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Bigsmak
2008-Nov-13, 07:26 PM
Hey all,

Love the site.

My Girlfriend is a teacher and is teaching 9 and 10 year old's about space. I've helped a lot. BUT this week its the big bang and I have confused the hell out of her, shes not as keen as me on the subject.

So - can anyone point us in the right direction for some kid friendly info? Maybe some easy to do practical experiments with balloons or something?

I've looked through the "resources on the web sticky" and coundn't find things on the Big Bang that the kids would get!

Thanks for your time!

01101001
2008-Nov-13, 07:35 PM
Welcome to BAUT Forum. I don't have any ideas. Most of the materials I've seen can be difficult for people twice that age to comprehend.


I've looked through the "resources on the web sticky" and coundn't find things on the Big Bang that the kids would get!

When they do get it, send them here to teach me. I want to get it, too.

Edit: Wait. I thought of one thing. The Bad Astronomer did a series of Q&A for... 6th-graders and one episode was about the Big Bang. I don't know if it's good for your target age group, but maybe the teacher will enjoy it. Video's about 6 minutes.
See BA Blog: Astronomy questions from sixth graders, Part 5 (phew!) (http://blogs.discovermagazine.com/badastronomy/2008/05/23/astronomy-questions-from-sixth-graders-part-5-phew/). But, I just re-watched it and half of it is praise for science, and asking questions, and a wrap-up for the series. It's got a few minutes of big-bang fun though.

Ken G
2008-Nov-13, 11:55 PM
I would say that it would be very easy to get caught up in the specifics of the Big Bang, which for children of that age would sound like little more than current dogma-- space expanding like a balloon with ants crawling on it, and so forth. They are not ready to think that way, it will probably just mess up their ability to grasp the usual concepts of space they need to learn at that age. So instead, I'd recommend stepping back and trying to get across the key elements of the Big Bang model:
1) the universe is in motion (and that motion is outward)
2) the universe changes with time
3) the universe has a finite age
We'll not worry that (1) should really be that the universe is dynamical, because we don't expect kids that age to understand the difference between dynamics and motion.

To get these three points across, I might imagine an exercise along the following lines. Give them each a ball, and say, their mission is to get every one of those balls in the air at the same time for two full seconds. Presumably you'll be in a room where two things will happen:
1) the students will throw their balls in the air
2) the students will have to throw them all up at the same time
That's the Big Bang. The universe is just like that-- in that we have evidence it has been like those balls in the air, except for 14 billion years rather than two seconds (and it doesn't appear to be coming back down, and we look like we're at the center, and the gravity comes from the balls not the ground, and so on into all the details that don't seem to matter as much but which might come out in the subsequent discussion).

stu
2008-Nov-14, 01:15 AM
A pet-peeve of mine that I think can still be conveyed to 10-year-olds ... the Big Bang does NOT describe how the universe formed / came into being, etc. It describes what happened AFTER that (at about 10^-44 seconds after). Common misconception ... like evolution doesn't describe the origin of life, just how it's changed afterwards.

Sam5
2008-Nov-14, 01:46 AM
A pet-peeve of mine that I think can still be conveyed to 10-year-olds ... the Big Bang does NOT describe how the universe formed / came into being, etc. It describes what happened AFTER that (at about 10^-44 seconds after). Common misconception ... like evolution doesn't describe the origin of life, just how it's changed afterwards.

In my opinion, ages 9 and 10 is too early to try to teach kids details about the big bang, especially if the teacher doesn't understand it.

Durakken
2008-Nov-14, 01:57 AM
The simplest explanation is... something happened that created an infinitely dense thing that exploded...expanding to the size of the universe that is still expanding... Though i wouldn't go much beyond that with most people because the logical conclusion of what will happen as the universe goes on is pretty scary and might drive some insane...

dodecahedron
2008-Nov-14, 04:36 AM
Simple. Creatio ex nihilo currently is the best way to describe creation. Explostions make it sexy to Hollywood and testosterone junkies. The absurd nature appeals to theists and reconciles science with their own philosophies.
It'd be a better exercise to ask the kids "How do you think everything started?", mention one or two secular theories regarding cosmology and then just dive into how the solar system was created which should me significantly more manageable.

Bigsmak
2008-Nov-14, 09:44 AM
might drive some insane...

lol.. I think my Girlfriend is feeling a little insane right now! ..



To get these three points across, I might imagine an exercise along the following lines. Give them each a ball, and say, their mission is to get every one of those balls in the air at the same time for two full seconds. Presumably you'll be in a room where two things will happen:
1) the students will throw their balls in the air
2) the students...... etc etc etc

Thats a good idea, I'll try and explain it to her!

--------------

OK .. we have a weekend to work on this.

Thanks for the help so far and I'll post something about what she did. (when we decide -.-.-.- lol) :lol:

Jeff Root
2008-Nov-14, 11:36 AM
1) the universe is in motion (and that motion is outward)
I would say that everything in the Universe is in motion.
Otherwise you've got a picture of the Universe zooming off somewhere.

I'd say that most galaxies are slowly coasting away from each other,
having started out 13.7 billion years ago all squeezed together. Like
a thousand Nerf balls squished into a box which is suddenly opened,
and they go flying out in all directions.



To get these three points across, I might imagine an exercise along
the following lines. Give them each a ball, and say, their mission is to
get every one of those balls in the air at the same time for two full
seconds. Presumably you'll be in a room where two things will happen:
1) the students will throw their balls in the air
2) the students will have to throw them all up at the same time
Two seconds requires a ceiling at least 16 feet high.

-- Jeff, in Minneapolis

Ken G
2008-Nov-15, 03:54 AM
Two seconds requires a ceiling at least 16 feet high.
That is a good point, it might be a little too long for most rooms. I didn't use 1 second because they wouldn't have to throw the balls up to get that. Ideally, it would be more like 1.5 seconds, though it's a little hard to measure. Still, with 10 foot ceilings, you'll have no choice but to use 1.5 seconds instead of 2.

ETA: better idea-- use 2 seconds, but do it outside. Kids like that, and it's more like the universe anyway.

Hornblower
2008-Nov-15, 12:58 PM
This seems to be a reasonable topic for discussion. When I was 9 years old I was reading a borrowed college-level astronomy book and asking questions about it.

My presentation to a child that age would be something like this:

"Astronomers have observed that the galaxies appear to be flying apart from each other. Their best explanation for this is that in the most ancient times everything was super compact, dense and hot, and was expanding rapidly toward what we see today. This expansion was so violent in early times that it may have resembled a giant firecracker going off. Thus the descriptive term 'big bang.'"

This would have to be tweaked for any individual child, depending on his/her understanding of galaxies and of the concepts of expansion, density, etc.

I would try to stay away from discussion of what caused it in the first place. That would be beyond what I could have handled at that age.

Ken G
2008-Nov-15, 04:22 PM
I would try to stay away from discussion of what caused it in the first place. That would be beyond what I could have handled at that age.It's beyond what we can handle now, as well!

bunker9603
2008-Nov-15, 04:54 PM
I don't know if this will help or not, but my kids go to this site. There is also a "Teachers Corner".

http://www.kidsastronomy.com/

Omega Red
2008-Nov-15, 05:50 PM
I would simply analogize to a regular explosion, and ask the children, "If I wanted to prove that an explosion occurred what evidence for it would I need?"

1) Debris spread about
2) A report or a noise

Okay, so now I would ask the children, how do you know someone simply did not just spread the debris around, and how do you know the noise wasn't related to some other event?

1) The debris' pattern is consistent with an outward force at some point central to the debris field.
2) The noise came from the same direction as the theorize location of the explosion from the pattern in the debris field

Next I would ask the children what they would be able to tell me about the strength of the explosion if they were just barely able to hear the explosion from 100m away, 1km away, 10km away... The conclusion would be that the further away you can hear the explosion the more powerful it is.

I would then explain that in our universe we have the exact same evidence that points towards their being an explosion in our early universe. All the matter of the universe is moving away from a "central" point, and we can still "hear" the explosion (The Cosmic microwave background radiation).

Finally, I would convert 14.7 billion light years into kilometers and write the number on the board. I would then ask the class, if you could still hear an explosion from this far away what does that tell you about the initial explosion?

Spaceman Spiff
2008-Nov-16, 03:25 AM
I would simply analogize to a regular explosion, and ask the children, "If I wanted to prove that an explosion occurred what evidence for it would I need?"

1) Debris spread about
2) A report or a noise

Okay, so now I would ask the children, how do you know someone simply did not just spread the debris around, and how do you know the noise wasn't related to some other event?

1) The debris' pattern is consistent with an outward force at some point central to the debris field.
2) The noise came from the same direction as the theorize location of the explosion from the pattern in the debris field

Next I would ask the children what they would be able to tell me about the strength of the explosion if they were just barely able to hear the explosion from 100m away, 1km away, 10km away... The conclusion would be that the further away you can hear the explosion the more powerful it is.

I would then explain that in our universe we have the exact same evidence that points towards their being an explosion in our early universe. All the matter of the universe is moving away from a "central" point, and we can still "hear" the explosion (The Cosmic microwave background radiation).

Finally, I would convert 14.7 billion light years into kilometers and write the number on the board. I would then ask the class, if you could still hear an explosion from this far away what does that tell you about the initial explosion?

I don't mean to be a party-pooper, but nothing that we understand about the 'big bang' would describe it in terms of an explosion. An explosion is the result of an enormous pressure gradient at a particular location in space. As a result, matter moves outward through space away from that point in space with a resultant destruction of that gradient. None of these descriptions apply. In fact it is this very analogy that sticks in people's minds that then results in confusion!

As mentioned above, the standard big bang theory (http://en.wikipedia.org/wiki/Big_Bang) does not address initial conditions. (Even the inflationary model (http://en.wikipedia.org/wiki/Cosmic_inflation) probably does not fully address this, although it steps closer. There are also less mature models (http://www.sciam.com/article.cfm?id=big-bang-or-big-bounce) (the link is to an article in the October 2008 edition of Scientific American) that do attempt to tackle this issue head-on.) It merely predicts the dynamical behavior of matter-energy content over very large distance scales, within a universe that was already undergoing "expansion" from an extremely hot, dense state, as a function of time. And what is meant by "expansion of the universe" should be considered nothing more than that the matter-energy content of the universe is becoming more dilute over time.

I suggest having a careful read of this article (http://www.mso.anu.edu.au/%7Echarley/papers/LineweaverDavisSciAm.pdf) which appeared in the March 2005 edition of Scientific American? Then think about how to translate some of this information to a grade-schooler. It won't be easy, and there is only so much you can explain to 9-10 year olds, but selling them on misconceptions from the start won't do them any favors.

Jeff Root
2008-Nov-16, 01:56 PM
I don't mean to be a party-pooper, but nothing that we understand
about the 'big bang' would describe it in terms of an explosion.
I acknowledge that what you say here and in the rest of your post
is what is generally considered to be the "mainstream" description
of the Big Bang, but I question 1) Whether it really is mainstream,
and 2) Whether it is accurate.

I have heard many, many times that the Big Bang does not look like
an explosion. In every way that I can see, it looks like an explosion.
I have never seen any evidence to the contrary. None.



An explosion is the result of an enormous pressure gradient at a
particular location in space. As a result, matter moves outward
through space away from that point in space with a resultant
destruction of that gradient. None of these descriptions apply.
First, I see no reason why an explosion necessarily requires a
pressure gradient. I can imagine phenomenae which would look
very much like explosions which would not involve pressure. The
Big Bang was unique. We know of only one instance of it occuring.
So we shouldn't be surprised if it had unusual characteristics for an
explosion.

Second, what gives you the idea that none of the descriptions of a
pressure-gradient-caused explosion apply? You say that the gradient
is destroyed as a result of the explosion. The farthest back we can
see is the time of decoupling, 380,000 years after the explosion.
Plenty of time for the gradient to have vanished.



In fact it is this very analogy that sticks in people's minds that then
results in confusion!
A lot of things cause confusion. Claiming that the Big Bang was not
an explosion is high on the list. In every way that I know of it looked
like an explosion. If you insist that it was not an explosion, you look
like you are making a distinction without a difference. That is what
causes this particular confusion.



And what is meant by "expansion of the universe" should be considered
nothing more than that the matter-energy content of the universe is
becoming more dilute over time.
If I add water to a container of milk, that makes the milk more dilute.
Is that like what is happening to the Universe? No? Did you say what
you meant? You were tying to clarify what is meant, not make it more
obscure, weren't you?



Then think about how to translate some of this information to a grade-
schooler. It won't be easy, and there is only so much you can explain
to 9-10 year olds, but selling them on misconceptions from the start
won't do them any favors.
So I have to figure out how to describe what looks exactly like an
explosion as something that is definitely not an explosion... for what
reason? What reason do I have for not describing it as an explosion?
What difference is there between the Big Bang and an explosion that
a 9-10 year-old can understand, or that the average 9-10 year-old
would care about? What difference is there that anyone who is not
a cosmologist would give a rat's arse about? What difference is there
that a cosmologist should care about?

My personal preference, with the understanding I currently have, is
to describe the Big Bang as being like an explosion. I'm not committed
either way to the notion that it was or was not an actual explosion.

And I agree that Omega Red's suggestions focus unnecessarily on the
explosion-like aspects of the Big Bang, to the apparent exclusion of
aspects that are at least equally as important and less controversial.

-- Jeff, in Minneapolis

speedfreek
2008-Nov-16, 02:42 PM
To keep the explosion thing simple enough for the kids, why not say that rather than being a case of a big explosion in space and lots of stuff moving away from the focus of the explosion, think of it as an explosion of space and all the stuff in it, where the space is moving apart carrying the stuff along with it. I know this may introduce another possible misconception (expanding space) but to me it is far more subtle and easy to deal with later than the "we are at the centre of the explosion" problem.

Spaceman Spiff
2008-Nov-16, 04:38 PM
I acknowledge that what you say here and in the rest of your post
is what is generally considered to be the "mainstream" description
of the Big Bang, but I question 1) Whether it really is mainstream,
and 2) Whether it is accurate.

It is and it is - within the context of the standard big bang model. (And you acknowledge that it is a mainstream description and then question whether it is? :confused:)
Just as a start, why not give that article (http://www.mso.anu.edu.au/%7Echarley/papers/LineweaverDavisSciAm.pdf) I linked to above a careful read?



I have heard many, many times that the Big Bang does not look like
an explosion. In every way that I can see, it looks like an explosion.
I have never seen any evidence to the contrary. None.


By any definition of explosion and any that anyone has in their head, matter moves at high speed from a pre-existing point in that space through that pre-existing space. And yes, a pressure gradient is a difference in pressure between two points in pre-existing space, and indeed an explosion proceeds because of the existence of an extremely large pressure gradient. None of these is contained within the big bang model in the FRW solutions to the GR field equations. How can anything be more clear? (For everyone else -- some history -- this issue has come up between us in another thread, but I do believe it to be relevant.)

Indeed, time and time again, questions that people bring to astronomers start with conundrums that have their origin with the picture they have in their heads of galaxies flying away from some point in space out there in the universe. They want to know, in which direction was that explosion? (http://www.astro.ucla.edu/%7Ewright/nocenter.html) And then misconception (http://www.astro.ucla.edu/%7Ewright/cosmology_faq.html#ct2) after misconception (http://www.astro.ucla.edu/%7Ewright/infpoint.html) (and many more) arises from this wrong picture they had formed in their head. That's the reason I commented in this thread.

And as a matter of fact, we have good information about conditions going back to the first few minutes (big bang nucleosynthesis - and the resultant ratios of 2 isotopes of hydrogen, 2 isotopes of helium, and 2 isotopes of lithium), and even back to the first 10^-6 seconds with formation of protons, neutrons, electrons, photons, and neutrinos.



A lot of things cause confusion. Claiming that the Big Bang was not
an explosion is high on the list. In every way that I know of it looked
like an explosion. If you insist that it was not an explosion, you look
like you are making a distinction without a difference. That is what
causes this particular confusion.

If one understands neither, I suppose it is easy to conflate the two. But why remain in ignorance? Why not inform one's self of how things work (or rather, our best models of how things work)? If you disagree with the standard model or are addressing initial conditions, then those are other matters which have little or nothing to do with what is contained within the standard big bang model.


If I add water to a container of milk, that makes the milk more dilute.
Is that like what is happening to the Universe?

What I said is indeed consistent with the standard model. By adding water to milk, the milk molecule clusters are indeed moving farther apart from one another. If the clusters of water molecules form the "metric grid", then in some loose sense this could be used as an analogy (but it's not my job to defend your analogy). We're free to choose analogies, and some are better than others, depending on the context in which they are presented and in understanding their limitations. I suggest reading this paper (http://arxiv.org/abs/0707.0380), whose existence was pointed out in other threads on this topic.


To keep the explosion thing simple enough for the kids, why not say that rather than being a case of a big explosion in space and lots of stuff moving away from the focus of the explosion, think of it as an explosion of space and all the stuff in it, where the space is moving apart carrying the stuff along with it. I know this may introduce another possible misconception (expanding space) but to me it is far more subtle and easy to deal with later than the "we are at the centre of the explosion" problem.

(my emphasis) IMO that's better, but I'd also leave out the word "explosion" altogether and just describe it as "the expansion of space", meaning that its contents in matter/energy are becoming more dilute with time**. All analogies have their weaknesses, some just a lot more so than others, and others don't even get out of the starting blocks without being much less than useful.

(**It is important to understand that this true only over the vast distances in which matter/energy isotropy and homogeneity are approached. You and I do not expand, nor does our solar system, nor does our galaxy, or local cluster of galaxies.)

Spaceman Spiff
2008-Nov-16, 05:23 PM
I apologize for cluttering up this thread with the above reply to Jeff Root's post (http://www.bautforum.com/questions-answers/81244-teaching-kids-9-10-about-big-bang.html#post1366638). However, I hope that at least some of this will prove relevant and helpful to the question raised.

Ken G
2008-Nov-16, 05:35 PM
Yes, the "explosion" picture has certain advantages and some pretty unfortunate disadvantages. The advantages are, you get a Hubble law, a concept of a finite age, and a density and temperature that fall with time (but unfortunately also with radius, as I will shortly draw out). Those are all important concepts, and explain why Hoyle's tongue-in-cheek term "Big Bang" actually caught on. But Spaceman Spiff is right that the physics of an explosion are entirely different from the Big Bang, and Jeff Root is wrong that there are no observable consequences that distinguish an explosion from the Big Bang.

As was pointed out, the crucial physics of an explosion is a spatial contrast in pressure. This contrast must be present everywhere the effects of the explosion are evidenced, not just at the boundaries. So if you set up a constant pressure over a region, and a boundary to a lower pressure, you will only get expansion at that boundary. The pressure "gradient" has to eat its way into the volume before you will get expansion in the interior of the volume. That is exactly what we do not see in the Big Bang-- instead we have the "cosmological principle" that the expansion is the same at all locations, no evidence of any boundary which could be the seat of a pressure difference, and no resulting pressure gradient.

One might ask, could the pressure gradient just be too gradual to notice? If the spatial scale of the explosion were large enough, then yes, the gradient might not be noticeable over a much shorter spatial scale. Trouble is, if the observed distance scale was too small to see the gradient, you wouldn't see any evidence of dynamics-- you'd be using a steady state model. For an explosion, the spatial gradient must be of the same order as the changes we see with age. But all we see are the temporal changes, no evidence of any spatial gradient.

So it's just not an explosion. But since most people don't know the physics of an explosion, and they also don't know the physics of the Big Bang, sometimes the choice is made to count on that ignorance-- "what you don't know can't hurt you" kind of mentality. Teaching is a difficult art-- is the goal to create the illusion of understanding that will serve its purpose, or real understanding?

Bigsmak
2008-Nov-16, 06:55 PM
Again thanks for all the help.... She's writing the lesson plan now.

A lot of the things mentioned in the thread are way to advanced for these Kids. But its good for me and the better half to have read them so it's easier to teach the kids!

Lesson is tomorrow, I'll let you know what the kids say and what they were told!

Thanks

Spaceman Spiff
2008-Nov-16, 11:06 PM
A lot of the things mentioned in the thread are way to advanced for these Kids. But its good for me and the better half to have read them so it's easier to teach the kids!


That's the important thing! The teacher should understand the concepts at a deeper level than she/he introduces to her students -- and minimize misconceptions and less than useful analogies in doing so. The students will be able to go deeper later in their education as they experience more.

I do highly recommend that first Scientific American article (Misconceptions of the Big Bang (http://www.mso.anu.edu.au/%7Echarley/papers/LineweaverDavisSciAm.pdf)).

Good luck!

Durakken
2008-Nov-16, 11:19 PM
I've noticed that most of the people on these boards don't like anything but 100% facts. Not speculation or hypothesized or even various ways to explain things... If i tell you that I cut something I better be meaning separating molecules apart from each other and not farting or something else...so it's not very useful to ask things like this on this site which is kinda sad when it is supposed to be about helping people learn correct information... not being overly critical about how one come about understanding.

Ken G
2008-Nov-16, 11:41 PM
Hmm, you don't think Bigsmak benefited from asking the question here? Are we reading the same thread? Perhaps you have a different interpretation of "But its good for me and the better half to have read them so it's easier to teach the kids!" than I do.

Durakken
2008-Nov-16, 11:57 PM
I would assume any teacher would have a great enough understanding of the subject they are teaching and if not they shouldn't be teaching that subject. The important part should be how to convey the ideas which is not what many people here do.

The best way to teach people is to connect things they already know especially with stuff that is somewhat impossible by way of our normal way of thinking like so much of our science is now.

Don't get me wrong, the information is great, but what use is further information that doesn't matter when trying to teach the concept which is very basic when you look at it without all the math.

Spaceman Spiff
2008-Nov-17, 01:25 AM
I've noticed that most of the people on these boards don't like anything but 100% facts. Not speculation or hypothesized or even various ways to explain things... If i tell you that I cut something I better be meaning separating molecules apart from each other and not farting or something else...so it's not very useful to ask things like this on this site which is kinda sad when it is supposed to be about helping people learn correct information... not being overly critical about how one come about understanding.

Who here wasn't trying to provide "correct information"? How does "understanding" something differ from having "correct information"? How do you teach something to someone if you don't have a good understanding, at least conceptually at some level, and not fraught with misconceptions? This was the whole point of the above. No equations of General Relativity were presented, and I provided links that the educated non-specialist can read and learn from (like this one (http://www.mso.anu.edu.au/%7Echarley/papers/LineweaverDavisSciAm.pdf) linked at least twice before, above).

The original poster of this thread seemed to find this helpful (http://www.bautforum.com/questions-answers/81244-teaching-kids-9-10-about-big-bang.html#post1366777).

Durakken
2008-Nov-17, 01:30 AM
Most people know 6x7=42 but no clue why that is true.

Spaceman Spiff
2008-Nov-17, 01:36 AM
Most people know 6x7=42 but no clue why that is true.

You mean they don't understand that they are adding 6 sevens together or 7 sixes together? If so, how sad, indeed. I don't think you are suggesting that science is the dull memorization of "facts".

I'll leave this with these two quotes:


Science is built up with facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house. -Jules Henri Poincare
...science is not a database of unconnected factoids but a set of methods designed to describe and interpret phenomena, past or present, aimed at building a testable body of knowledge open to rejection or confirmation. -Michael Shermer

Durakken
2008-Nov-17, 01:47 AM
Which is my point... most of you argue that "this is the fact" without looking at any of the methods or reasonings on why or how something came about. It is this looking at these reasonings that is the best way to teach. Sure it's useful to know that 6x7=42, but unless you know and understand what that phrase is saying you really can't comprehend the full extent of what is being said in the first place.

And unfortunately school in the modern age is all about facts and memorization and not the critical thinking...

Jeff Root
2008-Nov-17, 02:17 AM
Most people know 6x7=42 but no clue why that is true.
Where?

-- Jeff, in Minneapolis

Spaceman Spiff
2008-Nov-17, 03:25 AM
Which is my point... most of you argue that "this is the fact" without looking at any of the methods or reasonings on why or how something came about. It is this looking at these reasonings that is the best way to teach. Sure it's useful to know that 6x7=42, but unless you know and understand what that phrase is saying you really can't comprehend the full extent of what is being said in the first place.

And unfortunately school in the modern age is all about facts and memorization and not the critical thinking...

I do not understand at all where you are coming from. The big bang isn't just some dumb fact taken at face value. It is the most useful model we have that unifies and explains the preponderance of a vast collection of data. Multiple, independent lines of evidence presently support this model. New questions arise everyday (via observation of the cosmos), but we learn from them.

And that last sentence is one of the motivations behind the postings by many of us in the Questions forum. So, again :confused:.


I've noticed that most of the people on these boards don't like anything but 100% facts. Not speculation or hypothesized or even various ways to explain things... If i tell you that I cut something I better be meaning separating molecules apart from each other and not farting or something else...

There is a forum (http://www.bautforum.com/against-mainstream/) for discussion and speculation independent of supporting scientific evidence. There is another (http://www.bautforum.com/general-science/) that takes a broader look at science, including philosophical discussions about science and its "method". The forum you're reading has the purpose of providing mainstream scientific explanations to questions posed. How well this is done -- well, your mileage may vary. :)

Science is not a democracy of ideas -- data are paramount, and nature cannot be fooled. But this is all getting way off topic.

Durakken
2008-Nov-17, 04:00 AM
That's a philosophic argument I'm not gonna argue ^.^

What you don't seem to get is whether there is this information or that information the answer is not important at least not in this. The theory of the big bang is really simple. To argue that "That explanation is not accurate" is just dumb. No one would say that universe exploded into existence...at least I'd hope not, but the analogy works to explain the concept.

Also the pure fact that facts and figures hardly ever help learn anything. You can give most people all the math in the world to prove all the things in the universe, but that won't prove anything to most people because it's just not how we learn. If you want someone to learn something you show them or give them it in some way that they can make sense of and numbers and facts just don't do that nor do words usually but meh oh well.

Jeff Root
2008-Nov-17, 09:17 AM
Most people know 6x7=42 but no clue why that is true.
What part of the world are you in where most people do not have a
standard fifth-grade education in number theory?

-- Jeff, in Minneapolis

Bigsmak
2008-Nov-17, 09:48 AM
I would assume any teacher would have a great enough understanding of the subject they are teaching and if not they shouldn't be teaching that subject.

Not sure which part of the world you are from, but in Scotland - UK we have 2 schools.

Primary School - where the kids go from the age of about 5 - 11
High School - Where the kids go from 11 - 18, they have subject specific teachers here!

The Primary School teachers teach everything from Maths, Art, Science, English, History, Geography, Personal Studies etc etc. They are not experts in everything they teach. I would say that specifically things like Quantum Theory and Advanced Astrology is something most of the Primary Teachers are not familiar with.

The Teachers do the best they can with the knowledge they have (she's much better at English - Honest :lol:) and sometimes we have to Google our asses off to help prepare for class.

I'm not having a go, but just wanted to clarify why we asked the question, and thank people for their time with their answers. - Some of which was a little too advanced for not only the kids, but both my GF and myself. However, we learned something and hopefully haven't told the Kids anything stupid!

Thanks again

PS - as for the 6 x 7 ... The kids are taught (at about 6yo) using a number square and understand that they are adding 6 more little squares at a time. Its visual and they get it!

hhEb09'1
2008-Nov-17, 10:52 AM
And unfortunately school in the modern age is all about facts and memorization and not the critical thinking...You probably learned that in the seventies, right? Times have changed. :)

Jeff Root
2008-Nov-17, 12:45 PM
things like Quantum Theory and Advanced Astrology...
Watch your language, young man!

-- Jeff, in Minneapolis

Durakken
2008-Nov-17, 02:12 PM
You probably learned that in the seventies, right? Times have changed. :)

Yes times have changed...to worse. Teachers are pressured into teaching mainly just specific facts about a specific group of subjects because if a school does bad on tests they lose government funding.

Spaceman Spiff
2008-Nov-17, 03:03 PM
What you don't seem to get is whether there is this information or that information the answer is not important at least not in this. The theory of the big bang is really simple. To argue that "That explanation is not accurate" is just dumb. No one would say that universe exploded into existence...at least I'd hope not, but the analogy works to explain the concept.

:confused:
Oh, come on, you must be joking, right?. I am an astronomer by profession. I also happen to work with K-12 science teachers. I get the same types of questions from them as the one that started this thread (why is the sky blue and clouds white? what determines whether an object is round? If the universe is 14 billion years old, why isn't the most distant object we can see 7 billion light years away? The list is very long -- but kudos to them for seeking and asking!). I also happen to post occasionally on this forum. I don't know any science teacher at the K-12 level who would agree with your statements. I don't know anyone in my profession who teach students from freshman non-science majors through graduate students in astrophysics who would make such statements. Astronomers (http://arxiv.org/abs/0707.0380) themselves (http://www.mso.anu.edu.au/%7Echarley/papers/DavisLineweaver04.pdf) are still coming to grips with the subtleties of the standard "big bang" model. And have you read some of the stuff people post on the various forums here and elsewhere? :eek: The statements above are at best loosely connected with reality.

From which I conclude one of following.
1) You're pulling our leg. Ok, I have a sense of humor, and can laugh with you. :lol:

2) You're actually an alien of an advanced race who has escaped from planet Zorg who has just blown his cover, before revealing the Answer to the Ultimate Question of Life, the Universe, and Everything (is it really as simple as 42?). I will alert my colleague, Stupendous Man, who also posts here.

or

3) Well...I think most of the readers have a pretty good idea of the remaining alternative.



Also the pure fact that facts and figures hardly ever help learn anything. You can give most people all the math in the world to prove all the things in the universe, but that won't prove anything to most people because it's just not how we learn. If you want someone to learn something you show them or give them it in some way that they can make sense of and numbers and facts just don't do that nor do words usually but meh oh well.

Agreed. Conceptual understanding is of utmost importance, whether one is in a survey course or a graduate course digging deep into foundations or even in writing up your findings in the Astrophysical Journal. As I said above, we are free to choose our analogies to illustrate the workings of our physical models, but in doing so we needn't introduce fallacious ones that down the road will sow greater confusion. The real challenge is to come up with effective analogies crafted for the appropriate audience, while understanding their limitations.

Cougar
2008-Nov-17, 03:06 PM
Yes times have changed...to worse. Teachers are pressured into teaching mainly just specific facts about a specific group of subjects because if a school does bad on tests they lose government funding.

Ah, well, that's another topic, and I'm sure many would be very interested in discussing the shortfalls of the American education system... and proposed solutions.... in the Off-topic Babbling forum (or possibly the general science forum). Please open such a discussion!

Argos
2008-Nov-17, 03:07 PM
Well Itīs not easy to teach the big bang for grown ups, let alone children. Any analogy, like bombshell explosions, baloons, etc, offer a very poor insight, because they imply seeing the universe from its 'outside'. The truth is: we donīt have means to teach it. The ideas we all have about the big bang are just lame approximations, and only generate misunderstandings. Live with that.

Durakken
2008-Nov-17, 03:23 PM
Spaceman Spiff... I never said the proofs for the big bang is easy to understand. It is the basic concept of it that is.

Also I'm not saying that one shouldn't say something isn't accurate when it doesn't in any way illustrate the point, but when it does the job, even if the physics and such behind it are wholely different than the physics involved in the thing your explaining, then it's self defeating.

Kinda like a hypercube... it's a 4 dimensional construct which we can't even truly imagine which I've heard a lot of people argue that it is wrong to use because of that, but that's not the point of illustrating it in such a way. The hypercube is just a way of explaining and understanding no matter how inaccurate it is in a true 4 dimensional space.

Spaceman Spiff
2008-Nov-17, 04:34 PM
Spaceman Spiff... I never said the proofs for the big bang is easy to understand. It is the basic concept of it that is.

Sorry, I'm not buying it. The big bang, along with the theory of evolution, are two of the most oft quoted and misunderstood of all scientific theories. Don't take my word on it. Look around. You don't even have to leave the BA bulletin board. Why do you think that is? One of the major reasons is misconception -- a less than useful analogy has been placed in their heads.

And perhaps you would like to share this "easy to understand ... basic concept" with the rest of us?



Also I'm not saying that one shouldn't say something isn't accurate when it doesn't in any way illustrate the point, but when it does the job, even if the physics and such behind it are wholely different than the physics involved in the thing your explaining, then it's self defeating.

Ok, that's great. But I am telling you from experience the whole "explosion" concept, even the unfortunate name of the theory ("big bang", Fred Hoyle's curse), is the starting place of nearly all questions of confusion regarding the big bang. So I contend, again from experience, the explosion analogy is not only physically inapplicable -- it does not work. Why do you think the number 1 misconception in that Scientific American article, "Misconceptions of the Big Bang (http://www.mso.anu.edu.au/%7Echarley/papers/LineweaverDavisSciAm.pdf)", has to do with this very question?

The challenge is to use our brains to find useful analogies that do work.

Durakken
2008-Nov-17, 04:42 PM
Two universes got together and banged...in 9 months came a brand new ba...universe.

Spaceman Spiff
2008-Nov-17, 04:55 PM
Two universes got together and banged...in 9 months came a brand new ba...universe.

Aren't you forgetting the stork? I think I said 'useful'. :whistle:

I guess this thread has run its course.

Durakken
2008-Nov-17, 05:01 PM
I was joking but if you think about it...it does work...

2 universes banged into each other and created a new universe and then that new universe, just like a baby grew up...

Although one would have to use a person with a thyroid? problem that made a person grow more than normal over time...and not to mention it's bit mature for 9 year olds lol

Cougar
2008-Nov-17, 05:14 PM
Obviously, analogy is going to be the way to go with 10-year-olds. I would vote against the balloon analogy, particularly since grown-ups seem to have a hard time with ignoring the interior and exterior of the balloon and focusing on just the outside surface of the balloon as the entire universe...

Still not perfect, but I think immensely better, especially for youngsters, is the raisin bread analogy. Of course, they might first have to be taught about bread and yeast and how bread rises and expands as it is heated (oops, it's just the opposite with the big bang - as things expand, they cool.) Anyway, this allows a more natural 3D picture of the expanding universe, with the distance between the embedded raisins increasing - similar to the distance between galaxies.

Unfortunately, much of the observational support for the big bang is rather beyond 5th grade curricula. Hubble, 1928, apparent motions of galaxies away from us appear to be correlated to their distance from us... A major finding, but full understanding relies on spectroscopy, which would likely need its own educational "unit." Then there's early universe nucleosynthesis, which is grounded in quantum mechanics and predicts the abundance of the elements and turns out to be (almost) right on. I suppose it could be done, but that's going to be a tough topic for 5th graders...

And unlike some massively dumbed-down accounts, the cosmic microwave background is not the flash from the big bang. It's when the universe cooled enough (at about 380,000 years old) to allow hydrogen and helium to capture and keep a hold of electrons, thus becoming neutral atoms and allowing the phrenetic photons to travel freely through space...

Sorry if I'm a bit late, but... well, let us know how it went. :)

Spaceman Spiff
2008-Nov-17, 06:26 PM
And unlike some massively dumbed-down accounts, the cosmic microwave background is not the flash from the big bang. It's when the universe cooled enough (at about 380,000 years old) to allow hydrogen and helium to capture and keep a hold of electrons, thus becoming neutral atoms and allowing the phrenetic photons to travel freely through space...

Well, as long as we're trying to be more precise with our choice of descriptions :), it was the "delayed" flash, if you will, of the big bang. All but a tiny fraction (~1 part in 1 billion) of the energy in the CMB originated prior to the epoch of nucleosynthesis (during the various matter/anti-matter annihilation episodes, mainly that pertaining to the baryons), with the tiny remainder arising from the recombination process itself. Post-recombination, matter and light had decoupled from one another, allowing the free-streaming of light through the universe.

speedfreek
2008-Nov-17, 06:47 PM
I'm still waiting for Durakkens "easy to understand" basic concept of the Big-Bang, as I have been trying my best to make this subject as easy to understand as possible for a couple of years now...

Durakken
2008-Nov-17, 06:54 PM
What's hard about nothing existing and then something popped into existence that expanded into the nothingness at ever increasing rate? That is the entire concept of the big bang. Sure the facts and how we know that is a bit more complex than that, but no more is really needed to understand the big bang. The hardest thing to make people understand is that when you say nothing you mean not just emptiness but absolute nothingness, but even that is in question, at least in regards to the big bang.

speedfreek
2008-Nov-17, 07:10 PM
What's hard about nothing existing and then something popped into existence that expanded into the nothingness at ever increasing rate? That is the entire concept of the big bang.

An ever increasing rate? What do you mean by that? I thought that the rate of expansion was decelerating for the first 7 billion years or so and only then did the rate start to increase. The rate of expansion was at its fastest to begin with and is a lot slower today than it was to begin with.

As for "expanded into the nothingness".... is that supposed to be easy to understand?



Sure the facts and how we know that is a bit more complex than that, but no more is really needed to understand the big bang. The hardest thing to make people understand is that when you say nothing you mean not just emptiness but absolute nothingness, but even that is in question, at least in regards to the big bang.

So the universe is (possibly) expanding into the absolute nothingness, which might not be the same as emptiness. Now everything is as clear as mud! :confused:

Durakken
2008-Nov-17, 07:47 PM
What are you talking about? Are you talking about the one theory that says that expansion happened then stopped and then started again? I'm pretty sure that isn't main stream and even that one after that minor time period, which was not 7 billion years, the universe has expanded exponentially since from all available evidence. But that is not important to even mention at the time so that you bring it up totally misses the point of trying to educate.

And as i said the expanded into absolute nothingness is hard to explain because if it's not absolute you have to explain membranes and if it is humans have no experience with absolute nothingness...the closest we have is space and even that doesn't come close. The most advanced mind wrestles with that so it's not fair to even try to get a child to understand it, but those are outside concepts that aren't exactly needed for a child to understand the big bang.

I think you are trying to make things more complex than they need to be.

speedfreek
2008-Nov-17, 08:38 PM
What are you talking about? Are you talking about the one theory that says that expansion happened then stopped and then started again? I'm pretty sure that isn't main stream and even that one after that minor time period, which was not 7 billion years, the universe has expanded exponentially since from all available evidence. But that is not important to even mention at the time so that you bring it up totally misses the point of trying to educate.

I was referring to your description of the universe expanding at an "ever increasing rate". The rate of expansion was decelerating until around 6 billion years ago, when everything at the large scales was far enough apart for the influence of dark energy to start the acceleration of that expansion. For the first 7 billion years or so, gravity was still slowing down the expansion. This is the current mainstream model.

I wasn't referring to inflation at all (although inflation is really just a period of superluminal expansion, rather than the expansion stopping and starting), just the rate of expansion since the CMBR was emitted. The surface of last scattering (the co-moving coordinate where the CMBR photons we detect today were originally emitted) was only 42 million light-years away when the CMBR was emitted, and that surface was receding from here at something around 58 times the speed of light at that time. That is a very fast rate of expansion, 58 times the speed of light at only 42 million light-years distance. The rate of expansion was decelerating and has been slower than that ever since (but started to accelerate a while back). Right now, co-moving coordinates 46 billion light years away are only receding at around 3 times the speed of light. It is expanding a lot slower now, than it was then - nothing only 40 million light-years away is receding at anything like 58 times the speed of light!

Until a little over a decade ago, we thought the rate of expansion was still slowing down, but observations of Type 1a supernovae told us that recently (in cosmic terms) the rate of expansion had started to accelerate.

Hardly a universe expanding at an ever increasing rate.

The only point I am trying to make here is that it is actually very hard to find an "easy to understand" basic concept that, without a lot of clarification, doesn't lead to misconceived ideas about the model.

Cougar
2008-Nov-17, 09:53 PM
The only point I am trying to make here is that it is actually very hard to find an "easy to understand" basic concept that, without a lot of clarification, doesn't lead to misconceived ideas about the model.

That's right. There just seem to be a lot of "prerequisites" to a reasonable understanding of the theory, beginning with the fact that the speed of light is finite.

Cougar
2008-Nov-17, 09:59 PM
Well, as long as we're trying to be more precise with our choice of descriptions :), it was the "delayed" flash, if [you] will, of the big bang. All but a tiny fraction (~1 part in 1 billion) of the energy in the CMB originated prior to the epoch of nucleosynthesis (during the various matter/anti-matter annihilation episodes...)...

Also correct, of course, :doh: although 380,000 years is a pretty long delay. :surprised

Spaceman Spiff
2008-Nov-17, 10:32 PM
With regards to posts by Durrakken (http://www.bautforum.com/questions-answers/81244-teaching-kids-9-10-about-big-bang-2.html#post1367073), above.

The statements above are at best loosely connected with reality.

From which I conclude one of following.
1) You're pulling our leg. Ok, I have a sense of humor, and can laugh with you. :lol:

2) You're actually an alien of an advanced race who has escaped from planet Zorg who has just blown his cover, before revealing the Answer to the Ultimate Question of Life, the Universe, and Everything (is it really as simple as 42?). I will alert my colleague, Stupendous Man, who also posts here.

or

3) Well...I think most of the readers have a pretty good idea of the remaining alternative.

Well the above exchange between Speedfreek and Durrakken now has me thinking that I will pick what's behind door number 3....sigh. :sick::wall:

Sum up: What was it Mr. Pauli said? "That's not right. It's not even wrong."

Spaceman Spiff
2008-Nov-17, 10:39 PM
Also correct, of course, :doh: although 380,000 years is a pretty long delay. :surprised

No more so than the sense that the energy carried by photons does not flow instantaneously out of a star, and for the same reasons (strong coupling between matter-radiation results in small photon mean free paths relative to the size of the star). If you exchange the spatial radial coordinate on the inside of a star for an expanding space-time coordinate, some interesting comparisons result going back to the epoch of primoridal nucleosynthesis. But don't run with the analogy too far! :lol:

Ken G
2008-Nov-18, 07:41 AM
That's an interesting comparison, yes. In terms of not taking the analogy too far, note that the density in the nucleosynthesizing core of a star is a lot higher than the density in the corresponding Big Bang phase, which is why hot enough stellar cores are good at making carbon and the Big Bang isn't. But other than that density difference, the photon behavior does seem quite analogous, now that you point it out!

astromark
2008-Nov-18, 09:09 AM
If you people are attempting to reveal the most basic understanding of the big bang. To a room full of 9 and 10 year olds. My experience with children is that it is always better to hold there interest by posing more questions than answers. They want to know. Working with astronomy and children is very rewarding. They are magnets for information. BUT... If you provide more detail than they want, they are gone.>>>>>> If they want more detail they will ask. Less is more. It works.

Spaceman Spiff
2008-Nov-18, 05:36 PM
That's an interesting comparison, yes. In terms of not taking the analogy too far, note that the density in the nucleosynthesizing core of a star is a lot higher than the density in the corresponding Big Bang phase, which is why hot enough stellar cores are good at making carbon and the Big Bang isn't. But other than that density difference, the photon behavior does seem quite analogous, now that you point it out!

Yes, thanks for mentioning that! (I just plain forgot.)