Friday Sprog Blogging: preparing for Kids Day at SLAC.


Thanks to longtime friend of the Free-Rides LO, the elder Free-Ride offspring will be participating in Kids Day @ SLAC, 2008 today.

Of course, the younger Free-Ride offspring is chagrined to be two years too young to participate as well. "You know, I'm about to start second grade, and I'm going to need to know a lot of science!"

It might have been a persuasive argument ... except for the fact that we've already seen the district's second grade science curriculum.

In any event, in preparation for today's activities, we took some time yesterday evening to review the carefully compiled safety information:

Elder Offspring: Yay! I get to slack around all day!

Dr. Free-Ride: Yup, you get to be a slacker. But you know that SLAC stands for Stanford Linear Accelerator Center, right?

Elder Offspring: I know nothing about that place.

Dr. Free-Ride: Physics is done there. High energy physics, if I'm not mistaken.

We then looked at the descriptions of the workshops for which the elder offspring is signed up, as well as the potential hazards of these activities.

Dr. Free-Ride: OK, for every hazard, they list a "mitigation", which is a way to prevent it or at least make the chances of the hazard less.

Elder Offspring: OK.

Mechanics 1: Build your own acrylic piggy bank; working with a mechanical technician assemble your very own piggy bank - COOL!

Cuts, bumps, or scrapes from dropping or slipping tools or sharp edges of parts.


  • Wear safety glasses.
  • Use clamps and keep your hands away from moving parts.
  • Pull hair back.
  • Wear safety glasses.

Elder Offspring: They put "wear safety glasses" twice!

Dr. Free-Ride: I guess they really mean it!

Dr. Free-Ride: Hey, the next workshop is biology. You were interested in having a biology activity.

Elder Offspring: Yeah, but I meant on real animals.

Dr. Free-Ride: Hello! Microorganisms are real animals!

Elder Offspring: I meant animals we can see without a microscope.

Dr. Free-Ride: I'm betting they have a more powerful microscope at SLAC than we're likely to get at home. Might as well take advantage of it to see the animals you can't see here.

Biology: Look closely at the world around you! Using microscopes, look at real structures - UGLY!

Cuts, bumps, scrapes from dropping or slipping tools.


  • Wash your hands after experiments; don't drink solutions; tell the instructor if you break a microscope slide and stay away from moving robot parts.
  • Wear safety glasses.

Dr. Free-Ride: I guess dropping or slipping tools are something they're generally concerned about.

Elder Offspring: Ooh, solutions! (rolling eyes) Do people really want to drink the solutions?

Dr. Free-Ride: In this case, drinking the solution could actually cause a problem.

Elder Offspring: "Stay away from moving robot parts"? Does that mean part of the microscope is robotic?

Dr. Free-Ride: I don't know.

Elder Offspring: And wear safety glasses!

Dr. Free-Ride: I think that's going to be a theme of the workshops.

Radiation: You will use different radiation detection instruments to find different types of sources and radioactive materials that are common. Suit-up, you will find hidden radiation sources - GET HOT!

Radiation (very small amounts - a fraction of what would be received from a medical x-ray).


  • Listen to your instructor.
  • Leave everything where you found it.

Elder Offspring: What do they mean, "very small amounts"?

Dr. Free-Ride: It says there, "a fraction of what would be received from a medical x-ray". That reminds me -- I need to schedule your orthopedist appointment, where you'll probably be getting another X-ray. So, the radiation from the workshop will be less than that.

Elder Offspring: So, it's not harmful?

Dr. Free-Ride: Not in these doses. If you were doing this kind of thing every day, you would wear a film badge to keep track of your exposure, and if it got to a high enough level, they'd probably make you take a break for a while so that your exposure stayed at a safe level. And, you see the mitigations listed.

Elder Offspring: What?! No safety glasses?

Dr. Free-Ride: I bet if you asked, they would provide safety glasses for you to wear.

Hydro Rockets: At SLAC we look at tiny sub atomic particles. We send our detectors into space on rockets - HAVE A BLAST!


  • Plastic bottle under pressure could rupture.
  • Getting hit by a rocket.


  • Stand back while bottle is pressurized and launched; pay attention and DO NOT TRY TO CATCH IT!
  • Wear safety glasses.

Elder Offspring: What's "rupture"?

Dr. Free-Ride: "Rupture" means "break".

Elder Offspring: Yay! Safety glasses again! So ... that's all I'm going to do?

Dr. Free-Ride: Does that not sound like a full day's worth of activities to you? That plus lunch plus the two talks? Hey, we should look at the descriptions of the talks.

Elder Offspring: Maybe I want to be surprised about the talks.

Dr. Free-Ride: Too late! Here's the first one:

Dr. Eleanor Schofield will speak about how she decided to pursue science as career and what she learned along the way.

Elder Offspring: In English, please?

Dr. Free-Ride: She decided to be a scientist when she grew up. So, how did she decide that, and what did she learn while trying to become a scientist and while being a grown-up scientist?

Elder Offspring: Oh. That sounds interesting. And it sounds a lot better when you say it in plain English.

Dr. Free-Ride: I have a feeling that when they wrote the description on this web page they were thinking about how to communicate with other adults rather than with 9- to 11-year-olds.

Elder Offspring: If the audience is kids, why not say it so they can understand it?

Dr. Free-Ride: You make a good point. Let's see if we can translate the description of the afternoon talk into kid:

Archimedes was a famous Greek mathematician who lived in the third century BC. It is hard to believe that some of his most important writings have only now been uncovered. How? With a powerful x-ray beam produced here at SLAC! Join Dr. Bergmann in a fascinating journey through 2000 years of science and history. We will also have 3-D glasses!

Elder Offspring: Cool! That description is pretty good.

Dr. Free-Ride: So you understood what that was about?

Elder Offspring: Yup.

Dr. Free-Ride: Do you have any guesses as to how the X-ray beam uncovered the works of Archimedes?

Elder Offspring: No.

Dr. Free-Ride: Well, that's a good question to have in your mind during the talk. By the end of the talk, I bet you'll know the answer.

Younger Offspring: When I'm old enough, I want to go to kids day at SLAC.

Elder Offspring: That means I'm going, too!

Dr. Free-Ride: Sure, but nothing says you have to sign up for the same workshops.

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Stupid kids.. get all the fun.. grumble grumble..

Hate world. Plot revenge

By Donalbain (not verified) on 15 Aug 2008 #permalink

Aaaaaaaaaawwwwhhhh . . . I want to go too!

Too old, you say? Well I hope that you will tell me all about it.

By Super Sally (not verified) on 15 Aug 2008 #permalink

I am lucky enough to have just witnessed Elder Offspring's rocket, which shot quite high and did not rupture. Elder Offspring did not actually have safety glasses on at the time (no one did). Elder Offspring did not try to catch said rocket upon re-entry, and I think Elder Offspring is doing a great job as a SLAC-er... Bravo!

Sounds like an awesome program.

I think we faithful readers deserve a guest post from Elder Offspring on how the day went and what she learned.

It was a pleasure sponsoring Elder Offspring (plus I got to go to parts of SLAC I normally never get to go to!).

>> "Dr. Free-Ride: Physics is done there. High energy physics, if I'm not mistaken."

That was once true. SLAC was a single-purpose lab, but SLAC has diversified its activities. Our mission now is to design, construct, and operate state-of-the-art electron accelerators and related experimental facilities for use in photon science, particle physics, and astrophysics research.

The first two workshops Elder Offspring attended (Radiation and Rockets) were related to the high-energy physics and astrophysics part of the mission. The hydrorockets were their own take on GLAST which was launched in June from Cape Canaveral.

The afternoon workshops were held in SSRL where they use synchrotron radiation to do many types of science from studying molecules and materials to exposing ancient manuscripts (a personal favorite for this archivist).

P.S. Did I ever mention that the director of SLAC is a Wellesley woman? Persis Drell W'77

Bob: I don't know, but now I want a pair of 3D safety glasses.