Explaining Black Holes to 5th Graders

  • Thread starter Lyuokdea
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  • #1
Lyuokdea
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Hi All,

So I'm a current physics grad student - who's supposed to give an outreach presentation (over skype) to some 5th graders who have been learning about Black Holes.

I have no problem with the technical content - but does anybody have some good ways to explain things to elementary students? I'm looking for good explanations which keep the subject intriguing but try to correct some of the media misconceptions....

Thanks,

~Lyuokdea
 

Answers and Replies

  • #2
MotoH
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Give the NDT speech about "spagettification" That will keep 5th graders interested for sure.
 
  • #3
magpies
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You'll probably be suprised at how much they already know.
 
  • #4
lisab
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What concepts do you plan to present?
 
  • #5
Lyuokdea
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What concepts do you plan to present?

They are supposed to be writing and asking questions - so I'm not sure what will come up. But I assume there are going to be asking fairly basic stuff

~Lyuokdea
 
  • #6
Char. Limit
Gold Member
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Watch out - some of those fifth graders are pretty smart.

You could always explain why black holes bend light...

Of course, without the math involved. I doubt even Feynman knew a tiny piece of the math involved in fifth grade.

I don't know if you can find it, but The Universe has a show on Black Holes that may give you an idea of what they might ask...
 
  • #7
magpies
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Any chance you get to use an astronomically large number do it they will eat it up.
 
  • #8
rootX
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https://www.youtube.com/watch?v=leZdJmUF4lM
https://www.youtube.com/watch?v=cW7BvabYnn8


National Geography/Discovery/BBC should have interesting explanations ..

Just keep it humorous and interesting.. Details are not important but the way you deliver the speech should be of more focus. I believe a high school student might have better explanation for the grade 5 students than a grad student.
 
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  • #9
humanino
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There is the analogy of the swimmer approaching a waterfall, passing beyond the "horizon" where the flow exceeds its speed and can not escape. I think it is a fair analogy.
 
  • #10
Matterwave
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You could always just derive the Schwarzchild metric for them. And for the overachievers you could get into the Kerr metric, but focusing more on the qualitative aspects such as frame dragging (deriving the Kerr metric from the EFEs may not be possible due to time constraints). I wouldn't try going for anything more complicated than that with fifth graders.
 
  • #11
TheStatutoryApe
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http://www.scribd.com/doc/402335/Explaining-science-and-scientists-to-kids [Broken]

Here's something that is supposed to explain science for kids. Since you are unsure of what questions you will be asked this may give you a general idea of how to go about explaining things.

I think that general guidelines are to keep it simple and try not to over-explain.
 
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  • #12
MotoH
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I think that as soon as you start going into the math behind black holes, you will lose almost the entire class.
 
  • #13
leroyjenkens
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I think that as soon as you start going into the math behind black holes, you will lose almost the entire class.

Almost? Whatever 5th grader isn't lost by the mathematics of black holes needs to be brought to a lab and studied.
 
  • #14
MotoH
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Almost? Whatever 5th grader isn't lost by the mathematics of black holes needs to be brought to a lab and studied.

There are going to be a select few that will not understand the math, but will still think it is interesting.
When you were in Geometry, did you not think Calc 3 stuff was interesting, even though you did not understand it at the time?
 
  • #15
Saladsamurai
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Just tell them that black holes are where the bad kids go.
 
  • #16
leroyjenkens
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There are going to be a select few that will not understand the math, but will still think it is interesting.
When you were in Geometry, did you not think Calc 3 stuff was interesting, even though you did not understand it at the time?

If I don't understand what the numbers and symbols mean, I don't see how I could find it interesting.

And since I still don't understand calculus, I wouldn't be interested in hearing some formulas talked about. I think it's interesting what calculus can do and I'd like to learn about it eventually, but I'd be lost if I heard someone explaining black holes in the language of math.
 
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  • #17
BobG
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There is the analogy of the swimmer approaching a waterfall, passing beyond the "horizon" where the flow exceeds its speed and can not escape. I think it is a fair analogy.

I would go one step further and push one of the kids down a dark well so deep you can't see the bottom. "This is what happens if you get too close to a black hole!"

An important lesson about life in general and black holes, in particular.
 
  • #18
Evo
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  • #19
waht
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Have you guys seen Neil Tyson. He was born for this:


https://www.youtube.com/watch?v=h1iJXOUMJpg
 
  • #20
MotoH
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Have you guys seen Neil Tyson. He was born for this:


https://www.youtube.com/watch?v=h1iJXOUMJpg

I had that in the first post. . .
 
  • #21
waht
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Give the NDT speech about "spagettification" That will keep 5th graders interested for sure.

Ahh, yes your are right. Took me a while to connect the dots.
 
  • #22
Lyuokdea
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There is the analogy of the swimmer approaching a waterfall, passing beyond the "horizon" where the flow exceeds its speed and can not escape. I think it is a fair analogy.

Great example...this is the sort of stuff i was looking for...

I'm getting an incomplete list of some of the questions they wrote down to ask (though they will probably be asking more questions spontaneously)...I'll try to put them on here when i receive them.

Thanks!

~Lyuokdea
 
  • #23
Jack21222
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I like telling people (including kids) about the different types of compact objects and how black holes form as well, and how dense matter can get. How a teaspoon full of white dwarf material weighs over a ton, and a teaspoon full of neutron star would weigh more than a mountain.
 
  • #24
Lyuokdea
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here are some of the questions that kids sent in.... this doesn't seem so bad now, as many of them are pretty good questions...some (specifically the quasars one) I think are quite hard to definitively answer...others show some misunderstanding of the concepts - which should be pretty easy to correct in a subtle, yet informative, way

Some kids did (and were encouraged) to, ask questions in various areas of astrophysics, as they are learning other astronomy topics in this chapter as well

Does a lunar eclipse affect earth?

How big is a blackhole?

How many stars are in the milky way?

How long do quasars take to form?

How long does it take for a blackhole to run out?

How big would the blackhole be when the sun burns out?

Are there planets with life in other galaxies?

If you could live when you were pulled into a black hole, where would it take you?
 
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  • #25
story645
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The Magic School Bus episode on space? (We watched some episodes for AP physics and it was awesome.)
 
  • #26
EnumaElish
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1. First introduce the concept of escape velocity in an "everyday example." We all know earth has gravity -- you cannot fly how hard you've tried, unless your family is the Incredibles. How can the planes fly? Because they go really fast -- but not fast enough to rise into space. The space shuttle goes faster than a plane, so it escapes earth's gravity and rises into space. But a giant planet like Jupiter is more massive so has more gravity; even a space shuttle could not escape Jupiter's gravity. The sun (a star) is even more massive.

2. What's the fastest thing out there? Faster than a rocket? Faster than any other thing you can imagine? It's light. Yep, kids, light is the fastest thing in the universe.

3. Imagine a "star" (or what used to be a star) which is so massive that a plane cannot escape it, the space shuttle cannot escape it, and even light, the fastest darn thing in the whole universe cannot escape from it. That type of a star is known as a black hole. It's black because light cannot escape it, so it appears black. And it's a hole because nothing that goes in can come out.

4. What happens when you approach a black hole? Etc...
 
  • #27
Char. Limit
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EnumaElish...

On 2, I'm imagining a tachyon. You are wrong!
 
  • #28
ideasrule
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Maybe you can introduce the formula F=GMm/r^2. It's one of the easiest formulas to intuitively understand: gravity is like light, thus the 1/r^2 relationship; force is proportional to one mass, so "M"; it's proportional to the smaller mass, so "m"; and of course we need a constant. Then explain that when a big mass gets compressed, r decreases, so surface gravity goes up.
 
  • #29
Pinu7
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You MUST talk about how space curves with a large mass and use this to explain gravity. Compare space to a trampoline. Talk about how light bends in gravitational fields, but is usually able to escape their pull...except for black holes.

DO NOT UNDERESTIMATE FIFTH GRADERS!
Some are really smart, and you do not want to bore them with facts they already know, your job is not to take away class time, it is to fish out prospective physicists.

Make sure to talk about:
-Event horizons
- Spacetime distortions around event horizons
- What "happens" when you enter a black hole
- Experimental evidence of black holes.
- Super massive black holes(especially Sagittarius A*)
- Talk about how lots of Physics doesn't work near black holes(try to explain T-symmetry)

Also include a couple videos on black holes like this:
http://q2cfestival.com/play.php?lecture_id=8242&talk=alice [Broken]
 
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