论文标题
费米悖论重新审视：技术签名与联系时代
The Fermi Paradox revisited: Technosignatures and the Contact Era
论文作者
论文摘要
提出了对费米悖论的新解决方案：推定外星文明的探测或访问的可能性很低，直到广播通信开始后文明达到一定年龄（称为接触时代）。如果生物行星很普遍，则推定的先进文明可能优先将探针发送给具有技术签名的行星，例如无线电广播。接触概率被定义为找到足够近的文明的机会，以便它可以检测到最早的无线电排放（放射线圈），并发送了目前可以到达太阳系的探针。发现除非文明非常丰富，否则当前的地球接触概率很低。由于辐射圈随时间扩展，接触概率也随之扩展。接触时代的定义是接触概率变为秩序统一的时间（由于无线电传输的发作）。当时，外星人探针（或消息）变得更有可能。除非文明高度丰富，否则接触时代被证明是数百到几千年的顺序，不仅可以应用于物理探针，还适用于传播（即SETI）。因此，表明文明不太可能在交流寿命至少几千年的时间内交流。
A new solution to the Fermi Paradox is presented: probes or visits from putative alien civilizations have a very low probability until a civilization reaches a certain age (called the Contact Era) after the onset of radio communications. If biotic planets are common, putative advanced civilizations may preferentially send probes to planets with technosignatures, such as radio broadcastings. The contact probability is defined as the chance to find a nearby civilization located close enough so that it could have detected the earliest radio emissions (the radiosphere) and sent a probe that would reach the Solar System at present. It is found that the current contact probability for Earth is very low unless civilizations are extremely abundant. Since the radiosphere expands with time, so does the contact probability. The Contact Era is defined as the time (since the onset of radio transmissions) at which the contact probability becomes of order unity. At that time alien probes (or messages) become more likely. Unless civilizations are highly abundant, the Contact Era is shown to be of the order of a few hundred to a few thousand years and may be applied not only to physical probes but also to transmissions (i.e. SETI). Consequently, it is shown that civilizations are unlikely to be able to inter-communicate unless their communicative lifetime is at least a few thousand years.
