导读：一直以来，人类关于外星文明(alien civilization)的探索都未曾中断。不久前，美科学家称，过去数十年来，外星人可能一直使用类似"宇宙版"的Twitter和地球人沟通，只不过我们不知道罢了。

外星人很可能会像发送微博一样，采用简短的定向信息进行发送

　　不久前，美国天体物理学家表示，地外文明搜索研究所（SETI）一直以来探索宇宙外星文明信号的方法可能并不正确。

　　The SETI Institute, listening to the cosmos for signs of signals from alien civilizations, may be monitoring the wrong "channels," a U.S. astrophysicist says.

　　美国加州大学尔湾分校的（科学家）格雷戈里·本福德近日称，试图跟人类建立联系的外星人很可能力求节约资源，只发送较短的定向信息，而不是漫无方向地持续发送信息。而SETI一直以来搜索的信息正是后者。

　　Gregory Benford of the University of California, Irvine, says such a civilization wanting to announce it presence would transmit "cost-optimized" narrowly focused signals, not the continuous omni-directional signals the SETI program has been scanning for, a university release said recently.

　　“这种方法更像是推特（Twitter），而大部头的《战争与和平》，”格雷戈里·本福德的孪生兄弟，物理学家詹姆斯·本福德说。

　　 "This approach is more like Twitter and less like War and Peace, " James Benford, Gregory Benford's twin and fellow physicist, says.

　　“不论是何种生命形式，进化都使他们选择资源节约的做法。穿越光年发送信息，要花费相当巨大的资源。”

　　"Whatever the life form, evolution selects for economy of resources. Transmitting signals across light years would require considerable resources."

　　这对兄弟说，外星人不会全方位的向外空间传送信号，而只是在1-10千兆赫的波段内定向发送。 但SETI采取的是大范围的信号扫描方式，这样一来，在外星文明发出"我们在这儿吶！"信息时，可能就已经错过SETI的扫描了。

　　They says alien signals would not be blasted out in all directions but narrowly directed in the one-to-10 gigahertz broadband signal range and SETI's broad sweeping search could leave many days when brief Twitter-like flashes of "here we are" from alien civilisations go undetected.

　　越来越多的科学家认为，这种简短、定向的信息（被称为本福德信号）才应该是SETI搜索的目标。

　　Such short, targeted blips, dubbed Benford beacons, should be the targets of SETI efforts, a growing number of scientists say.

　　本福德兄弟还建议科学家将搜索地点集中在银河系，特别是90％恒星所在的中心地区。

　　And the Benfords also suggest concentrating the search on our own Milky Way galaxy, especially its center where 90 percent of its stars are located.

　　“那里的恒星比太阳更早10亿年，”格雷戈里·本福德说，“这意味着那里更有可能存在着高等智慧生命。这比将SETI的天线对准银河系边缘更年轻恒星、也更稀疏的区域要好得多了。”

　　"The stars there are a billion years older than our sun," Gregory Benford says, "which suggests a greater possibility of contact with an advanced civilization than does pointing SETI receivers outward to the newer and less crowded edge of our galaxy."

　　CASIO辞海拾贝

alien civilization	外星文明
SETI Institute	地外文明搜索研究所
University of California, Irvine	美国加州大学尔湾分校
Milky Way galaxy	银河系