Mitch Cronin Posted February 25, 2014 Share Posted February 25, 2014 If, - the further you look back in space, galaxies are found to be, in a plotted curve of type 1a sn, above the expected straight line plot for a steadily expanding universe, - is the foundation for the supposition of Dark Energy... and I believe that's correct so far, yes?...It seems to me that should mean... in the past, everything was moving faster, since what they're seeing is the light's wavelength as radiated at that time, no? I've missed something, have I? Link to comment Share on other sites More sharing options...
boestar Posted February 25, 2014 Share Posted February 25, 2014 I have seen a few different theories on the expansion of the universe. One says it is slowing down and one says it is speeding up. Beyond that my brain starts to overheat just trying to comprehend infinity and our place within it. then I get drunk and all is better in the world Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 25, 2014 Author Share Posted February 25, 2014 Current theory is that it's expansion is accelerating.... I'm having trouble understanding how they came to that conclusion. Link to comment Share on other sites More sharing options...
Don Hudson Posted February 25, 2014 Share Posted February 25, 2014 malcolm;Re, "and who cares? :Grin-Nod:"I know that's in fun, but I think native human curiosity about one's existence and "place" in the face of increasing knowledge is what causes many to care. One doesn't need to join societies to exercise one's mind for find congenial company for one's curiosity. We are, after all, "star stuff" and when we look up, we see where we came from - it sends shivers up my spine every time I encounter that thought, (along with the huge snowfall, we've just had!) Link to comment Share on other sites More sharing options...
boestar Posted February 25, 2014 Share Posted February 25, 2014 Current theory is that it's expansion is accelerating.... I'm having trouble understanding how they came to that conclusion. you and me both fellow human Link to comment Share on other sites More sharing options...
boestar Posted February 25, 2014 Share Posted February 25, 2014 I watched a whole show explaining dark matter and dark energy and other dark stuff and still have absolutely no understanding of how one can prove the existence of something that by definition doesn't exist. Link to comment Share on other sites More sharing options...
conehead Posted February 25, 2014 Share Posted February 25, 2014 Mitch; do you ever read Reddit? http://en.reddit.com/r/askscience/ It always leads me down some interesting rabbit trails... Link to comment Share on other sites More sharing options...
JL Posted February 26, 2014 Share Posted February 26, 2014 This specialty in physics; the one that relies on the observation of other material to "see" the effects of the unseen, is pretty darn obtuse. In trying (rather poorly) to explain this to my kids I often use the explanation of how aircraft fly. We can't see air (most of the time) but we can see its effect on other things around it like moisture and the fact that an aircraft is suspended in it.I think this is how the whole dark matter thing is being explored. Link to comment Share on other sites More sharing options...
boestar Posted February 26, 2014 Share Posted February 26, 2014 Yea. Dark matter is the something that fills the nothing between the other somethings but we can't be sure. Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 That's true... and the confidence in the existence of dark energy is due to the observation of it's effect... i.e. the acceleration of the universe's expansion. But that's what I don't quite get, since the plots of the measurements I've seen, show the most distant objects as being redshifted greater than the straight line expectation for a constant expansion. When those measurements were done, they had been expecting the result to show a curve below that line, meaning the expansion would be slowing down due to gravity. So the observed curve in the results told them it was accelerating, thus, something more powerful than gravity was defeating it.... some dark (read unknown) energy.So my question is related to how they interpreted that, from - what I read as - galaxies further in the past were moving faster than expected, in the past? Shouldn't that tell you that indeed the expansion is slowing? I must be thinking of something wrong, or there's something about time I'm not considering maybe? Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 You already made it clear you don't care, so why are you in this thread 4 times now?...but in answer... I have a hard enough time opening my beak in here, where I generally feel somewhat comfortable... there's just no way I'm going to pop into some expert scientist forum and ask what they'd probably consider a laughable question. Since I know there are some cosmos studying enthusiasts here, I thought maybe I might be able to engage in some conversation here, and perhaps even find an answer to my question. Is there something wrong with that Malcolm? Link to comment Share on other sites More sharing options...
Moon The Loon Posted February 26, 2014 Share Posted February 26, 2014 My greatest failure in understanding current cosmological thinking is not only the single Big Bang, but observations of the distant universe and conclusions drawn thereon.F'rinstance: The edge of the known universe has been detected (cosmic background radiation) and it appears to be accelerating away from us...still. This observed edge is between 13.7 and 13.8 billion light years away indicating to some the time since the Big Bang. And here's where my failure to understand kicks in. What we "see" was there 13.75 (for the sake of argument) billion years ago. WHAT IF in the ensuing 13.75 billion years, the Big Crunch started? That light has yet to reach us. How do we know how much longer we have to play on this Pale Blue Dot?And on the subject of infinity, what is it that traditional cosmologists don't understand about the concept of "no beginning and no end"? If there IS a beginning, what makes the Big Bang the beginning? And if there was a beginning, why do "they" insist on using the word "infinite" in descriptions of time?And on the subject of "time", as much as I enjoy SF stories about time travel, I think "time travel" is completely, totally, infinitely impossible unless one moves forward, in real time.So waddya think about that head-full, Mitch?? With apologies to Andy Rooney... Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 I'm trying to answer but the system isn't letting me post my answer....? Link to comment Share on other sites More sharing options...
Guest rattler Posted February 26, 2014 Share Posted February 26, 2014 I'm trying to answer but the system isn't letting me post my answer....?Is our forum exhibiting "self censorship" ? Link to comment Share on other sites More sharing options...
conehead Posted February 26, 2014 Share Posted February 26, 2014 I'm trying to answer but the system isn't letting me post my answer....?I just spent 10 minutes composing a reply to another thread, and when I hit "post reply", it hung up on "submitting reply" wouldn't go any further... Then I lost my composition... Link to comment Share on other sites More sharing options...
Guest rattler Posted February 26, 2014 Share Posted February 26, 2014 Try posting just a short line and then reopen the post using the full editor. Link to comment Share on other sites More sharing options...
cp fa Posted February 26, 2014 Share Posted February 26, 2014 I dropped the f bomb in an earlier thread. The naughty word censor didn't catch it, and I was unable to edit my post. I had to delete it and start over.The forum's been wonky for a while now, but I'm sure Glen and Judy are doing their best to get it back on the rails. Link to comment Share on other sites More sharing options...
Guest rattler Posted February 26, 2014 Share Posted February 26, 2014 I dropped the f bomb in an earlier thread. The naughty word censor didn't catch it, and I was unable to edit my post. I had to delete it and start over.The forum's been wonky for a while now, but I'm sure Glen and Judy are doing their best to get it back on the rails.F bomb, .... fig, forget, fool, fly , fart, frag .....there are so many Link to comment Share on other sites More sharing options...
boestar Posted February 26, 2014 Share Posted February 26, 2014 Ok ponder this. If, in the beginning, the entire matter of the universe was compacted into a tiny, very dense "Thing". What was that "Thing" inside of? couldn't have been inside the universe since the universe was inside the "thing". Keeping in mind that ALL matter was in the "thing" both dark matter and regular matter. So outside the "thing" there was no matter of any kind at all. Just a pure absence of matter except for the "Thing". With me so far????Now. The "Thing" reaches a critical mass of some magnitude and explodes. Now the matter expands into the emptiness and fills it with....well....emptiness. Well now it can't be empty because it was empty before. So we need to name it something so we call it matter and dark matter. Then we figure, to explain the emptiness, we will call it anti-matter because theoretical physicists can do stuff like that to explain the un-explainable. So now we have an ever expanding thing inside nothing expanding to no where. and I just broke my brain. Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 lol... good one Boestar.Dr. Leonard Suskind (one of the originators of string theory and a very well respected physicist) says our brains aren't wired to understand such things, because that's not the world we interact within. Like visualizing a world with more than three dimensions of space... it's beyond us to do so, he says, because that's not "our world" so we're just not wired that way.?[i'd better post this before it's too long and gets eaten?] Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 My greatest failure in understanding current cosmological thinking is not only the single Big Bang, but observations of the distant universe and conclusions drawn thereon.F'rinstance: The edge of the known universe has been detected (cosmic background radiation) and it appears to be accelerating away from us...still. This observed edge is between 13.7 and 13.8 billion light years away indicating to some the time since the Big Bang. And here's where my failure to understand kicks in. What we "see" was there 13.75 (for the sake of argument) billion years ago. WHAT IF in the ensuing 13.75 billion years, the Big Crunch started? That light has yet to reach us. How do we know how much longer we have to play on this Pale Blue Dot?And on the subject of infinity, what is it that traditional cosmologists don't understand about the concept of "no beginning and no end"? If there IS a beginning, what makes the Big Bang the beginning? And if there was a beginning, why do "they" insist on using the word "infinite" in descriptions of time?And on the subject of "time", as much as I enjoy SF stories about time travel, I think "time travel" is completely, totally, infinitely impossible unless one moves forward, in real time.So waddya think about that head-full, Mitch?? With apologies to Andy Rooney...I'm gonna try again moon, but in the next post, in case it's the "quote" thing that fouls it.... Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 So far so good....First answer: (y'know, as best I can try, and just for fun... it's not as if I know anything!).... The expansion of the universe is ...universal, it's not like it's from the edge and out.... Similarly, if the universe was contracting, it would be , as they say, "space itself" that is contracting, so we'd be able to detect that from anywhere in the universe as well.... even if it was crunching, how much longer we've got will probably still depend on how much longer 'til the next "planet killer" rock comes-a-callin'.... else wise, the sun will burn us up before the Universe collapses. Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 Still working (keeping posts small so I don't lose 'em)next attempt to answer: ..... I think most cosmologists would be happy to admit they have no idea if the Big Bang was The Beginning, or just one bang in a series of other events.... But they will tell you they don't believe there's any way we can ever know that.... as far as endings... it's looks at the moment that there will be no ending..... unless you consider all atoms in the universe being torn apart and the universe being nothing more than a random collection of particles in space, an ending? ...because if expansion continues unabated, that's what they now reckon will have to be the eventual outcome.... Time is something altogether different. Most theoretical physicists seem to acknowledge we don't have a very good understanding of time either... and what we do know is often really bizzarre!(cont'd next post) Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 (I'm beginning to think it was just the quoting that fouled my ability to post?)Still trying to answer you Moon... Time.... I recently watched a documentary with Brian Greene where he admitted the possibility to go backward in time must exist.... but in terms of probability, it's no more likely than you being able to pass all the atoms in your hand through your monitor. ....which, given infinite time, like the monkey typing out the complete works of Shakespeare, will happen sometime. (hey, I'm just telling' ya what he said!).... otherwise, it's well known that the faster you travel through space, the slower you travel through time... so if you were to take a really (really!) fast ride away from Earth for say 25 years, turn around and come back for the next 25 years, you'd arrive at a time on Earth beyond the 50 years you'd experienced... you'd have essentially travelled into the future (how much would depend on how fast you travelled)... but it would be a one way trip with no return ability, and would probably cost more energy than we've ever made on this planet yet..... ?How'd I do? Link to comment Share on other sites More sharing options...
Mitch Cronin Posted February 26, 2014 Author Share Posted February 26, 2014 Ok ponder this. If, in the beginning, the entire matter of the universe was compacted into a tiny, very dense "Thing". What was that "Thing" inside of? couldn't have been inside the universe since the universe was inside the "thing". Keeping in mind that ALL matter was in the "thing" both dark matter and regular matter. So outside the "thing" there was no matter of any kind at all. Just a pure absence of matter except for the "Thing". With me so far????Now. The "Thing" reaches a critical mass of some magnitude and explodes. Now the matter expands into the emptiness and fills it with....well....emptiness. Well now it can't be empty because it was empty before. So we need to name it something so we call it matter and dark matter. Then we figure, to explain the emptiness, we will call it anti-matter because theoretical physicists can do stuff like that to explain the un-explainable. So now we have an ever expanding thing inside nothing expanding to no where. and I just broke my brain.In case this get's sucked into a black hole, I'll just leave this and try to respond in the next post also... Link to comment Share on other sites More sharing options...
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