July 08, 2012
Blast from the past: "If time travel is possible then there is no such thing as time."
The original post appeared here on April 25, 2005; it follows.
That [the quote in the headline up top] sums up the book I finished last night, "A World Without Time," by Palle Yourgrau.
The ostensible subject of the book is the deep friendship between Kurt Gödel and Albert Einstein in Princeton, New Jersey.
Both were early members of Princeton's Institute for Advanced Studies, where the greatest minds in the world were paid to be themselves and simply think about things.
No teaching, no publication requirements, just do what you like each day, forever.
Sounds a lot like bookofjoe, actually, apart from the "greatest minds in the world" part.
There are those who might argue that producing eight posts a day seven days a week is somewhat akin to a "publishing requirement" but I would counter that producing bookofjoe is who and what I am and so not a requirement at all, and certainly not onerous once considered in that light.
Here it is worth noting a definition of work coined by a University of Virginia psychiatry professor years ago, still the best one I've ever come across: "Work is what you're doing when you'd rather be doing something else."
So if this is my favorite thing to do and what I prefer above everything else then it could hardly be termed "work" and doing it regularly likewise is in no way meeting a "requirement."
But I digress.
Yourgrau believes that Gödel's 1949 paper proving that there are possible worlds described by Einstein's theory of relativity in which time — as we ordinarily understand it — does not exist, upended the world of philosophy.
Gödel went further: if time is absent from those theoretical universes, he showed, time does not exist in our world either.
Einstein instantly recognized Gödel's paper as a breakthrough but an overwhelming majority of physicists, mathematicians and philosophers have spent the past half–century–plus trying to either ignore or find fault with Gödel's conclusion.
Neither strategy has succeeded.
Gödel's reasoning, compressed, was this: he could mathematically demonstrate a universe that was closed and rotated on itself.
In such a universe time travel was not only possible — it was inevitable.
If, in that universe, time was travel was possible, and by this Gödel meant precisely what you and I think of as time travel, i.e., the ability to go back and see the past as often as desired, then that past wasn't over: in fact, it never disappeared, since you could go back and find it whenever you liked, exactly as you can travel to Paris as often as you like and expect to find it there in all its reality.
Since the past was there, not having gone anywhere, then there was no such thing as time in the sense that we think of it passing, since nothing had passed at all — it was right there, always accessible.
From the book:
From his discussions late in life ..., it emerges that Gödel believed that the proper philosophy should capture axiomatically — though not purely formally — the fundamental concepts that underlie reality, which he took to include "reason, cause, substance, accidens [a traditional Latin term], necessity, value, God, cognition, force, time, form, content, matter, life, truth, idea, reality, possibility." The goal of the great logician was not to make room in physics for one's favorite episode of "Star Trek," but rather to demonstrate that if one follows the logic of relativity further even than its father was willing to venture, the results will not just illuminate but eliminate the reality of time. Gödel wrote, "I love everything brief, and find that in general the longer a work is, the less there is in it." Gödel argued that if it was possible to return to one's past, then what was past never passed at all. It is provable that time fails to exist in the Gödel universe. It cannot, therefore, exist in our own: the final step is taken, and time really does disappear.
Odd, that I should have read the second half of this book in one sitting — or rather, one reclining, as my reading spot of choice (below, with the square red pillow bearing the indentation of my head)
requires assuming the [supine] position, with my legs covered with a chenille blanket and elevated on at least three pillows, thus returning as much oxygenated blood as possible to my cerebral cortex, which needs every last molecule it can get, trust me on this... but I digress — into the late hours, after watching Robert De Niro in John Frankenheimer's 1998 film "Ronin" on DVD.
Usually after a movie I go to bed, or read magazines or easy material, not books deconstructing the work of Kurt Gödel, considered by many the greatest logician and philosopher since Aristotle.
My smart time, if there is such a thing in bookofjoe world, is in the morning, as a rule: I get stupider as the day goes on. But last night I was compelled to go at this book, and once I got going I was like a cat with fluffy furniture and no owner at home — I just couldn't stop until it was all done.
Plug it into the 30-pin connector
BehindTheMedspeak: The 10 safest hospitals in the U.S.
It's almost an oxymoron, the term "safe hospital": hospitals are dangerous places, where bad things can happen with even the very best care, nurses, and doctors.
Note that I put nurses ahead of doctors in order of importance — that's a fact, not an opinion.
But I digress.
Having said all that, should we criticize those who would attempt to bring some clarity to the hospital environment, in terms of specifics and naming names?
I think not.
Eleanor Roosevelt once remarked, "If we wait till we're ready, we'll never get started."
Truer words were never spoke.
Consumer Reports looked at 1,159 U.S. hospitals, then rated them for safety.
Of course such rankings will be imperfect — but isn't it better to at least make a start?
I think it is.
Terrible things happen to patients at the Billings Clinic (Consumer Reports' safest hospital in the country), things that should never ever happen to anyone.
Equally terrible things happen at every hospital in the U.S. — and the world.
Trust me on this.
Having said that, sometimes there is no alternative but to be hospitalized.
Let us hope that this bold first step by Consumer Reports leads to improvement at all hospitals and even better objective assessments of the quality of care.
Here, how Consumer Reports performed its study.
Here, "Your hospital survival guide: The basics."
"World's smallest lamp"
Is that small enough for you?
Experts' Expert: Quickest way to snap an iPhone pic
Wrote Kit Eaton in the July 4 "App Smart" feature in the New York Times, "QuickShot for 99 cents on iOS... is designed to be the fastest way to snap a photo when you really need to. Press the icon, it starts up, snaps a photo, saves and closes the app again. SuperFastCam, free on Android, does much the same, but for video."
For 99 cents I'll try it.
I can't tell you how many times I've lost a picture I wanted to take right now because I couldn't get to my iPhone's camera quickly enough — or found it was set to Movie mode and, by the time I'd realized it and switched to Camera, lost the shot.
NunChops — Nunchuck Chopsticks
What is the sound of ninjas dining?
8"-long chopsticks + 2.5" chain.
First photo of the shadow of a single atom
"We have reached the extreme limit of microscopy; you can not see anything smaller than an atom using visible light," Professor Dave Kielpinski of Griffith University's Centre for Quantum Dynamics in Brisbane, Australia.
"We wanted to investigate how few atoms are required to cast a shadow and we proved it takes just one," Professor Kielpinski said."
Published this week in Nature Communications, "Absorption imaging of a single atom" is the result of work over the last five years by the Kielpinski/Streed research team.At the heart of this Griffith University achievement is a super high-resolution microscope, which makes the shadow dark enough to see.
No other facility in the world has the capability for such extreme optical imaging.
Holding an atom still long enough to take its photo, while remarkable in itself, is not new technology; the atom is isolated within a chamber and held in free space by electrical forces.
Professor Kielpinski and his colleagues trapped single atomic ions of the element ytterbium and exposed them to a specific frequency of light. Under this light the atom's shadow was cast onto a detector, and a digital camera was then able to capture the image.
"By using the ultra hi-res microscope we were able to concentrate the image down to a smaller area than has been achieved before, creating a darker image which is easier to see", Professor Kielpinski said.
The precision involved in this process is almost beyond imagining.
"If we change the frequency of the light we shine on the atom by just one part in a billion, the image can no longer be seen," Professor Kielpinski said.
Research team member, Dr Erik Streed, said the implications of these findings are far reaching.
"Such experiments help confirm our understanding of atomic physics and may be useful for quantum computing," Dr Streed said.
There are also potential follow-on benefits for biomicroscopy.
"Because we are able to predict how dark a single atom should be, as in how much light it should absorb in forming a shadow, we can measure if the microscope is achieving the maximum contrast allowed by physics."
"This is important if you want to look at very small and fragile biological samples such as DNA strands where exposure to too much UV light or x-rays will harm the material.
"We can now predict how much light is needed to observe processes within cells, under optimum microscopy conditions, without crossing the threshold and destroying them."
And this may get biologists thinking about things in a different way.
"In the end, a little bit of light just might be enough to get the job done."
Below, the abstract of the Nature Communications article.
Absorption imaging of a single atom
Absorption imaging has played a key role in the advancement of science from van Leeuwenhoek's discovery of red blood cells to modern observations of dust clouds in stellar nebulas and Bose–Einstein condensates. Here we show the first absorption imaging of a single atom isolated in a vacuum. The optical properties of atoms are thoroughly understood, so a single atom is an ideal system for testing the limits of absorption imaging. A single atomic ion was confined in an RF Paul trap and the absorption imaged at near wavelength resolution with a phase Fresnel lens. The observed image contrast of 3.1 (3)% is the maximum theoretically allowed for the imaging resolution of our set-up. The absorption of photons by single atoms is of immediate interest for quantum information processing. Our results also point out new opportunities in imaging of light-sensitive samples both in the optical and X-ray regimes.
[via Alan Fick]
Old Soviet-Era Calculator
From a February 14, 2007 English Russia post featuring 72 old Soviet calculators.