The FSL t-skew chart from Zapata forecasted strong east winds, but it was clear
that the winds were south east and in a good direction for heading north
northwest. The RUC, as interpreted by Dr. Jack, was also calling for east winds.
While there were a few cu's over Mexico, it was mostly blue over Zapata and to
the north. That is blue except for the wide bands of cirrus overhead and to the
north. It was not an inviting sky.
Manfred decided to give it a try at 10:30 with a few cu's twenty miles to the
south. He is able to get good lift to 3,500' and headed north. He later decided
to land at Carrizo Springs 115 miles to the north. Bo was chasing him.
The good cu's start forming around 12:30. They are found around the southern
part of the state but don't continue up to the north.
Manfred reported in after getting back to the airport in Zapata. Good lift for
thirty miles north of Laredo, but no sun on the ground after that. Still lift,
but things slowed down. The east wind direction kicked in but the wind lightened
up.
I just returned from the Virgin Islands, from a delightful event — a conference
in St. Thomas — that I organized with 21 physicists. I like small events, and I
got to hand-pick the people. The topic of the meeting was "Confronting Gravity.
" I wanted to have a meeting where people would look forward to the key issues
facing fundamental physics and cosmology. And if you think about it they all
revolve in one way or another around gravity. Someone at the meeting said, well,
you know, don't we understand gravity? Things fall. But really, many of the key
ideas that right now are at the forefront of particle physics cosmology, relate
to our lack of understanding of how to accommodate gravity and quantum
mechanics.
I invited a group of cosmologists, experimentalists, theorists, and particle
physicists and cosmologists. Stephen Hawking came; we had three Nobel laureates,
Gerard 'tHooft, David Gross, Frank Wilczek; well-known cosmologists and
physicists such as Jim Peebles at Princeton, Alan Guth at MIT, Kip Thorne at
Caltech, Lisa Randall at Harvard; experimentalists, such as Barry Barish of LIGO,
the gravitational wave observatory; we had observational cosmologists, people
looking at the cosmic microwave background; we had Maria Spiropulu from CERN,
who's working on the Large Hadron Collider — which a decade ago people wouldn't
have thought it was a probe of gravity, but now due to recent work in the
possibility of extra dimensions it might be.
I wanted to have a series of sessions where we would, each of us, try and speak
somewhat provocatively about what each person was thinking about, what the key
issues are, and then have a lot of open time for discussion. And so the meeting
was devoted with a lot of open time for discussion, a lot of individual time for
discussion, as well as some fun things like going down in a submarine, which we
did. It was a delightful event, where we defied gravity by having buoyancy, I
guess.
I came away from this meeting realizing that the search for gravitational waves
may be the next frontier. For a long time I pooh-poohed it in my mind, because
it was clear it's going to be a long time before we could ever detect them if
they're there, and it wasn't clear to me what we'd learn — except that they
exist. But one of the key worries I have as a cosmologist right now is that we
have these ideas and these parameters and every experiment is consistent with
this picture, and yet nothing points to the fundamental physics beneath it.
It's been very frustrating for particle physicists, and some people might say
it's led to sensory deprivation, which has resulted in hallucination otherwise
known as string theory. And that could be true. But in cosmology what we're
having now is this cockamamie universe. We've discovered a tremendous amount.
We've discovered the universe is flat, which most of us theorists thought we
knew in advance, because it's the only beautiful universe. But why is it flat?
It's full of not just dark matter, but this crazy stuff called dark energy, that
no one understands. This was an amazing discovery in 1998 or so.
What's happened since then is every single experiment agrees with this picture
without adding insight into where it comes from. Similarly all the data is
consistent with ideas from inflation and everything is consistent with the
simplest predictions of that, but not in a way that you can necessarily falsify
it. Everything is consistent with this dark energy that looks like a
cosmological constant; which tells us nothing.
It's a little subtle, but I'll try and explain it.
We've got this weird antigravity in the universe, which is making the expansion
of the universe accelerate. Now: if you plug in the equations of general
relativity, the only thing that can 'anti-gravitate' is the energy of nothing.
Now: this has been a problem in physics since I've been a graduate student. It
was such a severe problem we never talked about it. When you apply quantum
mechanics and special relativity, empty space inevitably has energy. The problem
is, way too much energy. It has 120 orders of magnitude more energy than is
contained in everything we see!
Now that is the worst prediction in all of physics. You might say, if that's
such a bad prediction, then how do we know empty space can have energy? The
answer is, we know empty space isn't empty, because it's full of these virtual
particles that pop in and out of existence, and we know that because if you try
and calculate the energy level in a hydrogen atom, and you don't include those
virtual particles, you get a wrong answer. One of the greatest developments in
physics in the 20th century was to realize that when you incorporate special
relativity in quantum mechanics you have virtual particles that can pop in and
out of existence, and they change the nature of a hydrogen atom, because a
hydrogen atom isn't just a proton and electron.
That's the wrong picture, because every now and then you have an electron
positron pair that pops into existence. And the electron is going to want to
hang around near the proton because it's oppositely charged, the positron is
going to be pushed out to the outskirts of the atom, and while they're there
they change the charged distribution in the atom in a very small, but
calculable, way. Feynman and others calculated that effect, which allows us to
get agreement between theory and observation at the level of nine decimal
places. It's the best prediction in all of science. There's no other place in
science where, from fundamental principles, you can calculate a number and
compare it to an experiment at nine decimal places like that.
But then when we ask, if they're there, how much should they contribute to the
energy in the universe, we come up with the worst prediction in physics. It says
if empty space has so much energy we shouldn't be here. And physicists like me,
theoretical physicists, knew they had the answer. They didn't know how to get
there. It reminds me or the Sidney Harris cartoon where you've got this big
equation, and the answer, and the middle step says "And then a miracle occurs".
And then one scientist says to another, "I think you have to be a little more
specific at this step right here".
The answer had to be zero. The energy of empty space had to be precisely zero.
Why? Because you've got these virtual particles that are apparently contributing
huge amounts of energy, you can imagine in physics, how underlying symmetries in
nature can produce exact cancellations — that happens all the time. Symmetries
produce two numbers that are exactly equal and opposite because somewhere
there's an underlying mathematical symmetry of equations. So that you can
understand how symmetries could somehow cause an exact cancellation of the
energy of empty space.
There appears to be energy of empty space that isn't zero! This flies in the
face of all conventional wisdom in theoretical particle physics. It is the most
profound shift in thinking, perhaps the most profound puzzle, in the latter half
of the 20th century. And it may be the first half of the 21st century, or maybe
go all the way to the 22nd century. Because, unfortunately, I happen to think we
won't be able to rely on experiment to resolve this problem.
But what you couldn't understand was how to cancel a number to a hundred and
twenty decimal places and leave something finite left over. You can't take two
numbers that are very large and expect them to almost exactly cancel leaving
something that's 120 orders of magnitude smaller left over. And that's what
would be required to have an energy that was comparable with the observational
upper limits on the energy of empty space.
We knew the answer. There was a symmetry and the number had to be exactly zero.
Well, what have we discovered? When we look out at the universe, if this dark energy
is something that isn't quite an energy of empty space but its just something
that's pretending to be that, we might measure that it's changing over time.
Then we would know that the actual energy of empty space is really zero but this
is some cockamamie thing that's pretending to be energy of empty space. And many
people have hoped they'd see that is because then you wouldn't need quantum
gravity, which is a theory we don't yet have, to understand this apparent dark
energy. Indeed, one of the biggest failures of string theory's many failures, I
think, is it never successfully addressed this cosmological constant problem.
You'd think if you had a theory of quantum gravity, it would explain precisely
what the energy of empty space should be. And we don't have any other theory
that addresses that problem either! But if this thing really isn't vacuum
energy, then it's something else, then you might be able to find out what it is,
and learn and do physics without having to understand quantum gravity.
The problem is, when we actually look out, every measure we've made right now is
completely consistent with a constant energy in the universe over cosmological
time. And that's consistent with the cosmological constant, with vacuum energy.
So if you make the measurement that it's consistent with that, you learn
nothing. Because it doesn't tell you that it is vacuum energy, because there
could be other things that could mimic it. The only observation that would tell
you, give you positive information is if you could measure it was changing over
time. Then you'd know it wasn't vacuum energy.
All if we keep measuring this quantity better and better and better, it is quite
possible that we will find out it looks more and more like a vacuum energy, and
we're going to learn nothing. And the only way to resolve this problem will be
to have a theory. And theories are a lot harder to come by than experiments.
Good ideas are few and far between. And what we're really going to need is a
good idea, and it may require an understanding of quantum gravity, or it may
require that you throw up your hands, which is what we're learning that a lot of
people are willing to do. In the Virgin Islands we had a session on the
anthropic principle, and what is surprising is how many physicists have really
said, you know, maybe the answer is an anthropic one. Twenty years ago if you'd
asked physicists if they would hope that one day we'll have a theory that tells
us why the universe is the way it is, you would have heard a resounding 'Yes'.
They would all say 'that's why I got into physics'.
They might paraphrase Einstein, who said, while referring to God but not really
meaning God, that the question that really interested him is did God have any
choice in the creation of the universe. What he really meant by that was, is
there only one consistent set of laws that works. If you changed one — if you
twiddled one aspect of physical reality — would it all fall apart? Or are there
lots of possible viable physical realities?
Twenty years ago most physicists would have said, on the basis of 450 years of
science, that they believed that there's only one allowed law of nature that
works, that ultimately we might discover fundamental symmetries and mathematical
principles that cause the nature to be the way it is, because it's always worked
that way.
So that is the way science has worked. But now because of this energy of empty
space — which is so inexplicable that if it really is an energy of empty space,
the value of that number is so ridiculous that it's driven people to think that
maybe, maybe it's an accident of our environment, that physics is an
environmental science — that certain fundamental constants in nature may just be
accidents, and there may be many different universes, in which the laws of
physics are different, and the reasons those constants have the values they have
might be — in our universe — might be because we're there to observe them.
This is not intelligent design; it's the opposite of intelligent design. It's a
kind of cosmic natural selection. The qualities we have exist because we can
survive in this environment. That's natural selection, right? If we couldn't
survive we wouldn't be around. Well, it's the same with the universe. We live in
a universe — in this universe — we've evolved in this universe, because this
universe is conducive to life. There may be other universes that aren't
conducive to life, and lo and behold there isn't life in them. That's the kind
of cosmic natural selection.
We're allowed to presume anything; the key question is, is it a scientific
question to presume there are other universes? That's something we were looking
at in the meeting as well. I wrote a piece where I argued that is a disservice
to evolutionary theory to call string theory a theory, for example. Because it's
clearly not a theory in the same sense that evolutionary theory is, or that
quantum electrodynamics is, because those are robust theories that make rigorous
predictions that can be falsified. And string theory is just a formalism now
that one day might be a theory. And when I'm lecturing, talking about science,
people say to me, evolution is just a theory, I say, in science theory means a
different thing, and they say, what do you mean? Look at string theory, how can
you falsify that? It's no worse than intelligent design.
I do think there are huge differences between string theory and intelligent
design. People who are doing string theory are earnest scientists who are trying
to come up with ideas that are viable. People who are doing intelligent design
aren't doing any of that. But the question is, is it falsifiable? And do we do a
disservice to real theories by calling hypotheses or formalisms theories? Is a
multiverse — in one form or another — science?
In my sarcastic moments I've argued that the reason that some string theorists
have latched onto the landscape idea so much is that since string theory doesn't
make any predictions, it's good to have a universe where you can't make any
predictions. But less sarcastically, if you try and do science with idea, you
can try and do real science and calculate probabilities. But whatever you do,
you find that all you get is suggestive arguments. Because if you don't have an
underlying theory, you never know.
I say, well, what's the probability of our universe having a vacuum energy if it
is allowed to vary over different universes? Then I come up with some result
which is interesting, and Steven Weinberg was one of the first people to point
out, that if the value of the energy of empty space was much greater than it is,
then galaxies wouldn't have formed, and astronomers wouldn't have formed, so
that gave the anthropic argument that, well, maybe that's why it is what it is —
it can't be much more.
But the problem is, you don't know if that's the only quantity that's varying!
Maybe there are other quantities that are varying. Whatever you're doing is
always a kind of ad hoc suggestive thing at best. You can debate it, but it
doesn't lead very far. It's not clear to me that the landscape idea will be
anything but impotent. Ultimately it might lead to interesting suggestions about
things, but real progress will occur when we actually have new ideas. If string
theory is the right direction, and I'm willing to argue that it might be, even
if there's just no evidence that it is right now, then a new idea that tells us
a fundamental principle for how to turn that formalism to a theory will give us
a direction that will turn into something fruitful. Right now we're floundering.
We're floundering, in a lot of different areas.
As a theorist, when I go to meetings I often get much more out of the
experimental talks. Because I often know what's going on in theory, or at least
I like to think I do. I was profoundly affected by the experimental talks. In
principle, we are now able to be sensitive to gravitational waves that might
change a meter stick that's three kilometers long by a length equal to less than
the size of atom!. It's just amazing that we have the technology to do that.
While that is not actually detecting any gravitational waves, there's no
technological obstructions, to going to the advanced stage. Gravitational waves
may be indeed allow us a probe that might take us beyond our current state of
having observations that don't lead anywhere. I was very impressed with these
findings.
At the same time, that we had a talk from Eric Adelberger at the University of
Washington, who's been trying to measure Newton's Law on small scales. You might
think, who would want to measure Newton's Law on small scales? But one of the
suggestions for extra dimensions is that on small scales and gravity has a
different behavior. There has been some tantalizing evidence that went through
the rumor mills that had suggested that in these experiments in Seattle they
were seeing evidence for deviations from Newton's Theory. And Attleburger talked
about some beautiful experiments. As a theorist, I'm just always amazed they can
even do these experiments. And gave some new results, there are some tentative
new results, which of course are not a surprise to me, that suggest that there
is as yet no evidence for a deviation from Newton's Theory.
Many of the papers in particle physics over the last five to seven years have
been involved with the idea of extra dimensions of one sort or another. And
while it's a fascinating idea, but I have to say, it's looking to me like it's
not yet leading anywhere. The experimental evidence against it is combining with
what I see as a theoretical diffusion — a breaking off into lots of parts.
That's happened with string theory. I can see it happening with
extra-dimensional arguments. We're seeing that the developments from this idea
which has captured the imaginations of many physicists, hasn't been compelling.
Right now it's clear that what we really need is some good new ideas.
Fundamental physics is really at kind of a crossroads. The observations have
just told us that the universe is crazy, but hasn't told us what direction the
universe is crazy in. The theories have been incredibly complex and elaborate,
but haven't yet made any compelling inroads. That can either be viewed as
depressing or exciting. For young physicists it's exciting in the sense that it
means that the field is ripe for something new.
The great hope for particle physics, which may be a great hope for quantum
gravity, is the next large particle accelerator. We've gone 30 years without a
fundamentally new accelerator that can probe a totally new regime of the
sub-atomic world. We would have had it if our legislators had not been so
myopic. It's amazing to think that if they hadn't killed the superconducting
Super Collider it would have been already been running for ten years.
The Large Hadron Collider is going to come on-line next year. And one of two
things could happen: It could either reveal a fascinating new window on the
universe and a whole new set of phenomena that will validate or refute the
current prevailing ideas in theoretical particle physics, supersymmetry etc, or
it might see absolutely nothing. I'm not sure which I'm rooting for. But it is
at least a hope, finally, that we may get an empirical handle that will at least
constrain the wild speculation that theorists like me might make.
Such a handle comes out of the impact of the recent cosmic microwave background
(CMB) studies on Inflation Theory. I read in the New York Times that Alan Guth
was smiling, and Alan Guth was sitting next to me at the conference when I
handed him the article. He was smiling, but he always smiles, so I didn't know
what to make much of it, but I think that the results that came out of the
cosmic microwave background (CMB) studies were twofold.
Indeed, as the Times suggested, they validate the notions of inflation. But I
think that's just journalists searching for a story. Because if you look at what
quantitatively has come out of the new results they're exactly consistent with
the old results. Which also validate inflation. They reduce the error bars a
little bit, by a factor of two. I don't know if that is astounding. But what is
intriguing to me is that while everything is consistent with the simplest
models, there's one area where there's a puzzle. On the largest scales, when we
look out at the universe, there doesn't seem to be enough structure — not as
much as inflation would predict. Now the question is, is that a statistical
fluke?
That is, we live in one universe, so we're a sample of one. With a sample of
one, you have what is called a large sample variance. And maybe this just means
we're lucky, that we just happen to live in a universe where the number's
smaller than you'd predict. But when you look at CMB map, you also see that the
structure that is observed, is in fact, in a weird way, correlated with the
plane of the earth around the sun. Is this Copernicus coming back to haunt us?
That's crazy. We're looking out at the whole universe. There's no way there
should be a correlation of structure with our motion of the earth around the sun
— the plane of the earth around the sun — the ecliptic. That would say we are
truly the center of the universe.
The new results are either telling us that all of science is wrong and we're the
center of the universe, or maybe the data is imply incorrect, or maybe it's
telling us there's something weird about the microwave background results and
that maybe, maybe there's something wrong with our theories on the larger
scales. And of course as a theorist I'm certainly hoping it's the latter,
because I want theory to be wrong, not right, because if it's wrong there's
still work left for the rest of us.
We've got two Swifts here and if Robin Hamilton comes down from Houston we'll
have three. He's up there watching all the weather models ready to pounce if it
looks like a record day. With Manfred down here ready to take away Robin's
records he's got to be ready to defend them.
Thick mid level clouds for much of the morning and they continue to affect our
normal path to the north all day. Armand Acchione took off at 10:30 AM in his
Swift and was able to stay near the airport at 2,000' AGL until it turned on
around 11 AM, then he could fly any where. With 10 mph southeast wind and no
retrieve, he came back and landed later at the airport. No one else flew in the
morning.
Armand went up for a late afternoon flight to 7,500' under billowy cu's and a 16
mph southeast wind.
Gary would like someone to take his loaner from near Chattanooga
to near Zapata.
(Zapata)
Gary Osoba is looking for someone to jump in a waiting SUV at the
glider port near Chattanooga and drive the SUV and the Silent 2 glider trailered
behind it to somewhere near Zapata, TX, as soon as possible. Contact him at:
Gary Osoba <wosoba> for more
explicit instructions, and the terms of the deal.
The forecast is for 10 knot northeast winds in the afternoon
(Zapata)
The winds are light (as forecasted) in the morning. Blue until noon with cu's
beginning to form to the south. By 1 PM the cu's are overhead and to a north a
bit. High cloud base and light winds. Nice cu's forming 100 miles further to the
north and up on the Edwards plateau up through the panhandle. Just no wind to
get you there.
No one takes off in the morning, other than David Glover who soloed his Cessna
150 after beginning instruction with Pete Lehmann and a ride with the airport
manager. Charlie, here.
Armand, Manfred and Pete Lehman took off in the afternoon in a light east wind
with cu's ever where that we could see.
This is the satellite photo at 3:25 PM. The east flow is clear in the south and
southeast further north. Nice to see all these little cu's throughout the state.
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