Neutrino communications

中微子通信

ET, phone home

外星人，致电家中

The world's first neutrino-messaging service

世界上首次中微子通信服务

PARTICLE physics is all very well for addressing trivial matters like "why are we here?" (see article). But some people question its practical usefulness. To answer such naysayers a group of physicists¹ at Fermilab have just submitted a paper to Modern Physics Letters A in which they describe how they have built themselves a neutrino-powered telephone.

粒子物理学总是能很好地解决我们生活中遇到的像"为什么我们在这里？"这类的琐事。但是一些人会质疑它的实际可行性。为了消除类似的质疑，费米实验室的一群物理学家刚向物理学界权威杂志Modern Physics Letters A提交了一篇论文，论文中描述着他们怎样为自己成功定制了利用中微子载波的无线电通信电话。

Naturally, their neutrinophone is digital. A pulse of neutrinos (small, elusive³ subatomic particles with no electric charge) corresponds to the digit² "1" while no pulse corresponds to "0". The neutrinos themselves are created by smashing bunches of protons into a target made of graphite. They are detected roughly 1km away by researchers who, in their day jobs, work on a neutrino collaboration⁴ called MINERvA. By modulating⁵ the pulses of protons the group was able to send a message in binary⁶ that, when translated, read "neutrino". Whether this will go down in history alongside Alexander Graham Bell's first message, "Mr Watson, come here, I want to see you," remains⁷ to be seen.

显然，他们的中微子电话通信是数字化的。一个中微子（一种不带电荷形态诡异的亚原子粒子）脉冲对应着逻辑电平"1"，没有脉冲时就对应着逻辑电平"0"。中微子产生于一些质子束轰击一个石墨目标后产生脉冲介子，介子随后衰变而成。整天工作于一个「主注入器之中微子V-A交互作用实验（MINERvA）的研究员们在大概在一公里远处能检测到中微子。通过对质子束脉冲的调制编码后，以二进制码的形式进行中微子传输。是否这将延续亚历山大?格拉汉姆?贝尔(Alexander Graham Bell)的历史，以"Watson先生，请过来，我想见到你"进行首次中微子通信，我们拭目以待。

The point, though, apart from sheer wackiness, is that neutrinos are not easily intercepted⁸ by collisions with other sorts of matter. If humanity wanted to broadcast its existence to intelligent life forms that might be out in the galaxy⁹ listening, a modulated¹⁰ beam of neutrinos would be a good way of doing so. Conversely, some people argue that listening for ET at radio frequencies is the wrong approach. The right one, they think, would be to build a neutrino-receiver. And that would mean plenty of work for neutrino physicists. Perhaps, then, from its makers¹¹' point of view, the neutrinophone is not such a nutty idea, after all.

然而，重要的不仅是其古怪性而且中微子在传输中当受到其他物质的撞击时不容易被破坏。如果人类想让远在银河系的地方听到充满智慧生命存在性的广播，那么经过调制的中微子光束则是使他实现的一种很好的方式。相反，一些人认为利用无线电广播频率收听外星人是一种错误的方式。他们认为正确的方式应该是搭建一个中微子载波的接收器。这就意味着中微子的物理学家将需要做大量的工作。那么，也许中微子电话的制造商会认为，毕竟中微子电话并非是一个疯狂的创意。