[In an earlier post that I recently deleted, I criticized Weinberg's recent writing and Steely Dan's Gaucho album for their cool mechanical/technical precision and lack of any hint that a human being was responsible for their creation.]
Let
me get down off my high-as-the-cat’s-back horse and say I’m not really equipped
to read Steven Weinberg’s Cosmology
textbook. Also, I need to listen to
Steely Dan’s Gaucho album again
before I comment on its crystalline production quality as a negative
aspect. There, I just put the album on. I’ll write while I’m listening to it. Here
come those Santa Ana winds again.
As regards Weinberg's book: I’ve told students before that there are three reasons why a person would have
trouble reading and understanding something.
One
reason is that the vocabulary is beyond what you know, meaning the material is
too advanced for your present state of knowledge. I think this is my problem with Weinberg’s
book. It is, after all, a graduate-level
textbook in cosmology and gravitation. I need to read and work some exercises
at an advanced undergraduate level before I can tackle it. Or else work harder at understanding it, and
not expect it to be an easy read. I've got a copy of J. V. Narlikar's Introduction to Cosmology (2nd ed, 1993) that uses general relativity at the advanced undergraduate level and also seems quite readable, with reasonable exercises at the end of each chapter.
Another
reason you might not understand what you’re reading is that you are not in a
tranquil enough emotional state to be able to concentrate. Okay, maybe tranquil isn’t the right
word. You can possibly be jazzed up on
caffeine and comprehend what you’re reading.
Usually my mind is going all over the place after drinking coffee—not an
ideal state for reading. The coffee buzz
is better for writing than reading (I’ve had a cup and a half so far this
morning). So let’s say one reason you might have trouble reading and
comprehending something is that your mind is not in the best possible state for
reading.
The
third reason is that the writing is not very good. That’s a matter of taste, partly. I guess many people enjoy Brian Greene’s
books, but I’m not one of those people. You
shouldn’t have to work at reading a book.
It should be enjoyable, no matter what the subject. I’ve tried to read The Elegant Universe and The
Fabric of the Cosmos, but to no avail.
Too much work.
Of
course, in the realm of textbooks the expectation for enjoyment is pretty low, but the book should be
well written nevertheless, with similarly well-written exercises that aren’t
overly obtuse and don’t require great cleverness to solve. I’m kind of getting off the subject now, back
into the complaint mode, so I’ll move on.
On Monday, walking
into the first floor entrance of the Pine Bluff library, I stopped to
look at some of the library books being offered for sale. Some books had been added to the sale since the last time
I stopped and looked, and Lo and Behold, the
first book I set my eyes on was The
Inflationary Universe, by Alan Guth!
It was among a bunch of physics and astronomy books that had been put in
the sale since last time I passed by the tables.
Actually the sale is more of a giveaway. No one is monitoring the books by sitting there to tell what the prices are or take money. It’s the honor system. A note taped to the wall says the prices are ten cents to fifty cents, which I guess means paperbacks are a dime and hardbacks are fifty cents. In order to pay, you have to go up in the elevator to the circulation desk , since the first floor is just the entrance to the children’s library and also where the library's one elevator is located. I usually don't use the elevator and instead go up the civic center steps outside and use the door on the main floor near the circulation desk.
Actually the sale is more of a giveaway. No one is monitoring the books by sitting there to tell what the prices are or take money. It’s the honor system. A note taped to the wall says the prices are ten cents to fifty cents, which I guess means paperbacks are a dime and hardbacks are fifty cents. In order to pay, you have to go up in the elevator to the circulation desk , since the first floor is just the entrance to the children’s library and also where the library's one elevator is located. I usually don't use the elevator and instead go up the civic center steps outside and use the door on the main floor near the circulation desk.
Guth’s
book, published in 1997, looks like a good one from what I’ve read of it so far. Another well-written book I’m reading is Sean Carroll’s From Eternity to Here.
He has a chapter on cosmic inflation, and he quotes what Guth wrote in a notebook in
December 1979 about the possibility of an inflationary period
in the early part of the life of the universe. (That the universe "started" sometime in the past, and especially that it started with a big bang, just gives me the epistemological and ontological willies. Hard to fathom.)
Guth didn't use the word "inflation" when he wrote down his "spectacular realization" as he called it. He instead used the word "supercooled," and that makes more sense to me than the word inflation. Fluids such as water can be supercooled and superheated, and suddenly freeze or boil, respectively, because of a slight disturbance. Our most common experience in normal life is a liquid that is superheated after being in a microwave oven. It is at the boiling point, but doesn't boil until you reach in to get it out. Moving the container is the disturbance that causes it to suddenly boil.
Supercooling can happen to steam or to liquid water. In the case of the liquid state, the temperature can be reduced to below water's freezing point, maybe very rapidly reduced, and the water doesn't freeze until there is a slight disturbance, then it all freezes at once. Similarly, steam that is supercooled can suddenly condense into liquid water all at once. These changes of state between gas, liquid, and solid, no matter how they occur, are known as phase transitions.
Guth didn't use the word "inflation" when he wrote down his "spectacular realization" as he called it. He instead used the word "supercooled," and that makes more sense to me than the word inflation. Fluids such as water can be supercooled and superheated, and suddenly freeze or boil, respectively, because of a slight disturbance. Our most common experience in normal life is a liquid that is superheated after being in a microwave oven. It is at the boiling point, but doesn't boil until you reach in to get it out. Moving the container is the disturbance that causes it to suddenly boil.
Supercooling can happen to steam or to liquid water. In the case of the liquid state, the temperature can be reduced to below water's freezing point, maybe very rapidly reduced, and the water doesn't freeze until there is a slight disturbance, then it all freezes at once. Similarly, steam that is supercooled can suddenly condense into liquid water all at once. These changes of state between gas, liquid, and solid, no matter how they occur, are known as phase transitions.
So
in the Big Bang, the very hot, early universe suddenly for some reason
supercooled by expanding exponentially for a short time period. Here is what Guth wrote in his notebook in December 1979, the same time I was finishing my work on a bachelor's degree in physics at Hendrix College:
March 14, 1979, by the way, was the hundredth anniversary of Einstein's birth. Nineteen-seventy-nine was also the year Steven Weinberg, Abdus Salam, and Sheldon Glashow won the Nobel prize for their theoretical work uniting the weak and the electromagnetic forces. So, while Alan Guth was having his December revelation on inflation in the early universe, Glashow, Salam, and Weinberg were receiving their Nobels and I was creating a new student lab at Hendrix that involved using a light-emitting diode to find Planck's constant.
Now that I'm remembering it, I have to tell about my discovery when I was working on that lab. LEDs were still something of a novelty in 1979. Almost all of them emitted red light, but some green ones were starting to come into use. The one I used for my lab was red, but the voltage I measured across it was not the right voltage I needed if my lab was going to predict an accurate value of Planck's constant. Actually it was not the right voltage to correspond to an LED that emitted red light. My lab project was looking pretty doomed at that point, in late November.
Then I decided to look more closely at the LED itself while it was on. I used a little cylindrical magnifier that I'd bought earlier that year at Radio Shack, made for inspecting a turntable's needle (stylus) for wear. Under magnification, the LED could be seen to emit green as well as the dominant red light! Green light takes more energy and therefore more voltage to produce. The voltage across the LED was just right for producing green light, and based on that, my idea of using an LED was a new way to measure Planck's constant (with a plus or minus 10% error) in a student lab. I tried other LEDs, both green ones and red ones, and found they could also be used reliably in the experiment.
Now I'll comment again on Gaucho, which I listened to while writing this. Throughout 1979 Steely Dan was working on this album, which was to be their last as a band. The songs just aren't very good compared to Steely Dan's previous albums. They sound more like they were produced by a programmed song-writing machine than by people. So all this effort--two years' worth--was put into producing a great-sounding album (Mark Knoppler plays on it, for instance), but the "content" was lacking.
Aja, Steely Dan's 1978 album that preceded Gaucho, is one of my favorite albums. The sound quality on it is also superb, as is Steve Gadd's drumming, but mainly the songs are good, especially Black Cow, Deacon Blues, and Aja: Up on the hill / they think I'm okay / or so they say.
SPECTACULAR REALIZATION: this kind of supercooling can explain why the universe today is so incredibly flat--and therefore resolve the fine-tuning paradox pointed out by Bob Dicke in his Einstein Day lectures.
March 14, 1979, by the way, was the hundredth anniversary of Einstein's birth. Nineteen-seventy-nine was also the year Steven Weinberg, Abdus Salam, and Sheldon Glashow won the Nobel prize for their theoretical work uniting the weak and the electromagnetic forces. So, while Alan Guth was having his December revelation on inflation in the early universe, Glashow, Salam, and Weinberg were receiving their Nobels and I was creating a new student lab at Hendrix that involved using a light-emitting diode to find Planck's constant.
Now that I'm remembering it, I have to tell about my discovery when I was working on that lab. LEDs were still something of a novelty in 1979. Almost all of them emitted red light, but some green ones were starting to come into use. The one I used for my lab was red, but the voltage I measured across it was not the right voltage I needed if my lab was going to predict an accurate value of Planck's constant. Actually it was not the right voltage to correspond to an LED that emitted red light. My lab project was looking pretty doomed at that point, in late November.
Then I decided to look more closely at the LED itself while it was on. I used a little cylindrical magnifier that I'd bought earlier that year at Radio Shack, made for inspecting a turntable's needle (stylus) for wear. Under magnification, the LED could be seen to emit green as well as the dominant red light! Green light takes more energy and therefore more voltage to produce. The voltage across the LED was just right for producing green light, and based on that, my idea of using an LED was a new way to measure Planck's constant (with a plus or minus 10% error) in a student lab. I tried other LEDs, both green ones and red ones, and found they could also be used reliably in the experiment.
Now I'll comment again on Gaucho, which I listened to while writing this. Throughout 1979 Steely Dan was working on this album, which was to be their last as a band. The songs just aren't very good compared to Steely Dan's previous albums. They sound more like they were produced by a programmed song-writing machine than by people. So all this effort--two years' worth--was put into producing a great-sounding album (Mark Knoppler plays on it, for instance), but the "content" was lacking.
Aja, Steely Dan's 1978 album that preceded Gaucho, is one of my favorite albums. The sound quality on it is also superb, as is Steve Gadd's drumming, but mainly the songs are good, especially Black Cow, Deacon Blues, and Aja: Up on the hill / they think I'm okay / or so they say.
