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PBS: NOVA's 'The Elegant Universe'
Sylvester James Gates, Jr., Ph.D.
Program Participant, 'The Elegant Universe'
Wednesday, October 29, 2003; 1:00 p.m ET
On PBS, NOVA presents a three-hour miniseries on the string theory, one of the the most ambitious theories defining the ultimate law and order of the universe. Based on the bestseller by author-physicist Brian Greene, "The Elegant Universe" uses lavish computer-animated explanations to relay the theory and visually explores the modern physics behind it.
'The Elegant Universe' program participant Sylvester James Gates, Jr., Ph.D. will be online Wednesday, Oct. 29 at 1 p.m. ET, to take your questions.
Submit your questions and comments before or during the discussion.
Gates is an elected fellow of the American Association for the Advancement of Science. A graduate of Massachusetts Institute of
Technology, his Ph.D. was conferred for studies of elementary particle physics and quantum field theory. His research thesis on “supersymmetry,” was the first devoted to this subject at MIT. His faculty positions include the University of Maryland and Howard University. In 1998, he was named the first John S. Toll Professor of Physics, the first African American to hold an endowed chair in physics at a major research university in the U.S. Gates has authored or co-authored over 120 research papers published in scientific journals, co-authored one book, and contributed numerous articles in others. He has also served as a consultant for the Department of Energy, Department of Defense, and Time-Life Books.
Editor's Note: washingtonpost.com moderators retain editorial control
over Live Online discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions.
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Springfield, Va.:
What a great show! I can't imagine how complex these theories really are, but you really did a great job explaining them to us regular folk. One thing that I didn't quite understand was the part about how general relativity worked well explaining big things like solar system and how quantum physics worked well explaining small things like atoms. At what point do the differences in these sciences start separating?
Jim Gates: Hi,
The point where things first seem to diverge is at the
molecular and atom level. At these sizes, quantum effects
become important. However, recently with the first
observation of the "Bose-Einstein Condensate," even at
larger scales we can observe the difference in the
laboratory.
_______________________
West Des Moines, Iowa:
Is String Theory falsifiable? That is, is there any way to DISPROVE the theory by observational or experimental means?
Jim Gates: Hi
String theory had better be falsifable or else it is not
science.
The criticism that come from scientists colleagues about
string theory not being falsifable is based on a misunder-
stand where we stand in its development.
Imagine you could go back in time to, say, 1920. If you
went to the greatest collection of theoretical physicists
in the world and asked, "What is quantum mechanics?" the
responses would be mystifying.
You see the physicist, Bohr first suggested the importance
of quantized behavior around 1912. But we did have a true
quantum theory until the work of Schroedinger and Heisenberg
in 1926. So in 1920, lots of physicists knew that something
new was coming, but they certainly did not know how to use
this to make detailed prediction and confirm the idea.
String theory today is sort of in this strange in "between
time." Criticizing string theory today is like criticizing
quantum theory in 1920.
_______________________
Portsmouth, Ohio:
I continue to hear that "the math of string theory
requires a 10-dimensional universe."
Can you elaborate, in layman's language, why this is
so?
Jim Gates: Well, that statement about "requiring" extra dimensions isn't
quite true. The more correct statement is that string theory
"allows" for the existence of extra dimensions.
The reason this happens is because of several "conspiracies."
Once you accept that strings are the basis for doing physics,
then you have to check whether this concept is consistent with
all the previous well established laws of physics. Two of
these are quantum theory and special relativity. If you use
the mathematics to check this consistency then the simplest
way to obtain this is to write a theory where there are
extra dimensions. But there are also more complicated
ways to get consistency that do not involve extra dimensions. But these ways are not simple nor pretty.
_______________________
Anchorage, Alaska:
I an thrilled with the new series, and I got my kids and wife to watch with me. They enjoyed it as well.
I was interested in the weightless particle and pondered:
In comparison to electron field microscopy would a gravitron form of microscopy yield a smaller view of atom?
Thanks
Jim Gates: If we could construct a microscope based on gravitons instead
of electrons, it would give us a different (not necessary
smaller) view of the atom.
You see in order to use "electrons" to "see" something, that
something must possess charges somewhere inside it. This is obvious if you stop and thing about shooting an electron at a neutral object.
But a graviton microscope would "see" not charge but mass and energy (since they are one in the same according to
Einstein's famous equation). So it could "see" even a
neutral object.
_______________________
Ft. Myers, Fla.:
Dr. Gates:
Is there room for God in String Theory? Is there evidence of design in String Theory?
Thank you.
Jim Gates: Physics is about what we, as finite humans, can measure.
So your question really is equivalent to asking whether
a finite being can measure an infinite one?
I often tell people that physics is too small to answer
questions such as yours. Physics is not a religion it
is what happens in the laboratory. As such it, and all
the rest of science, are perfectly mute on questions about
God.
_______________________
Grantsburg, Wis.:
If string theory succeeds as the unifying theory of everything, where does physics go from there? What else is left?
Jim Gates: This one reason why I hate the name "the theory of every-
thing." It easily leads to this misconception. I prefer
the name that Einstein originally gave to this class of
ideas when he called them. "unified field theory."
Even if we succeed in totally nailing down the structure of
string theory, that does not mean that we will have understood
"everything."
There is a famous example of this kind of thing in physics
right now.
Some year ago, in some laboratory experiments, "high tem-
perature superconductors" were discovered. This was a
totally unexpected surprise. Now we believe that the
equations of quantum theory and electromagnetic theory
ought to explain why these substances exist and how they
work. But, in fact, no one in the world understand this.
If someone did find an explanation, they'de win a Nobel
Prize in physics!
So having the complete equations for fundamental physics
is not enough to "know everything."
_______________________
Gaithersburg, Md.:
Jim:
Great show; I watched in awe. However: How much closer are we (if at all) to proving or fully accepting (?) Einstein's "unified theory?" Is string theory making that possible?
Jim Gates: String theory, I tell people, is the only game in town with
regard to proving Einstein's idea of unified field theories
are correct. Strings are unified field theories!
_______________________
Cannon Falls, Minn.:
If string theory proves out over the next decade or two, do you see any practical application of string theory, possibly space travel?
Jim Gates: If we completely nailed down string theory tomorrow, I
would predict that it would be at least 150 years before
it had any practical application. But at the end of that
time, it could very well lead to new abilities to manipu-
late space-time, i.e. possibly faster than light travel
or time travel. You might be interested in seeing the
comments I made at The Elegant Universe website about this.
The URL is
http://www.pbs.org/wgbh/nova/elegant/view-gates.html
or possibly
http://superstringtheory.com/people/jgates.html
_______________________
Memphis, Tenn.:
Incredible show and you have really sparked curiosity in me. One question pops into my head. Einstein stated that the fastest anything can travel is the speed of light. If this is the case, for all practical purposes is our number system actually finite instead of infinite? Or is it possible for things to travel the speed of light + 1?
Jim Gates: Hi,
Your statement confuses two things, physics and mathematics.
Since the latter exist in our imagination we can easily
describe infinite number systems.
On the other hand, Einstein's work does absolutely forbid
faster than light travel. The thing about supersting/M-theory
is that it may not totally agreed with Einstein! So with
a more complete understanding, who knows?
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Durham, N.C.:
I just wanted to say THANKS! Thanks for your time today, thanks for your work, thanks for sticking it out when you get frustrated at your work, and thanks for inspring the rest of us! Please tell all the people involved that we all appreciate the efforts!
Jim Gates: Hi,
Well, just let me say "THANK YOU" for understanding
what it is like to try to create work that goes beyond
Einstein, one of my childhood (and still) heroes!
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Beverly Hills, Mich.:
What a great show. I am an 8th grade teacher and am showing it to my students today as part of their physics class. They are spellbound!
Here is a question one of them asked:
Is there any possibility that the strings are made up of even smaller particles?
Jim Gates: Hi,
You have some very bright students! The answer to the
question may be "Yes." As may be mentioned in the coming
episode, about 5-8 years ago something called "M-theory"
began. One of its possible explanations is that it has
something to do with the smaller "bits" of strings.
Since you are a teacher let me give you some information
(maybe you have some of this already) that might be useful
to you and your students.
If you go to the webpage at
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
you will see an image of me that was taken from a poster
that was created to encourage young people to think about
physics. If you would like to have a copy of the poster
for your class, please send a separate e-mail to my
address at the end of this message.
You might be interested in encorporating this into your
curriculum planning. If so, the document on-line at
http://www.pbs.org/wgbh/nova/teachers/activities/
3012_elegant.html
should prove very useful. These newer resources can also
be used in conjunction with the materials at
http://www.nsf.gov/od/lpa/lecture/stringtheory.htm
http://www.superstringtheory.com/
http://www.superstringtheory.com/people/jgates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
http://insti.physics.sunysb.edu/~siegel/quo.html
to plan a curriculum on this topic. If this is not
useful to you directly, would you be so kind as to
pass this message along to an acquaintence for whom
this might be of interest?
Also there is an on-line lecture I gave on superstring
theory available via the internet at the first webpag
above.
Thank You,
Jim Gates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Millerstown, Pa.:
Dr. Gates, I was truly captivated by being able to "see" the idea of string theory without needing a degree to understand the physics or math equations. I am a 55-year-old pastor who loves learning and being exposed to new ideas. I will look forward to seeing this special again as I know I will learn more the second time I see it! Thank you for bringing this subject to my novice attention.
Jim Gates: Hi,
I am very glad to learn that the presentation permitted
you to have a closer glimpse of what my crazy community
has been up to doing.
You spoke of seeing the special again. There are actually
a few ways to do this. First, you can wait for re-broadcast.
But you can also purchase the video by going to
http://www.pbs.org/wgbh/nova/elegant/
and surf around a bit by clicking the hyperlink
"Buy the video" you can purchase it. Or better
yet click on "Watch the Program" and you can see
it on your computer anytime you wish!
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Gaithersburg, Md.:
Dr. Gates,
Thanks for taking part in this chat. Watching the program last night, I was impressed with your ability to take sophisticated and complicated ideas and express them in a way that allows the average person to at least understand the concepts behind them.
My question is, how difficult is it for you and other physicists to envision a universe with 10 dimensions or the peculiarities of quantum mechanics?
Jim Gates: Hi,
It is not difficult in one sense. As I said in the
interview at
http://www.pbs.org/wgbh/nova/elegant/view-gates.html
mathematics for the theoretical physicist is an
extra sensory perception organ. It is like an extra
set of eyes that let's us see things not so obvious.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Grand Blanc, Mich.:
Let's say that you had 100 pebbles that had exactly the same mass, but different shapes. If you bounced them off of a drum and they all made a different sound, even if only a minute difference, could that be used as a proof of string theory?
In other words, the same matter can be manipulated to create different occurances. AKA, one string made of only one matter can create countless variations.
Jim Gates: Hi,
Nope. It does not. The thought experiment that you
describe is totally unrelated to strings.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Reston, Va.:
Thank you for the great show!
Jim Gates: Hi,
THANK YOU for the message of encourgement. I am
glad to hear of your enjoyment of the show and hope
that it will encourage you to support education at
all level and scientific research aimed at fundamental
questions.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Fredericton, New Brunswick:
You mentioned the possibility of "Time travel" if string theory is validated. What do you mean by "time travel?"
Thanks!
Jim Gates: Hi,
I meant time travel just like H.G. Wells meant time travel.
With the laws of space and time as given to us by Einstein,
it is almost impossible to conceive of a time machine (well
there are some tiny possibilities). But you see with
superstring/M-theory those very laws would be change and
quite possibly superceded by new laws. Perhaps these
would permit time travel...but be aware this only a possibilty not guaranteed.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
William Paterson University, N.J.:
I love string theory, and I love theoretical Physics. I was just wondering how difficult is it to get to the point where you are able to play with equations that no one has solved? (basically, how much goes into being a physicist?)
Jim Gates: Hi,
How long does it take to become a professional tennis
player or golfer or musician? As best I can tell, this
is about a decade and a half.
Having invented and solved equation no one had done
before, I can tell you it is enormous fun!
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
New York, N.Y.:
I was disappointed that the series so
repetitively made the point that there is no
theory to explain both gravity and the other
natural forces, and that strings might be
the link, but the big HOW was so utterly
missing. By hour 1.5 my husband and I
were rolling our eyes and asking why
NOVA spent $3.5 million on
something that could have ben so utterly
fascinating, but proved so utterly empty
and redundant. Very frustrating! What
are strings? Why might they be the
link? big build up, small delivery. Maybe
NOVA should have waited a few years til
strings can be quantified.
Jim Gates: Hi,
I am sorry to hear of your frustation. I know that the
producers worked very hard to try to answer your question.
If you really want the answers, you'd have to spend about
a decade or so becoming a theoretical physicists.
Let me try to explain.
In our world, we know musics in two ways. Firstly,
we hear it all the time. So we have direct access to
it without any special training. But music exist in
another form. Namely you can write it as notes on
bars. This is another way to know musics. I am told
that people who can read music like this can "hear"
it in their imaginations.
Now let's imagine a world in which the ONLY way that
musics was known was by notes on bars. In such a world
there could be "musicians" and they would be the people
that write these symbols on paper and then discuss them
with each other. You could well imagine them talking
about the beauty and elegance of the music. But when
they go to explain this to their fellow beings, what do
they say? How do they explain what the symbols mean?
If you substitute
music --> mathematics & physics
musicians -- > theoretical physicists
then you can perhaps see why things are so very
difficult to explain for us physicists. The actual
answer for us reside in our mathematics... which must
be ultimately verified by experiment for us to know
we are describing our home, the universe.
I can almost guarantee you waiting would not have
helped.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Baton Rouge, La.:
-Just had to say "hello" Jim and to tell you that I am now happily at Louisiana State University. -So glad to see that you're doing this program with PBS!
Best,
Theda Daniels-Race, Ph.D.
Associate Professor
Dept. of Electrical & Computer Eng.
Jim Gates: Hi Theda,
It is always so good to hear from you! I hope that
things continue to go GREAT at LSU for you. One of
my wife cousins used to work there and now is at
Southern.
I'm glad to hear you saw the program!
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Edmonton, Alberta, Canada:
Hello Mr. Gates.
Could it be possible that the five string theories explain five possible universes, or does that mean that all of them explain ours?
Jim Gates: Hi,
If you watch the last episode, I think you will
see your answer. I don't want to give it away.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Torrance, Calif.:
Great program!
How does the "String Theory" apply to Dark Energy?
Is it possible that this energy is in another dimension -- one that is not visible to us?
Thanks
Jim Gates: Hi,
The short answer to this is that we just don't know.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Sprinfield, N.J.:
You are lucky to work in such a fascinating field. If in fact String Theory allows for the existence of six, or more, additional dimensions, how would the dimension of time behave within them? Thank you,
Jim Gates: Hi,
Almost all string theories only have a single time.
The extra dimensions, if there are there, behave
like space.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Arlington, Va.:
Fascinating program, but to me it ended a bit abruptly without clearly stating what the current consensus on string theory is (if there is one). Are there serious efforts to find proofs, or is it really a case of either you believe in it or you don't?
Jim Gates: Hi,
The major of what the community does is study proofs.
Contrary to what some people say, this really is serious
science. A scientist can say that he does not like the
assumptions of another one, but he cannot say he dis-
agrees with the calculations. And none can disagree
with an experiment.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Indianapolis, Ind.:
Dr. Gates, increasingly it seems that language is capable of expressing fundamental physics relationships that are difficult of follow through mathematics. My question is this, "Do you think that in the future, logic, as expressed through language, will play a greater role in guiding physicists towards the correct model(s) of physics phenomena?"
Jim Gates: Hi,
I am afraid that you have it precisely backward. Of all
of humanity's languages, mathematics is the only one with
about a 500 year long record of showing that it is capable
to precisely describing Nature. So I think there is less
than a 1/1,000,000 chance that language will ever surpass
mathematics is the tool by which scientist can understand
the universe.
For the theoretical physicist, mathematics is an extra
sensory perception organ.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Monroe, N.C.:
Loved the show. I'm sure it will encourage many new physicists. One question about strings: Is it possible that strings are really non-dimentional points acting as one-dimentional strings due to some kind of vibration?
Jim Gates: Hi,
I apologize, but I have no idea what your statement
means.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Edmonton, Alberta, Canada:
Hi, I am in no way a physicist or very educated in Physics. I do, on the other hand, think a heck of a lot about abstract things and believe I have a idea on how we could test the String theory. Now it's very wild, but feasable. If my understanding about String theory is correct. To sum it up -- in my understanding, everything in this universe and possible beyond is governed entirely by little micro strands of vibrating strings. Correct? O.K... Do they vibrate? And why? If they are like "sensory strings" and pick up vibrations is it possible to effect the vibrations through interconnecting light and created waves of music? That's a very vague question but does anyone understand what im am trying to describe?
Jim Gates: Hi,
They vibrate because the laws of quantum theory demand
that they must.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Houston, Tex.:
If time was accelerating what would be the first of the "unknown" or loosely defined dimensions to break down?
Jim Gates: Hi,
I apologize but I do not understand your question.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Palm Harbor, Fla.:
Hi Jim. Do you have concerns that we'll never have closure on this theory, because the very activities of monitoring or testing at such minute levels always affect the outcome? We can't truly "observe" without tainting the result? (and Thanks for making time for us today!)
Jim Gates: Hi,
I am hopeful that we eventually will have a complete
understanding of superstring/M-theory. But the bulk
of your comment pertains to the behavior of quantum
mechanical systems. There you don't have to worry about
such. For example, you safely use your cell phone and
do not worry about affecting the outcome.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Melville, N.Y.:
Spin, gravitons, black holes, string theory, dimensions, lines of force, points in space.
Ask Hawking what else is happening to matter at the event horizon. Where does matters and anti-matters "spin" go? What is contained in the black holes? Are strings being stacked (harmonized) or points (in space) being collected?
Jim Gates: Hi,
Since I have know Stephen since 1980, I am pretty
much up on what he says about the behavior of matter
near black holes. "Information loss" is what he
calls it. No one knows what is contained in a black
hole. The last part of your question I do not understand.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Austin, Tex.:
Jim, thank you for your participation today.
The show was incredible. I have a question regarding the fate of the universe as to whether it is closed or an open one. My question is if it was a closed one and eventually everything collapsed back together wouldn't time move backwards? And if so I think that rules out the closed theory, because I think it would be impossible for history to reverse itself.
Jim Gates: Hi,
Even if the universe if closed, there is no
evidence that time would run backward near
the its end.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Cleveland, Ohio:
Great show! Unfortunatly I had the same "HUH?" reaction that I had when I first was introduced to general relativity. That aside, as I understand general relativity things tend to "fall apart" at the surface of a black hole. Does string theory get through this area?
Thanks
Jim Gates: Hi,
String theory seems to improve our understanding of
black holes. But there are lot's of questions remaining
unsolved.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Greenville, Ill.:
I was wondering why the dimension limit is 11. The fact that time travel is possible would indicate infinite dimensions if you could travel in the past.
Jim Gates: Hi,
We don't defintively know if time travel will be
possible in the final form of string theory.
The number 11, like 10, 26 and 496 come essentially
from number theory, a branch of mathematics. It
turns out that since we can only explored string
theory (presently) with mathematics, this is what
determines a number of its features.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Red Lion, Pa.:
I really enjoyed the show, which really strived to explain physics to us "lay people." I enjoyed your interactions on the show, as well.
I don't quite "understand" the extra seven dimensions (of the 11 that the string theory proposes). My question: Is an extra dimension a place the same person exists simultaneously or is it devoid of humans?
Jim Gates: Hi,
The actual answer is that we presently understand the
extra dimensions as parts of the mathematics allowed
by string theory. We don't know anything what goes
on there...if they exist.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Rocky Hill, Conn.:
If we do understand strings, are we asking next - What are strings made of? Can this be an infinite process?
Now there are five different string formulas. If there are an infinite number of formulas, does this render string theory useless?
Jim Gates: Hi,
In the final show, you will see that there are
not five theories. So be sure to watch.
The problem of an infinite regression is a
possibility.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Atlanta, Ga.:
Mr Gates,
Is any of this science dangerous from the standpoint of damaging life as we know it? For instance is it in our capabilities of creating black holes, worm holes, etc.?
Jim Gates: Hi,
No, not yet and likely not for hundreds of years.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Medford, Ore.:
Can you recommend some books that perhaps introduces someone to the mathematics behind string theory?
Thanks.
Jim Gates: Hi,
I don't recommend any books since the subject is still
immature and developing. If you wish to peek at what
is known now there are some.
Go on-line and look for "String Theory" by Green,
Schwarz and Witten.
There is also a book by Joel Polchinski that you should
be able to find by going on-line.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Evanston, Ill.:
Can string theory explain the posibility of going back into the past "backward in time" by transending into parallel universes? In other wards can one meet one's self under these condidtions?
Jim Gates: Hi,
No, we do not definitively know if string theory
permits time travel. Maybe it does, maybe not.
This (and many others) will have to await a better
understanding of it.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Phoenix, Ariz.:
Having read the Elegant Universe twice, I was amazed at how much was left out of its television counterpart. Are there any key points you would have liked to have seen covered in more detail?
Thanks
Jim Gates: Hi,
There are things not covered in The Elegant Universe
at all that I'd have liked to seen discussed. Chief
among these is the fact that the extra dimensions
are only ALLOWED by string theory, not DEMANDED.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Columbia, S.C.:
If string theory were confirmed tomorrow to be true, what would be the most compelling impact on our general understanding of the future of the universe?
Jim Gates: Hi,
In 1864, Maxwell wrote his equations. If you had asked
him this, I suspect he'd have been as unable to answer
it then as I am now.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Albuquerque, N.M.:
Have you considered that general relativity is, simply, perpendicular to quantum mechanics?
Could the "vibrating strings" be a moving picture of a series of single slices (representing moments of time) through other parallel and closely adjacent lines of force perpedicular to the slice at varying distances to a stronger parallel single line of force that we also cannot see?
Jim Gates: Hi,
I have considered it, but not for very long. That is
what physicists did for almost 60 years.
The second part of you message is not something I can
understand. Sorry.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Lincoln, Neb.:
I was curious as to what string theory might say concerning the cosmological constant. Does string theory say anything about the fate of the universe?
Thank you.
Jim Gates: Hi,
Interesting enough, this is one of the most intriguing
questions in string theory. In 1984, I wrote the
first paper in the physics literature that showed that
the kind of cosmological constant seen in astronomy
recently, could occur in a special limit of string
theory called "N = 4 supergravity." So we know that
in this limit it is consistent with a cosmological
constant.
To the second part of your question, not yet.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Normal, Ill.:
Why do the strings, the fundamental elements of matter and energy, vibrate in the first place? Does something induce an outside force which makes them them vibrate, or do they will themselves into vibration, because I want to know how to make myself vibrate.
Jim Gates: Hi,
The short answer to this question is that the laws of
quantum theory demand that superstrings vibrate. So
it is not necessary for any outside agency to "cause"
the vibration.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Largo, Fla.:
One of the problems with string theory presented in the broadcast was that it seems to be impossible to verify by observation or experiment. Is this due to a limitation on our ability to observe things at the scale required (a lack of technology) or something more fundamental (along the lines of the Hisenberg uncertainy principle)?
Jim Gates: Hi,
Yes, the problem is one of technology. The basic
point is that it takes increasing amounts of energy
to investigate the structure of the universe at
smaller and smaller scales.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Gaithersburg, Md.:
From what I understand, there have been studies very recently that seem to suggest that Einstein's cosmological constant may not have been a blunder after all and that the universe will continue to expand forever. Does string theory say anything about the fate of the universe and whether Einstein's cosmological constant is necessary and/or valid?
Jim Gates: Hi,
I have long been interested in the cosmological constant.
In 1984, I wrote the first paper in the physics literature
that showed that the type of cosmological constant that
is of the type that has been recently observed could occur
in a special limit of superstring theory called "N = 4
supergravity." So I have never thought it was a blunder.
Extending this to the complete string is work that is still
being studied. So string theory has not made a definitive
statement about the cosmological constant yet.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Huntsville, Ala.:
I was disappointed with the way the show ended. It said there were five versions of the String Theory and pretty much ended. What is happening today with those theories? Has any one of them gained more support in the community than another? How far away are we from discovering or making the next step that will either disprove or invalidate one or some of the five theories.
Jim Gates: Hi,
The short answer will be given in the last show. So
I don't want to give it away.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Los Gatos, Calif.:
The thing that boggles my mind is the idea of energy vibrations without SOMETHING in
which they are vibrating, some matrix, some "substance." How can this be? If they
are the basic "everything" how can they be the vibrations and the matrix at the same time. This does violence to the perceived experience and concept of vibrations. I suppose the answer will come in terms of quantum probability which will be equally incomprehensible to me. Also, if true that no experiment can every confirm string theory how can we ever know, in a scientific way of "knowing", that this is not just the dreaming of physicists who throw a lot of mysterious equations at us and are asking us to take on faith that this is "truth"? Sounds like religion to me.
Jim Gates: Hi,
Your phrase "perceived experience" hold the key to avoid
this intellectual conumdrum. The point is that the way
we actually investigate string theory is to use mathematics.
Using this tool, it can be shown these vibrations do not
require anything else to exist.
It is not true that it is not possible to conceive of
an experimental test for string theory. The problem is
a technological one. It is difficult to conceive of the
technology that could create such an experiment.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Montreal, Canada:
In the many years the scientific world has accepted (and many times proven parts of) Einsteins's theory of relativity, why is it still just a theory and not an universal law?
Getting back to string theory, because this theory concerns itself at an imaginable microscopic level, is it not an extension or modifiction of quantum theory?
Also, why are so many dimensions necessary to support this theory, is it to confuse us even further? What evidence of any kind is there to support so many dimensions in our reality?
Finally, how does string theory relate to Einstein's theory of relativity?
Jim Gates: Hi,
Firstly, general relativity has been accepted as a
universal law. In fact, not only has it been accepted,
Just because the world theory is attached to something
does not mean it is not accepted. We also speak of
electromagnetic theory but that has been around for
over a hundred years.
This is something that is often confused in the public
discussion. When a scientist speaks of a "confirmed
theory," what is meant is a structure that explains
lots of facts. So in science, an accept theory is
stronger than a fact.
Yes, string theory (not yet an accepted one) is an
extension of quantum theory. It is the only reasonable
extension that can include general relativity.
This is something that is not often discussed by the
community, but string theory only ALLOWS for extra
dimensions. It does not DEMAND the existence of
extra dimensions as is so often stated. The consis-
tency of string theory is simpler if the extra
dimensions exist. There is no experiment evidence
for extra dimensions.
String theory contains general relativity as a special
limit, so GR is contained in string theory.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Haddonfield, N.J.:
I first read about strings in the mid to late ‘80s in books titled "Inventing Reality," and "Superstrings and the Search for The Theory of Everything." Both then, and after watching "The Elegant Universe," last night, the thought experiment about these
2-dimensional beings came to mind. We were asked to ponder what their understanding of 3D objects passing through their 2D plane of existence would be?
Are we at a similar crossroads with strings? Can we truly comprehend a string vibrating in 11-dimensional space -- which I thing is a prerequisite for experimentally proving their existence?
Jim Gates: Hi,
We can certainly comprehend this by use of mathematics.
This is how we investigate all aspects of string theory.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
_______________________
Las Vegas, Nev.:
After watching last night's NOVA show "The Elegant Universe," someone in the show said the strings probably produced multiple dimensions. Does that mean parallel universes are connected with our universe by strings in subspace? If so, is it possible to send an atom into a parallel universe using the string theory?
Jim Gates: Hi,
We do not know if we could send an atom into the
possible parallel universe. It is a matter of size.
Recall that in the program, it was mentioned that
the extra dimension may possess a size that is much
smaller than our universe. Suppose this size was
smaller than any atom in our universe. How could you
then get the atom to the parallel universe?
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S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
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College Park, Md.:
I watched last night's episodes on the history of physics and the notion of string theory with great interest. Many physicists were on record saying that they do not consider string theory a testable physics (ie, "hard science"), rather a philosophy, since it is presently impossible to test or observe. But, as a non-physicist, I think I missed something. Did Einstein actually "observe" the space-time fabric he postulated, or actuallly repeatedly test the notion of a more complex notion of gravitational space?
This debate is not unlike others found in social sciences. Anthropology is seen as too subjective for the tastes of many psychologists and economists. Not incidentally, economists who studied futures and options were seen as a subjective field within economics and therefore, not "real" economics. Nevertheless, because of these studies economics is a more robust field than ever. It seems like String Theory will have its day, especially since technology improves constantly, seemingly exponentially.
Just my 0.02
Jim Gates: Hi,
Yes, I agree with your final statement. But the truth
of the matter is that string theory presently has no
other serious competition as a description of phenomena requiring Einstein's principles from the theory of general relativity simultaneously with the principles of quantum theory. And yes, as our technologies improve we should be
able to make more direct access to testing string theory.
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S.J.Gates, Jr.
John S. Toll Professor of Physics and
Center for String and Particle Theory Director
University of Maryland Tel: 301-405-6025
Physics Department Fax: 301-314-9525
Rm. 4121 E-mail: gatess@wam.umd.edu
College Park, MD 20742-4111
http://www.physics.umd.edu/ep/gates/gates.html
http://nsbp.org/cgi-bin/nsbp.cgi?page=jgates
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