Overcoming common misconceptions of big bang cosmology

[Martin]

Chuck Lineweaver and his student Tammy Davis did everybody a big service by publishing a SciAm article covering the most common popular misconceptions about Expansion Cosmology (misnamed "Big Bang" Cosmology by someone who didn't like it.)

 

the article is used for the Princeton basic course, so it is online at the Princeton.edu site, and also in a slightly tattered version it is still online at the SciAm site.

 

To avoid making the worst fallacies, and wasting everyone's time, please please pretty please everybody who wants to discuss Cosmology make sure they either have read the article or already avoid making these very common naive mistakes.

 

If somebody keeps posting claims in Astro/Cosmo which show a lack of awareness of the most basic stuff, we will have the option to move them here so that we can deal with them efficiently. It can be like a holding tank, or a remedial room.

 

I am going to tack up on the wall some of the Lineweaver stuff, to learn from:

 

http://www.scienceforums.net/forum/showthread.php?p=384716#post384716

 

Lineweaver and Davis' Scientific American article Misconceptions about the big bang March 2005.

AS LONG AS THIS PRINCETON LINK WORKS IT IS BETTER THAN THE OTHERS

 

http://www.astro.princeton.edu/~aes/AST105/Readings/misconceptionsBigBang.pdf

 

Here are the links to the same article at the SciAm website. But these links have been going dead or else the GRAPHICS that you used to get have been disappearing. So these SciAm links may not be as good as the Princeton one

 

http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147

 

The Lineweaver Davis article had some very useful SIDEBARS giving pictorial diagrams with a question together with right and wrong answers explained. For easier access, here are links to individual sidebars.

 

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p39.gif

What kind of explosion was the big bang?

 

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p40.gif

Can galaxies recede faster than light?

 

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p42.gif

Can we see galaxies receding faster than light?

 

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p43.gif

Why is there a cosmic redshift?

 

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p44.gif

How large is the observable universe?

 

http://www.sciam.com/media/inline/0009F0CA-C523-1213-852383414B7F0147_p45.gif

Do objects inside the universe expand, too?

______________

 

maybe this thread will never get used, that would be nice

[Daecon]

Very cool. Thanks!

[swansont]

I think I fixed all of the links

[Martin]

thanks for fixing the links. I just checked and they all seem to work fine.

[mooeypoo]

Just a thought here -- I know that the title is the article's title too, but every time I see the Big Bang expressed as "Explosion" (instead of "expansion" / "rapid expansion") I cringe a bit...

 

[[ btw -- clarification -- this is a malcontent with this specific scientific american article.. not with your effort, Martin ]]

 

Aren't we confusing people with this, with all the confusion that already exists in the public misconception?

 

Other than that this is AWESOME Martin, long due -- GREAT job

 

~moo

[Martin]

Thanks for the approval, mooey!

The "something-from-nothing" fallacy has come up quite a bit recently. So I'll try to add something about it here.

BB theory is a family of mathematical models. Good discussion of this at Einstein Online (link in my sig) especially A Tale of Two Big Bangs which helps settle confusion arising from scientists' use of terminology.

Basically one mathematical model but it comes in several versions.

 

In no case I know that is currently being seriously considered is there a pre-BB state called "Nothing":D

 

Any math model has what is called its domain of applicability. One knows the limitations, if the model is not applicable past some point one knows not to apply it. Outside its domain the model just doesn't say anything. Period.

 

The classical BB model was not applicable closer than Planck range from the t=0 blow-up which came to be used as a kind of time-marker. One doesn't expect the blow-up to be real but it is a useful time-mark. Einstein Online explains this very well.

 

So everybody realized the classical BB model was incomplete.

In that model there is no t=0 state and of course no t<0 state (no "pre-BB" state) either! The model broke down as it approached, and simply stopped computing.

 

There are also quantum BB models. Nonsingular cosmology has become an active research area, lots of computer modeling, equation models, ferment.

In these versions of the BB theory, there is a pre-BB evolution and it is not "Nothing" . There is spacetime, energy, matter and so forth. A smooth causal evolution. Many versions of this have been run by different researchers and the basic features seem pretty robust. Testable predictions will hopefully be forthcoming before too long.

 

The point is, none of the currently studied BB models whether classical or quantum have this mysterious "something from Nothing" feature! When someone comes to SFN and starts talking about that I just assume they are trolling, or have been misled and confused by some other deluded person.

Edited January 12, 2009 by Martin

[The Bear's Key]

The point is, none of the currently studied BB models whether classical or quantum have this mysterious "something from Nothing" feature! When someone comes to SFN and starts talking about that I just assume they are trolling, or have been misled and confused by some other deluded person.

No, I just think the misconceptions about it have been spread far and wide.

 

And if a person who disliked the BB misnamed it, keep in mind that one way to discredit a concept among a political base is to squeeze every ounce you can from any related misconception, especially if the confusion mostly originates in the name itself. Thus, the guy who misnamed it probably didn't intend this end result, but the politicians whose twisting of religion was endangered by the Big Bang concept might have jumped at the opportunity. Stir in enough doubt, and mission accomplished. Like global warming, strong evidence can be weakened by muddying the big picture with doubt.

 

Science needs to take charge and rename the Big Bang, make it their own, and remove from it the politician's strongest leverage for intended confusion. Of course, it's possible for human error to be solely responsible for the misconceptions, and political trickery might actually have a minor role. But whatever the case, the science establishment isn't helpless. It's able to make the necessary changes to lessen the misconceptions, the easiest being a name change that's more accurate, with lesser chance of being inaccuracy-friendly.

[Airbrush]

Science needs to take charge and rename the Big Bang, make it their own, and remove from it the politician's strongest leverage for intended confusion.

 

...the science establishment isn't helpless. It's able to make the necessary changes to lessen the misconceptions, the easiest being a name change that's more accurate, with lesser chance of being inaccuracy-friendly.

 

I agree. If astronomers can get together to decide Pluto is no longer a planet, but rather a "dwarf planet" then why can't cosmologists get together and rename the Big Bang? It would be a newsworthy story. I don't know a more appropriate term, but how about "Cosmic Expansion"?

[swansont]

I agree. If astronomers can get together to decide Pluto is no longer a planet, but rather a "dwarf planet" then why can't cosmologists get together and rename the Big Bang? It would be a newsworthy story. I don't know a more appropriate term, but how about "Cosmic Expansion"?

 

Scientists don't have total control over what popular terms will catch on. There a number of just awful pop-science terms (some coined by scientists but not always) that mislead the public and are repeated by a credulous press that doesn't understand the meaning. In my area of atomic physics there's "quantum teleportation" and "stopped light," to name just two. There's the "god particle" for the Higgs. And many others.

 

"Catchy" seems to be more important than "correct."

[feign_ignorence]

Thank you for enlightening me with this thread

[Martin]

Thank you for enlightening me with this thread

 

You are most heartily welcome, but in truth I think sincere (not feigned) thanks are due to Chuck Lineweaver and Tammy Davis. They did a great job.

[liarliarpof]

Martin, Perhaps you should add "with sugar on top" to your plea for 'good measure'.

[Martin]

Martin, Perhaps you should add "with sugar on top" to your plea for 'good measure'.

 

Heh heh. Absolutely.

Please understand what the standard cosmo model says---get familiar with it---before you start criticising or making up your own. Pretty pretty please with LOTS of sugar on it

 

Everybody who posts in Astro/Cosmo should have tried out the Ned Wright calculator: google "Wright calculator"

and watched Wright's balloon model animation:

google "Wright balloon model"

 

Calculators like that and like Morgan's "cosmos calculator" I link to in my sig---calculators like that embody the equations of the standard model.

You dont know the model if you just know some words.

 

Basic shared cultural experience. A first exposure just takes 15-20 minutes.

 

And there's the Lineweaver Davis SciAm article. Generally recommended by many of us at SFN over the years.

[michel123456]

*censured*

[The Bear's Key]

Chuck Lineweaver and his student Tammy Davis did everybody a big service by publishing a SciAm article covering the most common popular misconceptions about Expansion Cosmology...

 

"Catchy" seems to be more important than "correct."

Martin's got it (perhaps unwittingly? ).* I think "Expansion Cosmology" is a really great name, maybe even perfect.

 

Light on the confusion.

 

 

*(Not quite you sly dog )

[michel123456]

So it is time to correct the thread's title.