Monday, February 12, 2024

The physicists philosophy of physics

Princeton astrophysicist PJE Peebles writes:
The starting idea of the natural sciences is that the world operates by rules that can be discovered by observations on scales large or small, depending on what interests you. In fundamental physics, the subject of this essay, the idea is narrowed to four starting assumptions.

A: The world operates by rules and the logic of their application that can be discovered, in successive approximations.

B: A useful approximation to the rules and logic, a theory, yields reliably computed quantitative predictions that agree with reliable and repeatable mea- surements, within the uncertainties of the predictions and measurements.

C: Fundamental physical science is growing more complete by advances in the quantity, variety, and precision of empirical fits to predictions, and by occa- sional unifications that demote well-tested fundamental physical theories to useful approximations to still better theories.

D: Research in fundamental physical science is advancing toward a unique mind-independent reality.

These sound reasonable, but they leave no room for many-worlds theory, string theory, simulation hypothesis, superdeterminism, or many of the ideas that are now fashionables.

The essay gives way too much attention to philosopher Thomas Kuhn.

It quotes Einstein:

The supreme task of the physicist is to arrive at those universal elemen- tary laws from which the cosmos can be built up by pure deduction.
This sounds a little like Weinberg's mythical Final Theory, also discussed.

No, trying to build the cosmos from pure deduction is foolishness.

8 comments:

  1. If you are going to even PRETEND to build the cosmos from pure deduction, it would be kinda nice if the standard model (which is what modern physics depends upon and considers the gold standard) included gravity. Right now it has nothing to say whatsoever about what allows you to sit there in your seat reading this.

    No gravity? then your 'deductive' cosmic model is bantha poo-doo.


    " I began my education at a very early age; in fact, right after I left college."
    Winston Churchill

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  2. You know, Roger, I don't give much credence to Kuhn either. *Any* one who doesn't *himself* do science is to be :susp: -ed. That's my first point.

    However, looking casually at his ``theory'' of sorts --- something that we back in our UG hostels [not an IIT hostel, Chetan Financials, not an IIT hostel] --- could have easily built, and then, with the better and later of my knowledge, I've this one comment now to make, more or less similarly, i.e., only as an aside:

    Think of a graph of $y = f(x)$ with some mild undulations going on for a while. Then, think of a sudden up-shoot. I mean: think of a truncated Fourier expansion of the Heaviside wave. (I mean, the square wave.)

    The $\Delta x$ interval stays the same. But, the $\Delta y$ doesn't. It shoots up. In a very short while.

    I mean, you don't have to buy the singularity of a catastrophe-theoretical explanation in the $N$-dimensional spaces and all. It all could be finite intervals-based.

    So, the point is this:

    The working scientist simply keeps plugging in, but, sometimes, suddenly, the real change is huge. Note: I didn't say ``impact factor''.

    So, may be the poor guy Kuhn might've had a point too, just the way the poor guy Popper might've had a point too, you know? I mean, who knows?

    Best,
    --Ajit

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    Replies
    1. But a certain Ayyangaar remains a III class both in your country and mine, haanh! For all the time.

      Delete
    2. Anonymous':

      So, for *obtaining* your ``fucked up'' money, *may* be through the H^3 sources as the *need* of the hour be, you the *reader* of *this* comment have been *relying* on my insisting on my putting my name to all of my comments, don't you?

      Or, do you? I mean, do you *even* have to?




      Delete
    3. Which means:

      You employed, first, for a a lot of few years, lex, and then NLP, and now, to save your own respective asses, also AI/ChatGPT/similar.

      Yeah, right. Oops. Left.
      Rich.

      Delete
    4. Which means, they don't matter.

      Not in the sense that a reader of Aristotle's would take them.

      But then, is that how it goes? in your country? Or mine, should you begin explicitly discussing it, Roger!

      Do they *really* not matter? Not even in one's own life? How does one square it *all* off?

      Best,
      --Ajit

      Delete
    5. Dear American,

      A JPBTI or equivalent only wants himself to be rich, but doesn't wan't to show, and once so become, spends his life convincing others that he never wanted to be so. Kulkarni, Ayyangaar, Gujju, Pandit, Oak, Mumukshu, H^1, H^2, H^3, H^4, you get the idea. Or do you? I mean, are you even smart enough to get such ideas?

      You idiots/morons/retards/etc.

      But rich.

      How come?

      Without the application of the physical coercion? on others?

      Just how come you are so rich even while being so bereft of ideas that you've to hack my machine too?

      Just how come, you Americans?

      Delete
  3. Roger,
    You might want to check out Sabine's latest entry on quantum computing on her site Backreaction.

    Oh dear lord, I apparently am an oracle, as I predicted exactly what happened. My magical powers of ordinary skepticism apparently predicted someone in a Chinese computer science lab would do the same operation of the big bad quantum computer....better, and at considerably less cost.

    Quantum computing is about milking a money cow to death, not making any real new computing discovery. It is easy to understand and predict where something will fail when no one is asking even remotely serious questions about the underpinning motives of the research.

    ReplyDelete