Category: Science Fiction

“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?

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

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:

Fri 10:00 PM in Crystal Ballroom Two (1 hour)
AUGMENTED REALITY
[Panelists: John Ashmead (mod), Earl Bennett, Rock Robertson, Bud Sparhawk]
We’ve all heard about virtual reality and the potential it holds for gaming, learning, medicine etc., but augmented reality, while less well-known, is more likely to have a major effect on everyday life. Imagine wearing a pair of glasses while driving that produce flashing arrows to indicate your turns, or looking at a city street through your cell phone screen and seeing each building labeled by name and type of business. Learn what’s happening now and what we can expect in the future.
Sat 11:00 AM in Plaza VII (Seven) (1 hour)
DOES TIME TRAVEL ALLOW FOR FREE WILL?
[Panelists: John Ashmead (mod), Michael F. Flynn, John Grant, Helen Collins, Lawrence Kramer]
Suppose that  three weeks in the future I come back and sit on this panel,does this not imply that nothing can happen in the future toprevent me from getting in a time machine and coming back? Does this mean that time travel implies that the future is pre-determined?
Sat 12:00 PM in Crystal Ballroom Two (1 hour)
YE CANNA CHANGE THE LAWS O’ PHYSICS! OR CAN YOU?
[Panelists: Paul Halpern (mod), John Ashmead, Jay Wile, Tony Rothman]
Are the laws of nature really the same across all space and time? No principal is more fundamental to physics than the idea that the laws of nature remain the same at all times and in all places. Much we believe to be true about the universe depends upon this concept. However, new observations have revealed anomalies that suggest that such physical laws as the fine structure constant and the speed of light may actually have changed over time. Will we soon have to rethink our ideas about physics and cosmology
Sat 2:00 PM in Crystal Ballroom Two (1 hour)
IS THE UNIVERSE A HOLOGRAM?
[Panelists: Paul Halpern (mod), John Ashmead, Jay Wile, Tony Rothman]
Is the universe a hologram? One of the strangest ideas to come out of modern physics is the holographic principal, which speculates that the universe may be a multi-dimensional projection of information encoded (in Planck length-sized  squares, each containing one bit of information) on a two-dimensional boundary called the cosmological horizon. A new experiment searching for gravity waves may have accidentally found evidence for this theory that was predicted by supporters.
Sat 3:00 PM in Crystal Ballroom Two (1 hour)
THE PHYSICS OF PARADOX
[Panelists: John Ashmead (mod)]
There is nothing in modern physics to rule out time travel, save paradox.  And — thanks to quantum mechanics — it seems any potential paradoxes would be self-canceling.  Therefore the only thing standing between us and time travel is not knowing how to go about it, exactly.  But several recent papers have proposed ways to use the Large Hadron Collider at CERN to create particle loops that
go backwards in time.  Now what?
Sat 5:00 PM in Crystal Ballroom Two (1 hour)
WHAT CAME BEFORE THE BIG BANG?
[Panelists: John Ashmead (mod), Paul Halpern, Eric Kotani, Tony Rothman]
Was there a time before the beginning? As incredible as it seems, new discoveries have given scientists clues about what may have existed prior to the beginning of our universe. Scientists at the University of Pennsylvania have developed a mathematical model that traces through the Big Bang to a shrinking universe that exhibits physics similar to ours. Measurements of the Cosmic Microwave
Background radiation reveal an imprint from the earliest stages of the universe may also shed light on what came before. The following links are offered as jumping off points to potential panelists who would like to investigate this topic:

The Physics of Paradox — Followup

Gave the Physics of Paradox talk at the Library of Congress Thursday (10/21/2010) & then again at Capclave Saturday (10/23/2010).   Good audiences both times, lots of good questions.  At Capclave talk was standing room only & Brent Warner, from the Goddard Space Center has asked if I would be interested in doing it there this spring.

I made some changes to the talk over the weekend, in response to audience feedback & further reflection.  The latest version is now up as Keynote (for Mac users), PowerPoint (for PC users), PDF in slides-only and also annotated forms.

I’d like to thank Dick Ladson, Walt Mankowski, Bruce Bloom, Shelley Handen, Ed & Marguerite Rutkowski, & of course Ferne Welch for their feedback at the dry run, which improved it immensely.  And I would like to thank Nathan Evans of the Library of Congress & Colleen Cahill of Capclave (& as it happens the Library of Congress) for having me.  Lots of fun!

Physics of Paradox

This talk — scheduled for the Library of Congress & for Capclave next week — is now up.

It was a lot of fun to put together:  I discuss time in relativity & quantum mechanics, kinds of time, some possible time machines, the three kinds of paradox (grandfather, bootstrap, & freewill), the Hawking & Novikov consistency conditions for avoiding paradox, some ways to implement those conditions, paradox noise, what the world might look like if paradox avoiding time travel were possible, and of course why this is likely.

I’ve got the talk on line as Keynote (for Mac users), PowerPoint (for PC users), PDF in slides-only and also annotated forms.

I’m doing a practice run on the talk in two days at the Radnor Memorial Library in the Winsor room from 6pm to 8pm (when we have to be out).  I start the actual talk about 6:30pm.  This is a dry run (well more of a wet run really) for the talks next week.

If you are not too far from Wayne, PA & have an interest in time & paradox (but then if not why are you reading these words?) please feel free to come!

Paradox Noise

saberhagen - after the fact “YOUR ONLY CHANCE LIES IN PREVENTING THE ASSASSINATION OF PRESIDENT ABRAHAM LINCOLN . . .”

“What?”

A burst of audio and visual static reduced reception to unintelligible noise. Then the paradox-generated interference was gone again, as suddenly as it had come.

” . . . Fourteenth of April at Ford’s Theater –” blast, crackle.

“. . . you must be within two meters of the President . . . just before the bullet smashes into Lincoln’s brain. Your total window of opportunity will be three seconds.”

– Fred Saberhagen’s After the Fact


If the block universe view is correct, if time is “nothing but” a space dimension, then we should be able to travel in it. Leaving aside the fact that we don’t quite yet know how to do this (but see some of the books under references) shouldn’t time travel be forbidden by the paradoxes it would otherwise make inevitable?  There are three kinds of paradox to consider:

Three kinds of paradox

Grandfather paradox

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.

– 1933 letter to Astounding Stories, as quoted in Nahin’s Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction

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Five Popular Talks

Over the last ten or fifteen years I’ve done a number of slide talks at Balticon, Philcon, & Farpoint, three local science fiction conventions. A number of these have been relatively heavy on the physics – within the context of a science fiction convention of course – and I thought it might be fun to post them. As Rod Sterling might have put it, presented for your consideration:
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