universal motion

Status
Not open for further replies.
R

rodneyb341

Guest
hi,guys....i'm new to this particular forum(well,not really NEW...i just haven't posted in quite some time),and i have a question that i really need to have answered.i'm aware that everything in the universe is in motion...i just can't figure out how we know it.if our galaxy is speeding thru space along with every other galaxy,how can we tell that we're moving?how do they know we're traveling at speed x,and in what direction?i don't have a problem believing and accepting these things...i'd just like to know how these things were figured out.
 
D

derekmcd

Guest
Einstein postulated that all motion is relative to the observer. Basically stating that we can only base our motion relative to what we see. In the cosmos, there is no direction up, down, right, left. Those are only notions that we use for our own bearings.<br /><br />As for our galaxy, we merely state we are travelling 'at speed x' <i>in relation to</i> another galaxy. When we speak in terms of our galaxy, I believe we base our speeds and directions based on our local group.<br /><br />I goes in scale something along this order:<br /><br />My speed is relative to the surface of the Earth... The Earth's speed is its orbit around the sun... The Sun is its orbit around the center of the Milky Way... The Milky Way to our Local Group... our Local Group to the Virgo Cluster... The Virgo cluster to the Great Attractor. <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>
 
N

newtonian

Guest
rodneyb341 - And just to add: Milky Way is on a sort of river in space heading for the Great Attractor along with thousands of other galaxies.<br /><br />Some of these galaxies are blue-shifted in respect to us - notably Andromeda galaxy with which we will probably merge in about 5 billion years or so.<br /><br />Most galaxies are red-shifted in respects to us and therefore heading away from us - many of these because of the expansion of our universe.<br /><br />And that, btw, involves two types of motion:<br /><br />1. Motion on (in) the fabric of space - this motion has a speed limit: the speed of light.<br /><br />2. The expansion of space itself, where with increasing distance there is increasing relative motion. I am not aware of any speed limit, though there may be one. It is certainly much faster than the speed of light.
 
D

derekmcd

Guest
And just to add: <img src="/images/icons/wink.gif" /><br /><br />You are correct on #2... but;<br /><br />Just so no one gets confused... though these very distant and unobservable galaxies may (and probably do) travel away from us and speeds greater than the speed of light, Einstein's proposal is not violated as no information can be transmitted to said galaxies. <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>
 
N

newtonian

Guest
derekmcd - Except by prayer. It is my belief that information can be transmitted FTL by prayer.<br /><br />One should not rule out the possibility that some forms of energy or matter may be able to exceed the speed of light - granted that the types of matter we have thus far scientifically observed is limited to light speed.<br /><br />Theoretical physicists have considered seriously the possible existence of tachyons - which would be matter which cannot decrease in speed to the speed of light.<br /><br />Such matter would be FTL.<br /><br />We also do not know the speed of dark energy.<br /><br />While this is beyond science at this moment (I think), we may some day have FTL dark energy telescopes which can tell us observationally some information about what lies beyond our visibility horizon.<br /><br />And, before that, there is also the possibility of cause and effect from beyond our light cone by a domino effect - in fact, the accleration of expansion of our universe could be caused by just such a domino effect whereby FTL matter from beyond influences matter near our lilght cone edge - where the two light cones overlap like dominoes (distant dominos cannot directly interact - but dominoes in between can transmit the effect).<br /><br />Note: in that latter model, which is my own personal model I have postulated before on SDC, the FTL matter is ordinary matter with FTL motion caused by expansion of space rather than motion on the fabric of space (/time). <br /><br />Note: gravity is probably limited to light speed - but if it is even slightly faster or not exactly constant or light speed is not exactly constant, over the past billions of years...........
 
Status
Not open for further replies.

Latest posts