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Time dispersion in Quantum Electrodynamics

Experimental test of quantum electrodynamics

I gave a talk in June at the IARD 2022 conference in Prague on “Time dispersion in Quantum Electrodynamics”. I can’t improve on the abstract so give it here:

Quantum electrodynamics (QED) is often formulated in a way that appears fully relativistic. However since QED treats the three space dimensions as observables but time as a classical parameter, it is only partially relativistic. For instance, in the path integral formulation, the sum over paths includes paths that vary in space but not paths that vary in time. We apply covariance to extend QED to include time on the same basis as space. This implies dispersion in time, entanglement in time, full equivalence of the Heisenberg uncertainty principle (HUP) in time to the HUP in space, and so on. In the long time limit we recover standard QED. Further, entanglement in time has the welcome side effect of eliminating the ultraviolet divergences. We should see the effects at scales of attoseconds. With recent developments in attosecond physics and in quantum computing, these effects should now be visible. The results are therefore falsifiable. Since the promotion of time to an operator is done by a straightforward application of agreed and tested principles of quantum mechanics and relativity, falsification will have implications for those principles. Confirmation will have implications for attosecond physics, quantum computing and communications, and quantum gravity.

I’ve written the talk up as a paper and submitted to the IARD’s Conference Proceedings, where it is undergoing peer review. I’ve also submitted it to the physics archive, so Time dispersion in quantum electrodynamics is generally available.

It’s a long paper, 95 pages, but in defense of that it is a large subject. A quick check on bookfinder.com showed over 1000 textbooks on QED — and at 3 centimeters a book (based on my personal library) the literature — just the textbooks — runs over 30 meters! The problem I had was how to extend QED in time without breaking it. QED has, after all, been confirmed to extraordinary precision: is there room for time within QED?

The basic trick was to write the extension as the standard theory times a “time correction”. So if the time correction is small enough, we won’t have seen it by accident. Since the time corrections will normally be about an attosecond in size (an attosecond is to a second as a second is to the age of the universe), that’s not hard to show.

The other trick is to show that there are cases where we could see the effects of these “time corrections”. Since we can now see stuff at the attosecond level — provided we know where to look — that’s OK as well.

The illustration at the top of this post is a proposed test of the Heisenberg Uncertainty Principle in time, which is particularly nice because in this case the effect can be made — in principle at least — as large as we like. But there are lots of other possibilities:

“With respect to the falsifiability of TQM [time correction to QED], the small size of the basic effect may be compensated for by the large number of experimental possibilities. If quantum mechanics should in fact be extended in the time direction then essentially any time dependent apparatus with time dependent detectors may provide a possible line of attack. By hypothesis, all quantum mechanical phenomena seen in space – interference, diffraction, uncertainty, entanglement, tunneling, … – apply in time as they do in space. 

But what are the odds of this being true? I give five reasons (explained in detail in the text):

  1. We have a version of QED which is manifestly covariant, treating all four dimensions equally. Simply being able to do this is interesting.
  2. We have a clear explanation of why time normally appears asymmetric at the level of the observer (due to statistical effects at the scale of Avogadro’s number) while still at the particle level being completely symmetric.
  3. We have a treatment which goes smoothly from the single to the multiple particle cases.
  4. We do not see the ultra-violet divergences. We still have to normalize the loops, but we no longer have to regularize them: that drops out of the formalism.
  5. And we have Gell-Mann’s principle: what is not forbidden is compulsory. If there is not a conservation principle or symmetry rule forbidding dispersion in time, it would be surprising not to see dispersion in time.

And if QED really should extend in time, there may be some significant uses:

High speed chemical and biological interactions, i.e. attosecond scale, should show effects of time dispersion. For instance, if molecules can sense into the future, it may affect their ability to find optimal configurations. There are potential applications for quantum communication and quantum computing. With TQM we have an additional channel to use for calculation/communication but also an additional channel to act as a source of decoherence.The implications for quantum gravity are particularly interesting: with manifest covariance, elimination of the ultra-violet divergences, some recent work by Horwitz, and earlier work by Verlinde, we appear to have all the pieces needed to construct a complete, covariant, and convergent theory of quantum gravity. Leaving the question of the odds of this being correct to one side, we note that recent advances in technique mean such a theory has a reasonable chance of being falsifiable as well. 

My personal favorite effect is the possiblity of tunneling in time. The posited symmetry between time and space forces this, but does it mean?

Debugging with PostgreSQL – A Strategic Approach

The PostgreSQL Elephant attacks a bug
Debugging with PostgreSQL – A Strategic Approach

The Philly PostgreSQL Meetup is holding an all day conference at the Wharton School in Philadelphia, July 19th, 2019. I will be giving my talk Debugging with PostgreSQL – A Strategic Approach at 11am.

Description:

Depending on the project, debugging can take 50 to 90% of development time. But it usually gets less than 10% of the press. PostgreSQL has great tools for debugging, but they are most effective when deployed as part of an overall strategy.

We will look at strategies for debugging PostgreSQL: how to find bugs, how to fix them, and how to keep them from happening in the first place.

We’ll look at root causes, technical tricks, and scientific strategies, and why — even if you can’t always write perfect code — it is usually a good idea to try.

We’ll hear from Bjarne Stroustrup, Sherlock Holmes, Kernighan and Ritchie, Pogo, & the experts of the PostgreSQL community.

Goal: less time debugging, more time building great tools and apps that stay up & get the job done.

Comments:

I’ll be doing this talk at FOSSCON 2019 as well. That will be Saturday August 17th, 2019.

While I’ve definitely built this for PostgreSQL, it turns out that most of the debugging advice is applicable not just to PostgreSQL but to database in general, and not just to databases, but to most programming langauges.

Mars or Bust at Philly Linux

I gave my “Mars or Bust” talk at PLUG North (Philly Linux Users Group/North) on January 1/8/2019. Great audience; lots of good questions. They captured video of the event & have posted to Google Photos. Presented, as the late great Rod Sterling would put it, for your consideration: Mars or Bust.

Recent Time Travel References

At the Worldcon 2018 I had a very interesting conversation with Rafaela Yilun Fan, who is pursuing a Ph. D in Time Travel! She asked me for a list of my own favorite references on time travel. I have my list from 2011 of course. But time travel waits for no traveler, and the list of interesting works has only gotten longer. Herewith a few of my favorites from the last few years:

Alan Burdock. Why Time Flies: A mostly scientific investigation. 2017. physics, psychology, et cetera of time.

Craig Callender. What makes time special? 2017. Unusually deep examination of what we mean by time.

Allen Everett and Thomas Roman. Time travel and warp drives: A scientific guide to shortcuts through time and space. 2012. Title says it all.

Matthew Jones and Joan Ormrod. Time Travel in Popular Media: Essays on Film, Television, Literature, and Video Games. 2015. Interesting collection of essays. Has a section on Asian Time Travel Films & Television Series.

Paul J. Nahin. Time Travel Tales: The Science Fiction Adventures and Philosophical Puzzles of Time Travel. 2017. Usual first rate work by Nahin.

Fraser A. Sherman. Now and Then We Time Travel. 2017. Very good coverage of film & television. Recommends Aetherco, Epguides, and Wikipedia. All good sources as well.

Ryan Wasserman. Paradoxes of Time Travel. 2018. Good review of various paradoxes from a philosophical point of view.

David Wittenberg. Time travel: the popular philosophy of narrative. 2013. My favorite as an explanation of what the function of time travel is, from a narrative point of view. Why do authors use time travel?

Time to the Power of Tim

Three Time Travel Tales by Tim Powers

Three Time Travel Tales by Tim Powers

This year the guest of honor at Capclave was Tim Powers. (Capclave is the Washington DC Science Fiction convention.) Tim is not only the author of many fine science fiction novels, but a very nice guy.

This turned out to be a good thing, as the initial proposal was to have Tim & I appear together and do something physic-y about his novels.  I have never done a talk with a live author before (dead authors are no problem, I have that down cold), so I was a bit nervous about the whole thing.

But it worked out well:  Tim was very helpful & gracious and when the audience asked him if one of my theories about the time travel in his novel The Anubis Gates was correct he said, essentially, “Now it is.” 🙂

I focused on three of his novels, The Anubis Gates — his first big success (with romantic poets & time-traveling Jackel Gods), Three Days to Never — something like the bastard child of John Le Carre & H. P. Lovecraft, and Medusa’s Web — who can resist the Time Spyders?

One of the distinctive features of Tim Powers working method is that he starts with a place and a time, researches it looking for the curious facts, bizarre details, & strange omissions that point to an unknown but dark reality, then gradually teases out the true story of whatreallyhappened!

“I made it an ironclad rule that I could not change or disregard any of the recorded facts, nor rearrange any days of the calendar – and then I tried to figure out what momentous but unrecorded fact could explain them all.”

So Tim builds his novels from the bottom up. As a result, they tend to differ wildly from each other.  Other authors, once they have got a setting that works, tend to reuse it, Tim builds anew each time.  No ten volume trilogies here!

And he also works out the timelines of all of his critical characters.  At each moment, he knows where each of his on and off stage characters are & what they are up to.  His notes on this are a kind of secret history of the secret history!

He has 20 or more novels out, so I focused on just three, all involving time travel.  And in each the theory of time travel was radically different!  I had a lot of fun linking each up to the corresponding physics and going back & forth about all this with my stage-mate Tim. 🙂

The talk, minus alas, the actual talking, is now up on slideshare.  Download if you will & any questions/comments please let me know!  thanks!

 

 

Stargates: The Theory & Practice

Doors and Portals and Stargates, Oh My!

Call them Stargates, Jumpgates, Fargates, Hypertubes or just an invitation to every unwanted pest from the far reaches of the Galaxy to visit, they are absolutely necessary if we are to have the glorious Science Fiction action we desperately need.  But could they actually be built?  We look at what modern physics has to say:  how to glue black holes together to build a wormhole, how to avoid the dangers of spaghettification, radiation poisoning, and paradox noise, and just what it would take to build one in practice.

This was a talk I did at the last Philcon, went over well.  And I had a lot of fun doing it.  I’ve got it up as a talk on slideshare.  And I may do variations on this at the 2017 Balticon & also Capclave.

It is the kind of subject you can go anywhere with!

 

Deadline Necronomicon: Tales from Miskatonic Library now open till 8/23/2015

Today is the official deadline for unsolicited submissions for the Tales from the Miskatonic Library.

However Darrell & I have decided to push the deadline back to 8/23, the end of Necronomicon, the Providence convention for all things Lovecraftian.  Darrell & I will both be there, and this will give us a chance to meet some of you in person.

And the mss are still flooding in!  So we want to make sure we have a chance to see everything that’s out there before making the final cut.

One question I’ve gotten a lot:  is there a maximum length?

Well we are only paying 3 cents a word, capped at $100, so that’s about 3333 words.  But all that means is if you go over, the payment is capped, we will still look at the story.

Really the best length is determined by the story itself. As Lincoln said once, a man’s legs should reach just far enough to get to the ground, more than that is a waste of leg.  Same for stories:  if they are good, they have a natural length of their own.

If you start when things are just getting interesting and keep going till it is clear what the final shape of the narrative is, wasting no time between, the length will tend to be about right.  After you’ve cut the story first by a half.  And then — and this will hurt — squeezed out another 25% of what is left.

But stick to point of view, in a short story there isn’t much time for anything but what happens & then what our hero or heroine did about that!

You’ve no time for backstory:  if our narrator has had a troubled past (& that is pretty likely in this case) it will show in how he or she responds to events, maybe a bit too fast to leap to conclusion X, a bit over sensitive to casual remark Y.  And if it doesn’t show in his or her responses, why does it matter?  Leave history to the historians!

And you have no time for fore-shadowing, for what is to come, it will be here soon enough, why trouble the already anxious reader?  There is only time to show what is happening now!

And in fact things are happening so quickly in your narrative — there is so much now now! — that you can barely relay a fraction of them to your reader!  You’re like a tour guide where the boat, car, motorized book cart, flying carpet, night gaunt, is going so fast you can only report one or two of the most salient details — the eyes reflected off what had seemed a bit of waste paper, the curious omission in the alphabetized records for Z, the orchid giving a cheerful wave as you pass by — before the next incident commands attention.  Not so quickly that the reader loses the thread of course — and therein lies the art.

So by the grace of ye eds, another two weeks.  Spend the golden seconds wisely!  Write, read, revise, reread, rewrite, & submit!

Be reading you!

John Ashmead

PS.  And as what we are looking for, as earlier, three requirements:

  1. Good story — pulls you in from first sentence.
  2. Gives you something to think about — leaves you going hmm after the last sentence.
  3. Fits into an anthology called Tales from the Miskatonic Library — without taking two pages of explanation by ye eds.

 

 

Unclassified Horrors

And speaking of Balticon, several Balticons back, I mentioned to my old friend Darrell Schweitzer (looks a bit like the Emperor Palpatine but is significantly less evil), that I had been thinking of a story about the Miskatonic University Library to be called Unclassified Horrors.

I have always been fascinated by Libraries in general & by the Miskatonic University Library in particular.  This is the place where the hero/victim of a Lovecraftian story will go to check out/steal/examine furtively an obscure but dangerous tome.  This is a particularly poor idea if you can’t break yourself of the habit of reading aloud.

See for instance the unfortunate consequences experienced by Evelyn Carnahan (“I … am a Librarian!”) in the 1999 film The Mummy.  She reads from the Book of the Dead.  Aloud.  And awakens the High Priest Imhotep, whom being buried alive for the last three thousand two hundred and thirteen years has not put in a good mood.  Difficulties ensue.  And the world is saved only by the pluck & luck of a few bold adventurers.

But I digress, something that happens to me a lot in libraries.  That is actually a design goal of libraries, think of them as an early form of the Intertubes, where when you go in you are planning to swot up on topic A and find yourself well among the Z’s or even On Beyond Zebra  before you know.  They deliberately arrange the cataloging systems so that interesting volumes will tend to be right next to target volumes.

What you think of as chance is in fact as so often a sinister plot:  the very scheme intended to create the illusion of order is meant to pull you in & leave you helpless & browsing on the floor when the final gong is rung & the library scraping machine comes by to scoop up the day’s victims.  As you slowly sort yourself out of the pile of your fellow victims at the back of the library, you may wonder how this happened — yet again!

It’s the fault of the Dewey Decimal System.

One of the innovations of the Dewey Decimal system was that of positioning books on the shelves in relation to other books on similar topics.

That’s the problem right there:  we are naturally associative thinkers; this well-intentioned positioning of topics near similar topics has the effect on the inquisitive mind of those elvish lights in Mirkwood that lure Bilbo & the dwarves into the spider’s lair (name World Wide Web a coincidence, I think not).

And if that were not suspect enough, consider the ninety one entries missing from the top nine-hundred and ninety-nine.  As Rex Libris, the Kick-Ass Librarian, put it:

Have you wondered why Section 217 is missing from the Dewey Decimal Classification System? …

Section 216, good and evil, is left just hanging there, with the obvious follow-up section completely, mysteriously AWOL.

Where did it go? Why is it missing? This question has plagued people for years.

Did Nietzsche have something to do with this? Are his attempts to go beyond good & evil, to explore Section 217, what led to his almost Lovecraftian madness?

And when I brought these & similar too-dangerous-to-commit-to-print questions up to Darrell he said — like all editor/writer/booksellers he can resist anything but a chance to make money —  ah, the perfect idea for an anthology.  And thus Tales from the Miskatonic University Library was born.  Surely if we present this as fiction, we will be safe from the attentions of the things that haunt the stacks.  But of this more in a subsequent post.

Now drops shoe the 3rd …

Give me the child. Through dangers untold and hardships unnumbered, I have fought my way here to the castle beyond the Goblin City to take back the child that you have stolen. For my will is as strong as yours, and my kingdom is as great…

Or, less poetically, I have (finally) finished checking the calculations in my dissertation.  The checked version is up & I hope to have it uploaded to the physics archive by the end of the weekend.

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