Interstellar Space - Is Its "Density" Measurably In Decline?

[zeestephen]

It's my understanding that all interstellar space contains some level of matter.<br /><br />For the sake of discussion, lets say every cubic meter of space has ten atoms.<br /><br />Because space is expanding, will there be some predictable point in time when space has only nine atoms per cubic meter?<br /><br />Also, space expands faster at greater distances.<br /><br />Will the number of atoms per cubic meter of space be higher close to an observer, but automatically lower at great distances from an observer?<br /><br />Let's say an observer on a distant planet measures the number of atoms per cubic meter in space near Earth. <br /><br />Let's say that observer snaps his fingers and arrives at Earth. Then, he takes the same measurement of the same space, but this time from Earth.<br /><br />Will the number of atoms per cubic meter of space be the same for both observations? <br />

 

[vogon13]

The time interval for a 10% reduction in intergalactic density is rather longish (like around 1,500,000,000 years) you can do the math for other time spans.<br /><br /><br />Observations capable of directly detecting a change in acceleration of distant quasar objects are expected to be feasible in the next 50 years or so.<br /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[derekmcd]

<blockquote><font class="small">In reply to:</font><hr /><p>Also, space expands faster at greater distances. <p><hr /></p></p></blockquote><br /><br />Not that I'm aware of. Space expands equally at all distances. That is why, from our perspective, distant galaxies are moving away from us faster than closer ones. And they same is true from that distant galaxy's perspective. <br /><br />The reason that distant galaxy if moving away faster is simply due to there being more space in between that is expanding. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[vogon13]

{it is possible that the expansion is non linear. The measurements I referred to being accomplished in ~50 years will address this odd little possibility}<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>