not_Fritz_Argelander

  1. The O III filter does wonders on the Lagoon Nebula

    by , 08-02-2017 at 07:08 PM
    Quote Originally Posted by j.gardavsky View Post
    Quote Originally Posted by not_Fritz_Argelander View Post
    This is an extremely interesting suggestion that makes excellent sense on physics grounds!
    Hello not_Fritz,

    these are not only the blue Balmer Series lines, but also lots of other ionized gases, even if these other lines are weak,
    Spectroscopy of planetary nebulae

    Moreover, this filter passes also the OIII doublet, Teleskop-Express: Baader CCD-Filter Blau - 1,25" - Interferenzfilter

    Around 2012-13, there used to be a small group
    ...
    Categories
    Uncategorized
  2. a different kind of "fifth force"

    by , 05-28-2017 at 06:30 PM
    Quote Originally Posted by not_Fritz_Argelander View Post
    Let me give a hint of my thinking about why fifth, sixth, ... nth forces might be reasonable. It has to do with gauge fields and their internal dimensions.

    Electrodynamics is a gauge field described by a 1 dimensional gauge group, U(1). That U(1) just means that the internal symmetry multiplies the wave function by a phase factor. The U means it preserves the wave functions probability. It's a fancy way of saying that adding a constant to the electric potential makes no difference.
    ...
    Categories
    Uncategorized
  3. a different kind of "fifth force"

    by , 05-28-2017 at 06:28 PM
    Quote Originally Posted by not_Fritz_Argelander View Post
    A general survey of the goodies that can come from testing GR at Sgr A* is found at

    https://arxiv.org/pdf/1512.03818.pdf

    Figure 1 is especially instructive as it parameterizes (by potential and curvature) all relevant gravitational astrophysical regimes and all available experimental and observational methods in separate graphs that can be compared.

    I beg forgiveness for headaches caused. I think that a search for additional forces (fifth, sixth, ...)
    ...
    Categories
    Uncategorized
  4. a different kind of "fifth force"

    by , 05-28-2017 at 06:27 PM
    Quote Originally Posted by not_Fritz_Argelander View Post
    in another thread started with the exciting data on Jupiter's magnificent storms as imaged by Juno there was a mention that recent results indicate that there is "no fifth force". there have been many proposals of "fifth forces". some previous discussions are in these threads.

    there is a class of fifth force ideas that are short range and testable only in accelerators:

    http://www.astronomyforum.net/astrop...ill-alive.html
    ...
    Categories
    Uncategorized
  5. Testing the refractors and binoculars optics with a laser pointer

    by , 05-13-2017 at 05:10 PM
    Quote Originally Posted by j.gardavsky View Post
    Hello all,

    this is a straight way how to test the lenses in the refractors with a laser pointer, as shown on the achromatic lenses of the 25x100 FB binoculars:

    Click image for larger version. 

Name:	Achromatic Binoculars 25x100 FB.jpg 
Views:	87 
Size:	62.9 KB 
ID:	155912

    The test can be made with a red laser pointer, but the green laser pointer is better suited.

    The laser pointer direction is under an oblique angle, and the viewing is under another angle to avoid risk of the laser reflection into the eyes.
    ...
    Categories
    Uncategorized
Page 1 of 6 123 ... LastLast
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 08:24 PM.