾熱難當,端看你是否面向太陽。你的背光面面對幾近真空的虛空;你的體熱慢慢地輻射到溫度 2.7K 的背景環境中。向陽面則會被高達 1,361 W/m² 的能量——也就是驅動衛星太陽能板的同一股能量——給烤熟。 順帶一提,我很驚訝地發現『液冷通風服』(LCVG)是太空漫步的標準配備。太空衣的主要任務其實是負責散熱,而不是讓太空人保暖! 現在,將太空漫步的你換成資料中心,就能看出問題所在了。 要冷卻一個塞滿高溫機架的太空資料中心絕非易事。太空中,唯一的散熱途徑是透過熱輻射。此方式效率極低,因此資料中心需安裝所謂『散熱器』的巨大面板——其表面積可能是 XPU 伺服器機架的數千倍大。 有些絕頂聰明的人說這事辦得到。我相信他們。這會是令人嘆為觀止的成就。 Space can be freezing cold or scorching hot depending on whether you are facing the sun. The shaded side of you faces a void nearly empty of particles; you'll radiate body heat slowly to the 2.7K background. The sunny side, however, will be—well, cooked—by the same 1,361 W/m² energy flux that powers a satellite’s solar panels. BTW I was surprised to learn that the LCVG (Liquid Cooling and Ventilation Garment) is a standard-issue for spacewalks. The suit's job is actually to remove heat, not to keep the astronaut warm! Now, swap the astronaut for a data center, and you see the problem. It is not easy to cool a...