Definitions of ...

[Erasmus00]

We have the Laws of Thermodynamics. We have the Perfect Gas Law. We have the three laws put forth by Newton (For every action there is ...) These are laws, not theories, right? If we can't trust them, and can't demonstrate them over and over and over again in a controlled environment like a laboratory, then why do we teach them to every child.

 

Actually, there are known exceptions to the third law of thermodynamics (glasses). The perfect gas law is an idealization (as you can tell by the name.) If you have precise enough equipment, you can easily find the exceptions to it. Newtons laws are known to require modification in certain situations. The second law of thermodynamics is meaningless on short time scales. The first law is only true up to the energy/time uncertainty. Every single "law" you quoted has known exceptions.

 

And yet these are all laws. I also point out that these are not theories. The "laws" are observational facts. A good theory explains the laws(and hopefully the exceptions), but the laws alone do not make a theory.

 

Newton's laws are explained and expanded by classical mechanics(which also is known to fail in places). Thermodynamics is explained by statistical mechanics,as are the properties of an ideal gas.

 

Are you in agreement that there are no such laws in physics?

 

As I said, physical laws are experimental observations, not the theories that explain them.

-Will

[Tormod]

I myself am not familiar with the experiments done by Davies, yet. However, I would suggest that his experimental results are theoretical at this time, until they are proven.

 

Of course. That's the point of this discussion, no? *Everything* in science is based on theory. Even the laws, which are simply theories that have been so successful that they have solved very fundamental issues (like [math]F=ma[/math]) and provided us with insight and helpful tools.

 

I highly recommend reading John Barrow's book "The Constants of Nature" which also mentions Davies' work. Barrow was involved with the studies done by Davies and gives a great account of how the constants of nature are not so constant, after all.

 

The speed of light and the results that govern its definition are well established by repeatable experimentation.

 

Yet this does not mean that the speed of light is unchangeable. Like I said above, that we rely on a constant speed of light (in vacuum) is the cornerstone of modern physics. It has become a written law of science yet the evidence supports a change over time.

 

There is nothing mystical about it - if it turns out to be true (the theory was bolstered by the observed *accelerating* expansion of the universe) it means that a varying speed of light over time is a function of our universe. It does not mean that [math]E=mc^2[/math] is wrong, only that it would yield slightly different results at different times in the universe.

 

Maybe Davies has something and it will become a part of the laws governing our definition of c, but I say they are laws not just theories.

 

As I said, it is a challenge to the perception that the speed of light is unchanging. In other words, it is a theory that shows that what we think is a law, may have to be rewritten. Thus my point above that laws must never be accepted as God-given or written in stone.

 

I don't think that just because any number of persons "thinks" that c may have varied over the years, that E=mc^2 is no longer trustworthy. Perhaps, E and m also varied so that the equation itself never changed, or perhaps Davies has some error. Either way, repeatable experimentation allows the verification of E=mc^2.

 

Please read up on this issue before you make further comments on Davies' theories, since you are misinterpreting my point.

 

About Paul Davies:

http://en.wikipedia.org/wiki/Paul_Davies

 

Here are some articles from Hypography on the issue. Some are old now but

 

Study: Light Speed May Have Changed

 

The Constants of nature (book review)

 

From other sources:

 

 

Speed of light may have changed recently

Article in New Scientist reporting on the findings by J. Webb et al (related to Davies' work)

 

A Simple Varying-alpha Cosmology

A paper by John Magueiro, John Barrow, and Håvard Sandvik, full text available.

 

Varying Constants

By Tamara Davis, who has worked with Paul Davies. Enlightening article on the subject, which explains the observations made and why they are so revolutionary.

 

It wasn't the realization that Newton was wrong. It was the realization that there was more than just gravity.

 

I disagree. It was the realization that Newton's assumption that gravity worked instantly over long distances that was found to be flawed. His concept of absolute time had to be wrong, and this forced new theories to be formulated that evolved into the laws of relativity.

 

Misapplication of a law does not mean that the law was wrong. Instead they found new things and made adjustments.

 

Agreed. But in this case the laws were based on a fundamental mistake (action at a distance). So the laws were correct when applied in the correct scenarions (we still use Newton's laws for non-relativistic settings) but they could not explain new observations and thus the laws were not good enough for modern applications like GPS satellites, which rely on relativity. Without relativity, we might never have got GPS satellites.

 

Also you say the best explanation. Perhaps this is a good point. Are there any other reasonable explanations? In my mind the best explanation for the existence of life and the universe is that God created everything according to the account in Genesis.[/quuote]

 

While it might suffice for you, it is not a good example because it is not a scientific explanation and cannot be tested according to scientific theories. So what you are quoting is not a law at all, it is a faith-based assumption, which is very different from scientific theory.

 

While I don't involve myself in whether or not Intelligent Design should be taught, and this is not a thread about that, I do have a problem with people saying that Evolution is verified, reproducable, and well-founded.

 

Whatever you think, evolution is indeed an old science which is studied by thousands of people all over the world. It makes predictions that can be tested. It is very much a science. ID is not, and belongs in theology classes, not science classes. I suggest participating in one of the (many) ID discussions in the Theology forum rather than posting it here.

 

Note that science does not require that everything can be reproduced. Evolution is a case in point - we cannot create nature all over, just like we cannot create another universe to study it's formation. A theory, however, needs an explanation of what it observes, and also an explanation of the steps on how to reproduce the results. That's very different.

[cwes99_03]

Yes, I will, happily read up on Davies.

 

 

So, if we were not to include absolutes, admitting that there is still much to learn, how to we get around the problem of calling everything a theory - which puts string theory on the same footing as evolution and greenhouse effect and SR and Newton's Gravity and Maxwell's E&M.

[Raskolnikov]

If there's a problem, it's that the language we use is somewhat ambiguous. String theory isn't really a theory if we mean it in the sense that a theory is a framework for making accurate, testable predictions. The other four concepts you mentioned are all theories in this fashion, though. Maybe to avoid confusion we should call the latter typs of things Theories with a capital 'T' or something.

[Tormod]

I frankly think we'll just have to cope with theories as they are. That's science. Until someone comes up with a scientific method that is not based on empiricism, we're stuck with non-provability.

[cwes99_03]

Non-provable? I don't like the concept, true, because what would be the point of studying science if you could never prove anything.

 

There has to be a level at which we accept that while not the final answer something is "well-established" as some other have said. Only then can we actually have that discussion on whether Evolution is well-established, or full of obvious holes.

[HydrogenBond]

The word theory has a range of definitions. In general, it is a way to organize observation, laws and theories to make predictions. This does not guarentee it reflects reality but only only that it correlates and predicts reasonable well.

 

If you look at evolutionary theory, it is good for correlating the past but it tells little about the future except in a very nebulous double talk way. If one asked what will be the next major evolutionary state of humans on earth, evolutionary theory can say nothing with certainty other than something will evolve. That is why it is stuck at theory and is not a law of nature that fully reflects reality. Something is missing that would take it to the next step. Evolutionary theory is not that good at predicting, only correlating what we see. It is useful, but being limited, may not fully reflect reality.

 

Newton's theory of gravity can tell us of the past and future of the earth's gravity with reasonable certainty. It helped put men on the moon. But if does not fully reflect reality in the sense, GR is not included. But even GR is just theory that has been proven to the satisfaction of many, but not to completeness, such as being included in the unification of force.

 

The difference between theory and law is that a law it is suppose to be used one way, without a lot of creative latitude. A theory is a little more flexible. Theory is more like a guideline instead of a law. For example, if one violates laws of science, there hell to pay. If one violates a theory nobody, accept a small group will hold it against you. If one says they have created perpetual motion, this is against the law. If someone challenges evolutionary theory with new evidence, this is not against the law, since a theory is a work in progress.

[cwes99_03]

OK, but are you willing to concede that some time in the future there may be perpetual motion machines?

I liked your post on another thread that made a statement of difference between theory and practical reality.

[Erasmus00]

If one asked what will be the next major evolutionary state of humans on earth, evolutionary theory can say nothing with certainty other than something will evolve. That is why it is stuck at theory and is not a law of nature that fully reflects reality.

 

On what are you basing this? What theories do you believe have made the jump from "theory" to "law?"

 

Again, laws are things that are explained by theories. Laws are usually simple, time tested experimental observations. Theories build edifices with these laws.

-Will

[Erasmus00]

So, if we were not to include absolutes, admitting that there is still much to learn, how to we get around the problem of calling everything a theory - which puts string theory on the same footing as evolution and greenhouse effect and SR and Newton's Gravity and Maxwell's E&M.

 

I disagree. Theories obviously have different degrees of how well tested they are. Most forms of string theory have never been tested. Electricity and magnetism are measured by undergrad physics/engineering students every day. However, Maxwellian E/M is still just a theory, still a model. So we have various degrees of confidence in our predictions.

-Will

[Tormod]

OK, but are you willing to concede that some time in the future there may be perpetual motion machines?

Although not aimed at me, I think this line of questioning is fruitless. Why should anyone concede to something that lies in the future?

 

It is very easy to say "yes" to a question that has a "maybe". In theory, everything is possible. But with our current understanding of what energy is, there can be no perpetual motion machines because of very many things: not least the assumption that our universe might come to an end in the future, barring the possibility for any perpetual motion machines.

 

I'd rather like to say that yes, there is a possibility (maybe even likelyhood) that we will find energy sources that are virtually endless (tapping the energy of stars, for example) and thus may last for thousands of years or even longer. But that is not perpetual.

 

This may all change. If we find out that the universe will never end (which is a prediction that cannot be proved with the current scientific theory, whether you like it or not) then perpetual motion machines may become a reality.

[HydrogenBond]

What theories do you believe have made the jump from "theory" to "law?"

 

One that comes to mind, which I beleive should be given the status of a law of nature, is the theory of special relativity. First it has been proven to be real. Secondly, it is universally accepted without competition or strong alternate theories with the same level of simplicitity. Thirdly, noone has been able to show many or any acceptions to the rule. Thats good enough for me to be obeyed as a law; Yes Sir, Mr Einstein!

 

I would like to compare hypothosis and theory. A theory is an advanced state of an hypothesis, that has verifying data. The path from hypothesis to theory is laced with human subjectivity. For example if two scientists came up with the exact same hypothesis, one from a rich culture and the other from a poor culture, the rich culture will be able to call it theory first. In other words, availability of money and resources can buy the bump-up.

 

If there were two scientists one who is illiterate and the other literate, if publication was the criterion, the literate will get the bump-up first, even for the same hypothesis with same data. Publishers wants all the ducks in row, for consistency and ease of review. Science rarely works this way. Rather a scientist needs to sort through choas to find order. If the purpose of a publisher was truth, chaotic form would not matter, since the truth is in there somewhere. But they set up a subjective criteria for judgement. Time is money, so again a bump-up to theory has to do with money.

 

Another subjective criterion is politics. For example, if an Administration is sensitive to global warming it will make money available to bump-up hypothesis connected to global warming. If the Administration changes and they see global warming the opposite way, the rate of new theories about global warming will fall, even if the number of hypothesis remain the same.

 

If we look at the example of cigarette smoking. This is a good theory based on strong data. It is only a theory since acceptions can be found. In spite of this, many people are using politics to make this theory a law for the ultimate bump-up. Such a law will not only have natural hazzards but also social hazzards due to the long arm of the law picking one's pocket. The cigarette manufacturers use their own money, resources, and political connections to show opposing data to prevent the bump-up to law. If they could they would also like to bump-down the theory back to hypothesis since this would be in their best business interests.

 

There is another angle connected to 20/20 hindsight. If we look at special relativity, in the context of history, it was almost a law right from the time Einstein concieved it, since it is the same today as back them. But initially it was treated as a hypothesis. Essentially what happened was that the expert of tomorrow (Einstein) was lorded over by the amateurs of tomorrow. Sort of like children of the future leading an adult of the future. This irrational situation again was connected to human subjectivity due to lack of understanding, with pride, prestige, power, money, resources being used to downgrade a law and hold it at hypothesis. Eventually it was bump-up to theory and now should be bumped-up to law.

 

In my opinion I look at hypothesis and theory as almost the same, since objectivity alone is not always the deciding factor for the bump-up. If subjectivity is part of the criterion, then hypothesis that require the least amount of prestige, money, resources, etc. to reach the level of theory is best type of hypothesis.

[Qfwfq]

"When I use a word," Humpty Dumpty said, in a rather scornful tone, "it means just what I choose it to mean, neither more nor less."

 

:)

[Tormod]

"When I use a word," Humpty Dumpty said, in a rather scornful tone, "it means just what I choose it to mean, neither more nor less."

 

Huh...that's exactly what my five year old daughter says. :eek:

[Qfwfq]

:eek: