Understanding Numerical Physics: Get Intuition & Memorize Constants?

  • Context: Undergrad 
  • Thread starter Thread starter tim_lou
  • Start date Start date
  • Tags Tags
    Numerical Physics
Click For Summary

Discussion Overview

The discussion revolves around the importance of understanding and memorizing numerical constants in physics. Participants explore the relationship between numerical values and conceptual understanding, particularly in the context of approximations and practical applications in physics.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses difficulty in grasping the significance of numerical constants like kT and the mass of a proton, seeking ways to develop better intuition around these numbers.
  • Another participant suggests that frequent use of constants leads to memorization over time, listing several fundamental constants as examples.
  • A different viewpoint argues that memorization is not crucial, emphasizing that understanding the physical meaning of equations is more important than recalling specific numerical values.
  • One participant mentions the utility of cheat sheets for constants, indicating that they can be looked up rather than memorized.
  • Another suggests thinking in terms of dimensionless ratios of constants as a potentially helpful approach.
  • A later reply advises using convenient units to avoid dealing with powers of ten, reinforcing the idea that frequent usage fosters familiarity with numbers.

Areas of Agreement / Disagreement

Participants exhibit a range of opinions on the necessity of memorizing numerical constants, with some advocating for memorization through usage and others arguing that understanding concepts is more critical. No consensus is reached on the importance of memorization versus conceptual understanding.

Contextual Notes

Participants acknowledge that the significance of constants may vary depending on the context of their use, and there is an emphasis on the subjective nature of memorization and understanding in physics.

tim_lou
Messages
682
Reaction score
1
It seems that understanding numbers in physics is often almost as important as understanding concepts, specifically when approximations to equations are made.

But I found myself lacking in intuitions in these numbers...

When my professor is lecturing, he always gives out numbers. for instance, kT for room temperature is about .026 eV (yes, he just remembers that) and rest mass of electron is about .51 MeV. From these numbers, my professor deduces how some approximations are valid. (When quantum mechanics can be applied, and/or a certain equation is valid)

It seems that I have a hard time grasping what those numbers really mean. I know it is a vague question but is there any way to get a better intuition out of numbers and/or numerical constants? Like when we say the mass of a proton is around 938 MeV, what does that tell us?

In addition, do most of you guys memorize important physics constants/numbers? like the constant G, h, k.. etc? in different units?
 
Last edited:
Physics news on Phys.org
well... the more use them.. and u will eventually remember them... like it or not :smile:
things like speed of light = 3x10^8 m/s, C=1.6x10^-19 and 0C=273K, pi=3.14159265358979323...
should be easy enough to remember

and no... I don't find them particularly intuitive either... they are just fundamental constants, not derived quantities after all
 
Personally I don't think it's that important to memorize all this stuff. I'm in grad school and just the other day when I had to numerically analyze a blazar energy spectrum, I completely forgot the value of h (and then another grad student commented that "you don't need to remember that crap" and photocopied his frequency to energy conversion cheat sheet for me). Oh sure, I remember some stuff, like the speed of light and the charge on an electron. But really, anything you can look up in a table, you don't need to remember. Even on exams you'll be given these values. And they don't aid your intuitive understanding of physics very much either. I couldn't remember kT for room temperature to save my life. It's more important that you understand the physical meaning of the equations you're using. For example, understanding the physical interpretation of the line integral of the magnetic field, and why it relates to current, is way more important than knowing the magnetic permeability of free space.

Just my opinion...
 
Last edited by a moderator:
Try to use convenient units, so powers of 10 don't enter.
Don't work on memorizing. If you use a number often, it will come naturally.
 

Similar threads

Undergrad Where are these neutrino masses coming from?
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad Trouble piecing together LS coupling
  • · Replies 0 ·
Replies
0
Views
889
Graduate CGS units confusions in plasma physics journal papers
  • · Replies 22 ·
Replies
22
Views
14K
How do i gain intuition to learn and remember physics?
  • · Replies 19 ·
Replies
19
Views
6K
Physics Experimental undergrad research in SOP for theoretical grad research?
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Reasoning behind Infinitesimal multiplication
  • · Replies 22 ·
Replies
22
Views
4K
Admissions Statement of purpose critique request (high-energy theory PhD application)
  • · Replies 7 ·
Replies
7
Views
4K
Studying Am I supposed to understand everything in a formula?
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad Am I understanding the concept of suction correctly?
  • · Replies 28 ·
Replies
28
Views
8K
Requesting suggestions for languages, libraries, and architectures for parallel (and sometimes non parallel) numerical and scientific computations
  • · Replies 8 ·
Replies
8
Views
5K