What is a Law of Nature?

What is a Law of Nature?

Edward Feser

But what exactly is a law of nature? Hawking and Mlodinow characterize a law as “a rule that is based upon an observed regularity and provides predictions that go beyond the immediate situations upon which it is based.”[2] Here too their position is no doubt a common one. But their answer is not terribly informative, because the terms “law” and “rule” are often used synonymously. Suppose you asked a political philosopher what liberty is and he told you that liberty is freedom. You would probably respond: “Yes, I already know that much, because the terms are more or less interchangeable. I wasn’t asking you for a synonym, though. I want to know the nature of the thing that the words ‘liberty’ and ‘freedom’ refer to.” In the same way, since the words “law” and “rule” are often used interchangeably, it isn’t very helpful to say that a physical law is a kind of rule. What we need to know is the nature of the laws or rules that are said to govern the physical world.

To be sure, Hawking and Mlodinow do say more than merely that a law of nature is a kind of rule. Again, they tell us that laws are inferred from observed regularities, and that we can derive predictions from them. They also tell us that “in modern science laws of nature are usually phrased in mathematics,” and that “they must have been observed to hold without exception… at least under a stipulated set of conditions.”[3] And they tell us that physical laws are “consistent principles,” in contrast with the arbitrary and “inscrutable” whims of the gods in terms of which pre-scientific cultures explain natural phenomena.[4]

But while somewhat informative, even these remarks still don’t really answer our question. Suppose you asked a geometer what a triangle is, and he told you that in Euclidean geometry the angles of a triangle summed to 180 degrees, that you could discover various features of triangles by constructing proofs, and so on. All of that is true, but it doesn’t really answer your question....

I'm repeating myself, but I think (at least if a law of nature is expressed in terms of real numbers) it has to be stated in a finite range of conditions and with some accepted level of tolerance (think of PV=RT). If this was the accepted formulation, I think it would eliminate all the wild extrapolation. Nobody would have the chutzpah to write, "Assuming this relationship holds over another 20 orders of magnitude.....".

David

"Laws of nature" are the ways in which according to all observation the world works, as a machine works according to its design. Intelligent design and teleology seem to me to be central to the concept. These are not synonyms for "laws of nature".

"Laws of nature" are the ways in which according to all observation the world works, as a machine works according to its design. Intelligent design and teleology seem to me to be central to the concept. These are not synonyms for "laws of nature".

So you would extend the idea that life has been constructed intelligently, to the idea that the whole universe has been constructed in that way?

This seems to be Stephen Meyer's approach, but he seems to accept physics and cosmology as it is told - which I don't think I do.

David

A law of nature is the mathematization of the observed regularities. I'm not sure what more you can ask.

~~ Paul

So you would extend the idea that life has been constructed intelligently, to the idea that the whole universe has been constructed in that way?

This seems to be Stephen Meyer's approach, but he seems to accept physics and cosmology as it is told - which I don't think I do.

David

Yes

A law of nature is the mathematization of the observed regularities. I'm not sure what more you can ask.

~~ Paul

Well, some seem to perceive the "laws of nature" to be set in stone, inviolable. That is, if something contradicts them, that something must be incorrect. With the amusing implication that it is "illegal", "unlawful" to break them, because they're "laws", "rules".

Nevermind that the "laws of nature" are just models based on observation. Models are always imperfect, by their very nature of being approximations.

Rupert Sheldrake actually brings this up in his TED talk ~ the language of the "laws of physics" are modeled after human legal systems, in a sense. Which carries certain connotations along for the ride.

Sheldrake rather preferred to perceive them as "habits" ~ "habits of nature". He brought up an example of the speed of light ~ that it was observed to change over time, even if only in small ways.

Sheldrake mentions that he talked to some professor who told him that they'd solved this problem by defining the meter in terms of the speed of light ~ so that the speed of light would remain constant, but now the actual length of a meter would be the thing changing instead.

An absurd "solution" to the problem, instead of just admitting that the "laws of physics" aren't so set in stone.

Here we go ~ starting from 5:58:

https://youtu.be/JKHUaNAxsTg?t=358

A law of nature is the mathematization of the observed regularities. I'm not sure what more you can ask.

~~ Paul

Hi Paul, it is good to see you here again!

The problem is that those observed regularities happen on a certain scale, and it is just assumed that the resultant laws still hold on a much larger scale.

Gravity (Newtonian or Einsteinian) has been observed to follow the inverse square law within the solar system, but scientists have chosen to claim that this must happen on much larger scales - across our galaxy and even between galaxies. Yet the only way they get that to work on a galactic scale is to arbitrarily kludge the equations with large quantities of 'dark matter' - just imagined into existence to make the equations work!

I think science would work much better if it stuck to what it really knows without all the wild extrapolations.

David

While the opening post references names such as Hawking and Mlodinow, for me the most interesting name in the linked article was Alexander Pope. Thinking in terms of an early 18th century poet tells us a lot more about the concept of a 'Law of Nature' than thinking of any modern scientist does.

To me the idea of a law of nature is much closer to a kind of folklore or folk-wisdom. The first two examples which came to my mind were:

• What goes up, must come down.
  
  
• Red sky at night, shepherd's delight.
  

There's a certain amount of truth, even scientific truth in both of these, but there can be found exceptions to both of them too.

That for me is the most important aspect of a law of nature: that it is a generalisation based upon observation, but there are likely to be exceptions.