Hi All,
I subscribed to this list a few days ago, and have been watching what has been
happening. This is my first posting, and I wonder how long it will take to
appear
in the archive.
As I have a Ph.D. in astrophysics, I should be able to deal with some points
that
come up in that and related subjects. This is specifically addressed to
Vernon
Jenkins.
To Vernon:
> To Glenn:
> In your list of facts ignored by YECs (Sunday last), you stated: "They
> even reject trigonometry as a means of determining distance. This is
> because we can directly triangulate the distance to supernova 1987a in
> which a gas cloud previously ejected from the star became visible by
> reflecting the light from the nova 6.5 months after the nova. Thus we
Technically it was a supernova, not a nova.
> KNOW that the ring is around 1.3 light years in diameter (and this is
> true regardless of whether or not the speed of light has changed through
> the history of the universe). We also can directly measure the angular
> size of that ring. These two measurements allow us to determine the
> distance according to simply geometric laws. That star was 170 thousand
> light years distant requiring a universe at least that old. Of course
> YECs know that trigonometry can't conflict with the bible so trig is
> erroneous in this case. (see Foundation Fall and Flood, p. 63)."
> The first question I would like to ask is this: Are you really speaking
> as a scientist when you claim that "a gas cloud (was) previously ejected
> from the star"? Clearly, no one can have witnessed this event! Thus we
> don't KNOW that this is a true explanation of the astronomers'
> observations, and to claim it to be proof that the velocity of light has
> remained constant over the past 170,000 years appears to be wishful
> thinking on your part.
In fact regardless of whether the gas/dust cloud was or was not ejected by the
progenitor star, it's still about 1.3 light years from the star, or whatever
the
measured value is, and was illuminated by the explosion. It thus gave us a
direct method of measuring the supernova's distant from the earth
independent of other methods, which it broadly agreed with. Any change in
the velocity of light, in particular a decrease as proposed by Barry
Settefield,
would be easily detected through various effects, both in classical physics,
and through relativity and quantum mechanics. There is no evidence what
so ever that the speed of light has changed in the last few billion years at
least.
> Next, you side with David in believing that YECs ignore the laws of
> radioactive decay. But these 'laws' are based on assumptions - as you
> must well know! What is observed today may not be what applied 1000
> years ago. Would you therefore not agree that you are proceeding by
> faith rather than by sight in respect of this?
Actually, radioactive decay depends on fundamental coupling constant
of the weak and strong nuclear forces, together with various other constants
such as the velocity of light and Planck's constant. As with the velocity of
light mentioned above, there is no evidence that any of these quantities have
changed. Indeed, supernova light curves are powered during certain phases
of their decay by a number of unstable isotopes, one such decay sequence is
56Ni -> 56Co -> 56Fe, the latter being stable. The half lives of such
isotopes
seen in distant supernova explosions are the same as measured in the lab.
Christopher M. Sharp
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