Potpourri:- Gravity

Interesting physics explained with many thought experiments and little math.
User avatar
SsDd
Science Officer
Posts: 113
Joined: Sat Dec 05, 2009 1:06 am
AKA: Abhi
Location: Michigan Tech

Potpourri:- Gravity

Post by SsDd » Tue Dec 07, 2010 7:07 am

The lecture video is embedded below.

Additionally, slides used in the lecture are embedded below, or can also be downloaded directly from here.

Questions after the lecture? Please feel free to post them in the same thread.

Click to play embedded YouTube video.



*********************************************************************************************

dougettinger
Curious Querier
Posts: 632
Joined: Wed Mar 17, 2010 5:55 pm
Location: Pittsburgh, PA

Re: Potpourri:- Gravity

Post by dougettinger » Wed Feb 09, 2011 5:46 pm

In referring to "Frame Dragging" an analogy of a rotating bucket of water was used to compare frame dragging of the universe and other large scale objects. It was suggested that the rotating bucket analogy can demonstate how jets may be emitted from active galaxies. I would also posssibly add jets being emitted from forming proto-stars. Mechanically how are these jets created ?

Doug Ettinger, Pittsburgh, PA 02/09/2011
Doug Ettinger
Pittsburgh, PA

User avatar
Chris Peterson
Abominable Snowman
Posts: 18529
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: Potpourri:- Gravity

Post by Chris Peterson » Wed Feb 09, 2011 6:24 pm

dougettinger wrote:In referring to "Frame Dragging" an analogy of a rotating bucket of water was used to compare frame dragging of the universe and other large scale objects. It was suggested that the rotating bucket analogy can demonstate how jets may be emitted from active galaxies. I would also posssibly add jets being emitted from forming proto-stars. Mechanically how are these jets created?
Jets are presumably caused by magnetic fields being twisted by rapidly rotating objects- supermassive black holes in AGNs, ordinary black holes with accretion discs, and protostars.

The bucket analogy is useful in all these cases, as it is in discussing frame dragging. But just because the same analogy works, don't mistake the two processes. The formation of jets is largely unrelated to frame dragging.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

dougettinger
Curious Querier
Posts: 632
Joined: Wed Mar 17, 2010 5:55 pm
Location: Pittsburgh, PA

Re: Potpourri:- Gravity

Post by dougettinger » Wed Feb 09, 2011 7:32 pm

Chris Peterson wrote:
dougettinger wrote:In referring to "Frame Dragging" an analogy of a rotating bucket of water was used to compare frame dragging of the universe and other large scale objects. It was suggested that the rotating bucket analogy can demonstate how jets may be emitted from active galaxies. I would also posssibly add jets being emitted from forming proto-stars. Mechanically how are these jets created?
Jets are presumably caused by magnetic fields being twisted by rapidly rotating objects- supermassive black holes in AGNs, ordinary black holes with accretion discs, and protostars.

The bucket analogy is useful in all these cases, as it is in discussing frame dragging. But just because the same analogy works, don't mistake the two processes. The formation of jets is largely unrelated to frame dragging.
The lecture for whatever reason connected the bucket analogy to jets emitting from active galaxies.

My idea of proto-star jets is that the incoming, rapidly rotating charged fermions create a very strong electromagnet like a huge solenoid coil. One dipole begins to favor one type of charge and the opposite pole then assumes collecting the oppositely charged fermions. Magnetic lines of force are created between the two poles that also intersect the perimeters of the protostar disk. Of course, then an electric circuit is created to aid the inward movement of charged fermions from the proto-star disk similar to Faraday's disk generator. The gravitational forces due to the density gradients are also performing their function, too.

As the electrons begin to follow and rotate around the magnetic lines of force outward from the poles they are accelerated to very high speeds; a stronger and stronger feedback is created whereby the rotating electrons (around magnetic lines of force or flux) form jets either from gravitomagnetism and/or gravity radiation. The angular momentum of the fermions is partially transferred to translational energy to form bi-polar jets or Herbig-Haro objects. Do these thoughts make any sense to you ?

Doug Ettinger, Pittsburgh, PA 02/09/2011
Doug Ettinger
Pittsburgh, PA