A calculation request

[stephbg]

BB was born on December 26 1958, and is thus due--in the normal course of things--to turn 50 years old on December 26 2008. This might not work out.

As a contingency measure I would like to offer a range of alternative dates for the celebration of his 50th year. We only need to slice a few weeks or months off half a century of calendar.



I don't want to say "So, it's September 27 (for example), but we'll have your birthday early in case you won't make it to December." I want to say "So, it's September 27 but it's actually your 50th birthday today if you include the time distortion effects of orbital wobble from all the satellites put in orbit since 1962". Or by making every 4th minute 1 second shorter for 50 years, your 50th year is on Octeber 2.

I am way to tired for speculative science, so this is your challenge:

Manipulate the definition of "year" so that 50 of them fit between 26 Dec 1958 and any time in the next month or two. The more birthday options the merrier.

Perhaps shave a few seconds off each day. Do something creative to leap years. Modify the orbit of the planet. Correct timekeeping rounding issues left over from the 18th century. Alter the physics of uranium decay. Change the gravity inside a pendulum clock. I want numbers, people. Show your work.

Please.

Comments

[alias_sqbr]

I've only just woken up and shall ponder, but would he object to binary, things like "20 000 days", gregorian calender etc? I don't know which if any of these would work but it's nice to know the limits of the exercise :)

EDIT: Also, if your flist can't come up with anything, there's lots of math nerd etc communities around who I'm sure would relish the challenge ie mathsex.

[stephbg.livejournal.com]

No limits. Thanks for the extra rec.

[alias_sqbr]

Sorry I took a while my brain was mush.

We have this site: http://www.timeanddate.com/date/durationresult.html?d1=26&m1=12&y1=1958&d2=17&m2=9&y2=2008&ti=on
and http://acc6.its.brooklyn.cuny.edu/~gurwitz/core5/nav2tool.html

So you can very easily get round numbers of seconds, 100 000 seconds is a little over a day. Thus you can celebrate 1,569,700,000 seconds tommorrow etc. 1,570,000,000 is around the 25th.

18181 days is 17 days from now.

Binary has not been very helpful.

And now I should do my actual job :)

[livelurker.livejournal.com]

If you ignored the worst/whateverest day of every year for the last 50 years that would make it 50 days earlier, which would be about the right ballpark.

Not particularly mathy, sorry.

[stephbg.livejournal.com]

Not mathy, but noteworthy.

[talmor.livejournal.com]

Due to tidal friction from the moon, the Earth's rotation is slowing, and the length of the day is getting longer by about one second every 60000 years, so when dinosaurs were around, one day was only 23 hours long. The actual length of the year isn't changing, but the number of days per year is.

By phrasing it right, using todays calendar for times in the past or future, and picking an appropriate era (like 'when human beings evolved'), you could get an assortment of dates that could match '50 years'. I'll work out some dates when I get home tonight.

[stephbg.livejournal.com]

Just the thing, excellent.

[redbraids.livejournal.com]

Time zone shifts will only buy you a day max...

Dog or cat years?

[talmor.livejournal.com]

Here are two possibilities, the second with a range of dates:

-----------------
The Earth actually takes 23 hours, 56 minutes, and 4 seconds to spin around once on its axis, as measured by the time it takes any given distant star to move from 'overhead' to 'overhead'. This period is called a 'Sidereal Day'. In that time, the Earth has moved 1/365th of the way the around its orbit the Sun, so the Earth needs to keep spinning for an extra 4 minutes or so before it 'catches up' to the new position of the SUn in the sky. This means that the time it takes the SUN to go from overhead to overhead, a 'Solar Day', is defined as exactly 24 hours.

If we were to apply the normal Gregorian calendar to Sidereal Days instead of Solar Days, the difference is exactly one day per year, so 50 'Gregorian Sidereal Calendar Years' from 26 Dec, 1958 works out to the 6th of November, 2008.

(this is exactly the same date as Shay's 'ignore the worst day of every year' idea)

----------------------

As the Earth rotates, gravitational tidal forces from the Moon deform the Earth, raising the planets crust by about half a meter and the oceans by much more. This deformation produces friction, which acts to slow the rotation of the Earth, and, conserving angular momentum, increases the speed of the Moon in its orbit.

This effect is tiny, with the length of a day increasing by 1 second every 60,000 years, but it means that 65 million years ago, when the dinosaurs were around, the day was only 23 hours long. If you apply the normal Gregorian calender to the era NNNN million years ago, when XXXXXXXX had just evolved, 50 calendar years of 365.246 days each would only be MMMMM orbits of the Earth around the Sun, and 50 calendar years from 26 Dec, 1958 would actually be equivilant to YYYYYYY.


Era: Year Date Evolved:
28 million BC 0.9946 2008/9/18 ?
27 million BC 0.9948 2008/9/22 ?
26 million BC 0.9950 2008/9/25 ?
25 million BC 0.9952 2008/09/29 Apes (Hominoidea)
15 million BC 0.9971 2008/11/3 Great Apes (Hominidae)
10 million BC 0.9980 2008/11/20 Hominini becomes distinct from ancestors of the Gorilla
7 million BC 0.9987 2008/12/1 Hominina becomes distinct from ancestors of the Chimpanzee
3 million BC 0.9994 2008/12/15 Australopithecines

I can't find anything specific that evolved 26, 27 or 28 million years ago - if anyone can think of a good specific year in that range, I can work out a date for it, or alternatively, if you want a particular date, I can work out a 'years ago' figure. With a slight change of wording, you could take it as years in the future instead (and that would actually make a bit more sense).