For the sake of this simulation, I assume that at lower speeds some type of vortex shedding creates a flipping tumble, while at hypersonic speeds it's squished into a semi-stable spheroid shape. However, this is little more than a wild guess. If anyone puts a steak in a hypersonic wind tunnel to get better data on this, please, send me the video. If you drop the steak from 250 kilometers, things start to heat up; 250 kilometers puts us in the range of low Earth orbit. However, the steak, since it's dropped from a standstill, isn't moving nearly as fast as an object reentering from orbit. In this scenario, the steak reaches a top speed of Mach 6, and the outer surface may even get pleasantly seared. The inside, unfortunately, is still uncooked. Unless, that is, it goes into a hypersonic tumble and explodes into chunks. From higher altitudes, the heat starts to get really substantial. The shockwave in front of the steak reaches thousands of degrees (Fahrenheit or Celsius; it's true in both). The problem with this level of heat is that it burns the surface layer completely, converting it to little more than carbon. That is, it becomes charred. Charring is a normal consequence of dropping meat in a fire. The problem with charring meat at hypersonic speeds is that the charred layer doesn't have much structural integrity, and is blasted off by the wind-exposing a new layer to be charred. (If the heat is high enough, it will simply blast the surface layer off as it flash-cooks it. This is referred to in the ICBM papers as the “ablation zone.”) Even from those heights, the steak still doesn't spend enough time in the heat to get cooked all the way through. We can try higher and higher speeds, and we might lengthen the exposure time via dropping it at an angle, from orbit.
在我进行模拟的过程中，我假设在低速下某些类型的涡流脱落会使牛排翻来覆去，而在高超音速下，牛排则会被挤压成半稳定态的椭球状。但这也只是我的大胆猜想，如果有人真的在高超音速风洞中放入了一块牛排以取得更准确的数据，请一定把视频发给我。如果你从250千米的高度释放牛排，牛排能达到的温度就更高了。250千米的高度已经在低地球轨道的范围里了，不过由于牛排是从静止开始下落，因而速度比不上那些脱离轨道再进入大气层的物体。在这种情况下，牛排的最高速度能够达到6马赫，这时牛排的外表面可能焦得恰到好处。但很不幸，内部仍然是生的，除非牛排在高超音速下猛地颠簸了一下炸成了碎片。如果从更高的地方落下，热量就会变得相当可观。牛排前方的激波将会达到数千度（反正不管用摄氏度还是华氏度都有几千度），这时牛排的表层会被彻底烤成焦炭。把肉扔到火里的一个正常后果就是变成焦炭。但高超音速的焦肉面临一个问题：被烧成焦炭的肉并没有多少结构强度，因而会被狂风吹走，使得更深一层的肉被烧焦。（如果热量足够高，牛排的表面会在被剥离的瞬间被烤熟，这个速度区域在弹道导弹论文中被称为“剥蚀区”。）即使在这么高的高度下，牛排所受的高温时间仍然不足以把整块肉从里到外都烤熟。3我们可以尝试更高的高度和更快的速度，我们甚至可以通过从轨道以一定角度扔下去以增加暴露在高温下的时间。
But if the temperature is high enough or the burn time long enough, the steak will slowly disintegrate as the outer layer is repeatedly charred and blasted off. If most of the steak makes it to the ground, the inside will still be raw. Which is why we should drop the steak over Pittsburgh.
但当温度高到一定程度，或者烧蚀的时间长到一定程度后，整块牛排就会慢慢解体，因为牛排的外层不断地被烧焦并被狂风剥离。如果大部分牛排能够坚持到最后落到地上，内部仍将会是生的。这也是为什么我们要在匹兹堡上空扔牛排。
As the probably apocryphal story goes, steelworkers in Pittsburgh would cook steaks by slapping them on the glowing metal surfaces coming out of the foundry, searing the outside while leaving the inside raw. This is, supposedly, the origin of the term “Pittsburgh Rare.”
有这么一个流传的故事，说的是匹兹堡的钢铁工人喜欢把牛排摔到刚出炉还在炽热发光的金属表面，把牛排的外层烤熟，但内部仍然保持生的状态。这大概就是“匹兹堡生牛排”的来历。
So drop your steak from a suborbital rocket, send out a collection team to recover it, brush it off, reheat it, cut away any badly charred sections, and dig in.
所以从一个亚轨道火箭上把牛排扔下来，并派出一支回收小队把它找回来，擦干净，再加热一下，去掉烧焦的部分，然后就可以开吃啦。
Just watch out for salmonella. And the Andromeda Strain.
要小心沙门氏菌，以及《天外来菌》哦。
1 I mean, intact. Not necessarily fine to eat.
1．我是说，看着没事儿，吃了不一定没事儿。
2 I know what some of you are probably thinking, and the answer is no - it doesn't spend enough time in the Van Allen belts to be sterilized by radiation.
2．我知道你们一些人在想什么，答案是不行——它在范艾伦辐射带里待的时间不够长，不足以通过辐射来消毒。
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