[PhilPhys] Warsaw Spacetime Colloquium: Samuel C. Fletcher (25 March on Zoom)

[Antonio Vassallo]

(With apologies for cross-posting)

On Friday, 25 March, Samuel C. Fletcher (University of Minnesota, Twin
Cities) will give a talk titled "What Gravitational Waves Really Teach Us
about Energy" (abstract below).

The meeting will be online on Zoom (17:00-19:00 CET). If you have not
registered yet, you can do so here <https://forms.gle/qpb8vVjtrF4y2nZ76>.

The Colloquium is organized by the Philosophy of Physics Group at the
Faculty of Administration and Social Sciences, Warsaw University of
Technology. The program for this semester is here
<https://ssqg.ans.pw.edu.pl/en/index.php/warsaw-spacetime-colloquium-2021-2022-online/>.
The videos of the previous meetings are available on YouTube
<https://www.youtube.com/playlist?list=PLM-1yNCyvJJC0KUgEqXTsFA38luoSiqXo>.

You can address any inquiry to antonio.vassallo at pw.edu.pl.

ABSTRACT
Gravitational wave solutions to the Einstein field equation of general
relativity are commonly regarded as examples proving how gravity in general
relativity transmits energy from a source body to a distant body. The
famous 1955 Feynman sticky bead thought experiment illustrates the reality
of this phenomenon by imagining two beads generating heat in a rod on which
they slide with friction, due to their changing proper distance in the
presence of the waves. I argue that while this lesson is not entirely
wrong, it is much too simplistic. It does not reconcile its conclusion with
the fact that conservation of local energy-momentum, in the sense that
appears in the field equation, prevents energy transmission across a
vacuum. Thus “energy transmission” must employ a different concept of
energy, raising the possibility of pluralism with regard to the energy
concept. Another (compatible) possibility is that gravitational waves,
rather than transmitting energy, facilitate the transformation between
different types or stores of energy locally. Key to these possibilities is
analysis of the Weyl tensor. Time permitting, I discuss these
possibilities’ implications for a re-evaluation of the scope of Mach’s
Principle, the idea that the distribution of matter determines the geometry
of spacetime.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://listbox.elte.hu/mailman/private/philphys/attachments/20220321/7a581c73/attachment.html>