Strange

The area of the Gulf of Mexico is 1,600,000 km2, while to total area of ocean is about 360,000,000 km2. Which suggest that the worst case (the entire Gulf's phytoplankton is wiped out) is that it could reduce oxygen production by less than 0.5%. However, as it is probably a small part of the Gulf that is partially affected, the effect is probably much smaller.

3,261,633.44 light years

You have used the words evidence, proof, hypoithesis and theory. Are you not ashamed? You might want to take a look at the "concepts of modern science" thread: http://www.scienceforums.net/topic/88098-basic-concepts-of-modern-science/

One thing that distinguishes a hypothesis from a theory is that a theory has been tested and confirmed (often in many different ways) by several different teams in different places. Whereas a hypothesis may only be confirmed by the original team that came up with it (and then published it so others can try and replicate the results). There isn't any formal process by which something is declared to be A Theory.

Interesting question. I suspect that because the proportion of oxygen that is converted to ozone is so tiny, there would be no noticeable effect until the amount of oxygen had been reduced drastically (and by then you would have other problems: like breathing!) But this might be dependent on how oxygen is mixed in the upper atmosphere, which I don't know anything about.

Oxygen makes up about 21% of the atmosphere, while ozone is less than 1 part per million. So you would need to increase the amount of ozone by many thousands of times to have a measurable effect on oxygen levels. (But then you would probably die from exposure to ozone at that level.)

Because for it to be "scientific" it must be testable (and therefore falsifiable). In order to be rigorously testable, it must make quantified predictions. So the prediction can't be something like: "the volume will increase as it gets hotter" - what does "increase" mean? 100%, 10%, 1%? What does "hotter" mean? 1°, 100°, 1000000°? So mathematics is required to express the relationship between temperature and volume in a precise way. And then mathematics is needed to analyse the results and determine if they support or contradict the hypothesis, given the errors in measurement, uncertainties in the hypothesis, etc. Because that is the definition of theory: Something that has been tested and found to be consistent with the evidence. Because any theory can, in principle, be overthrown by evidence at any time. It is hard to find examples where this has happened but one obvious one is "phlogiston". At one time the established theory was that combustion was caused by the release of a substance called phlogiston (almost the opposite of modern theory). For about 100 years, the evidence appeared to be consistent with this theory. Then more evidence was gathered and it was found that the theory was incorrect and it was replaced with the modern idea that combustion was caused by oxygen combining with other elements. Because we can never test every possible aspect of the theory or find every possible piece of evidence. This has been described as the "black sheep" problem. Imagine a farmer looking at a field of sheep. He notices that they are all white and forms the hypothesis that all sheep are white. Being scientific, he decides to test this. He visits his neighbours' farms and finds that all their sheep are white too. He writes letters to friends and relatives all over the country and finds out that all the sheep near them are white as well. So they all agree that there is enough evidence to say that it is a good theory: all sheep are white. Still, whenever he visits a new area or another country he checks the colour of the sheep and confirms they are all white. A very successful theory. Then one of his cousins visits Australia and writes back: "I have just seen a black sheep!" The established theory is instantly overturned.

Even ignoring quantum effects, chaos theory tells us that many (purely deterministic) systems cannot be predicted for more than a limited time into the future (one example is weather a simpler one is a double pendulum).

I don't know how to make my views any simpler or clearer. I am disappointed (in myself) because as a professional writer, that is supposed to be my main skill. Oh well ...

Of course. Without any evidence, his statements have zero credibility and are almost certainly wrong. And, for the avoidance of doubt and to pre-empt your next post: I am not saying he is lying. I am almost certain he is not lying. Please do not accuse me of calling him a liar. I do not think he is a liar.

It seemed a fairly obvious deduction. Are you saying you don't believe aliens walk among us? So what. I know someone who believes that perpetual motion is possible. I met someone who thought a famous Hollywood actress he had never met was his fiancée. Little children believe in the tooth fairy. People believe all sorts of strange things. Why should I care what he believes. Produce some evidence that aliens walk among us and it might be interesting. It might do if there was any evidence that these beings exist. I have said many times now that I do not believe he is lying. So please stop making false statements about my opinion. (You know what the word is for someone who repeatedly makes statements they know are not true?)

Thinking about the definition of a logical argument, it occurred to me that philosophy is often more concerned with the validity of an argument (i.e. is it logically well-formed) than about the truth of the results. Whereas science is more concerned with the soundness of the argument (i.e. are all the premises correct, the argument valid and therefore the conclusions likely to be correct).

I don't see any connection between that and relativity. Especially not special relativity, which is mainly just derived from Maxwell's equations....

As an example, Newton's law of gravitation is a mathematical model. It can be used to predict the path of cricket balls and planets and can therefore be tested. Any scientific hypothesis or theory must be based on one ore more mathematical models.

How did religion come into this? (Apart from the fact that Ant believes in aliens among us with no evidence, which therefore seems similar to a religious belief.)

Interesting questions. Here are my attempts to answer. I'm sure others can expand/improve ... I would say observations and evidence are the same thing. Maybe the only difference is that evidence means observations that are used to support a theory. Also, evidence could be the results of experiments while observation often means data from things we have no control over. Also, observations and evidence must be quantitative (i.e. objectively measured values) so they can be tested against the predictions of theories. So we can observe the red-shift of galaxies and we can also observe that all spiders have 8 legs. The first of these is evidence for the movement of galaxies and hence expansion. The second observation is not evidence for expansion. Wrong. A theory is a complete (mathematical) description of a phenomenon which has been repeatedly confirmed by observation/evidence. An unconfirmed idea which can give a feasible explanation is called a "hypothesis". A hypothesis must also be mathematical because it must make testable (i.e. quantitative) predictions that can be tested by being compared with observation or experiment. If a hypothesis is repeatedly tested and not contradicted by any evidence, then it will eventually be accepted as a theory. Note that a theory is the closest thing to "true" or "fact" that science gets to. However, theories are still continually challenged and tested and will be modified or discarded as required by evidence. Also (as you note later) a theory has a limited domain in which it is valid. Newton's theory of gravity is good enough most of the time but in some cases you need a more accurate model (e.g. GR is needed to calculate the precession of Mercury). In other words: a theory. That is a good point. A hypothesis is initially based on evidence. Different evidence is needed to confirm the hypothesis or theory. When there is a limited data set available, then it will often be split into two (randomly) with half used to build the initial hypothesis and then the second half used to test the predictions made by the hypothesis. Yes. Although maths is an essential part of any hypothesis or theory it is not enough by itself. The predictions of the maths must be confirmed by comparing against he real world. This is because it is possible to make up any valid mathematical model, but that description may not describe the real world. Wrong way round. See above. Argument means logical and mathematical reasoning to explain why a piece of evidence supports a hypothesis or theory. "In logic and philosophy, an argument is a series of statements typically used to persuade someone of something or to present reasons for accepting a conclusion." http://en.wikipedia.org/wiki/Argument Illogical doesn't (necessarily) mean that an argument is disproved by evidence or theory. It means that the argument does not follow the rules of logic, or uses any of the well known logical fallacies. Again, a logical argument isn't related to evidence. It is an argument that follows the rules of logic. This means that if the initial statements are true then the conclusions are true. For example a typical logical argument is:- All humans are mortal. - Socrates is human. - Therefore, Socrates is mortal. Note that an argument can be logical but still lead to wrong results. For example: - All humans are immortal. - Socrates is human. - Therefore, Socrates is immortal. This is the same logical argument. However the conclusion is wrong because one of the premises is wrong. An example of an illogical argument is: - All dogs are mortal. - Socrates is mortal. - Therefore, Socrates is a dog. The conclusion of this argument is wrong because it doesn't follow the rules of logic. This is not a well defined term. The best description might be: a mathematical rule derived from a theory. Also, a law can be purely observational. It may be used as the basis for developing a theory. For example Hubble's Law (the relationship between distance and red-shift) was initially purely a statement about the measurements had been made. There was no theory behind it. Then a number of hypotheses were suggested and tested and we eventually end up with the "big bang" theory/model.

Still no evidence, though.

I wouldn't be surprised (but it isn't a subject I know anything about). Similarly, I agree there are serious problems in many parts of the world. I also like chocolate ice-cream and gospel music (often at the same time). But none of these things have anything to do with the subject of this thread so I don't know why you bring them up.

True. But I was thinking of the "scientific myth" of popular science stories that the big bang was the creation of something from nothing (that isn't what the big bang model says). I am always puzzled, for this reason, that a lot of people reject the big bang model on religious grounds. You would imagine it would appeal to them... On the other hand, some people try and reject the model on the basis that one of the main physicists behind it also happened to be a Roman Catholic priest. Because expansion is purely about geometry: the points in your coordinate system getting further apart. You don't need any "stuff" to know calculate that.

None of which has anything to do with aliens.

As I say, I am sure he is sincere. However, there is no evidence so I will ignore these claims. No.

I'm not sure what you mean. It is the speed of light squared. It appears as a conversion constant for the equivalence of mass and energy (the famous e=mc2) and maybe other places, I can't think of right now. Because it is a scaling effect. Imagine three points: A........B........C Now, if the distance increases by 10% each second, then we get the follwoing: A.........B.........C A..........B..........C A...........B...........C A............B...........C A.............B............C Now, the speed of separation between A and B (or between B and C) is one dot per second. The speed of separation between A and C is two dots per second. If you draw the diagram with more points then you can see that the speed of separation between any two points is proportional to how far apart they are. Which is exactly what we see in the universe. What this means is that the "speed of expansion" depends on which two points you pick to measure the speed. The further apart they are, the greater the speed.

Because we don't know. Because there is no evidence for that. Because c2 is not a speed. And because expansion cannot be described in terms of speed.

As I said, I would put lying very low down the list of possible explanations. But I would put aliens even further down (because there is no evidence).

We don't know. 500 km/s/Mpc