Results 1 to 12 of 12

Thread: Staying Still?

  1. #1

    Staying Still?

    So we know that we are all in motion in the universe. And I know that, since we are moving, and everything around us is moving, we have to take that fact into consideration when we do any kind of calculation and observation. I think general relativity comes in handy here.

    But...

    Could we not measure how fast we are moving? and maybe launch a spaceship in the opposite direction enough so that we will come to a stand still in the universe? If that could happen, would everything become easy to measure? The expansion of the universe for example or the rate at which it expands? maybe?

  2. #2
    Join Date
    Apr 2005
    Posts
    11,562
    Quote Originally Posted by justinv3 View Post
    But...

    Could we not measure how fast we are moving?
    The ultimate question is, relative to what? Answer that, and the measurement is usually fairly easy.

  3. #3
    Quote Originally Posted by justinv3 View Post
    Could we not measure how fast we are moving? and maybe launch a spaceship in the opposite direction enough so that we will come to a stand still in the universe? If that could happen, would everything become easy to measure? The expansion of the universe for example or the rate at which it expands? maybe?
    First, we can't measure "how fast we are moving," since there is no absolute reference frame. People used to believe there was an "ether", but it was shown not to exist. So motion cannot be measured in the way you imagine.

    So that invalidates the second question.

    Then, for the third and fourth question, if one accepts the "cosmological principle", the expansion of the universe would be the same wherever you measure it from.
    As above, so below

  4. #4
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    18,983
    Quote Originally Posted by Jens View Post
    First, we can't measure "how fast we are moving," since there is no absolute reference frame.
    Actually, we can measure how fast we are moving, and what direction relative to the frame in which the Cosmic Microwave Background Radiation does not have a bipolar temperature distribution.

    We do not (currently) have the capability of building a rocket that could get a probe going nearly that fast.
    Forming opinions as we speak

  5. #5
    Join Date
    Apr 2005
    Posts
    11,562
    Quote Originally Posted by antoniseb View Post
    Actually, we can measure how fast we are moving, and what direction relative to the frame in which the Cosmic Microwave Background Radiation does not have a bipolar temperature distribution.

    We do not (currently) have the capability of building a rocket that could get a probe going nearly that fast.
    Actually? That is still not assured to be an absolute reference frame.

  6. #6
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    18,983
    Quote Originally Posted by hhEb09'1 View Post
    That is still not assured to be an absolute reference frame.
    I didn't claim it to be absolute, and the OP didn't say they were looking for absolute. The OP was about looking for a reference frame that required less work subtracting the effects of ou peculiar movement. I specifically named a frame of reference in which the probe would not be considered to be moving.
    Forming opinions as we speak

  7. #7
    Join Date
    Jun 2002
    Posts
    887
    Here's A lovely Image of the Cosmic Microwave Background Dipole
    Our local group of galaxies is moving at about 600 kilometers per second relative to the CMB.

  8. #8
    Join Date
    Apr 2005
    Posts
    11,562
    Quote Originally Posted by antoniseb View Post
    I didn't claim it to be absolute, and the OP didn't say they were looking for absolute.
    Sorry, I thought you were responding to Jens's post.

  9. #9
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    18,983
    Quote Originally Posted by hhEb09'1 View Post
    Sorry, I thought you were responding to Jens's post.
    I was, but if you read my brief post entirely you'd have seen the phrase:
    ...relative to the frame in which...
    I didn't read Jens as using the phrase absolute reference frame either. Those were your words needlessly injected into Jens request.
    Forming opinions as we speak

  10. #10
    Join Date
    Apr 2005
    Posts
    11,562
    Quote Originally Posted by antoniseb View Post
    I didn't read Jens as using the phrase absolute reference frame either. Those were your words needlessly injected into Jens request.
    I was confused by this response at first, until I noticed that Jens did not make a request. Are you confusing Jens with the OP justinv3?

    Jens did use the phrase, in their only post to this thread.

  11. #11
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    18,983
    Quote Originally Posted by hhEb09'1 View Post
    Are you confusing Jens with the OP justinv3?
    Yes, that is correct.
    Forming opinions as we speak

  12. #12
    Join Date
    Feb 2005
    Posts
    7,182
    This is a good idea for a sci-fi story.

    Sir--we nulled out our planets rotation around the sun, stopped outside the galaxy--and now we've dropped out of the universe altogether.

    Huh?

Similar Threads

  1. Trouble staying logged in
    By R.A.F. in forum Forum Introductions and Feedback
    Replies: 22
    Last Post: 2009-Nov-18, 08:05 AM
  2. Some problem with posting and staying logged in
    By Ari Jokimaki in forum Forum Introductions and Feedback
    Replies: 25
    Last Post: 2008-Jun-28, 12:40 PM
  3. Staying awake marathon
    By mickal555 in forum Off-Topic Babbling
    Replies: 72
    Last Post: 2006-Jan-03, 06:40 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •