Magnetic Poles, you have gotten to the point of parading your ignorance and there is nothing to be answered for that. If you are really interested in the speed of light measurements and experiments, please read the data.
http://www.setterfield.org/cx1.html
http://www.setterfield.org/report/report.html
The measured changes far exceed possible instrumental error. Also, when instrumental error was found to exist (see the first link), the measurements were not included in the records. Third, when the same method, by the same observatory (such as the Pulkova Observatory) was used, subsequent measurements were ALWAYS lower. If there were instrumental error, then the measurements should range on either side of the 'constant' speed of light, but they don't. There is a consistent slide downward, regardless of method used, people involved, or time. This is not instrumental error. Please get to know what you are talking about before you start talking. Men far wiser and more educated than you were discussing these changes in peer-reviewed literature in the first half of the twentieth century. These were not cave men.
johnp, since Genesis recounts physical creation, the first light was also physical and God is a spirit. His light is the Shekinah Glory and that is not what was shining on earth the first three and a half days. There was a physical light from a particular point in space and the earth was rotating. It is in the Second Creation when the light of God becomes the light of that creation. Please don't be afraid of actual science.
Also, 'yom' is like 'day' in the English language and it can have a variety of meanings, so you need to be careful. Yes, in Genesis 1 it definitely means approximately 24 hours, but when used with the equivalent of our prepositional phrases, it can mean an indefinite period of time: in the day OF THE LORD, for example. Or 'in the day of King David'... There are some other exceptions, grammatically. But yes, in Genesis, the use of 'yom' with ordinal numbers and defined by 'evening and morning' cannot be anything but a 24 hour day.
When someone says that it is just as literal to see an old creation as a young one in Genesis, they are destroying the meaning of words. "Literal" means it means what it says and both Exodus 20 and 31 define it, in case anyone missed the meaning in the first chapter of Genesis. MP is grasping at liberal straws, and straws is all they are.
I would also mention that in the Hebrew, the word for 'heavens' in Genesis 1 simply means 'that which is lofty' and the word translated 'earth' means 'that which is firm.' So be careful about what you are declaring there to be true -- what the Bible actually says or what interpreters are putting on to it. It is very possible that Genesis 1 is describing the creation, out of nothing, of the entire time/space/mass continuum we live in and is not referring to the earth in particular except for the fact of 'evening and morning' which definitely indicates a rotating mass. But the use of the word 'eretz', translated in Genesis 1 as 'earth' has a much wider meaning than 'earth' and is used in other ways later in the Bible, as in the time of Peleg when the continents were divided. The 'eretz' was divided.
It's just something to be careful about. Checking word meanings with a good Concordance or two can often save some problems from happening.