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Elementary Science Education

Bernard Nebel

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  • in reply to: Starting Vol. 2 soon–what type/brand of microscope? #7263

    Bernard Nebel
    Keymaster

    The Brock microscope is the one microscope that I DO NOT recommend. Focusing is very tricky. Then, when you wish to go from scanning to higher power you must disassemble, screw in the higher power lens, and refocus. Refocusing under the higher power is almost impossible.

    Therefore, go with the three-lens, par focal, standard student scope, an example of which may be seen at
    https://www.amazon.com/AmScope-M150C-I-40X-1000X-Biological-Microscope/dp/B00AM5XB5O/ref=sr_1_3?ie=UTF8&qid=1538751948&sr=8-3&keywords=microscope

    They are actually less expensive than the Brock.

    in reply to: Weightlessness during space travel? #7247

    Bernard Nebel
    Keymaster

    That’s a good question. I’ve had to think about it too. In answer, I changed the question to, “What do you need to feel gravity, i.e., have a feeling of weight?” My reasoning: You need to be on a platform (something to stand or sit on) that is holding its position within a gravitational field. An airplane is holding its up/down position within the earth’s gravitational field, forward motion notwithstanding. Therefore, aboard the airplane you experience gravity much as you do on earth. Either that or you must be accelerating or decelerating so you feel the inertial force, which is indistinguishable from gravity.

    Now, assume you have blasted off on a straight line mission to Mars. After gaining required speed, engines have been turned off; hence, you are neither accelerating nor decelerating so you feel no force from that. Nor is your rocket ship holding a position within a gravitational field. It may be traveling at great speed in a straight line, but it is not moving or holding a position counter to any gravitational field. Therefore, despite its straight line of travel, it and you in it are in a state of free fall within whatever gravitational field(s) are present. Therefore, you would feel weightless. Please ask further or give an alternative argument.

    in reply to: Determining Latitude D-18 #7239

    Bernard Nebel
    Keymaster

    The following video, which shows diagrams, provides an excellent demonstration of how latitude is determined from the North Star:

    Knowing that the sun, at the spring and fall equinox and at high noon (the sun at its zenith) will be 90 degrees exactly above the equator, you can do the same thing with reference to the sun. Of course, in this case, you have to subtract your measured angle from 90 degrees because the equator is designated as zero degrees latitude. By making proper adjustments, this process can be used for determining latitude at other times of the year and the day. Mariners had and still have tables for making those adjustments.
    The following video may be helpful. (Thank you for you question. I hope this answers it, but please ask further.)

    in reply to: Determining Latitude D-18 #7238

    Bernard Nebel
    Keymaster

    The following video, which shows diagrams, provides an excellent demonstration of how latitude is determined from the North Star:

    Knowing that the sun, at the spring and fall equinox and at high noon (the sun at its zenith) will be 90 degrees exactly above the equator, you can do the same thing with reference to the sun. Of course, in this case, you have to subtract your measured angle from 90 degrees because the equator is designated as zero degrees latitude. By making proper adjustments, this process can be used for determining latitude at other times of the year and the day. Mariners had and still have tables for making those adjustments.
    The following video may be helpful. (Thank you for you question. I hope this answers it, but please ask further.)

    in reply to: Reference Books #7161

    Bernard Nebel
    Keymaster

    “My children tend to forget…” Your children are not unique in this, nor is it just children. We all forget things that are not brought back and refreshed now and again. Call it review, but that review does not need to be from a book. In fact there is a better way.

    The whole objective of science is not to learn a bunch of facts; it is to become able to look at the real world, both natural and human-made aspects, and gain understanding as to why things are as they are and happen the way they happen. For example, suppose kids have learned about inertia (Lesson C-5). The best way to review this is not to read about it again in a book; it is to call it mind in real life situations. Why is important to fasten your seat belt? What is involved in kicking mud from your boots? … a dog shaking water from its fur?

    In short, I believe the best sort of review is bring kids to consider things/happenings in the real world and with Q and A bring them to consider the “what” and “why” in terms of their learning (or perhaps formulation of questions for future learning). For ideas in doing this, see the sections in each lesson: “Questions/Discussion/Activities to Review, Reinforce, and Assess Learning” and “To Parents and Others Providing Support”.

    I hope others will respond here as well.
    Best, Bernie Nebel

    in reply to: How did your kids do on Lessons C-1 to C-4? #7101

    Bernard Nebel
    Keymaster

    Thanks Peywuei for sharing your experiences with the lessons.

    Dr. Nebel is away for the week, but will be interested to read your note when he returns.

    Thanks again,

    in reply to: Branching out from Science #7065

    Bernard Nebel
    Keymaster

    Thank you, Shelly, for you kind words. I have toyed with the idea of writing a math curriculum, but so far, it has gotten no further. You words inspire me that I should give it more thought, but if I do start the finished product will be a couple years down the road. Would you be interested in co-authoring it with me. (Please email me at bnebel@erols.com)

    In the meantime, I hope you will consider putting a review of BFSU on Amazon or elsewhere. Bernie Nebel

    in reply to: Photons?! #6543

    Bernard Nebel
    Keymaster

    You do have a very smart son. He has caught an apparent contradiction that completely escaped me. The best I can do in way of explanation is to point out that photons are an entirely different sort of “particle”, so different that they should not be considered particles at all. It is better to think of them as fundamental units or just “dots” of light energy.

    The key difference is that all particles of matter have mass (a certain weight in the presence of gravity). The more particles of matter that are packed together, the greater the weight. Photons have no mass. Regardless of how many photons (how much light) you shine into a bucket, there is still no weight, and there is no way that you can pack photons together and get a mass with size and shape.

    Another and very significant difference between photons and particles with mass is that light (photons) can be easily seen as waves, not particles. A simple activity described in the text explains how to  do this. Even physicists have no way to explaining why/how photons behave as both waves and particles, but it definitely sets them apart from atoms and larger particles of matter.

    In conclusion, photons can not be considered as particles in the same sense as particles of matter.

    The second part of your post is also significant. Please reread “Students’ Questions and Suggested Responses, Type 5 Questions” (page 19, Vol. I, 2nd ed.)

    This may well raise further questions. Please ask them.

    in reply to: Co-op level question #4362

    Bernard Nebel
    Keymaster

    Hi “Theblueanura”,

    In response to “I don’t have a way to know what the background knowledge [of my students is], I suggest conducting a brief Q and A regarding a given lesson. Use the list of items under “Practices: Students who demonstrate understanding can:” as a basis for your questioning. Students’ responses will demonstrate their understanding or lack thereof, and it will also expose misconceptions that they may have. This can lead into the lesson itself, or aspects of the lesson that need clarification. If they show full mastery, you can immediately move on the next lesson in the same manner. At worst this will be a significant review.

    This does assume that you have familiarized yourself with the lessons and have materials/equipment for teaching/demonstrations at hand to begin addressing gaps that students expose. Utilize the links provided under specific lessons in BFSU community.com.

    I confess that I am confused by your implying that all the D lessons involve “year long observational studies”. This is true for lesson D-6 only. All the others can be compressed into a 45 session if you are well prepared with necessary materials at hand. I do hope that you will make more contact with the person you know who does this.

    I hope this helps, but please ask further.
    Bernie Nebel

    in reply to: Co-op level question #3853

    Bernard Nebel
    Keymaster

    If kids have not been exposed to and learned the basic ideas and concepts presented in Volume I, they are a good and necessary starting point for any age regardless of grade. The core idea/concept of any lesson can be presented in a manner that is age appropriate.

    Please don’t hesitate to ask further as you proceed.

    Bernie Nebel

    in reply to: Living or Biological Clarification #3750

    Bernard Nebel
    Keymaster

    Thank you for your comment and question, “kunchik”. My effort here is to view the world as a child views it and then to help them gain comprehension and understanding as to what they see. They readily see and interact with living/biological things, natural earth things and materials (rocks, air, water), and they also see and interact with all sorts of things and materials that are made/constructed by humans.

    The core idea of the lesson, however, is to go beyond the simple categorization and get kids to recognize that anything/everything human-made starts with one or more things/materials from the biological or natural earth categories. Nothing can be made from nothing! (See the discussion portion of the lesson.) This is a basic concept that is foundational to all industry and technology. It is also central to the concepts of conservation, preservation, ecology and other areas.
    I welcome further discussion. Bernie Nebel

    in reply to: Milk jug tub? #3739

    Bernard Nebel
    Keymaster

    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

    in reply to: Which group is more frequently visited? #3649

    Bernard Nebel
    Keymaster

    This group is much more visited and I a planning to spend more time with it to make it more useful. Thanks for coming back to BFSU.

    in reply to: Living or Biological Clarification #3628

    Bernard Nebel
    Keymaster

    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 Nebel
    Keymaster

    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

Viewing 15 posts - 1 through 15 (of 35 total)