# Retired physicist and enjoy discussing physics

1. Mar 8, 2013

### Popper

Greetings everyone. I'm new here as you can see. I'm a retired physicist and enjoy discussing physics. Keeps the wheels in the noggin spinning. I look forward to many interesting conversations. I usually spend most of my time in forums helping people learn math and physics. I hope to be useful here. Let's see what happens, shall we? :)

My handle "Popper" comes from my favorite pholosopher if science, Carl Popper. I actually know someone who knew him personally. I just got his book The Logic of Scientific Discovery. Have any of you ever heard of it or better yet read it? I also just obtained the book The Structure of Scientific Revolutions by Thomas Kuhn, my second favorite pholosopher if science. Are you familiar with him and/or his work too? I'd love to hear your thoughts on it. As Fritz Rohrlich said If you're not doing philosophy then you're not doing physics.[/i] I believe that wholeheartedly. How about you?

2. Mar 8, 2013

### Greg Bernhardt

Welcome Popper!

3. Mar 8, 2013

### Staff: Mentor

Welcome! Tell us, what is your favorite fish? I do so very much hope you say the majestic Salmon. If not that, then the swordfish is a good 2nd choice.

4. Mar 8, 2013

### Staff: Mentor

Experience: experimentalist, theoretician, industry based?

preference: classicist, relativist, quantum, particle, astrophysicist, entangled?

math interests?

5. Mar 9, 2013

### WannabeNewton

If this isn't the most inaccurate statement ever then I don't know what is . Comparing physics to philosophy is like comparing authentic New York City pizza to Dominos. Welcome xD

6. Mar 9, 2013

### strangerep

Popper, if you haven't yet read all the guidelines/rules on this forum, you'd better do that soon.

Philosophy tends to attract death stares around here -- mainly because no truly professional philosophers who knew their stuff would continue to moderate the Philosophy forum, and without a firm hand, such a forum quickly fills up with crackpot rubbish.

Best to stick to real world physics around here...

7. Mar 10, 2013

### Popper

Already read it. Why did you try to remind me. Is that what you do to all newcommers?

The point was that you're doing philosophy without knowing that you're doing it.

8. Mar 10, 2013

### strangerep

No. I just tried to caution in advance.

9. Mar 10, 2013

### Popper

Oh! Thanks for being so considerate.

10. Mar 10, 2013

### Popper

I strongly disagree. Let me think of some examples and I'll get back to you.

11. Mar 10, 2013

### strangerep

Last edited: Mar 10, 2013
12. Mar 10, 2013

### strangerep

I think they're both pretty ordinary (and yes, I've tried both).
Actually, I've been to many cities in the USA and never found a decent pizza. :tongue2:

13. Mar 10, 2013

### Popper

Swordfish :)

14. Mar 10, 2013

### DiracPool

Welcome Popper. Looking forward to some stimulating discussions! These guys are just trying to help with their caveat on philophical discourse. I think the thread link Strangerep provided would be good to peruse.

BTW, Dr. Popper's first name was spelled Karl, not Carl. I'm surprised the rest of the gang here didn't catch that. Oh yeah, I know why, they definitely ain't philosophers. Lol. In any case, I know it's just a trivial spelling difference, but, c'mon, he's your favorite philosopher of science and it's your handle, so, heck, it IS important:tongue:

15. Mar 10, 2013

### Popper

Computational Physics, digital signal processing, systems analysis and sfotware quality assurance (well ... I had to eat)

Classical Mechanics, Quantum Mechanics, special relativity, general relativity and cosmology

Differntial geometry, Digital signal processing, Computational physics, Tensor analysis, Fourier transforms and series.

16. Mar 10, 2013

### WannabeNewton

You take that back!

Do it before I start posting set theory proofs.

17. Mar 10, 2013

### strangerep

Well, I am a physicist first and mathematician second.
Therefore I rely on the experimental evidence to prove me right or wrong.

[Oops. Getting off-topic, though.]

18. Mar 10, 2013

### micromass

But did you make enough measurements to make such an accurate statement about the pizza's?? I imagine you would have to eat quite a lot to get to $5$ sigma certainty!!

19. Mar 10, 2013

### strangerep

What's this?? A mentor indulging in an off-topic subthread (which I just tried to terminate)?
Oh, what's the world coming to??

I didn't say there aren't any decent pizzas in the USA. I don't have enough data for that, yes.
But I can say I didn't find any in the cities I've visited.

Last edited: Mar 11, 2013
20. Mar 11, 2013

### Staff: Mentor

Yeah, this thread is done. Just to make it clear...no philosophy.

21. Mar 11, 2013

### atyy

Is Popper's claim falsifiable? Some would say no, rendering it unscientific.

Others would say yes, and that it has already been falsified. The example of an unfalsifiable scientific theory is commonly said to be Dirac's theory of a magnetic monopole. A single monopole would explain charge quantization. The theory seems unfalsifiable since it seems to require showing that monopoles do not exist. OTOH, it seems to be a theory we would want to consider scientific.

Suppose one day we do find a monopole, then the theory would undoubtedly be scientific, despite having been unfalsifiable.

Similarly, a single good pizza is sufficient to make strangerep's discussion on topic. http://www.yelp.com/biz/golden-gate-pizza-and-indian-cuisine-san-francisco

No. He ought to have said, "If you're not doing physics, you're not doing philosophy". :tongue2:

Last edited: Mar 11, 2013
22. Mar 11, 2013

### collinsmark

Yes, these things are interesting. There seems to be more to Fourier stuff than meets the eye.

[Edit: I'm serious about this. I can talk about Fourier transforms, Fourier series, Discrete Fourier Transforms, FFT algorithms, and the like until the cows come home. Isn't it strange that the far field effect of diffraction and interference can be modeled by the Fourier transform? In quantum mechanics, the position of a particle, or at least all we know about the position of a particle, can be expressed as its wavefunction. And that wavefunction can also be expressed as a function of momentum, with no loss of information. And the relationship between the position and momentum expressions?:Fourier transforms of each other. 4G cellular communication, LTE (or even WiMax for that matter) and recent WiFi standards, are based on orthogonal frequency division multiplexing and have Fourier transform stuff part-and-parcel to the very core of their implementation. I can go on and on. Okay, I'll stop now. Sorry for rambling.]

['Come to think of it, my very first post to PF was about Fourier transforms. Huh.]

[I am tempted to speculate about how quantum decoherence properties (i.e. the appearance of "wavefunction collapse") are a direct consequence of Fourier transform related phenomena, but since (overt) speculation is not allowed on PF I will refrain from doing so. I'll just shut up now.]

Last edited: Mar 11, 2013
23. Mar 11, 2013

### Staff: Mentor

Similar background: Comp Physics, no DSPm system analysis sw qa, sw test (also had to eat...)

BS Physics, MS Comp Sci, retired, rehired still working...

Interests in GR, QM and CM as well as Vector/Tensor Analysis, Computational Physics...

24. Mar 11, 2013

### atyy

For many of these, it's because the wave equation is linear. Then just as one can "diagonalize" a matrix in the process of solving a linear ordinary differential equation, the Fourier transform "diagonalizes" the wave equation.