![]() |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
![]()
Universe 156 Billion Light-Years Wide
http://www.space.com/scienceastronom...ay_040524.html "If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and it's a whopper. The universe is at least 156 billion light-years wide." |
#2
|
|||
|
|||
![]()
Klaatu wrote in message ...
Universe 156 Billion Light-Years Wide http://www.space.com/scienceastronom...ay_040524.html "If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and it's a whopper. The universe is at least 156 billion light-years wide." Sorry I can't buy that. I read the article and I'm no Astrophysist but... If the speed of light is a constant and the universe is some 13.5 billion years old... than the universe is expanding at a speed which is faster than the speed of light (which I am told is an impossibility). Now I'm fine with that provided that the speed of light isn't the constant that everyone makes it out to be. Sorry don't get it... |
#3
|
|||
|
|||
![]()
In article ,
David Jones wrote: Klaatu wrote in message ... Universe 156 Billion Light-Years Wide http://www.space.com/scienceastronom...ay_040524.html "If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and it's a whopper. The universe is at least 156 billion light-years wide." Sorry I can't buy that. I read the article and I'm no Astrophysist but... If the speed of light is a constant and the universe is some 13.5 billion years old... than the universe is expanding at a speed which is faster than the speed of light (which I am told is an impossibility). Now I'm fine with that provided that the speed of light isn't the constant that everyone makes it out to be. Sorry don't get it... In an issue of Scientific American decades ago, I read an alternate hypothesis: galileo measured uniform time units by *singing* and counting the beats. The human musical rhythm is amazingly accurate when no other timepiece is available. -- ---------------------------------------------------------------- Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN e-mail: pausch at stockholm dot bostream dot se WWW: http://www.stjarnhimlen.se/ http://home.tiscali.se/pausch/ |
#4
|
|||
|
|||
![]()
On 25 May 2004 10:28:59 -0700, (David Jones)
wrote: Sorry I can't buy that. I read the article and I'm no Astrophysist but... If the speed of light is a constant and the universe is some 13.5 billion years old... than the universe is expanding at a speed which is faster than the speed of light (which I am told is an impossibility). Who says? The "speed limit" is only for light. There is no known speed limit for the expansion of space. The present mainstream interpretation of very high redshift objects is that those objects are effectively receding at a speed greater than the speed of light. See: http://arxiv.org/PS_cache/astro-ph/pdf/0011/0011070.pdf If you don't interpret the data the same, and limit yourself to special relativity/doppler shift, then you must posit a force that would cause the far flung galaxies (or us) to actually be moving in space at very close to light speed. For example, a recently discovered redshift, z, of 6.4 would correspond to a recession velocity of 96.4% of the speed of light if the expansion of space is ignored. See: http://www.sdss.org/news/releases/20030109.quasar.html http://hyperphysics.phy-astr.gsu.edu...redshf.html#c2 And the farther we look back in time, the more galaxies that "pile up" at such incredulous recession velocities. The co-moving coordinates of expanding space seems an explanation easier to swallow for me. --- Michael McCulloch |
#6
|
|||
|
|||
![]()
I was thinking the same thing today at work. 156B ly wide? In what
direction? If you use the 3-D spherical model and inward toward the past and origin is 13.5B ly, then 'wide' is pi*d or 2*13.5*pi which is about 85B ly 'around'. Maybe they are using a complicated saddle shape? Kirk (David Jones) wrote in message . com... Klaatu wrote in message ... Universe 156 Billion Light-Years Wide http://www.space.com/scienceastronom...ay_040524.html "If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and it's a whopper. The universe is at least 156 billion light-years wide." Sorry I can't buy that. I read the article and I'm no Astrophysist but... If the speed of light is a constant and the universe is some 13.5 billion years old... than the universe is expanding at a speed which is faster than the speed of light (which I am told is an impossibility). Now I'm fine with that provided that the speed of light isn't the constant that everyone makes it out to be. Sorry don't get it... |
#7
|
|||
|
|||
![]()
This reminds me of a quote I saw
in "Galaxies" by Dr. Timothy Ferris: " He showed me a little thing, the quantity of a hazel-nut, in the palm of my hand and it was as round as a ball. I looked thereupon with the eye of my understanding and thought: What may this be? And it was answered generally thus: It is all that is made." ---St. Juliana Ed |
#8
|
|||
|
|||
![]()
This reminds me of a quote I saw
in "Galaxies" by Dr. Timothy Ferris: " He showed me a little thing, the quantity of a hazel-nut, in the palm of my hand and it was as round as a ball. I looked thereupon with the eye of my understanding and thought: What may this be? And it was answered generally thus: It is all that is made." ---St. Juliana Ed |
#9
|
|||
|
|||
![]()
(David Jones) wrote in message . com...
Klaatu wrote in message ... Universe 156 Billion Light-Years Wide http://www.space.com/scienceastronom...ay_040524.html "If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and it's a whopper. The universe is at least 156 billion light-years wide." Sorry I can't buy that. I read the article and I'm no Astrophysist but... If the speed of light is a constant and the universe is some 13.5 billion years old... than the universe is expanding at a speed which is faster than the speed of light (which I am told is an impossibility). Now I'm fine with that provided that the speed of light isn't the constant that everyone makes it out to be. Sorry don't get it... In The bit we are in we can see only as far back as 13.5billion light years, so we're "limited" to a bubble around us of roughly that distance (in each direction), or roughkly speaking we can see about 18% of the universe if we assume a spherical shape. Apparently that question of shape is very much up for grabs anyway, so the idea of a 'width' to the universe may be misleading. Imagine being on a balloon surface that expands extremely quickly so that light from one part, on the other side of the balloon, is quickly 'pushed' so far away that at the speed of light it simply cannot reach us a 'mere' 13-14 billion years into the beginning of light. The expansion itself need not break the speed limit of physical objects (or does it, i don't think so though) I've also read that the rate of expansion is increasing, so that infact we can't even sit around and wait for this light to get to us, all the stuff is being 'pushed' away outside of our horizon of view and theoretically all we'll eventually be able to get light enough to see is our local goup of galaxies. http://www.phys.cwru.edu/~krauss/01ENDrev.html That'll soon curtail any long term optimism you may have had! |
#10
|
|||
|
|||
![]()
(David Jones) wrote in message . com...
Klaatu wrote in message ... Universe 156 Billion Light-Years Wide http://www.space.com/scienceastronom...ay_040524.html "If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and it's a whopper. The universe is at least 156 billion light-years wide." Sorry I can't buy that. I read the article and I'm no Astrophysist but... If the speed of light is a constant and the universe is some 13.5 billion years old... than the universe is expanding at a speed which is faster than the speed of light (which I am told is an impossibility). Now I'm fine with that provided that the speed of light isn't the constant that everyone makes it out to be. Sorry don't get it... In The bit we are in we can see only as far back as 13.5billion light years, so we're "limited" to a bubble around us of roughly that distance (in each direction), or roughkly speaking we can see about 18% of the universe if we assume a spherical shape. Apparently that question of shape is very much up for grabs anyway, so the idea of a 'width' to the universe may be misleading. Imagine being on a balloon surface that expands extremely quickly so that light from one part, on the other side of the balloon, is quickly 'pushed' so far away that at the speed of light it simply cannot reach us a 'mere' 13-14 billion years into the beginning of light. The expansion itself need not break the speed limit of physical objects (or does it, i don't think so though) I've also read that the rate of expansion is increasing, so that infact we can't even sit around and wait for this light to get to us, all the stuff is being 'pushed' away outside of our horizon of view and theoretically all we'll eventually be able to get light enough to see is our local goup of galaxies. http://www.phys.cwru.edu/~krauss/01ENDrev.html That'll soon curtail any long term optimism you may have had! |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
knowledge is power | mostafa dia | SETI | 4 | August 7th 04 02:24 PM |
questions about the universe... | Roger | Space Science Misc | 5 | March 17th 04 05:18 PM |
The Colour of the Young Universe (Forwarded) | Andrew Yee | Astronomy Misc | 0 | December 19th 03 05:48 PM |
Incontrovertible Evidence | Cash | Amateur Astronomy | 6 | August 24th 03 07:22 PM |