So we figured out a lot about water and what happens to it as it is heated and cooled.  Since we know fog has something to do with water, this makes sense.  But it also makes sense to investigate what other other substances do with hotter and colder temperatures since other things like CCNs and air play a role in making fog.  So overnight, students brainstormed some Investigation Ideas to test this in Google Forms. Here are some of their results, and after a discussion...

We began the investigations, noticing what happened, and developing some models to see if air and other substances behave like water when it is heated and cooled.

We figured out a lot from all these investigations, and it seems that water, vinegar and air molecules all act the same way:

1.  Molecules move faster and take up more space when they're heated.
2.  Molecules move slower and take up more space when they're cooled.

From all our investigations, though, we would LOVE to see what is really going on with the molecules, since our ability to show movement with them is kind of limited being static on paper.  Is there a way we can better see what's going on at the molecular level...IN REAL TIME?

So we are leaning towards a temperature change being a missing factor to make fog. We've gotten lots of humidity in the air, and we've also added tons of CCNs. Still NO FOG!  So we're figuring out what's really going on with the molecules as they change temperatures.  W're doing this because we noticed in our weather data that every city that has fog has experienced some sort of temperature drop when the fog appears, and then the temperature increases when the fog disappears.  

We're making a public record of what we figure out, and so far, we've come to the following agreement:

1.  Hot water molecules move faster and take up more space than cold water molecules.
2.  Therefore, cold water molecules move slower and take up less space than hot water molecules.

We saw this happen in the food coloring demonstration, where the food coloring spread out SUPER quickly in the hot water but super slowly in the cold water.  And in the test tube demonstration, we saw the water expand up the tube as it was placed in a hot water bath and take up less space when it was cooled down.

Now the question is, does every substance do this?  Like air?  

So despite adding CCNs into the air with high humidity, we didn't make fog. We went back to the drawing board to see what else can help us figure out fog, especially since we have some really insightful questions on the DQB...like

"How do CCNs get into the air?"
AND
"How does water actually condense on a CCN?"

We don't really know where to go, but one factor that has been looming in the background is related to temperature.

We know that for water to "clump" together it has to get cooler like it did as it got farther away from the humidifier.  We also wanted to see if we saw any temperature changes with each of the cities we investigated early on that experienced fog.  And for every city, a trend began to appear that before the fog appeared, the temperature began to drop.  In some cities, there was a BIG drop in temperature, like by more than 10 degrees Fahrenheit.  In other cities there was a much SMALLER drop, but it was still a drop  by like 2 degrees Farenheit.  We also saw that when the fog disappeared, we saw an increase in temperature (again, but varying amounts, but still an increase).

We've got some questions about temperature's role with fog (especially since we don't think there's an "ideal" temperature for fog since it appears in cities with VERY different average temperatures (think Ashland, WI and Orlando, FL).  So we decided our next steps should be to investigate what happens to substances when they are heated and cooled, and we'd start with water since that's obviously needed for fog.

​M

We agreed that after putting some CCNs into the humid air produced by our humidifiers wasn't quite what we expected. So after brainstorming what could possibly have gone wrong, we updated our "We Didn't Make Fog Because..." lists to include:

1. Maybe we didn't put enough CCNs into the air?
2. Maybe we didn't  wait long enough?
3.  Maybe we didn't get it cold enough for the water molecules to condense on the CCNs?
4.  Maybe we weren't using the right CCNs?

We're kind of stumped.  We've got humid air, and we've got CCNs.  We're trying to make the water molecules condense onto the CCNs that are there (and we know are there because we added more to the air). But what are we missing???  Back to the drawing board today to think about what other factors may be playing a role in helping produce fog.  We can do this!

Students pushed to revisit the DQB now that we figured out a lot about fog and the role of CCNs!  So we did just that...publicly posting what we have figured out to a LOT of the questions we asked!  Anything you see on GREEN means it's a question students felt they had figured out and answered. All new questions are on pink Post-Its!  Questions that we still haven't answered are on light-yellow Post-Its. 

This is the other class' DQB updated.  Anything you see on yellow paper are questions students felt they answered.  Any all new questions are on orange Post-It notes.  

We then decided to honor everyone's investigation ideas and add CCNs to the humidity we could make in our classroom.  And here's some evidence of the fog we made...or wait!  Is it fog?!?!?!  We'll be looking into what may be the reasons behind what happened and honor other investigation ideas.  What about that fog juice thing?!??!

So from all our articles on fog appearances, we figured out that there was something else in the air along with high humidity when fog happens.  With some research, we discovered these really small, yet really important molecules, called cloud condensation nuclei, or CCNs for short.  These particles are things like dust, smoke, ash, or dirt and they allow water vapor to condense on them.  As water vapor molecules are attracted to one another and condense on a CCN, they make a fog droplet! As more and more water molecules condense, we think the fog must get thicker and thicker--or maybe the size of the CCN plays a role, we're not sure.  

From our modeling and feedback to one another through a gallery walk, we established consensus on how a fog droplet is formed:
​

We think that tomorrow we'll have some FOG!  Oh yeah!

So we had a complete agreement that we didn't make fog on Friday.  While we thought we made something (most likely steam), we definitely had consensus that it wasn't thick enough or long-lasting enough to be considered fog.

So...students mentioned in their reflections over the weekend that we should investigate a bunch of things next, and the vast majority said the following:

1.  Look into that fog machine!  What does it do differently than what we are doing to make our fog?

2.  Research natural fog more in depth--what is it that makes natural fog thicker and last longer than the fog we made?  Is there something more to it than high humidity?

3.  Change the temperature more--it seems like we couldn't make the water hot or cold enough when we wanted to and this might make the water clump together more.

So Mrs. Brinza decided to investigate student ideas and went to a Halloween Store to investigate the fog machine.  The store manager was kind enough to let her see the "info sheet" in a new fog machine box (Mrs. Brinza scored one on clearance and it didn't have an "info" sheet like a brand new one).  She took a picture and distributed the findings to students in class on Monday.  ​

From each of these articles where fog was present naturally, we uncovered some things.  First off, there always seemed to be humid air (which we already have figured out).  There was something to do with warm/cold air (which we're not really sure about).  And there was something about something else being in the air, like smoke, dust, tree particles, dust, or pollution.  Maybe these are the "missing factors" of what causes fog to happen!?!?!  What can we do next to see if this helps us make thick, long-lasting spooky fog?

Whoah!  What a crazy day!  We had a lot going on (blew two circuit breakers and burnt a little bit of plastic) but we all did an INCREDIBLE JOB designing our fog machines.  We had a lot of ideas being tested, but sadly....

NO THICK, LONG-LASTING, LOW-TO-THE-GROUND FOG.

Back to the drawing board.  What are we missing? What science ideas do we need to figure out still that's not causing our fog to look and act like the natural fog we see all the time?  Thank goodness we have the weekend to reflect!

So we decided to revisit our models of fog to prepare us well to design our fog machines!  It's important that groups come to a consensus for how they think fog is made so when they begin engineering, they'll know what to do!  Here are a few groups' models of the difference between when fog is present and when it's not present.

There were a couple ideas that surfaced:

1.  Fog happens when there's a lot of humidity in the air, so we would have to get a lot of water into the air with either the humidifiers or by boiling it.

2.  The water must clump together (we know water molecules are attracted to each other) and the the more they clump together, the more they are visible.  Since we see fog, we must have to push these pieces together either by forces them together with less space, or cooling them down.

And our conversations led us into our designs!  ​We planned out our initial fog machine designs individually, and then came together as a table.  Be on the lookout for our fog machine results!  Fingers crossed we make thick, low-lying, long-lasting SPOOKY FOG!

2. Recreate our models of fog knowing that since mid-September, we've figured out a lot about water, air, and humidity, which all play a role in the creation of fog.  Here are our "Gotta Have It" checklists for our models of fog (from the two classes of sixth graders):