Help! My Unicorn run away... (REDEEMED)

General physics and astronomy discussions not directly related to Celestia
Rassilon
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Post #21by Rassilon » 11.07.2003, 23:06

granthutchison wrote:Just to get back to the unicorn for a moment... The vexed and mysterious image of the unicorn in Blade Runner has much to say about the nature of reality and our perception of it, and I rather hoped Fridger was making a visual pun.
But (sigh) apparently not. And now I've looked at it again, I begin to fear that it might be the unicorn from Legend, instead. In which case Purgatory is too good a place for it ...

Grant


pff critics ;)

Ridley Scott also directed the movie ressurection with chris lambert which was well...bad I thought..bad as in poorly witten...

Legend however was fairly good considering most fantasy movies rely on special effects...This one also played on the imagination...

It did have that sappy ending we all love :mrgreen:
I'm trying to teach the cavemen how to play scrabble, its uphill work. The only word they know is Uhh and they dont know how to spell it!

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Post #22by Don. Edwards » 12.07.2003, 00:08

I always loved the make-up job they did on Tim Curry as Darkness (Devil) in Legend. Of all the representations his was the ultimate and best.

Don.
I am officially a retired member.
I might answer a PM or a post if its relevant to something.

Ah, never say never!!
Past texture releases, Hmm let me think about it

Thanks for your understanding.

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Post #23by chris » 12.07.2003, 01:14

Since everyone who posted to this thread practically begged to have it moved to Purgatory, here you go :)

Despite the risk of this degenerating into a general discussion forum, I'll leave it unlocked for a couple days . . .

--Chris

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Post #24by Guest » 12.07.2003, 10:41

Purgatory Contemplations on Extra Dimensions
=====================================================

Let us get back to this most basic question of extra dimensions, but
forget about the specific framework withing string theory that I
touched upon further up in this apparently irrelevant thread...
-----------------------------------

There exists a "lore" that convinces us that we live in

3 space + 1 time = 4 dimensions.

We also believe that these 4 dimensions are "non-compact".

[glossary: While an infinite line is a simple "non-compact"
manifold, we may simply arrive at its compactified "brother" by
identifying its +infinity and -infinity ends such as to make a
large circle of it! So the simplest "role models" for compact
spaces are always n-dimensional spheres, starting with the circle]

Once we are ready to contemplate about more than 4 spacetime
dimensions, we should be immediately overwhelmed by some most basic,
existential questions
:

Why on earth, are we then living in 4=3+1 and not in
5, 6 or 8 dimensions?? Is perhaps our very existence intrinsically
coupled to the number of dimensions being exactly 4? Why does there
only seem to be one time and not perhaps two or more? [ In relativity,
the time dimension is treated on exactly the same footing as space dimensions]

The answers to all those most fundamental questions are still pending,
but the quest for them makes people work very hard indeed...Recently
we might have seen some "light at the end of tunnel" though...

Normal matter that we describe within the so-called Standard Model of
strong, electromagnetic and weak interactions, cannot propagate a
large distance in possible extra dimensions without conflict with
observations. It has been recently recognized, however, that this
conflict can be avoided if the Standard Model is confined by
some mechanism to act only in a (3+1)-dimensional subspace, a
so-called "3-brane", embedded in a higher dimensional
environment (the so-called "bulk")!

[glossary: p-branes are extended p-dimensional objects
that derive their name from being higher-dimensional generalizations
of "membranes"; we are thus said to live on "brane-worlds" in the
respective literature]

However, this 3-brane trick for the Standard Model forces will not
work for gravity which necessarily propagates in all
existing dimensions
, since it is the dynamics of spacetime itself!

The outstanding experimental success of Newton's 1/r^2 law (=>
Celestia!) and general relativity would therefore seem to imply
four non-compact dimensions. n extra compact dimensions of size R would modify
Newton's law into a 1/r^(2+n) behaviour at distances r<<R. At large
distances r>>R the gravitational flux lines cannot penetrate anymore
in the extra dimensions and the familiar 1/r^2 law is always recovered!

About 5 years ago it was realized by some theorists from Stanford and
Trieste that tests of Newton's law did not exist at distances
smaller than about 1mm!. So in view of the above said, a huge
new 'fashion' took off, since suddenly there was the exciting possibility
that large extra dimensions of order ~1mm were "just next door"
and could be hunted for via deviations from Newton's law!

Let me stop [or break] here in order not to overdo;-)

Bye Fridger

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Post #25by t00fri » 12.07.2003, 10:46

Perhaps Chris can delete the above anonymous clone of my following post...

As a "starter", I can recommend reading ziggy's and my post in
http://www.shatters.net/forum/viewtopic.php?t=2809

Apparently, my "Help! My Unicorn run away" thread has meanwhile managed to run away both from CelestiaUsers and the Purgatory;-). Let's see where it will end...
Image Image

Since, after redemption of the 'Unicorn' from Purgatory, the above angel turned out to have obviously male gender, I preferred to rank a little plant around his waist in order not to endanger our many very young readers;-)

Contemplations on Extra Dimensions
============================

Let us get back to this most basic question of extra dimensions, but forget about the specific framework within string theory that I touched upon further up in this thread...
---------------------------------------------------------------------------------------------

There exists a "lore" that convinces us that we live in

3 space + 1 time = 4 dimensions.

We also believe that these 4 dimensions are "non-compact".

[glossary: While an infinite line is a simple "non-compact"
manifold, we may simply arrive at its compactified "brother" by
identifying its +infinity and -infinity ends such as to make a
large circle of it! So the simplest "role models" for compact
spaces are always n-dimensional spheres, starting with the circle]

Once we are ready to contemplate about more than 4 spacetime
dimensions, we should be immediately overwhelmed by some most basic,
existential questions
:

Why on earth, are we then living in 4=3+1 and not in
5, 6 or 8 dimensions?? Is perhaps our very existence intrinsically
coupled to the number of dimensions being exactly 4? Why does there
only seem to be one time and not perhaps two or more? [ In relativity,
the time dimension is treated on exactly the same footing as space dimensions]

The answers to all those most fundamental questions are still pending,
but the quest for them makes people work very hard indeed...Recently
we might have seen some "light at the end of tunnel" though...

Normal matter that we describe within the so-called Standard Model of
strong, electromagnetic and weak interactions, cannot propagate a
large distance in possible extra dimensions without conflict with
observations. It has been recently recognized, however, that this
conflict can be avoided if the Standard Model is confined by
some mechanism to act only in a (3+1)-dimensional subspace, a
so-called "3-brane", embedded in a higher dimensional
environment (the so-called "bulk")!

[glossary: p-branes are extended p-dimensional objects
that derive their name from being higher-dimensional generalizations
of "membranes"; we are thus said to live on "brane-worlds" in the
respective literature]

However, this 3-brane trick for the Standard Model forces will not
work for gravity which necessarily propagates in all
existing dimensions
, since it is the dynamics of spacetime itself!

The outstanding experimental success of Newton's 1/r^2 law (=>
Celestia!) and general relativity would therefore seem to imply
four non-compact dimensions. n extra compact dimensions of size R would modify
Newton's law into a 1/r^(2+n) behaviour at distances r<<R. At large
distances r>>R the gravitational flux lines cannot penetrate anymore
in the extra dimensions and the familiar 1/r^2 law is always recovered!

About 5 years ago it was realized by some theorists from Stanford and
Trieste that tests of Newton's law did not exist at distances
smaller than about 1mm!. So in view of the above said, a huge
new 'fashion' took off, since suddenly there was the exciting possibility
that large extra dimensions of order ~1mm were "just next door"
and could be hunted for via deviations from Newton's law!

Let me stop [or break] here in order not to overdo;-)

Bye Fridger
Last edited by t00fri on 12.07.2003, 16:11, edited 6 times in total.

Pixel
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Post #26by Pixel » 12.07.2003, 12:04

t00fri wrote:About 5 years ago it was realized by some theorists from Stanford and
Trieste that tests of Newton's law did not exist at distances
smaller than about 1mm!. So in view of the above said, a huge
new 'fashion' took off, since suddenly there was the exciting possibility
that large extra dimensions of order ~1mm were "just next door"
and could be hunted for via deviations from Newton's law!

Let me stop [or break] here in order not to overdo;-)

Bye Fridger



Do you mean that if my shoes were less than 1mm in size then I eventually will not be able to tie them beacause as we know knots exists only in 3-dimentional (spatial) space? If space had more than three dimensions, shoe-laces would not be useful.

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Post #27by t00fri » 12.07.2003, 12:21

Pixel wrote:
t00fri wrote:About 5 years ago it was realized by some theorists from Stanford and
Trieste that tests of Newton's law did not exist at distances
smaller than about 1mm!. So in view of the above said, a huge
new 'fashion' took off, since suddenly there was the exciting possibility
that large extra dimensions of order ~1mm were "just next door"
and could be hunted for via deviations from Newton's law!

Let me stop [or break] here in order not to overdo;-)

Bye Fridger


Do you mean that if my shoes were less than 1mm in size then I eventually will not be able to tie them beacause as we know knots exists only in 3-dimentional (spatial) space? If space had more than three dimensions, shoe-laces would not be useful.


No, since for consistency all the forces that keep your shoes and laces together have to remain confined to our 3-brane world. Only gravity interactions can ever communicate with possible extra dimensions (cf my above discussion).

So your shoes will never be able to transit into "knotless" higher dimensions. While, in higher dimensions there are no 3-dim knots, higher dimensional analogs of our knots will exist.

In the same sense my second "PR-image" for extra dimensions above, showing the Unicorn with parts of it being "sucked away" into extra dimensions, could not happen in reasonable setups that are compatible with our present knowledge!

Let me also add that during the last 5 years (since the "rush" started), further precision experiments have explored the regime between ~1mm and 20 micron
(1 micron = 10^-6 m = 0.001 mm) and not yet found any deviations from Newton's 1/r^2 law!


Bye Fridger

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Post #28by MalcolmP » 13.07.2003, 00:03

I'm quite out of breath chasing this b*&^%y unicorn all over the forums (fora ? cue extended linguistic debate :o )

t00fri wrote:Why on earth are we then living in 4=3+1
some folks have done it on the moon as well for a short time ;)

and not in
5, 6 or 8 dimensions?? Is perhaps our very existence intrinsically
coupled to the number of dimensions being exactly 4?
That's getting a bit anthropic, (,, just cos we have not met anyone living in 8-space ! doesnt mean that god or someone cant ! )
But seriously though -
Why does there
only seem to be one time and not perhaps two or more?
Prof. S.Hawking has proposed 2d-time, orthogonal, real- and imaginary- time

[ In relativity,
the time dimension is treated on exactly the same footing as space dimensions]

But in reality (!) the time dimension has quite different characteristics, it seems, so far,, I offer my existence as proof that my great-grandson has not traveled back to shoot me, etc&etc, where are all the time tourists ?

Can we all get back to Celestia now please ?? It is taking an inordinate amount of time these days to find the Celestia-related posts :( Sorry for my grumble

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Post #29by t00fri » 13.07.2003, 00:46

MalcolmP wrote:I'm quite out of breath chasing this b*&^%y unicorn all over the forums (fora ? cue extended linguistic debate :o )

Something is wrong with your keys!

Did you forget the title of this thread? "Help! My Unicorn run away";-)

t00fri wrote:Why on earth are we then living in 4=3+1


some folks have done it on the moon as well for a short time ;)

Hmm...

and not in
5, 6 or 8 dimensions?? Is perhaps our very existence intrinsically coupled to the number of dimensions being exactly 4?
That's getting a bit anthropic, (,, just cos we have not met anyone living in 8-space ! doesnt mean that god or someone cant ! )

There is nothing anthropic here: Suppose, you have a concrete "theory of everything" like String theory that starts off in 10 dimensions, say. Either it is wrong or you have to manifestly understand eventually what happens with the six dims that are too many and why you got rid of them...antrophic "explanations" are really not what most serious researchers concerns too much.

But seriously though -
Why does there
only seem to be one time and not perhaps two or more?
Prof. S.Hawking has proposed 2d-time, orthogonal, real- and imaginary- time

I am of course aware of this and also of other proposals. The questions about time I posed, since perhaps some people here have never looked at it this way...

[ In relativity,
the time dimension is treated on exactly the same footing as space dimensions]

But in reality (!) the time dimension has quite different characteristics, it seems, so far,, I offer my existence as proof that my great-grandson has not traveled back to shoot me, etc&etc, where are all the time tourists ?

Crossing world lines (time loops) are NOT excluded a priori from causality etc. The challenge is again to understand why these do not tend to happen.

Why does time flow steadily?

Can we all get back to Celestia now please ?? It is taking an inordinate amount of time these days to find the Celestia-related posts :( Sorry for my grumble


Why? This department here is specially devoted to "Physics and Astronomy... not directly related to Celestia", as you can easily read yourself on the index page. Everyone is free to leave it, of course...

I really do not understand what your problem is: Have a look e.g. in the Texture department. This is strictly Celestia related and many hundreds of people were reading e.g. my recent posts...Over 415 people have read this migrating;-) 'Unicorn' thread within a few days, so it can't be too boring for some;-)...

Bye Fridger
Last edited by t00fri on 13.07.2003, 01:27, edited 1 time in total.

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Post #30by LadyHawke » 13.07.2003, 01:20

t00fri wrote:I really do not understand what your problem is: Have a look e.g. in the Texture department. This is strictly Celestia related and many hundreds of people were reading my recent posts...Over 400 people have read this migrating;-) 'Unicorn' thread within a few days, so it can't be too boring for some;-)...

Bye Fridger


May I add that it also does bring a smile to ones face...and isnt that important also? I believe Rass said it very well in another thread....a little smile and laugh every once in awhile is what makes this life a bit more enjoyable....I for one have found this topic quite refreshing..thanks for the smile Fridger :D
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Post #31by t00fri » 13.07.2003, 01:34

LadyHawke wrote:
t00fri wrote:I really do not understand what your problem is: Have a look e.g. in the Texture department. This is strictly Celestia related and many hundreds of people were reading my recent posts...Over 400 people have read this migrating;-) 'Unicorn' thread within a few days, so it can't be too boring for some;-)...

Bye Fridger

May I add that it also does bring a smile to ones face...and isnt that important also? I believe Rass said it very well in another thread....a little smile and laugh every once in awhile is what makes this life a bit more enjoyable....I for one have found this topic quite refreshing..thanks for the smile Fridger :D


Oh definitely so: it's the mix of fun, phantasy and serious discussions about basic issues that I find most inspiring/relaxing, notably after "office hours";-)

Bye Fridger

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Post #32by Rassilon » 13.07.2003, 01:50

I can easily say that there will not be any defacing of the forums by Fridger as he holds Celestia sacred in a sense...so I would say no more of this off topic finger pointing until our glorious leader ;) says so...but its not my place ;)

I for one find it refreshing to spark some laughter from time to time...as long as its not at someone elses expense...those start flame wars...
I'm trying to teach the cavemen how to play scrabble, its uphill work. The only word they know is Uhh and they dont know how to spell it!

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Post #33by jamarsa » 13.07.2003, 07:23

MalcomP wrote:I'm quite out of breath chasing this b*&^%y unicorn all over the forums (fora ? cue extended linguistic debate )



LOL!!! :lol: :lol:
It hides in a different place each day!!! Maybe it's the true ten-dimension creature?

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Post #34by t00fri » 13.07.2003, 19:40

jamarsa wrote:
MalcomP wrote:I'm quite out of breath chasing this b*&^%y unicorn all over the forums (fora ? cue extended linguistic debate )


LOL!!! :lol: :lol:
It hides in a different place each day!!! Maybe it's the true ten-dimension creature?


;-) That was the idea of the plot for the "migrating" Unicorn. Hence it's title: "Help! My Unicorn run away";-). But I also confess that I wanted to get some interesting physics over without making things appear too serious...

Bye Fridger

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Post #35by Paul » 17.07.2003, 03:37

chris wrote:Despite the risk of this degenerating into a general discussion forum, I'll leave it unlocked for a couple days . . .

--Chris


What's wrong with having a general discussion forum?

Are you worried about forum users spending too much time arguing there? If so, it's just because they've got nothing better to talk about... the real solution is to spark more constructive Celestia-related discussion, or at least space-related discussion.

Cheers,
Paul

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How many angels....

Post #36by farfenoogan » 23.07.2003, 12:23

can dance on the head of a pin? IMO, the study of n-dimensions is an effort to answer that question, or one just like it.

I applaud the efforts to understand our universe....personally, I'd just like to understand my wife :wink: .

It does seems a bit futile, though. Akin to a group of clerics arguing about the nature of GOD. People are SO presumptuous, we assume that anything/everything is knowable. All we have to do is think about it long enough.

Robert Heinlein wrote a book I almost read called "Number of the Beast" that dealt with 6*6*6 dimensions. It wasn't his best work.

An earlier post suggested that time flowed smoothly....well, perhaps, but I've been in meetings before that seemed to violate that rule. Perhaps that phenomenon would be useful to study. There may be a government grant out there somewhere.

Perhaps all this would mean more to me if I hadn't studied anatomy, pharmacology, and music of the late 20th century (sex, drugs, and rock'n'roll) so faithfully, killing brain cells instead of exercising them.

Hey, brother, got any spare neurons?
The voice in your head is wrong

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Re: How many angels....

Post #37by Guest » 23.07.2003, 16:30

farfenoogan wrote:
I applaud the efforts to understand our universe....personally, I'd just like to understand my wife :wink: .

...

Perhaps all this would mean more to me if I hadn't studied anatomy, pharmacology, and music of the late 20th century (sex, drugs, and rock'n'roll) so faithfully, killing brain cells instead of exercising them.

Hey, brother, got any spare neurons?


Perhaps the latter is also the reason why you don't understand your wife...


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