Thursday, January 2, 2025

13 Physical Constants

School is back in session next week. That means today's post is a Thursday 13. But what to write about? I'm not in the mood to think too hard...

Oh, I know. How about some numbers? I'm going to list some physics constants. Just because.

  1. Speed of light in free space (c) = 2.9979 × 108 m/s
  2. 1 astronomical unit (AU) = 1.496 × 1011 m
  3. Mass of Earth (ME) = 5.9742 × 1024 kg
  4. Radius of Earth (RE) = 6.3781 × 106 m
  5. Avogadro’s number (NA) = 6.022 × 1023 /mol
  6. Mass of hydrogen atom (mH) = 1.0078μ = 1.6735 × 10−27 kg
  7. Electronic charge (e) = 1.6022 × 10−19 C
  8. Electron rest mass (me) = 9.109 × 10−31 kg
  9. Proton rest mass (Mp) = 1.6726 × 10−27 kg
  10. Compton wavelength of electron [λC = h/(mec)] = 2.4263 × 10−12 m
  11. 1 parsec (pc) = 3.086 × 1016 m
  12. Mass of Sun (M⊙) = 1.989 × 1030 kg
  13. Radius of Sun (R⊙) = 6.96 × 108 m
(I took the numbers from this list. I don't think anyone actually memorizes these numbers unless they use them regularly.)

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17 comments:

  1. Tomichan MatheikalJanuary 2, 2025 at 6:46 AM

    I appreciate this. But it's beyond my brains.

    ReplyDelete
    Replies
    1. Liz A.January 2, 2025 at 1:32 PM

      No need to remember them if they're easy to look up.

      Delete
  2. songbird's crazy worldJanuary 2, 2025 at 9:26 AM

    I stopped thinking about this stuff a long time ago

    ReplyDelete
    Replies
    1. Liz A.January 2, 2025 at 1:33 PM

      I wanted a list of things I didn't have to come up with on my own.

      Delete
  3. colleenJanuary 2, 2025 at 2:20 PM

    Numbers are Greek to me, or Geek?

    ReplyDelete
  4. Mary KirklandJanuary 2, 2025 at 2:30 PM

    My grandson will tell me random things like this. lol

    ReplyDelete
  5. Darla M SandsJanuary 2, 2025 at 2:47 PM

    Nice list. My husband and I agree that a lot of education, aside from the three R's, is about learning how/where to find answers rather than memorizing them. Be well!

    ReplyDelete
    Replies
    1. Liz A.January 2, 2025 at 3:14 PM

      One of the school's IT guys told me his job was basically Googling how to fix things. I don't need his help often, but when I do, it's something that's a mess.

      Delete
  6. Al PenwasserJanuary 2, 2025 at 2:53 PM

    Zero for thirteen (speed of light maybe...all I can remember about that is 186,000 miles per second).

    ReplyDelete
  7. peppylady (Dora)January 2, 2025 at 6:56 PM

    I know I won't remember any of this list.

    ReplyDelete
  8. CountryDewJanuary 3, 2025 at 8:31 AM

    OMG MATH! LOL. Actually it's a very interesting list of natural constants. Thank you for sharing.

    ReplyDelete
    Replies
    1. Liz A.January 3, 2025 at 2:19 PM

      It's nice to copy numbers from somewhere else.

      Delete
  9. KimJanuary 3, 2025 at 12:45 PM

    Totally over my head, but very interesting!!

    ReplyDelete
  10. AlanaJanuary 4, 2025 at 7:08 AM

    I know a person who would be absolutely fascinated by these numbers.

    ReplyDelete

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