[Bernard NebelKeymaster]

Sorry the text description is confusing. A way to do it is to lay the jug on its side on a table, handle up to one side or the other. Bracing your hand on the table, hold a marker so that its point is at the mid-level of the jug. Holding the jug firmly, side down on the table, slowly move and rotate it around against the marker so that you end up with line from the spout along one side, across the bottom, along the other side back to the spout. Cut along the line and you will have your tub with the half spout to act as a convenient overflow spot.

A half gallon cardboard carton might work as well but the smaller objects and volumes necessitated are likely to result in higher degrees of error. In either case, the sides of the “tub” will have to be supported with stacks of books or other objects

Yes, one or more photos and any comments regarding your experience with this exercise will be greatly appreciated. Can someone make a video of this?   Bernie Nebel

[Bernard NebelKeymaster]

Good observation. Consider that the cover photo shows that kids’ existing notions may lead to mistakes. However, take this as an opportunity to discuss and clarify the concept further.

[Bernard NebelKeymaster]

This is a great question. Thanks.
Water freezes by virtue of water molecules hydrogen bonding into a three dimensional solid structure (Google: molecular structure of ice). This structure, uniquely, has a larger volume than the non-structured liquid water. Hence it is less dense–ice floats.

Visualize water in a cylinder with a piston pushing down on it applying increasing pressure. If water turning solid (ice) involves increasing volume, the piston pressure holding volume small will prevent that structure form forming. Hence, under increasing pressure water remains in its liquid state.

With sufficient cooling under high pressure, there will be some point at which it may turn into an amorphous non-structured solid, but offhand I don’t know what point that would be.

Ask further as you wish. Bernie Nebel

[Bernard NebelKeymaster]

There are many people who still deny climate change/global warming. Can such denial stand up to evidence and rational reasoning?

For understanding global warming a key observation, which can be easily demonstrated, is the following. Given a constant heat input, a body does not get indefinitely hotter. Its temperature rises and then levels off at point where it gives off heat at a rate equal the rate of energy input. This can be demonstrated by putting a pan of water over a candle flame and measuring the temperature of the water over time. Expand this idea to the basic concept: The temperature of any body is a balance between incoming energy and outgoing energy. “Any body,” includes the whole Earth; the average temperatures experienced on Earth, despite all the perturbations, come down to a balance between the the rate of energy input, solar energy from the sun, and the rate of energy output, heat radiation from the Earth into  outer space.

How might this balance be upset in a way to raise the temperature? Reflect again on the pan of water over the candle flame. One might increase heat input, but in terms of the Earth, the sun provides a constant energy input that can’t be adjusted. A second possibility is to put additional insulation around the pan to reduce the rate of energy output. This can be demonstrated and one will observe that temperature rises to a new level. 

 

Here is the crux. CO2 absorbs outgoing heat radiation from the Earth. (It does not effect incoming solar (light) energy.) The amount of CO2 in the atmosphere is effectively the amount of insulation around the Earth. Are we changing the amount of CO2 in the atmosphere? Yes, the unavoidable waste product of burning fuels is CO2, and much of this CO2 is accumulating in the atmosphere leading to a sharp increase.  (see http://climate.nasa.gov/climate_resources/24/) Increasing temperatures due to this increasing insulating effect of CO2 are unavoidable. The only questions are in the timing, degree, and effects  of temperature increases. There are numerous observations that show they are already occurring (http://climate.nasa.gov).

 

Bernie Nebel

[Bernard NebelKeymaster]

The depth of BFSU is in addressing and having your kids master and connect the basic idea(s) and concept(s) presented in each lesson. There are no BFSU lessons that don’t aim at presenting a basic idea or concept. Therefore, with you older child, I would follow the same path as recommended in the text. That is starting at the top and moving back and forth across the flowchart working your way down. However, older kids with their greater background of experience will be able to move through the early lessons much more quickly, pausing to take more time with anything new and not familiar. This is not sacrificing depth for speed. It a matter of helping your kids refresh, organize, and recognize the significance of what they are already familiar with. Thanks for the question, Bernie Nebel

[Bernard NebelKeymaster]

The first and second editions of BFSU Volume I are very much the same. The first edition will work perfectly well in giving your kids a solid background in beginning science. The second edition is only somewhat adjusted to make it more in tune with the Next Generation Science Standards (NGSS), which may or may not be of any concern depending on the state you live in. In this regard, the second edition of Volume I, contains two additional lessons: C-3A Energy and Force, and B-5A Adaptations and survival. Thanks for your question.

[Bernard NebelKeymaster]

Hi buddingnaturalis,
I think the current edition of BFSU Volume III, preceded by Vols. I and II, provides a gook background preparation for any further studies in science, as well as a good foundation of “scientific literacy.” Therefore, I have no plans at this time for a second edition of Volume III.
However, if there are particular topics you would like to explore or expand on, that is what this forum is for.
Thanks for question.
Bernie Nebel

[Bernard NebelKeymaster]

Hear is a site that shows a simple device you can make that will show the idea of a hydraulic lift:
http://www.ehow.com/how_7724623_make-hydraulic-lift-school-project.html
However, it does not really illustrate the
f x d = f’ x d’ principle. You will have to add that in.
I hope others may find or create a more useful site. Thanks for your question Jackie. Bernie Nebel

[Bernard NebelKeymaster]

The three volumes of BFSU are an unbroken continuum of lessons that build understanding in logical, systematic steps all the way from K to 8. Hence early lessons are prerequisite to later lessons. Therefore, I recommend actually doing a quick review of Volume I, since it was several years ago, then moving through Volume II before tacking Volume III. All lessons can be addressed in an age-appropriate manner.

I hope that others who have faced the same problem will comment as to what their experience has beed.

[Bernard NebelKeymaster]

Yes, I would classify crude oil as biological since it is derived from living organisms AND it would not be present without those organisms having lived. The same may be said for most of the natural gas, methane on Earth. However, methane is found to exist on other planets quite apart from life. Therefore, it might also be classified as a Natural Earth material. Recognize that the final breakdown products of biological materials, e.g., carbon dioxide and water, are natural earth materials. Methane seem to fall in the “crack” between.

[Bernard NebelKeymaster]

Thanks Kaxy, I think everyone will appreciate the idea of mind mapping.
Bernie Nebel

[Bernard NebelKeymaster]

Reflecting on your question, I believe the point of confusion, which I did not make clear, is this. The attraction between particles is commonly a magnetic attraction, an attraction between positive and negative charges. Visualize actual magnets. You readily experience that the attraction between magnets, or between a magnet and iron, rapidly decreases with distance. When magnets are a few inches or more apart, you don’t feel their mutual attraction at all; when they are only a hair’s breadth apart, you feel it strongly. Note that it is not the nature of the attractive force that is changing; it is simply that the nature of that force is such that the strength of attraction deceases rapidly with distance.

Coming back to the lesson and particles, the increased jiggling that occurs with increasing temperature pushes the particles further apart. Thus, you are right, the attraction between them becomes less. Hence, they begin to slip and slide about each other (liquify) or go off independently (become gas). But again, it is not because the nature of attraction has changed; it because the increased jiggling has pushed them further apart where there is less attraction.

Thank you for your question. I hope this clarifies it. Do ask again as you need.

• This reply was modified 6 years, 5 months ago by  Bernard Nebel.

[Bernard NebelKeymaster]

You have discovered and brought our attention to an error. Thanks “knitgrl”. On testing this further, you are quite right. I too find that the magnetic field extends through the can and attracts a paper clip on the other side. The attraction, I estimate, is only somewhat weaker than in the absence of the can’s “short-circuit”.

The science lesson is that what is observed will trump what it says in the text. Bernie Nebel

BTW, I think your horseshoe magnet is fine. I have never seen or heard of a magnet constructed as you describe.

[Bernard NebelKeymaster]

You have discovered and brought our attention to an error. Thanks “knitgrl”. On testing this further, you are quite right. I too find that the magnetic field extends through the can and attracts a paper clip on the other side. The attraction, I estimate, is only somewhat weaker than in the absence of the can’s “short-circuit”.

The science lesson is that what is observed will trump what it says in the text. Bernie Nebel

BTW, I think your horseshoe magnet is fine. I have never seen or heard of a magnet constructed as you describe.

[Bernard NebelKeymaster]

Try typing into your browser:
_______ (Region)______ (season) photos

I just did it for New England, spring, summer, fall, and winter (separately) and got nice photos representative of each season. Of course, your will need to express what the temperatures are like as well. Good luck. Bernie Nebel

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