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.
Nesmrtnost. V filmih kralji vedno iščejo skrivnost nesmrtnosti. Toda ali je nesmrtnost res dobra stvar? Za desetletnika je eno leto 10 odstotkov njegovega življenja. Za njegovo štiridesetletno mamo je eno leto le 2,5 odstotka življenja. Isto leto, 365 dni, lahko različni ljudje čutijo različno. Če živimo 82 let, je to okoli 30,000 dni. Če bi ta fant živel 30,000 let, bi se mu eno leto zdelo dolgo kot en dan. In če bi njegova čustva zdržala morebitni dolgčas milijone let dolgega življenja, bi utegnil postati zelo osamljen in žalosten, saj bi vedel, da bo preživel vse, ki jih je kdajkoli imel rad. Kaj pa, če bi bili vsi nesmrtni? Hja, velikost Zemlje je omejena. Kje bi vsi živeli? (godrnjanje) "Oprostite!" "To je moj obraz!" "Nehaj!" "Se opravičujem." "Malo tesno je tukaj!" Se spomnite, kaj ste počeli lani ali ko ste imeli pet let? Koliko preteklosti ste pozabili? Če se le stežka spomnite, kaj ste počeli pri petih letih, kako se boste spomnili, kaj se je dogajalo pred tisoč leti? Pred milijonom let? Ne spomnimo se vseh podrobnosti iz preteklosti, saj imajo možgani omejene zmožnosti in nepomembne spomine kot je kombinacija šolske ključavnice nadomestijo s pomembnimi informacijami. Če se bo ta nesmrtni fant vsakih sto let zaljubil, bo imel deset tisoč punc v milijonu let. In koliko imen od teh deset tisoč punc si bo lahko zapomnil? To spremeni pomen "resne zveze", kajne? Nesmrtnost ima še en trik: ljudje niso vedno izgledali enako. To pojasni Darwinova teorija evolucije. Če recimo ženske privlačijo visoki moški, bo več visokih moških imelo otroke, kar bo v genski bazen prineslo več genov za visokoraslost. Zato bo v naslednji generaciji več otrok imelo gene za visokoraslost. Ponovite postopek skozi milijon let in povprečna višina bo veliko večja kot je danes, če seveda ne pride do naravne katastrofe, ki bo uničila vse visoke ljudi. Naši predniki so bili majhne kosmate opice. Še vedno smo poraščeni, a ne izgledamo več kot opice. Če ste edina nesmrtna oseba, medtem ko se vsi razvijajo, eno generacijo za drugo, boste sčasoma izgledali zelo drugače od tistih okoli vas. "Živjo, kako si?" Če je kak naš opičji prednik še živ, koliko ljudi se bo spoprijateljilo z njim, namesto da bi poklicali Prirodoslovni muzej? Še ena fizična zadeva pri nesmrtnosti: brazgotine. Konec koncev nesmrtnost ni avtomatsko tudi nepremagljivost, pomeni le, da ne morete umreti. Ne zagotavlja pa, v kakšnem stanju boste. Poglejte se in preštejte svoje brazgotine. Če jih imate že doslej toliko, koliko jih bo šele, če boste živeli tisoč let! V ZDA opravijo približno 185,000 amputacij na leto. Te poškodbe so posledica bolezni ali nesreč. To je nizek delež glede na celotno prebivalstvo, če živite samo sto let. Če pa bi živeli več kot milijon let, bi bilo malo možnosti, da bi še imeli vse okončine. Kaj pa majhni dodatki, kot so oči, nos, ušesa, prsti na nogah ali rokah? Kaj pa vaši zobje? Kako verjetno je, da boste sto let obdržali zdrave zobe? Tisoč let? Milijon let? Morda boste na koncu izgledali kot kakšna zmečkana igrača brez delov telesa in brez zob. Si res želite večno živeti? No, katero nadnaravno moč želite raziskati zdaj? Spreminjanje velikosti in vsebine telesa? super hitrost, letenje, super moč, nesmrtnost, in... nevidnost.