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What's happened since the universe started? The time spiral shown here features a few notable highlights. At the spiral's center is the Big Bang, the place where time, as we know it, began about 13.8 billion years ago. Within a few billion years atoms formed, then stars formed from atoms, galaxies formed from stars and gas, our Sun formed, soon followed by our Earth, about 4.6 billion years ago. Life on Earth begins about 3.8 billion years ago, followed by cells, then photosynthesis within a billion years. About 1.7 billion years ago, multicellular life on Earth began to flourish. Fish began to swim about 500 million years ago, and mammals because walking on land about 200 million years ago. Humans first appeared only about 6 million years ago, and made the first cities only about 10,000 years ago. The time spiral illustrated stops there, but human spaceflight might be added, which started only 75 years ago, and useful artificial intelligence began to take hold within only the past few years. Explore Your Universe: Random APOD Generator
最新异域文明研究活动 发起新活动
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双腿残疾的我，下半生的心愿
发表于：2023-03-22 15:47:16
睡梦中与女孩亲吻
发表于：2023-04-23 03:51:36
看了几个视频，非常担忧孤独终老
发表于：2022-10-05 17:22:25
再次回忆北京五道口吃饭时遇到的女孩
发表于：2022-09-08 15:52:55
对视频择偶的规划
发表于：2022-06-25 02:39:14
经常在半夜凌晨来访的长春网友（根据百度统计），以后可能打扰你了
发表于：2022-03-29 16:34:51
越来越惶恐
发表于：2022-07-17 09:01:27
考虑做一个回忆类网站
发表于：2023-04-09 15:48:16
秋天到了
发表于：2022-08-21 02:43:54
努力达到目标，祈祷，阿们
发表于：2023-01-02 01:36:26
科技渴求榜 渴求
今天，又是渴求大奖
(IMP: 2700 )
一直为表弟的肾衰竭担心，异域文明请传授治疗技术
(IMP: 700 )
我的人生生存和发展基础难道是可鄙的？
(IMP: 200 )
用户，头衔，积分
User 吴鹏 has points :990200 .
ACQs :
34
CCAs:
16
ACCS:
7
User peng wu has points :48400 .
ACQs :
2
CCAs:
0
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0
User wup has points :3800 .
ACQs :
0
CCAs:
0
ACCS:
0
User 我来自于星空 has points :1200 .
ACQs :
0
CCAs:
0
ACCS:
0
User Ernestnip has points :1000 .
ACQs :
0
CCAs:
0
ACCS:
0