Jay-qu Posted June 18, 2005 Report Share Posted June 18, 2005 if it where possible to pinpoint an exact position in space ( but im not sure if this is possible because of expansion) could you then calculate earths net velocity relative to this 'stationary' point? if so has this been attempted? Quote Link to comment Share on other sites More sharing options...
Harzburgite Posted June 18, 2005 Report Share Posted June 18, 2005 There are no fixed points in space. Velocity can only be measured relative to something else. Here are some examples: Earth's average orbital velocity around the sun: 29.8 km/second relative to the sun Astronomers sometimes find it convenient to imagine that there is a sort of fixed point in space as you have described. For example they will refer to the Local Standard of Rest (LSR). This is an imaginary circular orbit around the galaxy lying within the Galactic plane. At our distance from the galactic centre a star that followed that orbit exactly would be travelling at 220 kms per second relative to the galactic centre. The Solar system's orbit is not exactly circular (nor does it remain in the galactic plane). So, it has a motion, relative to the LSR, towards the constellation of Hercules, of between 17 and 22 kms/sec. Our closest large neighbour galaxy is the Andromeda galaxy. We are approaching it at about 140 kms/second and will eventually collide in around 3 billion years. Quote Link to comment Share on other sites More sharing options...
UncleAl Posted June 18, 2005 Report Share Posted June 18, 2005 A relativistic universe has four distinct distances: luminosity (inverse square), angular diameter, parallax, and proper motion. No two of them need agree to maintain consistency. Clocks can only be synchronized by being local. Pick a point, measure a Doppler shift, get a number. It's mathematically consistent but is it physically meaningful? Depends on how far away the point is and how much accuracy you need. Quote Link to comment Share on other sites More sharing options...
Little Bang Posted June 19, 2005 Report Share Posted June 19, 2005 If there was a big bang then there must have been a center. Why would this view be inconsistant with anything? Quote Link to comment Share on other sites More sharing options...
Aki Posted June 19, 2005 Report Share Posted June 19, 2005 If there was a big bang then there must have been a center. Why would this view be inconsistant with anything? The Big Bang did not occur at the center of the universe, it occured at every location in the universe. Quote Link to comment Share on other sites More sharing options...
Boerseun Posted June 19, 2005 Report Share Posted June 19, 2005 If there was a big bang then there must have been a center. Why would this view be inconsistant with anything?Space itself grew out of the Big Bang. In other words, if the universe and all its components were compressed to a pinhead, which exploded and subsequently expanded, space was tied to this pinhead as well. And space has been expanding ever since as well. So, as Aki said, in an expanding universe, every cubic millimetre was the core, location, and origin of the Big Bang - therefore, every point in the Universe is static, and the rest of the Universe is in motion relative to that point. It's the space between the points that's stretching. I have to add that this is only theory and conjecture, and can change when the next Einstein makes his appearance.To confuse you even more; you live in a different universe than I do. The edges of your universe is a couple of milliseconds off-set from the edges of my universe, seeing as you're on the other side of the world. Each individual therefore inhabits a different universe, althoug the practical volume of everybody's universe intersects, so it doesn't matter in the least. It's just a cool thought. Quote Link to comment Share on other sites More sharing options...
chatlack Posted June 19, 2005 Report Share Posted June 19, 2005 That's ridiculous. "The bigbang point" was probably moving too. Its possible that we are moving at lightspeed or not moving , only moving in time...That was what relativity said, right? Quote Link to comment Share on other sites More sharing options...
Tormod Posted June 19, 2005 Report Share Posted June 19, 2005 That's ridiculous. "The bigbang point" was probably moving too. Its possible that we are moving at lightspeed or not moving , only moving in time...That was what relativity said, right? I think you need to read up on relativity, chatlack. Anyway, this has been discussed at length before. Quote Link to comment Share on other sites More sharing options...
chatlack Posted June 19, 2005 Report Share Posted June 19, 2005 Sorry. I could have made a mistake.I think I mixed up some theories. :rant: But its the part that fits my opinion. Quote Link to comment Share on other sites More sharing options...
Boerseun Posted June 19, 2005 Report Share Posted June 19, 2005 That's ridiculous. "The bigbang point" was probably moving too. Its possible that we are moving at lightspeed or not moving , only moving in time...That was what relativity said, right?...moving? Compared to what? What else was there that was moving at the time? Nothing? Exactly. There wasn't anything else to judge velocity by. I know - it's counterintuitive, but that's the way it works... :rant: Quote Link to comment Share on other sites More sharing options...
UncleAl Posted June 20, 2005 Report Share Posted June 20, 2005 If there was a big bang then there must have been a center. Why would this view be inconsistant with anything?The Big Bang was not an explosion in space, the Big Bang was an explosion of space. All 4(pi)steradians of every point in the universe exactly points to the Big Bang. EVERY point in the universe is at its exact center. At the end of every direction in which you look, that's the Big Bang. Reality is not Euclidean, Galilean, or Newtonian. Live with it. Quote Link to comment Share on other sites More sharing options...
Little Bang Posted June 20, 2005 Report Share Posted June 20, 2005 I realize this is the current view, but does't it leave a little bit of a sour test in your own personal logic, it does mine. One problem I have is that if the universe is a sphere this view grates on my nerves, if it is a torus I can understand it. Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted June 20, 2005 Author Report Share Posted June 20, 2005 ok so relative to a fixed point is pretty much impossible because there are no 'fixed points' so how about relative to our local group of galaxies? if someone told me where i can get the data then i guess i could do it myself... Quote Link to comment Share on other sites More sharing options...
chatlack Posted June 20, 2005 Report Share Posted June 20, 2005 I cant understand why people say "space" to area that galaxies exist. Space is everywhere for me. Saying "space is an area" is logically wrong, i think.Space is not groving, galaxies passing through it.... Quote Link to comment Share on other sites More sharing options...
lindagarrette Posted June 20, 2005 Report Share Posted June 20, 2005 If there was a big bang then there must have been a center. Why would this view be inconsistant with anything?The center of what? There was nothing there. After the bang, it was everywhere - no center. The universe is not a sphere. Quote Link to comment Share on other sites More sharing options...
Tormod Posted June 20, 2005 Report Share Posted June 20, 2005 One problem I have is that if the universe is a sphere this view grates on my nerves, if it is a torus I can understand it. It is not a sphere. In fact, the shape of the universe comes in many flavors depending on what theory you subscribe to. Quote Link to comment Share on other sites More sharing options...
Tormod Posted June 20, 2005 Report Share Posted June 20, 2005 I cant understand why people say "space" to area that galaxies exist. Space is everywhere for me. Saying "space is an area" is logically wrong, i think.Space is not groving, galaxies passing through it.... Okay. Then *what* is space? And *where* is it? ;) (And how can galaxies be moving through it if it is *not* what the galaxies exist in)? Quote Link to comment Share on other sites More sharing options...
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