Not Your Grandfather’s Gravity – 3rd time is the charm

I did this talk — basically interesting developments in gravity & related subjects — for the third time at Philcon this last Saturday.  The talk was scheduled for 1pm, so I spent a few hours in the morning refreshing it.

The big news was that the OPERA project had done a second version of the experiment that saw superluminal neutrinos, dealing with some of the objections (objectinos?) to their first results.  They sacrificed quantity of neutrinos to quality:  going from 16,000 to 20, but getting much tighter time resolution.   This made the New York Times Saturday morning, so I clipped the headline for use in a slide.  Good stuff, but of course everyone wants to see Fermilab & others reproduce the experimental results.

However the combination of refreshing the talk, roadwork on Interstate 76, & a parade or some such on the Benjamin Franklin Parkway meant I got in with no time to check the AV setup before the talk.  While the impromptu AV crew wrastled the difficulties into submission (thanks Margaret Trebling, Jay Wile, Ron Bushyager, & Ferne Welch!) I invited the audience to “open the theater of your mind” & painted word pictures thereon till the AV was working.  Didn’t take the crew long:  we hadn’t even gotten past the Black Death slide before we had light!  Actually I think the difficulties may have helped the talk go over; shared troubles create bonding between speaker & audience.  Lots of good questions; SRO crowd.

As I promised then, I have posted the talk as Keynote, PDF, PowerPoint, & HTML.  Comments, questions, and suggestions very welcome!

Had a lot of fun on the six panels I was on; will post on them over the next few days.

11/23/2011 I’ve just updated the references page to include the references from the talk.

“Not Your Grandfather’s Gravity” at the Philadelphia SF Convention

I’ll be doing my Not Your Grandfather’s Gravity talk this coming Saturday at Philcon at 1pm.   I’ve been scheduled for six panels as well, five as moderator.  These are on Fiction of China Mieville, Alien Life in the Solar System (besides us), Future War, Tapping the Quantum Foam (entertaining nonsense:  crank up the balonium generators), What Makes H. P. Lovecraft Unstoppable (ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn), and Dark Matter gets Darker.

Full schedule:

Fri 8:00 PM in Plaza V (Five) (1 hour)
THE FICTION OF CHINA MIEVILLE (771)

   [Panelists: John Ashmead (mod), Meredith Schwartz, Andrew C. Murphy]

   Exploring the work of the popular author of Perdido Street Station
   and others.  What makes his work so special

Sat 12:00 PM in Crystal Ballroom Two (1 hour)
ALIEN LIFE IN THE SOLAR SYSTEM (848)

   [Panelists: John Ashmead (mod), Alexis Gilliland, Eric Kotani]

   Making up planets around stars we do not know is relatively easy.
   Let's talk about a more difficult approach... imagining alien
   lifeforms in the solar system as we now know it

Sat 1:00 PM in Plaza III (Three) (1 hour)
NOT YOUR GRANDFATHER'S GRAVITY (890)

   [Speaker: John Ashmead]

   Einstein's theory of gravity is our best to date -- even though it
   is known to be incomplete. Now it is in the crosshairs! Several
   competitors -- string theory, loop quantum gravity, emergent gravity
   -- have come out in the open & it's a horse race! We'll look at
   weird twists of space & time, dark energy, neutrinos just spotted
   going faster than light, the curiously shy Higgs particle, & the
   whole universe from its birth in the Big Bang to its death -- &
   possible rebirth

Sat 7:00 PM in Plaza II (Two) (1 hour)
FUTURE WAR (748)

   [Panelists: Alexis Gilliland (mod), John Ashmead, Amy Bailey, Frank
   O'Brien]

   It's commonly said among Air Force officers today that the last
   human fighter pilots have been born. Drones and remotely-piloted
   planes are the future of air warfare. What about the other branches
   of the armed forces? Robots are filling more and more roles. Will
   there come a point where there are few or no human soldiers? What
   are the implications? Is this a good or bad development

Sat 8:00 PM in Plaza V (Five) (1 hour)
TAPPING THE QUANTUM FOAM: CAN "ZERO POINT" ENERGY EVER BE REAL? (902)

   [Panelists: John Ashmead (mod), Jay Wile, Marvin Kaye]

   Infinite free energy drawn from the quantum vacuum - con games and
   pseudoscience today. But does our present understanding of quantum
   physics suggest it could ever become reality? Would the process pose
   any dangers

Sat 10:00 PM in Plaza III (Three) (1 hour)
WHAT MAKES H.P. LOVECRAFT UNSTOPPABLE? (826)

   [Panelists: John Ashmead (mod), James Chambers, Chris Pisano,
   Darrell Schweitzer, Eric Avedissian, Roman Ranieri]

   Great writers, we contend, are the ones the critics cannot stop.
   Major critics, notably Edmund Wilson, tried, but to no avail. Today
   Lovecraft is famous world-wide.  Yet when he died in 1937, his only
   published book was a wretchedly amateur production which had barely
   sold a hundred copies.  What made the difference?  Was it all those
   role-playing games and plish Cthulhu toys? The movies? Or something
   inherent in the texts

Sun 1:00 PM in Plaza V (Five) (1 hour)
DARK MATTER GETS DARKER: NEW DISCOVERIES, NEW MYSTERIES (904)

   [Panelists: John Ashmead (mod), Paul Halpern, Jay Wile, Eric Kotani]

   Dark matter detection experiment CoGeNT has seen a possible signal,
   similar to the much-disputed DAMA/LIBRA result, that might confirm
   the controversial claim that dark matter has not only been observed,
   but that it varies with the seasons. Meanwhile the XENON100 detector
   has just released results from its most recent rum: they don’t see
   anything. 

   Are we closing in on dark matter, or is it getting more mysterious?

Not your grandfather’s gravity redux at Capclave

I’m doing “Not Your Grandfather’s Gravity” this evening at Capclave:  had to revise a lot:  added in the superluminal neutrinos from the OPERA project, the curious incident of the Higgs particle detection, and the Nobel just given out for Dark Energy:  half the slides changed!  PDF, HTML.

I’m also doing panels on Hard SF & Alien Cultures, Making Fictional Cities Come Alive (when real ones do, run!), and Astronomy & Science Fiction.  If you are in the DC area, I look forward to seeing you.

Not your grandfather’s gravity

Talk tomorrow at the Baltimore Science Fiction Convention:

Several possible modifications to Einstein’s theory have been proposed & may even have some experimental support; in addition to string theory & loop quantum gravity, is gravity a thermodynamic effect? Astronomers are looking hard at gravity waves in search of clues as to the origin of the universe (or even as to whether the universe had an origin), and …!

I’ve just finished the talk — main problem, too many interesting possible side channels — and have uploaded it as pdf,  keynote, power point, & html.  Comments welcome!

Temporal Paradoxes Talk Done: World Safe for Grandfathers

Had a very good time at NASA’s Goddard Space Center doing my talk Temporal Paradoxes.  Nice crowd; lots of good questions.  NASA’s audio-visual support was first rate, as you would expect, and the talk should be up on their site in a bit.  I’ll post a link here when that happens.

I’d like to thank Brent Warner & his colleagues for their warm welcome & all the feedback during the talk.  Brent tells me he particularly liked the quote from an Astounding Science Fiction reader (1933):

“Why pick on grandfather? It seems that the only way to prove that time travel is impossible is to cite a case of killing one’s own grandfather. This incessant murdering of harmless ancestors must stop. Let’s see some wide-awake fan make up some other method of disproving the theory”*

As I say in the talk, if the current literature is on target, the grandfather & other paradoxes are cancelled out by interference by the time machine’s wave function with itself.

Brent & his NASA colleagues were kind enough to provide lunch & a fascinating tool of the facilities:  they manage the Hubble & are working on the James Webb.  Huge rooms with vast devices for subjecting equipment to high G’s, vacuum, heat, noise, vibration, & every other insult that it will need to be able to withstand during launch or in space:  gives one a real sense of just how hard it is to get this stuff to work!

*as quoted by Paul Nahin in his Time Machines: time travel in physics, metaphysics, and science fiction

Temporal Paradoxes Talk Online

I had a lot of fun putting my NASA talk Temporal Paradoxes together.  The feedback I got from the assembled multitude at the Radnor Library last week was extremely helpful, leading to a near complete rework of the talk, in the interests of making it clearer.   Thanks!

The pdf & keynote versions are now online.

Practice Run Thru on Temporal Paradox Talk

I’m doing a practice run thru on my Temporal Paradoxes talk at NASA.

The run thru will be at the Winsor room at the Radnor Memorial Library on March 12 at 2pm.  This is a few hundred feet from the main intersection in Wayne, PA.

The talk is basically the Physics Of Paradox talk, but more focused on the physics than the science fiction (tho in this area it can be hard to tell them apart) & with animations.

Since this is a complete redo of the talk, I’m hoping to get feedback on timing & clarity & focus & such like!

Please come!  And criticize!

Thanks!

— John Ashmead

Temporal Paradoxes Talk at NASA

I’ve been asked to do a talk, Temporal Paradoxes, at NASA.  This will be on the 21st of this month, at 3:30pm.  This is a NASA-fied version of my previous Physics of Paradox talk, meaning more animations & less science fiction, and perhaps a few equations in a grayish font.  Abstract:

ABSTRACT — Einstein’s general relativity is the leading theory of gravity. Simple and elegant, it has passed all available experimental tests including: deflection of light by gravity, precession of orbital apsides, gravitational time dilation (used in GPS), and frame-dragging.

However, general relativity makes a number of counter-intuitive predictions. In particular, trajectories looping around massive, rapidly rotating stars or passing through a wormhole can close on themselves in time, creating closed timelike curves (CTCs).

This creates the possibility of “grandfather” and “bootstrap” paradoxes. Recent work by Greenberger & Svozil, and others, however, questions this conclusion. That work suggests that when quantum mechanical effects are included, the paradoxes become self-canceling, eliminated by destructive interference within the wave function. If the paradoxes are self-canceling, then closed time-like curves are possible. If they are possible, can we create or detect them?

Several authors have suggested that we look for evanescent wormholes with the Large Hadron Collider. If we find them, we may be at the edge of temporal paradox. While the only safe prediction in this area is that there are no safe predictions, we look at the implications of this for general relativity, quantum mechanics, & causality.

Reality versus free will, escaping the Holodeck, are the laws of physics “more guidelines than rules”?, and more!

I’m doing five panels and my Physics of Paradox talk at the Philadelphia Science Fiction Convention, starting in a few hours.

Quite a lot of fun subjects for my panels:  Augmented Reality (for those who can’t get enough reality), Time Travel & Free Will, Are the Laws of Physics Laws (or really more just Guidelines?), Is the Universe a Hologram (& can I leave the Holodeck?), my Physics of Paradox talk in its final & perfected version, & What Came Before the Big Bang (& are we in trouble with whatever it is?)

[I’ve augmented the reality of the Physics of Paradox slides by adding the spoken text to them:  see the Keynote (for Mac users), PowerPoint (for PC users), and  annotated pdf version.]

My complete schedule is:

The Physics of Paradox — Followup