ice melting

On hot summer days you might really enjoy a glass with ice, just because you like a cold drink. Have you watched the ice in your glass up close?

This glass of ice water shows that the ice floats at the top. You probably see this all the time.

We’ve done a few investigations just watching ice melt. By taking some video and speeding it up, you get to see the whole process in just a few seconds. Here’s an example where we take ice that’s made from water with red dye. This way, as the ice melts you get to trace where that new liquid goes.

The red ice makes it easy to see where it goes after it’s turned into a liquid. (Food coloring in water is really fun to watch even when it isn’t from melting ice. Maybe we’ll try this later!) Also, these particular ice cubes are made in Han Solo frozen in carbonite ice cube trays. You can’t tell, but maybe you or your parents can appreciate this. Sorry, Captain Solo!

When you watch the ice melt, it’s funny that it goes from the top of the glass and falls to the bottom. What makes it do this? Why did it float in the first place? What would make it sink?

There are other liquids besides water that we can’t drink, but we can still put ice in them (as long as we’re very careful and label these liquids so we don’t accidentally put them in our mouths). We decided to compare what regular (water) ice does when it melts in water compared to when it melts in rubbing alcohol (isopropyl alcohol) that you can get at a pharmacy or grocery store.

Here’s a fast timelapse of these two, side-by-side. We think there’s a lot of interesting things going on, even at the beginning before any melting has happened. We added some salt at the bottom of the isopropyl alcohol to make it a little easier to see and to make some salt water as the ice melted.

Ice melts in water and isopropyl alcohol in different ways. You might notice where the ice goes and how it changes in each glass. You can also see some things happening outside the glass that might be interesting.

We like making these videos because then we can replay these episodes really quickly and make comparisons. But it’s also great just to see how ice melts in different ways in real time. You could make videos; or, you could write notes or take pictures or just observe and talk to your family about what you’re seeing. And then you can try melting the ice in other ways. We’d be excited to hear what you observe!

yard aliens

When we’re in the parks, we often find that there are great critters to look at hiding in the grass or in the bark of trees. It’s great that on See It! days we have lenses and microscopes to see these crawling things up close.

Lately, since we’re not in parks, I’ve been paying more attention to the strange alien forms that I find in my own neighborhood and yard, especially at different times of day. Like, this fantastic creature:

A dragonfly perched on a small tree.

I wonder why the wings are shaped this way? Why are there 4 of them? Can it see me through those eyes? Why does it like to land here on the top of this small tree? Why don’t I see it other times of year? And where did it come from?

A few days later I found a few of these babies scrambling around on some leaves in my garden:

A baby preying mantis in my lettuce.
A baby preying mantis in my lettuce, staring back at me.

Do they look familiar to you? How big do you think they might get? And what are they doing on my lettuce?

And most mysterious of all, I found this empty bug. Really! The outside of the bug was there, but the inside seems to have escaped and left behind this shell!

A left-behind exoskeleton.

Isn’t it funny how the outside of this creature is still clinging to this plant? I wonder what the inside of this alien looks like. And where did it go? And why would it do this kind of escape from its own body, anyway?

What I’m learning is that there’s lots of really interesting life outside that I can discover if I just take the time to watch for it. I’m starting to notice more and different kinds of bees than I remember; and there are birds stopping by that I haven’t seen before. And I’m sure that this will continue to change throughout the summer.

What aliens have you noticed around your home?

sunshine spots

It was a nice morning, and I thought it would be a good choice for me to sit in my backyard and read a book. But it’s easy for me to get distracted, and soon I was really interested in a spot of light that was on my chair:

A spot of sunlight on my chair.
Reading outside, I saw this spot of light on my chair.
(For more information about this great book, see:
https://www.hepg.org/hep-home/books/science-in-the-city)

I wondered what made this spot and I turned around to see how sunlight was coming through this tree behind me:

Sunlight coming through the tree's leaves.
Sunlight coming through my tree.

What I think is really amazing is how all of these leaves and the gaps between them are different shapes, but the light coming through makes circles. I used a white notecard to find more of them:

Spots of sunlight.
Round spots of sunlight made by my tree and the sunlight going through it.

You’ve probably seen spots like this before, maybe without even knowing it. (Once you start to see them in a few places, you might have a hard time not seeing them!) Sometimes under a tree we say that there’s “dappled light,” but it doesn’t matter what you call it. There are funny shapes and a kind of light that photographers and artists like, all made by the overlapping circles of light like this.

Can you find circles of light like this in other places? What do you think makes these circles? Why are there so many? Are there other ways to make these sunshine spots? Could these circles be a picture of something else?

jello optics

Some science investigations are especially fun to do at home. Playing with light and playing with jello are each great activities for indoors. This investigation prompt puts these two things together.

Here’s a video that Adam made himself, in his own home, with no fancy lab or equipment — the kind of setting we that is our favorite for making science. This is just to give you some ideas of where you can start, but there’s lots more you can play with and do.

Adam plays with light and jello at home.

In summary, all you need to do is make a gelatin dessert in your choice of flavor/color. Plain gelatin works great, too, but it doesn’t smell as good. When we make it, we just use half as much water (or don’t add any chilled water) and let the gelatin set in the refrigerator overnight. Then, cut out any shapes you’d like and put them on a surface like wax paper, a cutting board, or even just a clean table. Use a small flashlight or laser pointer to shine through the jello from the side, and observe what the light looks like as it goes into, through, and out of the jello. In my investigation in the video, I discovered some new things about how the light gets bent and focused; and I learned that my yellow jello lets through certain colors of light, but not others. I thought this was all really surprising and interesting, especially knowing that it was all caused by my 99 cent box of generic, lemon dessert.

Many other people do jello optics as well. Our friends at the Exploratorium in San Francisco showcase jello optics as one of their “science snacks.” Once you get started you’ll probably find other experiments to create on your own, and we’d be happy to have you share them with us, either by contacting us or leaving a comment here. Have fun!

Grab-and-Go Science Kits

Today we are going to try a grab-and-go science kit as part of a small demonstration for a local group of kids. Below are instruction videos to use the experiments provided in those kits.

Each kit should include:

10 UV beads

1 film canister

2 alka seltzer packets

2 helicopter templates

2 paper clips

Instructions: