为何我们不把垃圾发射到太阳上？

On BBC Radio 4, Drs Adam Rutherford and Hannah Fry have been answering intriguing scientific questions from listeners and the BBC Future audience.

在BBC广播4频道，广播听众和BBC《未来》栏目的观众就一些有趣的科学问题进行提问，亚当·卢瑟福博士和汉娜·弗莱博士给予相应的回答。

One vexing query the pair have been exploring rocketed in from Elisabeth Hill, via BBC Future’s Facebook page, who asked:“Could we shoot garbage into the Sun?”

伊丽莎白·伊尔在BBC《未来》栏目的脸书主页上问了一个困扰她的问题：“我们可以把垃圾扔到太阳上吗？”两位主持人对这个问题进行了探讨。

Fair question. After all, if we can detect gravitational waves, or send a probe to land on a comet, surely we can send some rubbish to our nearest star?

这是个不错的问题。毕竟，如果我们能探测到引力波，能发送探测器到彗星上，那我们为什么就不能将垃圾送到离我们最近的星球上去呢？

Though as Rutherford and Fry discovered in the radio episode, it’s not so simple:

不过，正如卢瑟福和弗莱在广播节目中为我们解释的那样，事实并没有这么简单：

The primary problem is weight. The average person in the UK produces 1.85kg of waste per day; in the US, it’s 2.3kg.

主要的问题在于重量。在英国，平均每人每天会制造1.85千克垃圾；在美国，每人每天制造2.3千克垃圾。

As Andrew Pontzen of University College London points out, it costs $200m to get the Ariane V rocket into an orbit ready to travel further into space. With a payload of approximately 7,000kg, that works out at around $41,000 per kilogram. A hefty price to pay for a few plastic wrappers and a bottle or two.

英国伦敦大学学院的安德鲁·波岑指出，将亚利安五号运载火箭发送至预备轨道需要花费2亿美元。火箭可装载垃圾约7吨，折合每千克运载费用约4.1万美元。对于塑料垃圾和破瓶烂罐来说，这样的费用太高昂了。

In the coming decade, commercial operations like SpaceX hope to make cheaper rockets – closer to $90m per launch – and in the far future, space elevators might be an option too.

未来十年，太空探索技术公司等商业运载机构有望制造出更便宜的火箭，每次发射花费或限于9000万美元。并且，在遥远的未来，太空电梯也有可能实现。

But even then, the Sun is 93 million miles away, and you’d still need an enormous amount of (expensive) fuel to get the rocket to plummet into the Sun if you took the direct route. Pontzen reckons that, unless you plan the mission very carefully, you’d need about 10 times more energy for the trip between Earth and the Sun’s surface than you’d already spent getting into orbit.

但即使到那时，如果想要火箭直抵太阳，仍然需要燃烧大量昂贵的燃料，因为太阳离地球有9300万英里远。波岑认为，除非你将飞行线路计划得十分周密，否则从地球到太阳表面需要的能量，约为从地球到轨道的10倍。

So, theoretically possible? Yes. But realistically desirable? Probably not.

所以，理论上有可能吗？有。但实际可行吗？不太可行。