Comments on: October 28th http://yaserzt.com/blog/archives/257 Shadowlessness, and how it feels. Fri, 30 Dec 2011 19:29:04 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: MatGill http://yaserzt.com/blog/archives/257/comment-page-1#comment-8730 MatGill Sat, 08 Nov 2008 22:25:41 +0000 http://yaserzt.com/blog/?p=257#comment-8730 Well, the whole point is that you are making an assumption for yourself that not everyone follows. I could say you can think of the angular position of the moon towards the earth as your anchor (which means you'll have 12 birthdays a year). Or I could just use the half-time disappearance of a radioactive substance or any other made up timeline. The big picture is that not everyone goes with the same calender, and as long as that is the case, you are bound to have 0, 1, 2, or more birthdays a year. In any case, I'd rather have more than one birthday (cake) in a year. It's more fun. And you can chill out if you get at least one birthday :D Well, the whole point is that you are making an assumption for yourself that not everyone follows. I could say you can think of the angular position of the moon towards the earth as your anchor (which means you’ll have 12 birthdays a year). Or I could just use the half-time disappearance of a radioactive substance or any other made up timeline. The big picture is that not everyone goes with the same calender, and as long as that is the case, you are bound to have 0, 1, 2, or more birthdays a year.

In any case, I’d rather have more than one birthday (cake) in a year. It’s more fun. And you can chill out if you get at least one birthday :D

]]> By: yzt http://yaserzt.com/blog/archives/257/comment-page-1#comment-8726 yzt Sat, 08 Nov 2008 21:50:56 +0000 http://yaserzt.com/blog/?p=257#comment-8726 OK, I won't argue with that. However, from an engineering perspective, the difference in velocity you mention is not enough (in my physics-and-math-impaired opinion,) to cause a noticeable discrepancy in viewer time comprehension. Therefore, I'm personally willing to forget about any mathematical differences. I think the specific state of Earth relative to the Sun (including position, spin state, etc.) can be used to define an exact (enough) and location-independent birthtime for people. Wouldn't you agree? And I still think you shouldn't chill out! Why should anyone stop thinking? But you can chill enough to start seeing the world as an engineer (and be content with that,) instead of a mathematician, if you want a simpler and less abstract life. OK, I won’t argue with that.

However, from an engineering perspective, the difference in velocity you mention is not enough (in my physics-and-math-impaired opinion,) to cause a noticeable discrepancy in viewer time comprehension.
Therefore, I’m personally willing to forget about any mathematical differences. I think the specific state of Earth relative to the Sun (including position, spin state, etc.) can be used to define an exact (enough) and location-independent birthtime for people. Wouldn’t you agree?

And I still think you shouldn’t chill out! Why should anyone stop thinking? But you can chill enough to start seeing the world as an engineer (and be content with that,) instead of a mathematician, if you want a simpler and less abstract life.

]]> By: MatGill http://yaserzt.com/blog/archives/257/comment-page-1#comment-8725 MatGill Sat, 08 Nov 2008 21:19:57 +0000 http://yaserzt.com/blog/?p=257#comment-8725 You've just been out-geeked! You’ve just been out-geeked!

]]> By: MatGill http://yaserzt.com/blog/archives/257/comment-page-1#comment-8724 MatGill Sat, 08 Nov 2008 21:11:33 +0000 http://yaserzt.com/blog/?p=257#comment-8724 Do you still think I should not chill out? :D Do you still think I should not chill out? :D

]]> By: MatGill http://yaserzt.com/blog/archives/257/comment-page-1#comment-8723 MatGill Sat, 08 Nov 2008 21:10:59 +0000 http://yaserzt.com/blog/?p=257#comment-8723 Hehe! When you get detailed, be sure not to get too detailed :D I could argue that you can never define that specific time, because people at different sides of the globe have relative moving speed between them (actually huge relative speed), and thus simultaneous events for them are defined differently (check out relativity of simultaneity). It basically means that A and B being born right now (as I see 'now') one here in Montreal and one there in Tehran are not born at the same time to your eyes. So my definition of the birthdate should have the same value for A and B, and yours should make them be different, which means that birthdate is a function of the place you are on the globe. Mind bugling, isn't it? I think there is a space/speed invariant definition of simultaneity in special relativity. Hehe! When you get detailed, be sure not to get too detailed :D I could argue that you can never define that specific time, because people at different sides of the globe have relative moving speed between them (actually huge relative speed), and thus simultaneous events for them are defined differently (check out relativity of simultaneity). It basically means that A and B being born right now (as I see ‘now’) one here in Montreal and one there in Tehran are not born at the same time to your eyes. So my definition of the birthdate should have the same value for A and B, and yours should make them be different, which means that birthdate is a function of the place you are on the globe.

Mind bugling, isn’t it? I think there is a space/speed invariant definition of simultaneity in special relativity.

]]> By: yzt http://yaserzt.com/blog/archives/257/comment-page-1#comment-8715 yzt Sat, 08 Nov 2008 16:11:18 +0000 http://yaserzt.com/blog/?p=257#comment-8715 You do have a point. Birthdays may be implicitly dependent on birthplace in our minds. However, I think you agree with me that someone's "birthtime" is absolutely definable, since wherever and whenever someone is born (if on Earth or in its orbit) the Earth must have had a specific place relative to the Sun. This can be defined using the portion of the year that has passed (or remaining.) One can use the Autumnal Equinox and the Solstices as marker points through the year. Now that I think about it, our (Persian) first half of the year is longer than the second half by several days! However, Wikipedia claims that the Autumnal Equinox is usually on September 22nd (our first day of Fall) and I think it can move at most one day to one direction on leap years and whatnot. I must research the matter more! Whatever this issue is, unlike those friends of yours, I don't think this is irrelevant or that you should chill out! You do have a point. Birthdays may be implicitly dependent on birthplace in our minds.
However, I think you agree with me that someone’s “birthtime” is absolutely definable, since wherever and whenever someone is born (if on Earth or in its orbit) the Earth must have had a specific place relative to the Sun.
This can be defined using the portion of the year that has passed (or remaining.) One can use the Autumnal Equinox and the Solstices as marker points through the year.
Now that I think about it, our (Persian) first half of the year is longer than the second half by several days! However, Wikipedia claims that the Autumnal Equinox is usually on September 22nd (our first day of Fall) and I think it can move at most one day to one direction on leap years and whatnot.
I must research the matter more!

Whatever this issue is, unlike those friends of yours, I don’t think this is irrelevant or that you should chill out!

]]> By: MatGill http://yaserzt.com/blog/archives/257/comment-page-1#comment-8700 MatGill Sat, 08 Nov 2008 06:58:10 +0000 http://yaserzt.com/blog/?p=257#comment-8700 Well, technically speaking your birthday could be both of those days. It actually depends on either where you were born or where you reside (or wish to reside) today, which is of course totally bazaar! In fact if you take it to be the function of where you are, then you might end up not having a birthday at all if you travel on a particular schedule. Check out the discussion on an old post on my blog: http://blog.360.yahoo.com/blog-YjgwYDI8dq8HKmpWliyQ8xn1Dg--?cq=1&p=1098 Well, technically speaking your birthday could be both of those days. It actually depends on either where you were born or where you reside (or wish to reside) today, which is of course totally bazaar! In fact if you take it to be the function of where you are, then you might end up not having a birthday at all if you travel on a particular schedule.

Check out the discussion on an old post on my blog:
http://blog.360.yahoo.com/blog-YjgwYDI8dq8HKmpWliyQ8xn1Dg–?cq=1&p=1098

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