Is Prof Stephen Hawkins correct

Status
Not open for further replies.
G

Gary_Peck

Guest
<p>Is the universe 15 billion years old? </p><p>He&nbsp;suggest all the evidence points to this. How do they reach this conclusion? I think they are using the hubble telescope to reach these conclusions. Are they basing all this on how far they can see? I wonder what they would conclude if they put the Hubble telescope at the farthest point they could see. I bet they would see just as far again and then new calculations would have to be made. Personally I think it is Thousands of billions x billions of years old and we will never know it's true size or age. Any opinions.</p>
 
M

MeteorWayne

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Is the universe 15 billion years old? He&nbsp;suggest all the evidence points to this. How do they reach this conclusion? I think they are using the hubble telescope to reach these conclusions. Are they basing all this on how far they can see? I wonder what they would conclude if they put the Hubble telescope at the farthest point they could see. I bet they would see just as far again and then new calculations would have to be made. Personally I think it is Thousands of billions x billions of years old and we will never know it's true size or age. Any opinions. <br />Posted by Gary_Peck</DIV><br /><br />First of all, it's Hawking, not Hawkins.</p><p>Second, he's not the one who says that. It has been determined by decades of well supported astronomical measurements by thousands of researchers. I'd suggest you read this for some background, which you seem to be sorely lacking.</p><p>http://en.wikipedia.org/wiki/Age_of_the_universe</p><p>Third, the exact age (with zero error bars) will never be known, but the current value is estimated to be accurate within a few hundred million years. Since nothing from that era exists it will never be known with abolute precision.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
G

Gary_Peck

Guest
<p>I do apologise for spelling his name wrong. He himself suggests this but no doubt agrees with others on these findings. Reading this page on his web site. (link)&nbsp;They are only assuming and no doubt are entirely wrong. They need to build a bigger and better telescope than the&nbsp; Hubble one. When they do, I think their guessing will have to be recalculated. Before Hubble was put in Space I said there would be more galaxies and everything else associated with space further than what we could see. Hubble as proved me right. I think the next generation of telescopes will confirm what I say.</p><p>http://www.hawking.org.uk/index.php?option=com_content&view=article&id=62&Itemid=66</p>
 
M

MeteorWayne

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I do apologise for spelling his name wrong. [/QOUTE]</p><p>You should ! <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-smile.gif" border="0" alt="Smile" title="Smile" /></p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>He himself suggests this but no doubt agrees with others on these findings. Reading this page on his web site. (link)&nbsp;They are only assuming and no doubt are entirely wrong. </DIV></p><p>On what basis do you say that the entire astronimical community is wrrong. Because you say so with no physics or science to back you up? Because it makes sense to you, who hasn't even made the effort to understand what they are talking about?</p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>They need to build a bigger and better telescope than the&nbsp; Hubble one. When they do, I think their guessing will have to be recalculated. Before Hubble was put in Space I said there would be more galaxies and everything else associated with space further than what we could see. Hubble as proved me right. I think the next generation of telescopes will confirm what I say.http://www.hawking.org.uk/index.php?option=com_content&view=article&id=62&Itemid=66 <br />Posted by Gary_Peck</DIV></p><p>Again, another failing of your understanding about time and distance. You could build the biggest telescope imaginable and it won't help overcome the primary problem. Since the Universes is only ~ 13.7 Gy old, you can only see as far as light has traveled in that time. Whatever lies beyond that time/distance can never be seen by us.<br /></p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
G

Gary_Peck

Guest
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>First of all, it's Hawking, not Hawkins.Second, he's not the one who says that. It has been determined by decades of well supported astronomical measurements by thousands of researchers. I'd suggest you read this for some background, which you seem to be sorely lacking.http://en.wikipedia.org/wiki/Age_of_the_universeThird, the exact age (with zero error bars) will never be known, but the current value is estimated to be accurate within a few hundred million years. Since nothing from that era exists it will never be known with abolute precision. <br />Posted by MeteorWayne</DIV><br /><br />I have read the wikipedia page link. I believe they have made flaws with their diagrams and calculations. Because the Earth is so small and contained in something so big how can true measurements be made. What about the galaxies on the edge and final limits of what the Hubble telescope can see. They are only making decisions of objects within a confined area. Even this area is massive.
 
M

MeteorWayne

Guest
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I have read the wikipedia page link. I believe they have made flaws with their diagrams and calculations. Because the Earth is so small and contained in something so big how can true measurements be made. What about the galaxies on the edge and final limits of what the Hubble telescope can see. They are only making decisions of objects within a confined area. Even this area is massive. <br />Posted by Gary_Peck</DIV><br /><br />The answers are obvious to anyone who has investigated the subject. You need to spend some time educating yourself about current theoretical understanding before you start making stuff up. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
U

UFmbutler

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I have read the wikipedia page link. I believe they have made flaws with their diagrams and calculations. Because the Earth is so small and contained in something so big how can true measurements be made. What about the galaxies on the edge and final limits of what the Hubble telescope can see. They are only making decisions of objects within a confined area. Even this area is massive. <br /> Posted by Gary_Peck</DIV></p><p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/7/15/77228a97-fdcd-4407-af52-2acac78c6cab.Medium.gif" alt="" /></p><p>Do you understand the Hubble law and how you derive the age of the universe from the Hubble constant?&nbsp; If the universe were truly much older, the Hubble constant would be very different and would certainly not fit the data.&nbsp; How can you explain this discrepancy which is certainly way out of even the most generous error bars?&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
S

SpeedFreek

Guest
Don't you just love people who "know" that modern science must be wrong but don't actually understand the science. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>
 
M

MeteorWayne

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Don't you just love people who "know" that modern science must be wrong but don't actually understand the science. <br />Posted by SpeedFreek</DIV><br /><br />Oh yeah, I "Love" them.</p><p>It seems so obvious that you should have some idea of what you are talking about before creating new ideas....but I ask too much.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
G

Gary_Peck

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> Do you understand the Hubble law and how you derive the age of the universe from the Hubble constant?&nbsp; If the universe were truly much older, the Hubble constant would be very different and would certainly not fit the data.&nbsp; How can you explain this discrepancy which is certainly way out of even the most generous error bars?&nbsp; <br />Posted by UFmbutler</DIV><br /><br />That is if the information is correct.&nbsp; - (NASA summarizes existing data to <u>i<strong>ndicate</strong></u> a constant of). - &nbsp;(<strong><u>if</u></strong> spacetime is <u><strong>assumed</strong></u> to be flat). - &nbsp;I could pick other possible discrepencies. - (The galaxies at the edge of what the Hubble can see appear to be younger). - What if they are not, but much older. One small error in all these calculations can throw everything out of perspective. Which would have serious affects on other calculations.</p><p>Look at the evidence. As we look out into Space in any direction, We see galaxy after Galaxy, after Galaxy. The evidence&nbsp; supports it just goes on & on & on. Just get in a earoplane and fly along the equator and do not stop till you find the edge of the Earth. Where do you stop.&nbsp;To me the evidence suggests it is thousands of billions years old. There must be a point when light is unable to carry on travelling. </p><p>If I&nbsp;was to shine&nbsp;a 1oo watt light bulb at the moon. I know it would not reach there.How far would I have to be to be able to notice it was just about visible? Has anyone taken this into account or does light go on forever being visible no matter how far away you are?</p>
 
U

UFmbutler

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That is if the information is correct.&nbsp; - (NASA summarizes existing data to indicate a constant of). - &nbsp;(if spacetime is assumed to be flat). - &nbsp;I could pick other possible discrepencies. - (The galaxies at the edge of what the Hubble can see appear to be younger). - What if they are not, but much older. One small error in all these calculations can throw everything out of perspective. Which would have serious affects on other calculations.Look at the evidence. As we look out into Space in any direction, We see galaxy after Galaxy, after Galaxy. The evidence&nbsp; supports it just goes on & on & on. Just get in a earoplane and fly along the equator and do not stop till you find the edge of the Earth. Where do you stop.&nbsp;To me the evidence suggests it is thousands of billions years old. There must be a point when light is unable to carry on travelling. If I&nbsp;was to shine&nbsp;a 1oo watt light bulb at the moon. I know it would not reach there.How far would I have to be to be able to notice it was just about visible? Has anyone taken this into account or does light go on forever being visible no matter how far away you are? <br /> Posted by Gary_Peck</DIV></p><p>Clearly you haven't looked into this any further than looking at press releases.&nbsp; There's a reason why we think distant galaxies are younger...the most distant ones are observed to be in a completely different phase of galactic evolution, specifically the quasar/AGN stage where the supermassive black holes at the center of the galaxies are still accreting a large amount of material.&nbsp; We do not see any nearby quasars, but since galaxies, such as our own, still have black holes it is a reasonable assumption that quasars are a common early phase of evolution.&nbsp;&nbsp;</p><p>Your concept of light travel is entirely wrong.&nbsp; If you shine a 100 watt light bulb "at" the moon, of course an observer on the moon won't be able to see it, but photons still arrive.&nbsp; As the beam from the bulb travels, it begins to spread out by the 1/r^2 relation, so maybe not many&nbsp; of the photons hit the moon, but unless they are all reflected back down to the surface of the earth by the atmosphere or absorbed, some will certainly travel past the moon and beyond.&nbsp; Even so, for astronomical sources they don't emit at just one wavelength.&nbsp; While visible photons may be obscured by interstellar extinction, other wavelengths(i.e. infrared) make it through most dust clouds.&nbsp; By the time the light gets here it is much dimmer(for example, a typical "dilution factor" for starlight is 10^-14, meaning the energy density of starlight we observe locally is 10^-14 times what it would be if oyu were right next to the star).&nbsp; We can still see other stars though.&nbsp; People have even detected quasars from a measly 3 detected photons. &nbsp;</p><p>You keep saying the evidence shows you that the universe is "thousands of billions of years old"...where is this evidence?&nbsp; If you don't intend on putting up solid evidence aside from just bad analogies, I think this is in the wrong forum..&nbsp; </p> <div class="Discussion_UserSignature"> </div>
 
E

emperor_of_localgroup

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp; Posted by UFmbutler</DIV></p><p><font size="2">Just a thought suddenly came to me.&nbsp;We &nbsp;can see a young galaxy of 15B years ago. That galaxy&nbsp;now &nbsp;definitely doesn't look like what it looked like 15 B years ago. Which means the galaxy since then have undergone several major changes. </font></p><p><font size="2">If we can see the galaxy what it looked like 15B years ago, shouldn't we also be able to &nbsp;see the same galaxy&nbsp; what it looked like, say, &nbsp;14B, 13B, 12B........1B years ago?&nbsp; Shouldn't we see it&nbsp;like a movie&nbsp; being played in reverse on&nbsp;each &nbsp;galaxy? Why do we have missing links even with galaxies?</font></p><p><font size="2">Just a wild thought!!<br /></font></p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>
 
O

origin

Guest
Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Just a thought suddenly came to me.&nbsp;We &nbsp;can see a young galaxy of 15B years ago. That galaxy&nbsp;now &nbsp;definitely doesn't look like what it looked like 15 B years ago. Which means the galaxy since then have undergone several major changes. If we can see the galaxy what it looked like 15B years ago, shouldn't we also be able to &nbsp;see the same galaxy&nbsp; what it looked like, say, &nbsp;14B, 13B, 12B........1B years ago?&nbsp; Shouldn't we see it&nbsp;like a movie&nbsp; being played in reverse on&nbsp;each &nbsp;galaxy? Why do we have missing links even with galaxies?Just a wild thought!! <br />Posted by emperor_of_localgroup</DIV><br /><br />Yes, we could do that but it would take very long to make that movie.&nbsp; We won't see the galaxy as it looke 14B years ago until 1B years from now.&nbsp; We won't be able to see how that galaxy look 1B years ago until 14B years from now.&nbsp; The worst part is it will take that amount of time only if the universe was not expanding - it will actuall take longer than those times. <div class="Discussion_UserSignature"> </div>
 
E

emperor_of_localgroup

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Yes, we could do that but it would take very long to make that movie.&nbsp; We won't see the galaxy as it looke 14B years ago until 1B years from now.&nbsp; We won't be able to see how that galaxy look 1B years ago until 14B years from now.&nbsp; The worst part is it will take that amount of time only if the universe was not expanding - it will actuall take longer than those times. <br />Posted by origin</DIV><br /><br /><font size="2">The movie you are describing is a movie played 'forward'. I was thinking of a movie being played in reverse. Suppose galaxy A is 15B yr old, and galaxy B is 14 yr old, but B is physically &nbsp;closer to us than A.&nbsp;&nbsp;Assume B is evolved from A. We'll see B's light before we see A's light. That's why it is reverse.</font></p><p><font size="2">In your scenario, B is moving away from both us and A. That's why we have to wait 1B yr to see B.</font></p><p><font size="2">Another weird thought. Why do we see a moving galaxies or&nbsp; distant stars as a point objects? should n't we see them as streaks of light?&nbsp; Has anyone thought about this?</font></p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>
 
M

MeteorWayne

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The movie you are describing is a movie played 'forward'. I was thinking of a movie being played in reverse. Suppose galaxy A is 15B yr old, and galaxy B is 14 yr old, but B is physically &nbsp;closer to us than A.&nbsp;&nbsp;Assume B is evolved from A. We'll see B's light before we see A's light. That's why it is reverse.In your scenario, B is moving away from both us and A. That's why we have to wait 1B yr to see B.Another weird thought. Why do we see a moving galaxies or&nbsp; distant stars as a point objects? should n't we see them as streaks of light?&nbsp; Has anyone thought about this? <br />Posted by emperor_of_localgroup</DIV><br /><br />What you need to grasp is that we are looking at light emitted at one instant in time. The galaxy 12 BY away, emitted that light 12 BY ago. It would only smear if we were seeing light emitted at different times, but we don't. We only see light emitted exctly 12 BY ago. A hundred years from now, we will see the light emitted 12BY+100 years ago. Hope that helps!</p><p>Wayne</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
C

CalliArcale

Guest
<p>Hello, and welcome to Space.com! </p><p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That is if the information is correct.&nbsp; - (NASA summarizes existing data to indicate a constant of). - &nbsp;(if spacetime is assumed to be flat). - &nbsp;I could pick other possible discrepencies. - (The galaxies at the edge of what the Hubble can see appear to be younger). - What if they are not, but much older. One small error in all these calculations can throw everything out of perspective. Which would have serious affects on other calculations.Look at the evidence. As we look out into Space in any direction, We see galaxy after Galaxy, after Galaxy. The evidence&nbsp; supports it just goes on & on & on. Just get in a earoplane and fly along the equator and do not stop till you find the edge of the Earth. Where do you stop.&nbsp;To me the evidence suggests it is thousands of billions years old. There must be a point when light is unable to carry on travelling. If I&nbsp;was to shine&nbsp;a 1oo watt light bulb at the moon. I know it would not reach there.How far would I have to be to be able to notice it was just about visible? Has anyone taken this into account or does light go on forever being visible no matter how far away you are? <br /> Posted by Gary_Peck</DIV></p><p>It sounds to me that the main reason you doubt the generally accepted age of the Universe is because there could be more galaxies beyond our current observable horizon, correct?&nbsp; (Our current observable horizon means the limit of our observational abilities.)</p><p>If that is so, then you are definitely oversimplifying the way that age is calculated.&nbsp; It is not merely a matter of seeing how far we can look and then assuming that to be the edge.&nbsp; In fact, the most distant galaxies that we can presently observe are quite a bit *younger* than the Universe, so astronomers expect the universe to go on a fair bit past that.&nbsp; I'm not an astrophysicist, so I can't really explain it very well, but as I understand it, the number is based on the maximum age it could be given currently observed expansion, the light speed limit, and so on.</p><p>Now, it could indeed be that the calculations are based on some wrong assumptions, or that there is a hitherto unknown error in the data.&nbsp; That's okay.&nbsp;&nbsp; The generally accepted age of the universe is not considered an absolute fact.&nbsp; (Absolute facts are vanishingly rare in science, as it happens.)&nbsp; Rather, it is considered the best estimate that anybody's come up with so far.&nbsp; It is expected that the value will be refined, and perhaps completely replaced as new information becomes available.&nbsp; That's how science works.&nbsp; ;-)</p><p>But for scientists to change their mind about the age of the Universe, they need something more than a hunch.&nbsp; In this case, they'll need some fairly persuasive evidence that some of the basic assumptions underlying the estimate are wrong, and that's not a simple thing.&nbsp; For instance, one of the assumptions is that light speed is an absolute limit, and so far that particular assumption has stood up remarkably well to testing.&nbsp; It would take something extraordinary to surpass it. </p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
C

CalliArcale

Guest
<p>I thought of a simpler way to say what I just said.</p><p>It is correct that all the evidence currently points towards the Universe being about 15 billion years old.&nbsp; This does not preclude the possibility that new evidence will come up showing that this figure is wrong.&nbsp; Perhaps the Universe is older.&nbsp; Perhaps it is younger.&nbsp; But that conclusion will have to wait for new evidence. </p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
A

Aaupaaq

Guest
I wonder, if the 'current' understanding involves what we understand as constants?&nbsp; What if the whole universe manifested, in a rate faster than the speed of light?&nbsp;&nbsp; Is this even possible?&nbsp; a bubble being blown, at a really fast rate!&nbsp; This would probably make this universe a lot younger, according to our understanding!&nbsp; Because of the size, the light travels from one end to us like 15 billion years.&nbsp; Wow, the universe is big! <div class="Discussion_UserSignature"> We always walked on water, like skating! </div>
 
R

robnissen

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I thought of a simpler way to say what I just said.It is correct that all the evidence currently points towards the Universe being about 15 billion years old.&nbsp; This does not preclude the possibility that new evidence will come up showing that this figure is wrong.&nbsp; Perhaps the Universe is older.&nbsp; Perhaps it is younger.&nbsp; But that conclusion will have to wait for new evidence. <br />Posted by CalliArcale</DIV></p><p><font size="3">Actually he missed his best "evidence" that the universe is older than about 14B years.&nbsp; If we can see light from galaxies 13B LY away, then that galaxy had to be 13B LY away, 13B years ago, which means that it had been separating from the earth for 13B years, which in turn would give an age of at least&nbsp;26B for the universe.</font></p><p><font size="3">The problem with that "evidence" is that it ignores inflation.&nbsp; Due to inflation, the 13B ly galaxy we are seeing now, was about 6 B LYs away shortly after the big bang.&nbsp; During the subsequent time that light has been traveling from that galaxy, the distance between us and that galaxy has inflated by about another 7B ly, which is why the light took 13b ly to get here.</font></p><p><font size="3">BTW, since the light left that galaxy, inflation has continued such that that galaxy is now about 42B ly away.&nbsp; Thus, we know the universe is now at least 84B ly in diameter.&nbsp; But it may be many orders of magnitude larger.&nbsp; There is no way of knowing the size of the original singularity.&nbsp; It may have been the size of a quarck, a dime, the earth, the MW, or larger than the entire visible universe.&nbsp; If it was much larger than a quark, then the visible universe is only a very small part of the entire universe, which could be trillions of ly across</font></p><p>&nbsp;</p><p>&nbsp;</p>
 
S

SpeedFreek

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'><br /> Posted by robnissen</DIV></p><p>Sorry Rob, but even though the concepts you are trying to convey are essentially correct, your figures are way out and you seem to be mixing different redshift distances.</p><p>The highest redshifted (z=7) galaxies we have seen were only around 3.5 billion light-years away, 13 billion years ago. During the time their light has been travelling towards us the universe has expanded and their distance has increased, putting them at something around 30 billion light-years away by now.</p><p>So the highest redshifted galaxies are the ones whose light has been travelling the longest and thus are the most distant galaxies today, and they were closer to us when their light was emitted, as you said, but it was a lot closer! These are the galaxies with the largest co-moving distance to us (which means their distance if they have subsequently receded with the expansion of the universe since their light was emitted).</p><p>The most distant galaxies we have seen at the distance they were when they emitted their light have lower redshifts (z=1.4) and are the galaxies that were receding at the speed of light when their light was emitted. Those other higher redshift&nbsp; (z=7) galaxies emitted their light when they were receding a lot faster than light, which is why their light took 13 billion years to reach us when it was emitted only 3.5 billion light years away.</p><p>Those lower redshift galaxies were the ones that were 5.7 billion light-years away when they emitted their light, but they only emitted the light we see 9 billion years ago. It was also at that time that the light from the higher redshift galaxies passed that distance on its journey towards us, and from then on all the light that is 9 billion or more years old was moving towards us through regions of space that were receding from us at less than the speed of light.</p><p>To sum up:</p><p>z=7 galaxy. Light emitted 12.9 billion years ago at a distance of 3.5 billion ly. Current distance 29 billion ly.</p><p>z=1.4 galaxy. Light emitted 9 billion years ago at a distance of 5.7 billion ly. Current distance 13.7 billion ly.</p><p>It seems to me you were getting the two somewhat mixed up.</p><p>&nbsp;</p><p> <img src="http://img.photobucket.com/albums/v105/speedfreek/misc/redshifts.gif" border="0" alt="Photobucket" /></p><p><em>Here is a little animation I knocked up a while back to try to illustrate things, but I'm not sure whether it helps or hinders! The right hand edge represents our viewpoint and the white lines are photons on our light-cone. The top line represents the CMBR (although galaxies would be there now, I should have animated it transforming into a galaxy perhaps!), the middle line is a z=7 galaxy and the bottom line is a z=1.4 galaxy.</em></p> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>
 
R

robnissen

Guest
<font size="3">The numbers I posted were ones that I read somewhere.&nbsp; (If its on the internet, it MUST be true.)&nbsp; Thanks for the correction. <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-smile.gif" border="0" alt="Smile" title="Smile" /></font>
 
Y

yevaud

Guest
<p>Just to throw in here - since some astute people have already been answering everything else - Steven Hawking is not known for anything in determining the age of the universe.&nbsp; His claim(s) to fame are:</p><p>1.&nbsp; Determing precise mechanisms whereby Singularities exist.</p><p>2.&nbsp; Theorizing about what we now know as Hawking Radiation, e.g. how a singularity can "evaporate" (lose energy) and ultimately vanish (as it detaches from our spacetime manifold).</p><p>3.&nbsp; What's known as the "Wave Function of the Universe," possibly his most outre' theory.</p><p>Just thought y'all should know. </p> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
D

derekmcd

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Is the universe 15 billion years old? He&nbsp;suggest all the evidence points to this. How do they reach this conclusion? I think they are using the hubble telescope to reach these conclusions. Are they basing all this on how far they can see? I wonder what they would conclude if they put the Hubble telescope at the farthest point they could see. I bet they would see just as far again and then new calculations would have to be made. Personally I think it is Thousands of billions x billions of years old and we will never know it's true size or age. Any opinions. <br /> Posted by Gary_Peck</DIV></p><p>They use the Wilkinson Microwave Anisotropy Probe (WMAP).&nbsp; Here are the data from its most recent measurements:</p><p>http://lambda.gsfc.nasa.gov/product/map/dr3/parameters_summary.cfm </p><p>Keep in mind, though... the WMAP works under the assumption of the parameters of the LambdaCDM model and states as much under the data.&nbsp; To date, the LambdaCDM model is the best working model we have.</p><p>Here's a good description of other observations that place limits on the age of the universe that don't rely on the LambdaCDM model:</p><p>http://www.astro.ucla.edu/~wright/age.html </p> <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>
 
Status
Not open for further replies.

Latest posts