Immortality. In movies, kings are always searching for the secret to immortality. But is immortality really a good thing? To a ten-year-old boy, one year is the same as 10% of his life. To his forty-year-old mother, one year is merely 2.5% of her life. The same year, 365 days, can feel differently to different people. If we live until we're 82, that's about 30,000 days. If this boy lives for 30,000 years, a year to him could feel like a day. And if this boy's emotions sustain through the potential boredom of living for millions of years, he might become extremely lonely and sad, knowing he has and always will outlive everyone he has ever loved. But what if everyone were immortal? Well, first off, Earth is only so big. So, where would we all live? (Grunts) "Excuse me!" "That's my face!" "Stop it!" "Pardon me." "Tight in here!" Do you remember what you did last year or when you were five? How much of your past have you forgotten? If you have trouble remembering what you did when you were five, how will you remember what happened if you were alive a thousand years ago? A million years ago? We don't remember every single detail of our past because our brains have a limited capacity and we replace useless memories, like middle school locker combinations, with relevant information. If this immortal boy finds a companion to fall in love with once every hundred years, he would have ten thousand girlfriends in a million years. And how many of those ten thousand girls' names will he be able to remember? This changes what a meaningful relationship means, doesn't it? Another tricky thing about immortality: Human beings have not always looked the same. This can be explained by Darwin's theory of evolution. For instance, if women find taller men more attractive, then more tall men would mate and have children, putting more tall genes in the gene pool. That means, in the next generation, more children will have the genes to be taller. Repeat that process for a million years and the average height will be a lot taller than the average height today, assuming there's no natural disaster that wipes out all the tall people. Our ancestors were short, hairy apes. We still have body hair, but we don't look like apes any more. If you're the only person who is immortal, while everyone else keeps evolving, generation after generation, you will eventually look quite different than the people who surround you. "Hi, how you doing?" If one of our ancestors, apes, is still alive today, how many people will make friends with it instead of calling the Museum of Natural History? And one more physical consideration for immortality: Scars. After all, immortality doesn't automatically translate to invincibility, it just means you cannot die. But it doesn't guarantee what condition you'll be alive in. Look at your body and count how many scars you have. If you have made this many permanent scars within your life, imagine how much damage you would have if you were one thousand years old! Now, there are approximately 185,000 amputation-related hospital discharges every year in the U.S. These injuries are due to accidents or illnesses. Certainly the percentage is low comparing to the total population if you only live for a hundred years. However, if you've been alive for over one million years, the odds of still having all your limbs are pretty slim. What about little accessories, like your eyes, your nose, your ears, fingers or toes? What about your teeth? What are the odds of you keeping your dental health for a hundred years? A thousand years? One million years? You might end up looking like a horribly scuffed-up Mr. Potato Head with missing pieces and dentures. So, are you sure you want to live forever? Now, which superpower physics lesson will you explore next? Shifting body size and content, super speed, flight, super strength, immortality, and -- invisibility.
长生不老 在电影里 国王们总是在寻找关于长生不老的秘密 但是长生不老真的那么好么? 对于一个十岁的男孩来说 一年相当于他一生的10% 对于他的四十岁的母亲 一年仅仅是她一生的2.5% 都是一年 365天 会使不同的人有不同的感受 如果我们一生能活82岁 也就是大约30,000天 如果这个男孩能活30,000年 一年对他来说就相当于一天 并且如果这个男孩的内心忍受着 要度过数百万年的 枯燥生活 他就可能变得极度孤独和悲伤 他了解他已经 并且将要 见证每一个爱他的人的离去 但是 如果每个人都能长生不老呢? 首先 地球只有这么大 那么我们该住到哪里? “不好意思!” “那是我的脸!” “停!” “请原谅” “好挤啊!” 你还记得你去年做了些什么吗? 那五岁那年你做过的事呢? 你已经忘记多少了你的过去? 如果你觉得记起 五岁那年你做的事很困难 你又怎么会记起 一千年前你活着的时候发生的事? 一百万年前? 我们不记得我们的过去中的每一个细节 因为我们的脑容量有限 并且我们取代无用的记忆 就像中学柜子的排列顺序 和其他类似的事情 如果这个能长生不老的男孩找到一位伴侣 和她共度了一百年的时光 那么,在一百万年中,他就可以有一万位女朋友 不过 在这一万个女朋友中 有多少个人的名字能被他记住? 这改变了传统意义上的“关系” 不是么? 另一个关于长生不老的有趣之处 所有的人并不是一样的 达尔文的进化论可以解释这一点 比如说 如果女人们认为长的高的男人更加吸引她们 那么 更多的高个男人就能找到伴侣并且生育后代 把更多的高个基因引入基因库 这就意味着 在他们的下一代中 更多的孩子会拥有高个基因并且长得高 在一百万年中重复这个过程 平均身高就会比现在的平均身高 高上许多 假设没有自然灾难 除掉所有高个子的人 我们的祖先是猿类 他们很矮 全身都是毛发 虽然我们也有体毛 但我们长的不再像猿类 如果你是唯一能长生不老的人 其他的人都在一代又一代的 不断进化 你最终会成为你身边人中的 异类 ”嗨!你感觉怎么样“ 如果我们祖先猿类中的一个如今还活着 又有多少人愿意和他做朋友 而不是戏称他为自然历史博物馆? 还有一个关于身体上的顾虑 关于长生不老 伤疤 毕竟,长生不老并不等同于 不会受伤 它只代表你不会死 但他无法确保你的身体条件的好坏 所以,看看你的身体 然后数一数你有多少道伤疤 如果你已经有了这些永久的伤疤 在你过去的生活中 想象一下如果你能活一千岁 你还会有多少伤疤 在美国 每年大约有 185,000位截肢的病人出院 185,000位截肢的病人出院 这些伤害源于事故或是疾病 当然 这个比例很低对于全体的人类而言 这个比例很低 如果你只活100年的话 然而 如果你能活 超过一百万年 你还拥有完整的肢体的可能性非常低 那么 其他的小的器官 像你的眼睛 你的鼻子 你的耳朵 手指头或者脚趾头 你的牙齿 会怎么样? 你保持牙齿健康的概率有多大 在一百年中 一千年中 甚至一百万年中 你可能最终 看起来像一个被磨坏了的薯头先生 身体不再完整 还带着一副假牙 那么 你还确定你想永远不死么? 现在 哪个个超能力的课程 你将会参加? 快速变身 超快的速度 飞行 力大无穷 长生不老 还是