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        riddles >> hard >> BIRTHDAY TWINS
        
(Message started by: borg472918433 on Jul 24th, 2002, 1:18am)
Title: BIRTHDAY TWINS
Post by borg472918433 on Jul 24th, 2002, 1:18am
Hiya,

I have a stupid answer for this one.  It can't be real so I post it here.  =)

It read:
<BEGIN>
BIRTHDAY TWINS

Sheila and He-Man are twins; Sheila is the OLDER twin. Assume they were born immediately after each other, an infinitesimally small - but nonzero - amount of time apart. During one year in the course of their lives, Sheila celebrates her birthday two days AFTER He-Man. How is this possible?
<END>

I say "AFTER" means He-Man is dead.  So I speculate that He-Man dies 2 days before their birthday.  So Sheila celebrates her birthday 2 days after He-man (dies).  How about that?  Hehhehe


Borg #472918433
Title: Re: BIRTHDAY TWINS
Post by fishnugget on Jul 24th, 2002, 4:17pm
hmm. i like your idea. It's definitely valid in a way :)
I'm stumped on this one. At first i thought that this could happen if the younger twin was born on leap year's day -feb 29th. But that didn't make any sense either.
Title: Re: BIRTHDAY TWINS
Post by Dr. D on Jul 25th, 2002, 5:37am

Assume they were born in a plane crossing the date line at the end of february.
Title: Re: BIRTHDAY TWINS
Post by ryser2k on Jul 25th, 2002, 7:44am
Assume that He-Man is born at midnight on Feb. 28 (not a leap year) and Sheila is born the next day (March 1).  In this case, Sheila is already celebrating her birthday the day after He-Man's.  Now when a leap year rolls around, the extra day in between will separate their birthday celebrations by two days.
Title: Re: BIRTHDAY TWINS
Post by Yottabyte on Jul 25th, 2002, 6:10pm
It doesn't say he-man can't celebrate early.....
Title: Re: BIRTHDAY TWINS
Post by Cathy on Jul 25th, 2002, 8:33pm
Originally, I was focusing on the leap year idea,too. But then I figured this approch would never work because Sheila is the OLDER one.
Then I realize, it could work with the help of the time zone difference. Say, on a leap year, the twins were given birth on an airplane (or a boat) as it was crossing the pacific ocean travelling from East to West. Sheila was born on one side of the time zone, on March 1st (before 1am). And right after the transportation device had crossed to the next time zone, He-Man was born. Because the western time come after eastern time, so the clock was set back for one hour. Which means He-Man was actually born on Feb 28th (right before 00:00am).
Therefore, even though Sheila is biologically OLDER, He-Man actually has the birthday first in term of callendar.
So, He-Man has the birthday 2 days before Sheila every leap year.
p.s. Feel free to point out the errors I might have in explaining the time zone concepts, for geography has always been a subject I willfully neglected. But I believe the idea in my explanation is correct.
Title: Re: BIRTHDAY TWINS
Post by PKo on Jul 29th, 2002, 7:17am
Why do you think Sheilla is a girl and He-Man a boy ?

If Sheilla is a boy, and He-Man a girl, then , there is nothing special in Sheila celebrates her birthday two days AFTER He-Man

Ok, 'after' is written upper case, so what ?
;D

I refer to the 28 fev - 01 mar solution on a leap year.
Title: Re: BIRTHDAY TWINS
Post by Pko on Jul 29th, 2002, 7:23am
Forget the previous message :)

My english is poor and I misunderstood the sentence.

After some thought I like Cathy answer.

Shella is born first on the 01 mar, the they crosses the changing date line and He-man born on 28 feb.

On a leap year, Sheilla has her birthday two days after He-Man.
Title: Re: BIRTHDAY TWINS
Post by Jon L on Dec 10th, 2004, 10:14am
It can actually be 3 days as well.  There are a couple time zones in the world that are +13 and +14 from Universal Time (Zulu Time)  That means for a brief 1 or 2 hour window you could cross the dateline and actually go back 2 calender days.  If you also add that to the leap year then it will be 3 days.  Prob someone has mentioned this in another thread but I have not looked at others yet.

Jon
Title: Re: BIRTHDAY TWINS
Post by Bobbin on Jan 17th, 2005, 6:30pm
I think this is a terrible riddle. While an independent carrier is in motion over international waters, the carrier acts not as an "independent country", but rather as the country of the pilot's nationality. Got that? What this means is that the international date line does not come into it because we are going by the national time of the pilot's nationality, which therefore means the only way it COULD happen is if one was legitimately born on 28Feb at 23.59, and the next on March 1 0.01

Anyhow I do have a legitimate solution. Father and Mother are crossing international waters each on their own raft. They've split up, however they agreed to meet for the birth of their twins, and that Mother gets the older child, and Father gets the younger child. Father is a Kiwi, Mother is a hermit from Baker Island. Mother goes by her time for her daughter, Father goes by his time for his son.
Title: Re: BIRTHDAY TWINS
Post by rmsgrey on Jan 18th, 2005, 7:36am

on 01/17/05 at 18:30:23, Bobbin wrote:
I think this is a terrible riddle. While an independent carrier is in motion over international waters, the carrier acts not as an "independent country", but rather as the country of the pilot's nationality. Got that? What this means is that the international date line does not come into it because we are going by the national time of the pilot's nationality, which therefore means the only way it COULD happen is if one was legitimately born on 28Feb at 23.59, and the next on March 1 0.01

Anyhow I do have a legitimate solution. Father and Mother are crossing international waters each on their own raft. They've split up, however they agreed to meet for the birth of their twins, and that Mother gets the older child, and Father gets the younger child. Father is a Kiwi, Mother is a hermit from Baker Island. Mother goes by her time for her daughter, Father goes by his time for his son.

Or the captain could die of a heart attack at the appropriate moment, being replaced by someone of the appropriate (different) nationality
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Jan 18th, 2005, 7:54am

on 01/17/05 at 18:30:23, Bobbin wrote:
I think this is a terrible riddle. While an independent carrier is in motion over international waters, the carrier acts not as an "independent country", but rather as the country of the pilot's nationality. Got that? What this means is that the international date line does not come into it because we are going by the national time of the pilot's nationality, which therefore means the only way it COULD happen is if one was legitimately born on 28Feb at 23.59, and the next on March 1 0.01


OK, then maybe SHE is born just before landing, and the pilot's nationality is from a country just west of the date line, and HE is born just after the landing, in a country just east of the date line.  There can be a 2-day difference.  If it happened when most of Earth is on March 1, the time zones extend from feb 28 (timezone -13) to march 2 (timezone -13).  On a leap year the birthdays are 3 days apart.

If then HE celebrates his birthday on the first possible occasion on Earth, and SHE celebrates it in the last possible minute, it can be up to 4*24h later.
Title: Re: BIRTHDAY TWINS
Post by Icarus on Jan 18th, 2005, 3:08pm

on 01/17/05 at 18:30:23, Bobbin wrote:
I think this is a terrible riddle. While an independent carrier is in motion over international waters, the carrier acts not as an "independent country", but rather as the country of the pilot's nationality. Got that? What this means is that the international date line does not come into it because we are going by the national time of the pilot's nationality,


Sorry, but I don't buy that at all. For starters, unless the pilot comes from a small country, there is no "national time of the pilot's nationality". The USA has at least 6 time zones. If you count territories, we have more. Which time zone gets used? Using the local time is not "acting as an independent country". Time zones in international waters are a matter of international treaty. Any country recognizing the treaty (and just about all do) also recognizes the international date line.
Title: Re: BIRTHDAY TWINS
Post by Amanda Gallagher on Jan 31st, 2005, 8:00am
Close.  One was born on the 28th of Feb, and the other on March 1st.  Thus, when leap year comes around, one celebrates on the 28th, and the other two days later, on March 1st. :D
Title: Re: BIRTHDAY TWINS
Post by Icarus on Jan 31st, 2005, 4:39pm
Sorry, Amanda, but that does not solve it. According to the puzzle, it is the older twin who celebrates her birthday two days after the younger twin. It is this reversal of birthdays that make this problem non-trivial.

[There are several other threads for this puzzle, and at least two of them tell the solution.]
Title: Re: BIRTHDAY TWINS
Post by relativity on Feb 2nd, 2005, 3:21am
I just showed this riddle to someone and he pointed out another interesting solution, wich relies on physics actually.
If Sheila is put on a spaceship and then returned to earth after an appropriate time, her own clock will be late (yet right for her!) when comparing to earth time - so she can celebrate her birthday before her brother.
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Feb 2nd, 2005, 4:09am
That would make the older twin becomes the younger twin.  Wouldn't it? ;)
Title: Re: BIRTHDAY TWINS
Post by relativity on Feb 2nd, 2005, 10:31am
that depends on your point of view! :)
Title: Re: BIRTHDAY TWINS
Post by THUDandBLUNDER on Feb 2nd, 2005, 11:26am

Quote:
that depends on your point of view!

IIRC, it is the twin who experiences acceleration/deceleration that ages less.
Title: Re: BIRTHDAY TWINS
Post by nusuth on Feb 20th, 2005, 1:51am
"Bonus: What is the maximum amount of time by which Sheila and He-Man can be apart in their birthday celebrations during the same year?" Assuming dates less than 365 days apart are in the same year, Sheila can celebrate 354 days after He-Man. He-man celebrates his nth birthday on October 15, 1582 and Sheila celebrates her nth birthday on October 14, 1583.
Title: Re: BIRTHDAY TWINS
Post by The Puzzler on Oct 6th, 2005, 1:17pm
I had some of my mom's students try and figure this out, and here are the top two answers.

~One was born February 28 and one was born moments later on March 1. That would cause them to be born 2 days apart

~~~~~~~~~~~~~~~OR~~~~~~~~~~~~~~~~

~ They were born on the same day, but celebrated their birthdays on differents sides of the worlds when there birthday came along.
Title: Re: BIRTHDAY TWINS
Post by Icarus on Oct 6th, 2005, 8:15pm
Neither answer works, though the first is part way there. Note that the YOUNGER twin celebrates his birthday 2 days BEFORE the OLDER twin.
Title: Re: BIRTHDAY TWINS
Post by The Puzzler on Oct 12th, 2005, 8:59pm
If we are almost there will you please take pity on us who go nuts when they can't figure out something and tell us the answer. My hit on the head for me saying, "Duh" won't bother me as much as not knowing. :'(
Title: Re: BIRTHDAY TWINS
Post by new shoes on Oct 13th, 2005, 2:03am
what if they're not each others twins?
sheila is born in australia and then he-man is born in america. america is a day behind australia so he is born on a wednesday and she is born on a thursday.. they then travel to each others respective countries. he celebrates his birthday on wednesday which is tuesday for her so she has to wait TWO days to celebrate her birthday.
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Oct 13th, 2005, 5:29am
I think it is easy.  Assume A (she) is older than B (him), they are born the same day in the same place.  Where is not important.

There are places near the date line that have timezone -12 and other +12.  In these places it is the same time but the official day is one day apart.

B celebrates his birthday on the first minute of nis birthday west of the date line.  It takes 24 hours for this day to reach the other side.  It takes 24 more hours for the day to finish on the east side.  So, A can celebrate her birthday almost 48 hours after B did.

I believe there is even a +13 time zone which gives them a one hour window to celebrate at a 48 hour interval.

Of course, since they celebrate near midnight, it is more accurate to say A celebrates 2 *nights* after B, not 2 days.
Title: Re: BIRTHDAY TWINS
Post by Icarus on Oct 13th, 2005, 2:58pm

on 10/12/05 at 20:59:39, The Puzzler wrote:
If we are almost there will you please take pity on us who go nuts when they can't figure out something and tell us the answer. My hit on the head for me saying, "Duh" won't bother me as much as not knowing. :'(


I can give you a big hint in how to find the answer:

ACTUALLY READ THE PREVIOUS POSTS! It's right there in gray and white.
Title: Re: BIRTHDAY TWINS
Post by y0ung_j1n on Aug 1st, 2006, 11:55pm
sheila DOB: 12/31 11:59:59 PM
he-man DOB: 1/1  12:00:00 AM

after he-man celebrates his birthday, 364 or 365 days later sheila, the older one, celebrates hers, during the same year no?
Title: Re: BIRTHDAY TWINS
Post by towr on Aug 2nd, 2006, 1:41am

on 08/01/06 at 23:55:42, y0ung_j1n wrote:
after he-man celebrates his birthday, 364 or 365 days later sheila, the older one, celebrates hers, during the same year no?
Yes, but 364 or 365 days aren't 2.
The riddle states she celebrates her birthday two days later, at least once in their lifetime.
Title: Re: BIRTHDAY TWINS
Post by y0ung_j1n on Aug 2nd, 2006, 10:53pm
oh snaps im answering the bonus haha.   ;D
Title: Re: BIRTHDAY TWINS
Post by casual_kumar on Aug 18th, 2006, 2:45am

on 02/02/05 at 11:26:37, THUDandBLUNDER wrote:
IIRC, it is the twin who experiences acceleration/deceleration that ages less.

According to Special Theory of Relativity, this is a Paradox. Both the twins will see the other twin as travelling and hence each will see the other as lived less.
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Aug 18th, 2006, 4:39am
It is not a paradox.  Each will see the other younger than himself, but only as long as they speed away from each other.  For each of them, the point in spacetime where the brother reaches their own present age is in the future.  But as soon as one of them stops and accelerates towards his brother, the change in speed will change his referential and the same point will be projected in the past.  That means that if one brother stops and then accelerates enough to reach his brother, he will find him older on arrival.
Title: Re: BIRTHDAY TWINS
Post by D on Feb 16th, 2007, 11:07pm
The max number of days in a year would of course would be 365.
First it would have to be a leap year.
Second, Sheila would be born on dec 31,
he-man on jan 1. So He-man will celebrate first on Jan 1, Sheila 365 days later on dec 31. Thus the elder celebrates after the younger. :)
Title: Re: BIRTHDAY TWINS
Post by D on Feb 16th, 2007, 11:43pm
Since they were born in a short time apart, the time zone births can be at most 1 hour. The days do not matter.
First, Sheila would be born on lets say Jan 3 at 12.01 am. He-man would be born on the other side on Jan 2 11.01 pm ( One day gained). Supposing the birth took place near the time line.
Then on any given year, they have to celebrate their birthdays in time zones 24 hours apart. He-man celebrating in the earlier one. (another day gained)
Then, He-man would be able to celebrate the birthday 2 days before Sheila. :)
Title: Re: BIRTHDAY TWINS
Post by rmsgrey on Feb 17th, 2007, 5:58pm

on 02/16/07 at 23:43:11, D wrote:
Since they were born in a short time apart, the time zone births can be at most 1 hour. The days do not matter.
First, Sheila would be born on lets say Jan 3 at 12.01 am. He-man would be born on the other side on Jan 2 11.01 pm ( One day gained). Supposing the birth took place near the time line.
Then on any given year, they have to celebrate their birthdays in time zones 24 hours apart. He-man celebrating in the earlier one. (another day gained)
Then, He-man would be able to celebrate the birthday 2 days before Sheila. :)

So what happens if they're Pisces instead?
Title: Re: BIRTHDAY TWINS
Post by tiber13 on Mar 10th, 2007, 10:06pm
if 1 of them was orn on the 27th, and the other on the 28th, on a leap year the younger 1 would be selebrating his birthday 4 years after the older 1...
Title: Re: BIRTHDAY TWINS
Post by star on Mar 20th, 2007, 5:02pm
ooooooooooooooooooooooo

it took me forever to get this one
Title: Re: BIRTHDAY TWINS
Post by balanagireddy.tcs on Mar 22nd, 2007, 4:17am
Dude..grimbal..what are you saying...?
Use your BRAIN. How can twins born from two different places...Twins are born for the same lady...
Dont give solutions for the sake of stars...Use what god has given you..:)
Title: Re: BIRTHDAY TWINS
Post by Iceman on Mar 22nd, 2007, 5:55am

Quote:
Sheila and He-Man are twins; Sheila is the OLDER twin. Assume they were born immediately after each other, an infinitesimally small - but nonzero - amount of time apart. During one year in the course of their lives, Sheila celebrates her birthday two days AFTER He-Man. How is this possible?

Alien, because of the experiment on female brain, abducted Sheila. His flaying saucer has time travel capabilities, so after the lobotomy, alien punched in the wrong day, that is, two days into future.

Or Sheila is a working girl. So Sheila celebrated her birthday two days after him because she was too busy. Her boyfriend cares about her, even though she rarely sees him because of her career.    

Or He-Man takes his sword, and makes Sheila to celebrate her birthday two days after him, because he always wanted to be the older twin.

Or Sheila is a moron, not He-Man, so she thinks that two seconds are two days, regarding their birth.  
Title: Re: BIRTHDAY TWINS
Post by rmsgrey on Mar 22nd, 2007, 9:57am

on 03/22/07 at 04:17:35, balanagireddy.tcs wrote:
Dude..grimbal..what are you saying...?
Use your BRAIN. How can twins born from two different places...Twins are born for the same lady...
Dont give solutions for the sake of stars...Use what god has given you..:)

Very few people are born at in exactly the same place at exactly the same time. It takes less than a second to move between time zones...
Title: Re: BIRTHDAY TWINS
Post by Icarus on Mar 22nd, 2007, 4:49pm
Rmsgrey - she was referring to Grimbal's remarks about the "Twin Paradox", not the actual puzzle.


on 03/22/07 at 04:17:35, balanagireddy.tcs wrote:
Dude..grimbal..what are you saying...?
Use your BRAIN. How can twins born from two different places...Twins are born for the same lady...
Dont give solutions for the sake of stars...Use what god has given you..:)


It's a bad mistake to think Grimbal posts anything just for more stars (besides which, he can't get any more than he already has - uberpuzzler is the top ranking).

The "Twin Paradox" arises from a misunderstanding of Einstein's Special Theory of Relativity. The idea is this: two twins get in rocketships and accelerate to near the speed of light, then travel at constant speed away from each other. According to STR, since their speed is now constant, each of their viewpoints are equally valid. From twin A's viewpoint, he and his rocket are still, while B is traveling away at nearly the speed of light. Because of time-dilation (a prediction of STR), he sees B as hardly aging, so he himself is getting older, while B is barely doing the same. Ergo, he is, in his point of view, now older than B.

The problem is, B has exactly the same view of A. So how can A be older than B and B older than A?

The answer is, this can be because they are moving relative to each other, so their division of Spacetime into space and time differs. To illustrate, think of your monitor screen as a two-dimensional space time, with one direction being space, and the other perpendicular direction being time. But the question is, which direction is space, and which is time. To A, time is http://www.ocf.berkeley.edu/~wwu/YaBBImages/symbols/uparrow.gif and space is http://www.ocf.berkeley.edu/~wwu/YaBBImages/symbols/longrightarrow.gif. To B, time is http://www.ocf.berkeley.edu/~wwu/YaBBImages/symbols/nearrow.gif and space is http://www.ocf.berkeley.edu/~wwu/YaBBImages/symbols/searrow.gif. Because of this disagreement, A can the point where he was his brother's "current" age as being in the past, while B sees that same point (when A reaches B's current age) as being in the future.

The reply of the "Paradox" is then "What happens if one of the twins turns his ship around and accelerates even faster, so that he eventually catches up to and passes his twin. Then they can look out the window at each other. Which will see an older version?" Grimbal's remark addresses this idea. By changing direction and speed, one of the twins changes how he sees spacetime divided into space & time. What was once a future event is now a past event, just like his brother sees it, and some past events become future events (though only too far away for him to have been aware of them as past events before they made the switch). STR does not say that his point of view and his brother's are equivalent while he is accelerating. So his brother has no balancing switch. As a result, when they overtake, each is now in agreement as to which is older. The "Twin Paradox" is called this because it violates common assumptions we make - but those assumptions are not always true. It is not a real paradox.
Title: Re: BIRTHDAY TWINS
Post by JiNbOtAk on Mar 22nd, 2007, 5:41pm

on 03/22/07 at 16:49:09, Icarus wrote:
Ergo, he is, in his point of view, now older than B.



I know it would be something I won't understand when Icarus starts to use the word Ergo..   :P
Title: Re: BIRTHDAY TWINS
Post by Icarus on Mar 22nd, 2007, 6:17pm
Hey, I am a mathematician!;D

That means I have to have lots of ways to say "what I just said implies what I am about to say. Trust me, it really does! Would I lie to you?"::)

"So", "therefore", "hence", "thus", "ergo", "whereby", "it follows that", "and", ...
Title: Re: BIRTHDAY TWINS
Post by Whiskey Tango Foxtrot on Mar 22nd, 2007, 6:59pm
That was a very thorough explanation, Icarus.  I've seen the "paradox" many, many times and have explained it to others as well but I must say that one rarely explains it so transparently, especially without using any diagrams.  Well done.  :)
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Mar 23rd, 2007, 2:09am

on 03/22/07 at 16:49:09, Icarus wrote:
It's a bad mistake to think Grimbal posts anything just for more stars (besides which, he can't get any more than he already has - uberpuzzler is the top ranking).

WHAAAT? :o  There is no higher rank? :'(  Damn! >:(  All this time I thought I was working towards something, that kept me going. :(  I guess I better restart with another nick name. :-/

PS: ;)

Regarding Icarus's explanation, there is at least one mistake.  Space moves the other way round.

Let's take a clock dial to describe directions.

From A's point of view, A's time arrow is at 12 o'clock and his space arrow is at 3 o'clock.  If B moves relatively to A and B's time arrow is at 1 o'clock, then B's space arrow is at 2 o'clock.

You can convert from A's point of view to B's point of view by squeezing your clock at 1:30 and 7:30 and pulling at 4:30 and 10:30.  In effect, the dial flattens towards a diagonal.  In the process B's time arrow moves to the vertical, 12 o'clock for B, and his time arrow moves to the horizontal, 3 o'clock for B.  Also, A's time arrow moves to B's 11 o'clock and A's space arrow moves to B's 4 o'clock.

In the above description the size of the arrow is another issue.  When I say B's time arrow is at 1 o'clock, it is only the direction.  It actually moves along a hyperbola with asymptotes at x=+/-y.
Title: Re: BIRTHDAY TWINS
Post by towr on Mar 23rd, 2007, 2:22am

on 03/22/07 at 16:49:09, Icarus wrote:
The reply of the "Paradox" is then "What happens if one of the twins turns his ship around and accelerates even faster, so that he eventually catches up to and passes his twin. Then they can look out the window at each other. Which will see an older version?" Grimbal's remark addresses this idea. By changing direction and speed, one of the twins changes how he sees spacetime divided into space & time. What was once a future event is now a past event, just like his brother sees it, and some past events become future events (though only too far away for him to have been aware of them as past events before they made the switch). STR does not say that his point of view and his brother's are equivalent while he is accelerating. So his brother has no balancing switch. As a result, when they overtake, each is now in agreement as to which is older. The "Twin Paradox" is called this because it violates common assumptions we make - but those assumptions are not always true. It is not a real paradox.
What if both brothers mirror each other actions and both turn around at the same time (and in the same way) to meet?
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Mar 23rd, 2007, 3:14am
Then both will experience an acceleration, both will change point of view in a way that the point in space-time they considered as the place where the other is in the present becomes a point where the other was in the past, while a point where the other will be in the future becomes the present.  Each will suddenly see the other much older, not because any sudden aging of the other, but because the label of what is "the present" for A in B's time line moved to the future.

Both will have the same age when they meet.  From any point of view, they spent as much time at each speed, so they aged the same overall.
Title: Re: BIRTHDAY TWINS
Post by Icarus on Mar 23rd, 2007, 7:30pm

on 03/22/07 at 18:59:27, Whiskey Tango Foxtrot wrote:
That was a very thorough explanation, Icarus.  I've seen the "paradox" many, many times and have explained it to others as well but I must say that one rarely explains it so transparently, especially without using any diagrams.  Well done.  :)


Thank you, but it was actually far from thorough, and not even entirely accurate, as someone just had to point out! ;) For the lack of thoroughness, note that I didn't even say which twin would be the elder when they passed, much less actually explain why.

The lucid parts came simply because I was expanding on Grimbal's already lucid, if short, earlier post.


on 03/23/07 at 02:09:01, Grimbal wrote:
Regarding Icarus's explanation, there is one mistake.


Only ONE! Wow, I'm doing better than I thought! And I obviously left out a word by mistake here:

Quote:
A can the point where he was his brother's "current" age as being in the past


Ergo, all that other stuff you are going on about must have been okay in my post after all! ::)
Title: Re: BIRTHDAY TWINS
Post by deestore on Jun 10th, 2007, 2:08am
I think this is a two factor problem.  I think He-man was born February 29 just before midnight and Sheila just after midnight, on March 1st.  As the years go by, Shiela turns another year older every March 1st, but He-man only turns a year older every four years (since there's only a 29th of February every four years).  Thus, Shiela is the OLDER twin.  Ok, so now I've resolved why Shiela is older.

Then, consider it to be another year that has 29 days  in February.  He-man celebrates his birthday on the 29th.  Then, Sheila would celebrate hers on March 1st.  But that's only one day later.  However, if we put He-man on one side of the dateline and Sheila on the other, we can actually make the celebrations two days apart.  He-man would celebrate on the 29th.  Sheila would celebrate two day's later in a location where it is still March 1st for her, but March 2nd for He-man.

To answer the bonus question:  I haven't researched time changes over the dateline, but I think it can be almost three days between celebrations, if He-man celebrates his birthday at the stroke of midnight on the 29th where he's at and Sheila celebrates at the last possible second on the 1st where she's at :D.
Title: Re: BIRTHDAY TWINS
Post by ThudanBlunder on Jun 10th, 2007, 5:11am

on 03/22/07 at 16:49:09, Icarus wrote:
It is not a real paradox.

What is a real paradox?
Title: Re: BIRTHDAY TWINS
Post by Grimbal on Jun 10th, 2007, 11:00am

on 06/10/07 at 05:11:41, ThudanBlunder wrote:
What is a real paradox?

Ah...  :-/

What paradox is not real?

OK, I should have said: "I can explain that".
Title: Re: BIRTHDAY TWINS
Post by shadon on Apr 18th, 2008, 2:54pm
[quote author=Icarus link=board=riddles_hard;num=1027807787;start=25#41 date=03/22/07 at 18:17:53]Hey, I am a mathematician!;D

\quote]


A mathematician, eh? Here's a challenge, then.
say I have a set of twins. one is four, and the other is sixteen. How is this this possable, and what are the odds of this happening?
Title: Re: BIRTHDAY TWINS
Post by Qaster Qof Qeverything Q42 on Apr 18th, 2008, 3:38pm
[hide]one was born on feb 28/march 1, the other feb 29.[/hide]

[EDIT] 365*.03 [EDIT]
Title: Re: BIRTHDAY TWINS
Post by ThudanBlunder on Apr 18th, 2008, 4:13pm

on 04/18/08 at 15:38:27, Qaster Qof Qeverything Q42 wrote:
[EDIT] 365*.03 [EDIT]

Probability of being born on a leap day
= 97/((97*366) + (303*365))
= 97/146097
= 0.0006394244919471310156950519175616...
Title: Re: BIRTHDAY TWINS
Post by MichaelSel on Nov 12th, 2008, 7:40am
my answer is 8 years
fabuary has a 29th day every four years,
but not every 400 years, so
suspose one of the twins is born at fabuary 28 23:59:59
and the other on fabuary the 29th
on 1796 so there birth day is one day a part
but until 1804 fabuary will not a 29th day.
(fabuary has a 29th day every for years exept in years that divide by 400)
hance my answer in 8 years.
Title: Re: BIRTHDAY TWINS
Post by shadon on Nov 12th, 2008, 8:26pm
HUH? I didn't ask for a time span. I asked for the how and the probability for having a set of twins wherin one is currently four, and the other is currently sixteen. thunderblunder and, umm, Mr. Q, you are partly there, but read my question again.

(And I need # to # odds  ;) )
Title: Re: BIRTHDAY TWINS
Post by hamzak on Nov 25th, 2008, 5:56pm
i have a guess

they could celebrate earliers so they can feel like there own individual which is a problem among twing nowadays

the riddle says infinitley small amount of time non zero. imagine how long everything ( the universe , dinasours , i mean everything beginning of time) an infinitley small amount of that could easily be 2 days


those are just guesses i hope there right :)
Title: Re: BIRTHDAY TWINS
Post by hamzak on Nov 25th, 2008, 6:06pm
alright i just made a post but an idea popped in.

ok, in the book around the world in 80 days , im sure you all heard of it  for those who haven't if the title of the book doesnt say it all to you the main character phileas fogg was a rich dude bla bla and he made a bet with another rich dude and he went on a bunch of adventures and such but he arrived " 2 days late" but while his servent was out he thought that with the earth rotation and a bunch of math that they were actually 2 days earlie y so he one the bet and happily ever after

but back to the riddle  if they were traveling in a plane which go extremley fast they can in theory travel time ( the faster you go the more time zones you skip.) so as sheila is born in timezone A there is an airplane going say 1000 mile per hour ( i dont know how fast planes go) in theory they could be born and have there birhtdays 2 days apart without any of that  without " they can celebrate their birth days early" crap. i just want to see the two explain that to there friends:)
Title: Re: BIRTHDAY TWINS
Post by towr on Nov 26th, 2008, 12:21am

on 11/25/08 at 18:06:06, hamzak wrote:
but he arrived " 2 days late" but while his servent was out he thought that with the earth rotation and a bunch of math that they were actually 2 days earlie y
You only gain one day by going around the world.


Quote:
but back to the riddle  if they were traveling in a plane which go extremley fast they can in theory travel time ( the faster you go the more time zones you skip.)
Err.. that's not even close to how things work. You gain/lose a day when you cross the date-line, but you lose/gain it again when you go around the world.


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