Crossfire Fusor

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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dnavas
Posts: 84
Joined: Sun Nov 11, 2007 3:59 am

A bit off-topic, but worth noting

Post by dnavas »

krenshala wrote:The problem with that is aberration which shows, for example, that the direction of the force of gravity from the sun always points directly* at the sun's calculated position in the sky and not its light-lagged visible position. The information I read indicated that if gravity is not instantaneous then it would have to be at least a thousand times faster than the speed of light in vacuum to match observations.

* or as directly as we are able to calculate, anyway.
http://math.ucr.edu/home/baez/physics/R ... speed.html

D Tibbets
Posts: 2775
Joined: Thu Jun 26, 2008 6:52 am

Re: A bit off-topic, but worth noting

Post by D Tibbets »

dnavas wrote:
krenshala wrote:The problem with that is aberration which shows, for example, that the direction of the force of gravity from the sun always points directly* at the sun's calculated position in the sky and not its light-lagged visible position. The information I read indicated that if gravity is not instantaneous then it would have to be at least a thousand times faster than the speed of light in vacuum to match observations.

* or as directly as we are able to calculate, anyway.
http://math.ucr.edu/home/baez/physics/R ... speed.html
My brain was itching when I was thinking about the apparent position of the Sun based on visual vs gravatational effects. I couldn't remember what it was till your reminder. I think what I had heard was something to do with Solar Eclipses. After doing a Google search, mostly I saw references to what happens if the Sun suddenly dissapears, till I found this site, which explains things well, just let me clear the mud off my glasses. I read parts briefly, enough to know that the answer about the speed of gravity is ... Uh...

The link:

http://www.gravitywarpdrive.com/Speed_of_Gravity.htm


Dan Tibbets
To error is human... and I'm very human.

alexjrgreen
Posts: 815
Joined: Thu Nov 13, 2008 4:03 pm
Location: UK

Post by alexjrgreen »

Aberration and the Fundamental Speed of Gravity in the Jovian Deflection Experiment
http://arxiv.org/PS_cache/astro-ph/pdf/ ... 1063v6.pdf
Ars artis est celare artem.

Aero
Posts: 1200
Joined: Mon Jun 30, 2008 4:36 am
Location: 92111

Post by Aero »

I found this article which describes the follow-up to the Breakthrough Physics Propulsion Project (BPPP).
http://www.centauri-dreams.org/?p=542&cpage=1

I like the quote:
“The challenge with the emerging technology, which builds on known physics, is the ‘incessant obsolescence postulate’. This states that no matter when an interstellar probe is launched, it will be passed by a more modern probe launched later. The question then isn’t so much ‘can we’ but what are the most important design factors to work toward: cheap, available now, quickest trip, size of payload, etc?
I figure others here might be interested.
Aero

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