Jump to content




Welcome to Unexplained Mysteries! Please sign in or create an account to start posting and to access a host of extra features.


- - - - -

Expanding Universe


  • Please log in to reply
38 replies to this topic

#31    joc

joc

    Adminstrator of Cosmic Blues

  • Member
  • 14,465 posts
  • Joined:12 Dec 2003
  • Gender:Male
  • Location:Milky Way Galaxy 3rd planet

  • They're wearing steel that's bright and true
    They carry news that must get through
    They choose the path where no-one goes

Posted 03 January 2008 - 02:36 AM

Lovelynice on Jan 3 2008, 02:27 AM, said:

Nobody seems to want to answer this question, or discuss it.

I see the problem is that without the excuse of redshifting being being blamed solely on an object moving away, and not on other possible reasons such as the depletion of energy through entropy and distance, gravitational distortion, or cosmic dust, there is no real evidence for the claim that the further away glaxies are, the faster they are moving away. The expanding universe claim depends on redshshift, but if redshift is caused by something else besides movement away, not just movement, then there doesn't seem to be much evidence for an expanding universe.

Perhaps that is why no one wants to discuss it? wink2.gif

Posted Image
once i believed that starlight could guide me home
now i know that light is old and stars are cold

ReverbNation

#32    Startraveler

Startraveler

    Fleet Captain

  • Member
  • 4,539 posts
  • Joined:25 Jun 2006
  • Gender:Male
  • Location:New England

  • Knowledge Brings Fear.

Posted 03 January 2008 - 03:37 AM

Quote

I see the problem is that without the excuse of redshifting being being blamed solely on an object moving away, and not on other possible reasons such as the depletion of energy through entropy and distance, gravitational distortion, or cosmic dust, there is no real evidence for the claim that the further away glaxies are, the faster they are moving away. The expanding universe claim depends on redshshift, but if redshift is caused by something else besides movement away, not just movement, then there doesn't seem to be much evidence for an expanding universe.


In fairness, it was shown (using the best understanding of gravity on large scales we have, general relativity) that a static universe would be unstable before Hubble made his observations. This discovery actually prompted Einstein to alter his equations by inserting a term to prop the universe up against collapse under its own gravity. Indeed, you could go even further back; Newton had to struggle with the difficulties his own law of gravity created for static conceptions of the universe. Unless there's something else going on that we're not very familiar with (which certainly is not impossible), the universe ought to be either expanding or contracting.

Now, about the redshift: there was a good amount of debate following Hubble's discovery as to whether the redshift was really a product of cosmological expansion or whether, as you suggest, some other physical process could account for it (these alternative ideas usually fall under a category of ideas labeled "tired light hypotheses"). But nobody was ever able to figure out how to come up with an alternative that could successfully deal with all the observed aspects of cosmological redshift as well as an expanding universe model could (i.e. aspects like uniformity across all wavelengths, a lack of blurring, etc). You'd likely need to invent some new physics to get these desired results. As a consequence, the redshift-as-a-consequence-of-expansion point of view gathered steam.

Given what we know, the evidence fits together nicely to paint a picture of an expanding universe. It's possible that it's not correct but, accounting for the facts as we understand them, not very likely.


#33    Lovelynice

Lovelynice

    Ectoplasmic Residue

  • Member
  • Pip
  • 248 posts
  • Joined:03 Dec 2007
  • Gender:Female
  • Location:Japan

Posted 03 January 2008 - 06:48 AM

Startraveler on Jan 3 2008, 12:37 PM, said:

In fairness, it was shown (using the best understanding of gravity on large scales we have, general relativity) that a static universe would be unstable before Hubble made his observations. This discovery actually prompted Einstein to alter his equations by inserting a term to prop the universe up against collapse under its own gravity. Indeed, you could go even further back; Newton had to struggle with the difficulties his own law of gravity created for static conceptions of the universe. Unless there's something else going on that we're not very familiar with (which certainly is not impossible), the universe ought to be either expanding or contracting.

Now, about the redshift: there was a good amount of debate following Hubble's discovery as to whether the redshift was really a product of cosmological expansion or whether, as you suggest, some other physical process could account for it (these alternative ideas usually fall under a category of ideas labeled "tired light hypotheses"). But nobody was ever able to figure out how to come up with an alternative that could successfully deal with all the observed aspects of cosmological redshift as well as an expanding universe model could (i.e. aspects like uniformity across all wavelengths, a lack of blurring, etc). You'd likely need to invent some new physics to get these desired results. As a consequence, the redshift-as-a-consequence-of-expansion point of view gathered steam.

Given what we know, the evidence fits together nicely to paint a picture of an expanding universe. It's possible that it's not correct but, accounting for the facts as we understand them, not very likely.


Your last conclusion doesn't follow though.

Read through what you wrote, especially this part; "But nobody was ever able to figure out how to come up with an alternative that could successfully deal with all the observed aspects of cosmological redshift as well as an expanding universe model could"

Being unable to figure out a lack of an alternative within the theories known, should be cause to drop the theories that don't work, and start looking for something else - not just ignore the problem because you can't think around it.

The other funny statement was this; "Unless there's something else going on that we're not very familiar with (which certainly is not impossible)"

The way you word that as if implying the likelihood of being wrong was small, but given that we don't know what the something else(s) might be, and given that the redshift only due to movement explanation is resulting in something equally inexplicable (the further away something is, the faster it seems to be moving away), then it would be logical to conclude that the theories are wrong, and accept the more rational conclusion; WE DON'T KNOW. instead of feigning a "knowing" of what's going on.

Time to move to other theories, I think. The old ones aren't good enough.



#34    Startraveler

Startraveler

    Fleet Captain

  • Member
  • 4,539 posts
  • Joined:25 Jun 2006
  • Gender:Male
  • Location:New England

  • Knowledge Brings Fear.

Posted 03 January 2008 - 07:17 AM

Quote

Being unable to figure out a lack of an alternative within the theories known, should be cause to drop the theories that don't work, and start looking for something else - not just ignore the problem because you can't think around it.


I'll admit I haven't read much of what's come earlier in this thread: are you under the impression that big bang cosmology doesn't work well?

Quote

The way you word that as if implying the likelihood of being wrong was small, but given that we don't know what the something else(s) might be, and given that the redshift only due to movement explanation is resulting in something equally inexplicable (the further away something is, the faster it seems to be moving away), then it would be logical to conclude that the theories are wrong, and accept the more rational conclusion; WE DON'T KNOW. instead of feigning a "knowing" of what's going on.


Hubble's law (recession velocity is proportional to distance) isn't inexplicable, it's the definition of a homogeneous expansion. Without knowing exactly what's troubling you about that, it's difficult to know how to respond. Can you explain what it is about that idea that strikes you as inexplicable (apologies if you already have)?



#35    Lovelynice

Lovelynice

    Ectoplasmic Residue

  • Member
  • Pip
  • 248 posts
  • Joined:03 Dec 2007
  • Gender:Female
  • Location:Japan

Posted 03 January 2008 - 08:07 AM

Startraveler on Jan 3 2008, 04:17 PM, said:

I'll admit I haven't read much of what's come earlier in this thread: are you under the impression that big bang cosmology doesn't work well?


I pointed out a major problem with the evidence used. There's clearly a problem with the theory.


Startraveler on Jan 3 2008, 04:17 PM, said:

Hubble's law (recession velocity is proportional to distance) isn't inexplicable, it's the definition of a homogeneous expansion.


Sounds like religion to me,

The redshift being used for BOTH distance and movement is a major problem.

Making up a rule and putting a grand name on it doesn't solve that problem, it only seeks to hide it behind a pretend explanation that is seeking to avoud a problem.



#36    magnetar

magnetar

    Astral Projection

  • Member
  • PipPipPipPipPip
  • 726 posts
  • Joined:28 Aug 2005

Posted 03 January 2008 - 10:32 AM

read. discuss.


http://www-int.stsci.edu/~ariess/index.htm


#37    Lovelynice

Lovelynice

    Ectoplasmic Residue

  • Member
  • Pip
  • 248 posts
  • Joined:03 Dec 2007
  • Gender:Female
  • Location:Japan

Posted 03 January 2008 - 03:49 PM

magnetar on Jan 3 2008, 07:32 PM, said:



"Dark energy", yes that sounds like more mumbo-jumbo names to hide the unknown again.

They can't find the Higgs Boson either
No HIggs Boson - it doesn't apper to exist


#38    Startraveler

Startraveler

    Fleet Captain

  • Member
  • 4,539 posts
  • Joined:25 Jun 2006
  • Gender:Male
  • Location:New England

  • Knowledge Brings Fear.

Posted 03 January 2008 - 06:20 PM

Quote

Sounds like religion to me,


The Hubble law is an empirical relationship.

Quote

The redshift being used for BOTH distance and movement is a major problem.

Making up a rule and putting a grand name on it doesn't solve that problem, it only seeks to hide it behind a pretend explanation that is seeking to avoud a problem.


The redshift isn't used to determine distance (not when demonstrating Hubble's law, anyway), although once you've shown the rule is true by other methods, presumably you can use it. There's a toolkit of methods, carefully designed and refined over the past century, for determining distances at all scales called the cosmic distance ladder (ranging from standard candles like Type 1a supernovae to the discovery of a certain fact about the luminosity of certain galaxies called the Tully-Fisher relation, etc). So, again, I'm not sure what the problem is that you're referring to.


#39    dest_titor1

dest_titor1

    Conspiracy Theorist

  • Member
  • PipPipPipPipPipPipPip
  • 886 posts
  • Joined:05 Oct 2007
  • Gender:Male
  • Location:Outer ring of the Sombrero Galaxy

  • Are you in Plato`s cave, or are you on the surface?
    (Plato`s cave allegory)

Posted 05 January 2008 - 01:39 AM

Darkwind on Dec 10 2007, 03:30 AM, said:

Could the Universe be expanding because the so called big bang never stopped and some where in the Universe there is a point were material from "the bang" is still spewing into a hot section of the Universe?


-note-the Higgs field is a field of energy that goes through all particles, and each movement of each particle (spin) causes each particle to have a differing mass/energy, like a group of star may be dark matter and cannot move quickly through a crowd, and ordinary people pass through a crowd easily (photon)

well, the Higgs field energy is dropping and will continue to drop to a minimum yet non zero mass, the field is enter linked with space, and space holds energy (quantum energys) and hence must drop, and to drop it must expand. Since this energy actually jumps around and random but yet usually rare times it may cause it to stick to a complete whole number for its energy field (so mass must also be equal), meaning, if all goes well, the universe may stop expanding. In the beginning they (Inflationary scientists) think that gravity turned backwards (which it can under certain aspects make gravity push, the sun does it to mercury, that is why its orbit is chaotic), this means that in the early universe gravity that PUSHED was dominant, causing the initial area of space to expand, and when this happened the Higgs field was set free, and it was hot!, so hot new energy and mass arose from the warping of space time (during the time when 3 of the 4 forces were converged into one), and it then started dropping causing spacial expansion.

So in a way yes, the big bang is still happening.  

(To anyone wondering ware I got this info, I got it from Brian Greene`s "Fabric of the Cosmos" sub-chapter "What banged?")

Edited by dest_titor1, 05 January 2008 - 01:43 AM.

Death may be the greatest of all human blessings

Socrates

Silence is the virtue of fools.

Sir Francis Bacon

The glass is never half full or half empty, the glass is just twice as tall as it should be!

Religion is a great tool for the smart and poor and hopeless, but a weapon in the hands of the ignorant and moronic and violent persons.

Religion does not start wars... Idiots that contrive and twist it to their own plot do.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users