Minutes of the 409th meeting
The 409th Meeting of the Altrincham and District Astronomical Society, held at Timperley Village Club on Friday 7th October 2005 at 8pm
Those present were:
Paul Clark, Kevin Thurstan, Tony Aremia,
Terry Bailey, Norman Thurstan, Geoff Flood,
Graham Sinagola, Peter Baugh, Mark Crossley,
Chris Suddick, Richard Bullock, Geoffrey Walton,
Nick Odom, Colin Bowler, Nick Dixon,
Ged Birbeck, Phil Masding, Stuart Oldbury, Roger Livermore, Mary Stewart, 1 other (Total 21)
The chairman Paul Clark opened the meeting by welcoming everyone to the meeting and announcing that tonight’s speaker would be Nick Odom, who would be delivering part two of his talk on “Relativity” this time focusing on general relativity following on from his previous talk on special relativity.
The Chairman also announced that Graham Sinagola had brought in a DVD of the transit of Venus on 8th June last year if anyone was interested in it.
Nick Odom then started his talk on general relativity by summarising some of the points of special relativity to help as background.
He stated that it took Einstein ten years from 1905 when he published his theory on special relativity before in 1915 he published his theory on general relativity. It was believed the laws of physics are the same irrespective of the speed of the observer and that the speed of light in a vacuum is constant. However Newton’s laws of gravity break down at high speed and Einstein wanted to reconcile relativity with gravity.
Nick then went on to explain in more detail, how the effects of gravity must travel at the same speed as light in gravitational waves, the fact that a man falling off a roof couldn’t feel gravity led Einstein to a flash of inspiration that gravity mimics acceleration, that gravity slows down time and time runs slower for an observer on the surface of the earth than it does for a spaceman in orbit, the higher the gravity is the slower time runs. Gravity also refracts light, distorts space and that the effect of gravity is greater in general relativity as opposed to Newton’s laws. We then heard about general relativity and black holes.
He finished off by explaining some of the observational conformation we have on general relativity including the perihelion of mercury, the displacement of star images during a solar eclipse, gravitational red shifting of Sirius b and radio astronomy observations of everything from the inner planets to binary pulsars and quasars.
The meeting then had a break for tea.
The Chairman Paul Clark then did a sky diary on the coming month concentrating mainly on the area around the constellation of Cygnus and mentioned how mars was going to be at its best over the next couple of months.
In any other business the Chairman reminded us that next months talk was to be by Andrew Greenwood from Macc AS on the subject of Mars.
The Secretary then reminded everyone that on the coming Friday, 14th October, the society had been invited again to Delamere Forest Park visitor Centre and would be providing several talks on astronomy, and that we still required speakers to help out, we need others to support the occasion with their presence or turning up with scopes to put on display and maybe even use if the sky was clear.
Richard Bullock offered his services and said he would be able to do a talk on the moon.
The meeting was then brought to a close.
Those present were:
Paul Clark, Kevin Thurstan, Tony Aremia,
Terry Bailey, Norman Thurstan, Geoff Flood,
Graham Sinagola, Peter Baugh, Mark Crossley,
Chris Suddick, Richard Bullock, Geoffrey Walton,
Nick Odom, Colin Bowler, Nick Dixon,
Ged Birbeck, Phil Masding, Stuart Oldbury, Roger Livermore, Mary Stewart, 1 other (Total 21)
The chairman Paul Clark opened the meeting by welcoming everyone to the meeting and announcing that tonight’s speaker would be Nick Odom, who would be delivering part two of his talk on “Relativity” this time focusing on general relativity following on from his previous talk on special relativity.
The Chairman also announced that Graham Sinagola had brought in a DVD of the transit of Venus on 8th June last year if anyone was interested in it.
Nick Odom then started his talk on general relativity by summarising some of the points of special relativity to help as background.
He stated that it took Einstein ten years from 1905 when he published his theory on special relativity before in 1915 he published his theory on general relativity. It was believed the laws of physics are the same irrespective of the speed of the observer and that the speed of light in a vacuum is constant. However Newton’s laws of gravity break down at high speed and Einstein wanted to reconcile relativity with gravity.
Nick then went on to explain in more detail, how the effects of gravity must travel at the same speed as light in gravitational waves, the fact that a man falling off a roof couldn’t feel gravity led Einstein to a flash of inspiration that gravity mimics acceleration, that gravity slows down time and time runs slower for an observer on the surface of the earth than it does for a spaceman in orbit, the higher the gravity is the slower time runs. Gravity also refracts light, distorts space and that the effect of gravity is greater in general relativity as opposed to Newton’s laws. We then heard about general relativity and black holes.
He finished off by explaining some of the observational conformation we have on general relativity including the perihelion of mercury, the displacement of star images during a solar eclipse, gravitational red shifting of Sirius b and radio astronomy observations of everything from the inner planets to binary pulsars and quasars.
The meeting then had a break for tea.
The Chairman Paul Clark then did a sky diary on the coming month concentrating mainly on the area around the constellation of Cygnus and mentioned how mars was going to be at its best over the next couple of months.
In any other business the Chairman reminded us that next months talk was to be by Andrew Greenwood from Macc AS on the subject of Mars.
The Secretary then reminded everyone that on the coming Friday, 14th October, the society had been invited again to Delamere Forest Park visitor Centre and would be providing several talks on astronomy, and that we still required speakers to help out, we need others to support the occasion with their presence or turning up with scopes to put on display and maybe even use if the sky was clear.
Richard Bullock offered his services and said he would be able to do a talk on the moon.
The meeting was then brought to a close.
posted by Kevin at 5:38 PM
