多少天是自寒武纪大爆发?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 07 - 08 - t20:58:45z //www.hoelymoley.com/feeds/question/19414 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/19414 3 多少天是自寒武纪大爆发? 佩里安斯沃思 //www.hoelymoley.com/users/19099 2020 - 03 - 09 - t23:37:23z 2021 - 08 - 16 - t08:51:09z < p >我想知道如何计算的天数从地球过去的事件,并使用寒武纪大爆发为例。< / p > < p >我定义一天是地球对太阳的一个旋转。关键是,地球自转减慢经过数百万年的进化,所以它不会那么简单用365年的时间。< / p > < p >是有公式的天数x年前我可以简单地集成到找到答案吗?或者其他方法来近似? < / p > //www.hoelymoley.com/questions/19414/-/19418 # 19418 3 由samcarter_is_at_topanswers回答。xyz有多少天是自寒武纪大爆发? samcarter_is_at_topanswers.xyz //www.hoelymoley.com/users/17730 2020 - 03 - 10 - t11:00:31z 2020 - 03 - 10 - t17:30:27z < p >作为一个非常粗略的近似,可以先从Arbab方程(9)(2009),< a href = " https://arxiv.org/abs/physics/0304093 " rel = " nofollow noreferrer " > https://arxiv.org/abs/physics/0304093 < / >每年得到有效天数:< / p > < p > <跨类= " math-container " > $ $ {eff T_{\识别文本。}}= T_0 \离开(\压裂{t_0-t} {T_0} \右)^ {-2.6}$ $ < / span > < / p > < p >与< / p > < ul > <李> <跨类= " math-container " > t < / span >美元现在的时差,然后李< / > <李> <跨类= " math-container " > T_0 = 365.25 < / span >美元目前每年的天数< /李> <李> <跨类= " math-container " > $ T_0 =(0.021)下午13.799 \ \ cdot 10 ^ 9 $ < / span >当前宇宙的年龄(从普朗克协作et al . (2015), < a href = " https://arxiv.org/abs/1502.01589 " rel = " nofollow noreferrer " > https://arxiv.org/abs/1502.01589 < / >) < /李> < / ul > <人力资源> < p >假设寒武纪大爆发发生在<跨类= " math-container " > $ t_c =(0.13)下午541 \ \ cdot 10 ^ 6 $ < / span >年前(包荣et al。(2007), < a href = " https://core.ac.uk/download/pdf/62875。pdf nofollow noreferrer“rel = > https://core.ac.uk/download/pdf/62875.pdf < / >),然后自的天数< a href = " https://www.wolframalpha.com/input/?i=evaluate + % E2 ab_0 88% % % 5 ec + 365.25 * % 281 - t % 2 fa % 5 e % 28 - 2.6 29% % 29 dt在c + + + % 3 d % 28541 * 10% 5 2 c + % e6 % 29% 3 d % 2813.77 * 10% 5 e9 % 29“rel = " nofollow noreferrer " >可以近似为< / > < / p > < p > <跨类= " math-container " > $ $ n = \ int \ limits_0 ^ {t_c} T_0 \离开(1 - \压裂{t} {T_0} \右)^ {-2.6}\ mathrm {d}左t = \ [0.625 \ cdot T_0 T_0 \离开(1 - \压裂{t} {T_0} \右)^{\压裂{8},{5}}\右]_0 ^ {t_c} \大约2.1 \ cdot 10 ^ {11} $ $ < / span > < / p > < p >(当然必须记住,错误在这个值是相当大的,但是有一些大概的数字应该是足够好)< / p > < p >比较<跨类= " math-container " > t_c \ cdot 365.25美元= 1.98 \ cdot 10 ^ {11} $ < / span > < / p > //www.hoelymoley.com/questions/19414/-/19420 # 19420 5 由user18590回答多少天是自寒武纪大爆发? user18590 //www.hoelymoley.com/users/0 2020 - 03 - 10 - t14:37:37z 2020 - 03 - 12 - t12:32:22z 从< p > < a href = " https://physics.stackexchange.com/a/112339 " >这个答案< / >现代是1,7 ms的时间比一个世纪前。数据是取自维基百科,但采购< a href = " https://books.google.es/books?id=fjFVW3-LGigC&redir_esc=y" rel="nofollow noreferrer">this book.

Asuming the slowing down on earth's rotation has been constant since Cambrian, and that the sideral year duration has been constant too, it can be aproximated with a script:

#Constants yearsSinceCambrian = 541000000 slowDownSecondsDayEachYear = 0.000017 daysPerYearPresent = 365.25 secondsDayPresent = 86400 #Initiallizate the variable daysSinceCambrianExplosion = 0 #Calculate the number of days of each year def sumYearDays(year): secondsDay = secondsDayPresent - slowDownSecondsDayEachYear*year hoursDay = secondsDay/3600 daysYear = daysPerYearPresent*24/hoursDay return daysYear #Sum all days from Cambrian Explosion to year 0 for i in range (0,yearsSinceCambrian): daysSinceCambrianExplosion += sumYearDays(i) #Sum days since year zero daysSinceYearZero = 737875 daysSinceCambrianExplosion += daysSinceYearZero #Print the result print (str(daysSinceCambrianExplosion) + " days approximately since life explosion.")

Output

208929424039.7131 days approximately since life explosion.

Said $2.09 \cdot 10^{11}$ days.

I know the moon has moved away since Cambrian, so I assume as a constant wich is not. There are some extra days not summed.

I calculated the days the year had 510 my ago on my script and I got 406 days. In this publication from NASA 510 million years ago the year had 424 days, apparently; 18 more days. I think they know it because of fossils. I must say if paleontologists are rigth, if you examine the table published the slowing down ratio has not been constant. Ocean basins and tectonic should influence. So I can't be sure to use 1,7ms/century is accurated for the hole serie. In the past it migth have been 1,8 or 1,9 ms/century who knows.

To estimate the epsylon of the script, you can multiply the half of the 18 extra days on Cambrian for the total years of the serie.

$9 * 541000000 = 4.9*10^9$.

That would give a total of $2.14 \cdot 10^{11}$ days. This is not very far from what the script calculates, so you can use it to calculate from other events, knowing it is an aproximation.

The exact number of days can't be calculated, but there is not neither a exact known day when Phanerozoic started. Nobody can say the Phanerozoic started a 1st january 541002020 years ago, as assumed in the script.

I will say so @samcarter_is_at_topanswers.xyz calcs should be correct and approximately $2.1 \cdot 10^{11}$ days ago.

 //www.hoelymoley.com/questions/19414/-/22703 # 22703 0 答案由Arbab Arbab多少天是自寒武纪大爆发? Arbab Arbab //www.hoelymoley.com/users/23271 2021 - 08 - 16 - t08:51:09z 2021 - 08 - 16 - t08:51:09z < p >这是合适的出版物,计算一天的长度在整个地球的历史。< a href = " https://www.researchgate.net/publication/26541355_The_Length_of_the_Day_A_Cosmological_Perspective " rel = " nofollow noreferrer " > https://www.researchgate.net/publication/26541355_The_Length_of_the_Day_A_Cosmological_Perspective < / >谢谢。麦克斯韦< / p >
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