The physics paper I’ve been working on for several years, Time & Quantum Mechanics, has been accepted for presentation at a plenary session of the 2018 meeting of the IARD — The International Association for Relativistic Dynamics. I’m very much looking forward to this: the paper should be a good fit to the IARD’s program.

#### Abstract:

In quantum mechanics the time dimension is treated as a parameter, while the three space dimensions are treated as observables. This assumption is both untested and inconsistent with relativity.

From dimensional analysis, we expect quantum effects along the time axis to be of order an attosecond. Such effects are not ruled out by current experiments. But they are large enough to be detected with current technology, if sufficiently specific predictions can be made.

To supply such we use path integrals. The only change required is to generalize the usual three dimensional paths to four. We treat the single particle case first, then extend to quantum electrodynamics.

We predict a large variety of testable effects. The principal effects are additional dispersion in time and full equivalence of the time/energy uncertainty principle to the space/momentum one. Additional effects include interference, diffraction, resonance in time, and so on.

Further the usual problems with ultraviolet divergences in QED disappear. We can recover them by letting the dispersion in time go to zero. As it does, the uncertainty in energy becomes infinite — and this in turn makes the loop integrals diverge. It appears it is precisely the assumption that quantum mechanics does not apply along the time dimension that creates the ultraviolet divergences.

The approach here has no free parameters; it is therefore falsifiable. As it treats time and space with complete symmetry and does not suffer from the ultraviolet divergences, it may provide a useful starting point for attacks on quantum gravity.

I’ve posted my talk on the Theory & Practice of Invisibility to ShareShare. I’ve given the talk at Balticon, FOSSCON, & Capclave, & will be giving it at Philcon in a few weeks.

At Capclave, NASA asked if I would give it at their Goddard Space Center, once the sequester is lifted. Nice to be asked!

Balticon records the talks in the science track, so at some point a video record should be online. The last page on SlideShare has the references; I’d start there.

I’m not really sure why I decided to do invisibility for Balticon; Miriam Kelly, who organizes the science track at Balticon, asked me what I was going to talk about this year, & the next morning I woke up knowing the title. Then there was the awkward few weeks while I tried to attach a talk to the title.

It’s a great subject; the main problem was really to throw enough out that the rest would fit into a 50 minute hour. Seemed to go OK, lots of questions during the talk & afterwards in the halls. That’s the real test.

One thing I like about the subject is that it leads in so many directions, among which:

- It’s about the math. One of the limiting factors is just getting enough control over the mathematics of bending light to create the appropriate cloaking effect. Any subject that borrows math from general relativity in the interests of simplifying itself is complex!
- It’s about the money. The more money, the more transparency! In general, you can make things invisible from specific angles, over specific frequency ranges, to a certain level of quality.
- It’s
*not* about the media: the general approaches for making something invisible are the same for visible light, for radar, for sound waves. One application under discussion is to make cities invisible from earthquakes: arrange for the seismic shocks to pass around the city for instance.
- The hype to results ratio is still pretty high. This is normal when an area is just starting; longer term, the most important uses are likely to be ones we haven’t even dreamt of.
- Making things invisible & making them visible are two sides of the same coin, like attack & defense in war, to master either we must master both.
- And, finally, while the future of invisibility may not be clear, our motives in studying it are transparent: it’s interesting, potentially profitable, and fun.