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Supersymmetry and Parallel Dimensions [profile of Harvard physicist Lisa Randall]
The Harvard Crimson ^ | January 6, 2006 | Adrian J. Smith

Posted on 01/12/2006 11:54:38 AM PST by snarks_when_bored

Supersymmetry and Parallel Dimensions
Harvard Physicst Randall among world’s leading string theorists
Published On Friday, January 06, 2006  1:00 AM

Professor of Physics Lisa Randall ’83, recently named one of Newsweek’s most influential people of 2006, rose to the top with her theories on gravity. (Photo credit: CRIMSON/GLORIA B. HO)
Professor of Physics Lisa Randall ’83 saw how strong gravity could be during a climbing fall in New Hampshire two years ago.

She was performing a “challenging” move when she took a surprising fall, she says. Instead of stopping the fall, her support ropes pulled her at the wrong moment and her heel slammed into the rock.

The accident that put her on crutches for several months should not have happened, Randall says.

“It was bad luck. It was a hard climb and I was just trying out a move,” Randall says.

Although the accident prevented her from rock climbing for a while, it did not stop her ascent in the field of theoretical physics. Randall has gathered the attention of scientists and the media for possibly answering a question that has long baffled physicists—why gravity is so much weaker than other forces.

Randall believes the answer to what physicists call the hierarchy problem may lie outside our visible world. Gravity may be weak compared to forces such as electromagnetism, because it is concentrated in another dimension.

Along with Raman Sundrum of Johns Hopkins University, she published two papers in 1999 that have changed how physicists think about the structure of space. Randall proposed that the universe has more than four dimensions (three of space and one of time) and that these extra dimensions could be infinitely large.

Randall has influenced string theorists, who also claim that extra dimensions exist. String theory is a model of physics in which building blocks are one-dimensional objects called strings instead of zero-dimensional particles like electrons.

Until now, string theorists have accounted for the fact that we can detect only three dimensions by claiming that the extra dimensions are curled up into infinitesimal loops and thus imperceptible.

Randall claims that these dimensions could be infinitely large provided that space has a warped geometry. In effect, we could be living in a three-dimensional pocket of higher dimensional space. Randall refers to these pockets in space as branes. Like a bead on a wire that can only move along one dimension, a brane may restrict our motion to three dimensions although other dimensions exist.

With branes, Randall discovered a way to explain how extra dimensions could be hidden and infinitely large. Because the math behind her theory works, theoretical physicists have paid close attention to her research.

In an article profiling the most influential people of 2006, Newsweek calls her “one of the most promising theoretical physicists of her generation.” From 1999 to 2004, she was the most cited theoretical physicist in the world.

According to Randall, the world as we know it may only be a three-dimensional pocket, a “brane,” of a higher dimensional space. Though our brane restricts our motion to three dimensions, other dimensions still exist. (Photo credit: CRIMSON/)


THE HIERARCHY PROBLEM

While working with Sundrum, Randall stumbled on a possible answer to why gravity is so weak compared to other forces. Gravity may not appear weak to the casual observer. But, as Randall explained to the crowd at a Science Center Research Lecture last month, a small magnet holding a paper clip resists the gravitational pull of the entire Earth.

Randall was dealing with another problem before she considered the hierarchy problem: examining supersymmetry, a theory that claims every fundamental particle has a partner (like an electron with a negative charge and a positron with an equivalent positive charge).

But the theory currently predicts particle interactions that don’t actually occur.

“What happens is that you end up with interactions you really don’t want to have. It is really hard to write down theories where those interactions don’t occur,” Randall says.

In trying to better understand supersymmetry, Randall discovered that extra dimensions of space could solve its problems. If other dimensions exist, then it becomes possible to separate particles and to prevent unwanted interactions.

According to Randall, the world as we know it may only be a three-dimensional pocket, a “brane,” of a higher dimensional space. Though our brane restricts our motion to three dimensions, other dimensions still exist. (Photo credit: CRIMSON/)


Randall’s theory of extra dimensions also would answer the hierarchy problem. With the help of Andreas Karch of the University of Washington, Randall found that gravity could be concentrated somewhere in an extra dimension.

The force’s strength becomes exponentially weaker further from the gravity brane.

“Gravity is so strongly peaked near the brane that gravity doesn’t leak away,” Randall says. “If you are anywhere except the brane where gravity is concentrated, you would see gravity as very weak.”

‘NOT A TALENT THAT YOU NEED’

Randall continued to work on her book after the climbing accident.

Lying on a couch with her leg raised to prevent infection, she started to rewrite her book “Warped Passages: Unraveling the Mysteries of the Universe’s Hidden Dimensions.” The book presents her research on the geometry of space, extra dimensions, and gravity in an entertaining style.

Andrew Strominger, professor of physics at Harvard and a string theorist, says he was impressed by the quality of the book.

“It was a side of her I hadn’t seen before,” Strominger says, “I didn’t know that she could write so well. It is not a talent that you need as a theoretical physicist.”

Karch adds that he’s glad to see theoretical physics promoted to a broader audience.

“Warped Passages” has received critical acclaim and has also attracted the general public to the complex field of theoretical physics. It was among the New York Times’ “100 Notable Books of the Year” for 2005 and Amazon.com’s “Top Ten in Science.” Her book has led her to give many public talks, including speeches at the Smithsonian, New York’s American Museum of Natural History, and Boston’s Museum of Science.

She also presented her ideas to a packed lecture hall at her Science Center lecture, part of a series promoting the research of Harvard’s most prominent scientists.

‘VERY INTUITIVE’

Randall has always been a science prodigy.

While attending Stuyvesant High School in New York, she won the Westinghouse Science Talent Search—now known as the Intel Science Talent Search—with a number theory project on complex numbers. After Stuyvesant, Randall entered Harvard College in 1980 and graduated in three years as a physics concentrator. She says that Expos was one of her favorite classes, although she described it as “challenging.”

While Randall was always interested in physics, a summer internship before her final year at the College narrowed her focus. She spent the summer working for Fermi National Accelerator Laboratory, a high energy particle accelerator near Chicago, Ill.

“That made me interested in particle physics. It then became clear as a graduate student what I wanted to do,” Randall says.

Randall returned to Harvard for graduate school, where her Ph.D. advisor was Mallinckrodt Professor of Physics Howard Georgi ’68.

Randall was the first tenured woman in the physics department of Princeton University and the first female theorist at the Massachusetts Institute of Technology, according to the Boston Herald. In 2001, Randall returned to Harvard where she became the third woman to get tenure in physics, according to the Times.

Randall, who teaches Physics 253a, “Quantum Field Theory I” for first-year graduate students, says that she enjoys working at Harvard.

“Students here are great, so it is very rewarding to teach at Harvard,” Randall says.

Her colleagues at Harvard praise her instinctual approach to physics—many say she seems to know the answers beforehand and then attempts to prove them.

“She is very intuitive. She often understands things in her own mind before she is able to formulate it mathematically,” Strominger says.

Karch, who worked with Randall on the hierarchy problem, says that he was impressed by her knack for physics.

“Randall is full of interesting ideas, often too many to work out all of them,” Karch writes in an e-mail. “She usually knows the right answer to begin with and then needs to spend some time trying to convince others (and herself) that it is really the right answer.”

Randall says that she often has an incomplete sense of her results before starting her research.

“People sometimes say that I have the ideas before the math, but many times that’s not really true,” Randall says. “Sometimes we have some of the math, but I then figure out what it means. That was the case with the work on infinite extra dimensions.”

‘A BIG IF’

Technology is coming closer to verifying string theory and Randall’s work.

Randall hopes that the Large Hadron Collider, a giant particle accelerator near Geneva, Switzerland will test her theories. Colliding proton beams at a combined energy of 14 trillion electron volts, it will start operation in 2007. The collider could produce particles such as the sought-after graviton believed to convey the gravitational force, or it could produce actual strings.

Unlike current particle accelerators, the collider should have enough energy to show particles that travel in or through the extra dimension.

Randall says she looks forward to the opportunity to test her theories.

“If these ideas are proven correct, it can be really big. But whatever the [collider] finds will be big news,” Randall says.

Nima Arkani-Hamed, a professor in the physics department who has written several papers with Randall, says he is excited about the collider’s potential findings and their significance for particle physics.

“We will see which one of these ideas from the last 25 years is right,” Arkani-Hamed says.

Evidence of a fifth dimension could signal a new era in physics and could mean significant accolades for Randall. The Boston Herald speculates she would be a “shoe-in” for the Nobel Prize if the collider proves her correct.

But Randall says that she prefers to think about her research.

“It is a big if,” Randall says. “I am thinking about what I am doing at the moment.”

—Staff writer Adrian J. Smith can be reached at smith9@fas.harvard.edu.


TOPICS: Miscellaneous; Technical
KEYWORDS: branes; braneworld; cosmology; extradimensions; gravitons; gravity; lisarandall; physics; stringtheory; superstrings; supersymmetry
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And here's a link to a 2003 Edge interview with Randall:

THEORIES OF THE BRANE: LISA RANDALL


1 posted on 01/12/2006 11:54:41 AM PST by snarks_when_bored
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To: RadioAstronomer; longshadow; grey_whiskers; headsonpikes; PatrickHenry; Iris7

Ping


2 posted on 01/12/2006 11:55:14 AM PST by snarks_when_bored
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To: snarks_when_bored

My brane isn't big enough to understand this.


3 posted on 01/12/2006 11:58:36 AM PST by SlowBoat407 (The best stuff happens just before the thread snaps.)
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To: VadeRetro; Junior; longshadow; RadioAstronomer; Doctor Stochastic; js1138; Shryke; RightWhale; ...
SciencePing
An elite subset of the Evolution list.
See the list's explanation at my freeper homepage.
Then FReepmail to be added or dropped.

4 posted on 01/12/2006 11:59:18 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry

Thanks for the ping!


5 posted on 01/12/2006 12:00:30 PM PST by Alamo-Girl (Monthly is the best way to donate to Free Republic!)
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To: All
Obligatory for a Lisa Randall thread:


6 posted on 01/12/2006 12:00:41 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: snarks_when_bored

--b--


7 posted on 01/12/2006 12:01:16 PM PST by rellimpank (Don't believe anything about firearms or explosives stated by the mass media---NRABenefactor)
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To: snarks_when_bored

This is fascinating...I think.

Alas, I was but a poor history major.


8 posted on 01/12/2006 12:01:29 PM PST by RexBeach ("There is no susbstitute for victory." -Douglas MacArthur)
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To: snarks_when_bored
Brilliant and attractive.
A winning combo.
9 posted on 01/12/2006 12:02:38 PM PST by Semper Paratus
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To: snarks_when_bored
String theory is fascinating.

I first saw articles on it a couple of years ago now almost every monthly I pick up has something on it.

BTW I find intelligent women extremely sexy.
10 posted on 01/12/2006 12:03:01 PM PST by HEY4QDEMS (Learn from the past, don't live in it.)
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To: snarks_when_bored
How does this square with Hypersphere Packing?

I thought I'd read about a 24 dimension theory some time back?

11 posted on 01/12/2006 12:03:14 PM PST by TexasCajun
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To: PatrickHenry
Ah, Lisa. With her branes and my looks, what a team we could be!
12 posted on 01/12/2006 12:03:41 PM PST by VadeRetro (Liberalism is a cancer on society. Creationism is a cancer on conservatism.)
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To: snarks_when_bored


She was at Princeton, and there's no mention of Witten in the article? (Not that it is required but...)


13 posted on 01/12/2006 12:06:38 PM PST by in hoc signo vinces ("Houston, TX...a waiting quagmire for jihadis.")
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To: snarks_when_bored

14 posted on 01/12/2006 12:10:51 PM PST by fishtank
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To: Semper Paratus
Brilliant and attractive. A winning combo.

But in a pinch, brilliant will do.


15 posted on 01/12/2006 12:11:38 PM PST by Physicist
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To: snarks_when_bored

I caught a bit of her on CSPAN - she was giving a talk in NYC - the contrast between her looks and the freakshow that was her audience was amazing. The audience looked like people had all just walked out a Larsen Far Side cartoon!


16 posted on 01/12/2006 12:15:08 PM PST by 2 Kool 2 Be 4-Gotten (Is your problem ignorance or apathy? I don't know and I don't care.)
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To: All
Some of the papers Lisa Randall has written (alone and with others):

Search results for "Lisa Randall" at arXiv.org

Reading the abstracts is fun...

17 posted on 01/12/2006 12:15:51 PM PST by snarks_when_bored
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To: PatrickHenry

Nice one...


18 posted on 01/12/2006 12:16:17 PM PST by snarks_when_bored
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To: Physicist

Poor Emmy...


19 posted on 01/12/2006 12:17:21 PM PST by snarks_when_bored
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To: snarks_when_bored

20 posted on 01/12/2006 12:18:43 PM PST by Ouderkirk (Funny how death and destruction seems to happen wherever Muslims gather...)
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To: snarks_when_bored

Bump!


21 posted on 01/12/2006 12:20:36 PM PST by Jaxter ("Vivit Post Funera Virtus")
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To: snarks_when_bored

"Brane and brane: what is Brane!" (with apologies to Captain Kirk)


22 posted on 01/12/2006 12:24:50 PM PST by Zeppo
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To: snarks_when_bored
Poor Emmy...

Poverty is relative.


23 posted on 01/12/2006 12:25:58 PM PST by Physicist
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To: Physicist
Now I understand this better (I'd never seen a picture of her before)

Edmund Landau, when asked if he did not agree that Noether was an instance of a great woman mathematician: "Emmy is certainly a great mathematician; but that she is a woman, I cannot swear."

John Derbyshire's article about Emmy Noether

24 posted on 01/12/2006 12:29:33 PM PST by Virginia-American
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To: snarks_when_bored

Yeah, I'm all about that "weakbrane" thing...


25 posted on 01/12/2006 12:29:56 PM PST by Redbob
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To: snarks_when_bored

Quantum physics is shortly going to prove that evolutionists and creationists could BOTH be right, at the same time. Then the real fun will begin.


26 posted on 01/12/2006 12:32:37 PM PST by GovernmentShrinker
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To: GovernmentShrinker
Quantum physics is shortly going to prove that evolutionists and creationists could BOTH be right, at the same time.

Except that the creationists will only be right on some other brane.

27 posted on 01/12/2006 12:40:49 PM PST by Physicist
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To: GovernmentShrinker

"Quantum physics is shortly going to prove that evolutionists and creationists could BOTH be right, at the same time. Then the real fun will begin."

I agree with you. Being a physics reading geek for some time now...there will be a "singularity" soon...


I know, I know... lame pun.

;)


28 posted on 01/12/2006 12:46:09 PM PST by taxed2death (A few billion here, a few trillion there...we're all friends right?)
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To: snarks_when_bored
“We will see which one of these ideas from the last 25 years is right,” Arkani-Hamed says.

2007, eh?

29 posted on 01/12/2006 12:53:57 PM PST by siunevada (If we learn nothing from history, what's the point of having one? - Peggy Hill)
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To: Physicist

That's a woman?????

But-- she has sideburns that my Elvis impersonator husband would envy!


30 posted on 01/12/2006 12:54:40 PM PST by stands2reason (I'm BAAAAAAAAAAAAAACK!!!!!!!!!!!!)
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To: snarks_when_bored
I don't pretend to be a theoretical physicist, but this jabber about string theory just feels wrong. It's like Copernicus being forced to define a geocentric solar system. It can be done, yes, but only by torturing the numbers to fit the concept. Maybe I'm wrong. Maybe this is the opposite, the simplest mathematical route. But it just doesn't seem right to me, for whatever that's worth.

It would be interesting to see a version of this "for Dummies." I think I could grasp the concepts, although I admit the theoretical math eludes me.

31 posted on 01/12/2006 12:54:59 PM PST by IronJack
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To: Physicist
Except that the creationists will only be right on some other brane

IMO, Quantum Theory helps the creation theory.

In order for man to make the proper life decisions, ALL decisions and resulting consequence must exist - somewhere.

If every action we take has consequence, and if under free will, we may take any action, and if God allows free will, then He must be ready for any decision we make..allowing one universe for each action taken by each person.

Is this too much for a newbie to say without total ridicule?

32 posted on 01/12/2006 12:55:54 PM PST by EequalsMC2
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To: IronJack
It would be interesting to see a version of this "for Dummies."

"String Theory For Dummies" would be a tough book to write.

33 posted on 01/12/2006 12:56:56 PM PST by Semper Paratus
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To: snarks_when_bored
We need to consult another expert in the "field":


34 posted on 01/12/2006 12:58:59 PM PST by mikrofon (Professor Grande Deluxe, University of Oz)
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To: snarks_when_bored
I have proof there's a Fifth Dimension:

Image hosted by Photobucket.com

35 posted on 01/12/2006 1:00:14 PM PST by Freedom_Fighter_2001 (When money is no object - it's your money they're talking about)
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To: IronJack
It would be interesting to see a version of this "for Dummies." I think I could grasp the concepts, although I admit the theoretical math eludes me.
Galileo's take (from The Assayer):
Philosophy is written in this vast book, which continuously lies upon before our eyes (I mean the universe). But it cannot be understood unless you have first learned to understand the language and recognise the characters in which it is written. It is written in the language of mathematics, and the characters are triangles, circles, and other geometrical figures. Without such means, it is impossible for us humans to understand a word of it, and to be without them is to wander around in vain through a dark labyrinth. . .

36 posted on 01/12/2006 1:05:08 PM PST by snarks_when_bored
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To: siunevada
“We will see which one of these ideas from the last 25 years is right,”

If any, that would be the first.

37 posted on 01/12/2006 1:16:36 PM PST by RightWhale (pas de lieu, Rhone que nous)
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To: snarks_when_bored

Thanks for posting this.


38 posted on 01/12/2006 1:20:25 PM PST by Rocky (Air America: Robbing the poor to feed the Left)
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To: VadeRetro
Ah, Lisa. With her branes and my looks, what a team we could be!

Lisa, Lisa ... Why don't you freepmail me? We were meant to be. Surrender to the inevitable.

39 posted on 01/12/2006 1:21:24 PM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry
When I do attempt to contact her, remind me to tell her to ignore you.
40 posted on 01/12/2006 1:26:04 PM PST by VadeRetro (Liberalism is a cancer on society. Creationism is a cancer on conservatism.)
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To: snarks_when_bored

On the other hand She could be WRONG..


41 posted on 01/12/2006 1:30:23 PM PST by hosepipe (CAUTION: This propaganda is laced with hyperbole..)
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To: EequalsMC2
If every action we take has consequence, and if under free will, we may take any action, and if God allows free will, then He must be ready for any decision we make..allowing one universe for each action taken by each person.

Do you have any idea how much RAM that would require? :)

42 posted on 01/12/2006 1:42:45 PM PST by cj2a (When you're pathetic, but you don't know you're pathetic, that's really pathetic.)
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To: snarks_when_bored

Real understanding of how gravity works could initiate a technology revolution as great as that from understanding how electricity works.


43 posted on 01/12/2006 1:48:21 PM PST by Restorer
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To: snarks_when_bored

Placemark for later reading.


44 posted on 01/12/2006 1:54:26 PM PST by Reaganesque
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To: cj2a
Do you have any idea how much RAM that would require? :)

ROFLOL! Spew beer. Keyboard gone. You owe me.

45 posted on 01/12/2006 1:55:03 PM PST by EequalsMC2
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To: 2 Kool 2 Be 4-Gotten
"The audience looked like people had all just walked out a Larsen Far Side cartoon!"

Whence came his material did you suppose?

46 posted on 01/12/2006 2:38:40 PM PST by YHAOS
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To: Semper Paratus

I just read an excerpt from some of Richard Feynman's theses. I've got some background in math, but this stuff was indecipherable. And that was the "simplified" version!


47 posted on 01/12/2006 2:48:25 PM PST by IronJack
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To: snarks_when_bored

WEAK BRANE!!!! I know how that feels.


48 posted on 01/12/2006 3:11:42 PM PST by furball4paws (The new elixir of life - dehydrated toad urine.)
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To: PatrickHenry

So did you use the same line on the Kansas dynamic duo?


49 posted on 01/12/2006 3:12:42 PM PST by furball4paws (The new elixir of life - dehydrated toad urine.)
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To: EequalsMC2

Actually I have another question.

I God is omniscient then he knows everything that is going to happen even before it happens. If that is correct then he knows every decison we are going to make before we make it, so how can we have free will. Our lives must be pre- determined. Anything we decide to do, if he is all-knowing God already knew we were going to do it right?


50 posted on 01/12/2006 3:30:47 PM PST by redangus
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