Mankind has always been curious about the possibility that “we’re not the only ones in the universe.” A great deal of effort has been spent on the attempt to find extraterrestrial life. Unfortunately for us, we may not even know what we’re looking for.
The New Scientist says that life is so incredibly hard to define that we may never know if it’s out there.
Citing over 280 definitions of life–all of which miss the point somewhat– Sohan Jeeta, an astrobiologist, floated his own definition this week at an astrobiology conference:
“Life is a thermodynamically open chemical system with a semi-permeable boundary. It contains an information-based complex system with emergent properties, part of which drives a metabolism based on a proton gradient. The said gradient generates the necessary potential difference across the semi-permeable boundary. The information is heritable and coded in such a way as to allow variation and thus evolution.”
Schoolchildren all over the world are rejoicing over the possibility of this being on a test. But why does life need a definition?
Because without one, we won’t know if what we find out in interstellar space is indeed life. The vast differences in environment would obviously create a form that’s almost entirely unrecognizable to us. Looking for amino acids, or any other essentials to life on earth, would leave us missing the point with something that’s adapted to a completely different world.
First defining life, and in the most open-ended manner possible, is the only way to design experiments and instrumentation to be able to look for aliens. Unless, of course, they show up and try to kill us. That’s always an option, too.
译文:
或许我们已经发现外星人,只是没有意识到罢了
人类总是乐此不疲地讨论着一个话题”我们是不是宇宙唯一的生物”, 于是人类为了找寻外太空生命, 做出了大量努力. 但可悲的是, 我们甚至连我们要找的是什么都不知道.
新科学家认为由于生命很难定义,所以我们可能永远不会知道生命是否已经在那里诞生了.
Sohan Jeeta 是一名太空生物学家, 他在这个星期的太空生物会议上举了超过280个关于各生物体,生命的定义来引证自己对于生命的定义.
"从热力学角度来说,生命是一个有半渗透边界的开放化学系统. 它包括一个会放出物质的复杂的信息系统, 其中部分会刺激以质子升降为基础的新陈代谢,这里所说的质子升降会产生生物体所需的潜在差异穿过半渗透边界.这些信息通过这种方式变成可遗传的,可编码的, 因此产生物种的不同, 进而发生进化."
全世界的小学生都在为这个正在进行的实验感到欢欣雀跃. 可是,生命为什么需要定义呢?
因为如果没有一个定义,我们很难判断在太空中找到的到底是不是生命.环境中所产生的巨大差异性肯定会创造出一个我们完全不认识的生命形式. 寻找氨基酸或地球上生命的其它组成体会让我们变的迷失, 忽略了原来有些物质生命是适应另一个完全不同的世界.
先给生命下个定义, 然后以最开放的方式,来设计实验和仪器,这是我们现在唯一能用来找寻外星人的方法. 当然, 要是外星人出现,想要灭绝人类,我们还是会有其它办法的.