Jump to content

Longest Running Thread EVER


Recommended Posts

Back 40 to 50 years ago, "astrophysical accuracy" was acknowledged as being wretched. Stellar parallaxes (which are what give you distances) were especially bad. The largest one is/was about 0.75 arcseconds, with uncertainties no better than 0.10 arcseconds, and distance in pc is 1 divided by the parallax.

 

There were a number of measured parallaxes which were five times their standard deviation -- which is one rule of thumb for what you could beleive -- except the value was negative, which is physically impossible. Such situations indicate a systematic error rather than a random one, and statistics don't help you much in that situation.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...