HRM Parent Blog

On June 6th of this year, a very rare event will occur in our skies at sunset: the planet Venus will meander through its orbit along a path that takes it between the Sun and the Earth, making it visible during the day as a dark spot on the bright disc of the Sun. This isn't an eclipse (scheduled by the way for May 20th); this is something very rare, and a bit different - a transit.

Planets all orbit around the Sun at different rates, so every now and then, they line up. When the Moon crosses between us and the Sun, it blocks it out briefly, but planets are farther away and much smaller, so they appear as little dark spots crossing the bright disk. From our perspective, Venus transits the Sun twice (in two events eight years apart) every hundred or so years. The last one was in 2004, and the next two will be in December of 2117 and 2125, respectively. Hopefully that gives you a sense of how rare this is!

We cannot, of course, look directly at the Sun. Building a Solar viewer is very easy though - you only need two pieces of stiff poster board (or similar), some aluminum foil and a pin. By covering one piece of board with aluminum foil and poking a pinhole in it, the image of the Sun can be shone on the second piece. Simply place your pinhole board between the plain board and the Sun, and you can focus an image by moving the pinhole board closer and farther from the projection surface (plain board).

It is also possible to use binoculars or a telescope to project an image onto a page or piece of board, but these need to be covered or aimed away from the Sun frequently (at least every minute or so) to avoid damaging their lenses (from overheating!). Never look directly at the Sun without specially-made Sun viewing filters, especially through binoculars, a telescope or a camera.

If you're looking for another rare opportunity you've got to check out the Discovery Centre's upcoming new exhibit - Be the Dinosaur. This exhibit, the first time in Canada, will give you the opportunity to become a T-Rex or Triceratops through a sophisticated but super-cool video simulation that puts you right in the middle of a dinosaur world. Rare indeed!

For more great things to discover - visit the Discovery Centre on Barrington Street in Halifax, check out their website  or join them on facebook. 

Halifax’s famous fog is becoming more common with the weather warming up, and there is no better way to investigate it than making your own at home – in a bottle!

You will need a clear plastic bottle with a cap, some hot water and optionally, a match. A funnel may also help, but is not necessary. Your water need not be boiling but ensuring it’s hot enough to at least see steam rising from it will help you along. Of course, be very careful when working around hot things with kids – we recommend ongoing supervision.

Pour a small amount of hot water into your bottle: a few centimetres in the bottom is plenty, and don’t worry about the plastic becoming deformed, that’s normal. There are two ways to produce a cloud using this setup. You may be able to produce fog by simply capping the bottle and squeezing it as hard as you can. Alternatively, light and blow out a match, drop it quickly into the bottle and then put on your cap.

The bottle will get warm when full of hot water, but it should be safe to touch above the waterline.

Fog is essentially a cloud that we see at ground level, and these clouds are formed through two processes: evaporation and condensation. Water transitions most visibly from liquid to gas (water to steam) at 100°C, but this process of evaporation happens in small amounts all the time when water is relatively warm (even only as warm as lakes and rivers). This water vapour in the air will turn back to tiny droplets of liquid when the air pressure around it increases sharply, or when it is given a small particle to stick to – this can happen with particles as diverse as smoke, dust and pollution in the atmosphere or even the salty spray from the ocean (that’s our infamous “salt fog”). Squeezing your bottle increases the air pressure inside, and adding a smoking matchstick offers plenty of particles for water to stick to. Both create perfect environments for clouds (fog!) to form.

If fog and April showers chase you inside, bring the family down to Discovery Centre. Our most popular exhibit ever Grossology is only here until May 13!

For more great things to discover - visit the Discovery Centre on Barrington Street in Halifax, check out their website  or join them on facebook.     

It's that time of year again - Spring is in the air! This means melting snow, the school year's home stretch and the return of Nova Scotia's migrating birds. There is no better way to welcome back the birds than to put out birdfeeders.

There are hundreds of birdfeeder designs at local stores in your area, but birdfeeders can also be made at home from old yogurt and ice cream containers, empty pop bottles, mesh bags, tea cups, PVC pipe and pretty much anything else that you might have lying around! For this reason, we'll leave the design up to you and your family, and focus on what and when to feed the birds.

Now is the time to start. Birds decide where the best food spots are as soon as they arrive. Having food out early will increase your chances of being the favourite place to eat.

Birds have evolved to prefer different types of food. I suggest making two or three feeders of different types, and keeping a journal to see which types of birds like which kinds of foods! Stores sell huge bags of wild birdseed mix, which is a great start, particularly for birds like finches and grosbeaks. Suet (animal fat - often lard or kitchen leftovers), sometimes with seeds mixed or rolled into it, is perfect for birds that prefer insects - like woodpeckers and nuthatches . Chickadees like both! And for hummingbirds which usually eat nectar from flowers, we recommend a brightly-coloured red feeder that gives them sugary syrup (1 C of sugar in 4 C of boiling water) to start with in the spring and then during growing season, plant some red flowers like impatiens, salvia or bee balm to attract them.

Keep your feeders full, and make sure to clean a hummingbird feeder every couple of days with vinegar, otherwise it will grow mould.

When placing feeders, try to keep a metre of open space around them so birds can be wary of predators (neighbourhood cats), and consider whether you want to attract squirrels. If not, try to place a metal pie plate or plastic cone approximately one metre from the ground around your feeder support (or a bit closer above the feeder, if it hangs) as this will impede squirrels from climbing to the food. This is a good time of year to put out swept-up pet hair, old feathers and bits of scrap cloth. Birds will use these to make nests, and will be more likely to stay nearby.

And speaking of nesting- if you're looking for a summer camp home for your children - the Discovery Centre has the perfect solution for you! Our week-long summer camps run from July through the end of August, and are open to children from 6-12. We guarantee a scientific blast - but beware - they fill up early!

 For more great things to discover - visit the Discovery Centre on Barrington Street in Halifax, check out their website  or join them on facebook.     

Now that cold and flu season is upon us (trust me - this year, it's a doosie), it seems a good time to jump back into the kitchen to make something homemade and comforting. It's also a good opportunity to see how germs (bacteria) can actually be helpful rather than harmful.

This experiment is to make your very own butter in your kitchen. All you need is 250 ml of heavy cream, a jar and some water.

Let your cream sit at room temperature overnight, and then refrigerate it again in the morning. Once it's cool, pour it into a jar, put on the top and give it a good, solid shake - then keep on shaking. The goal isn't to shake the jar quickly like a paint-shaker, but to give firm, regular shakes in one direction - like your ketchup bottle is running out (you can use a food processor for a less intense work out!). After a couple of minutes, you'll notice that something is clearly forming in the bottom of your jar: butter! Pour off the liquid (which is buttermilk), shake a bit more with some fresh, cold water, and pour the liquid back off. The remaining solid is butter.

Butter is a fat that occurs naturally in mammalian milk - cow, goat, etc. - and exists in some quantity in most types of milk (for example 1% milk is 1% butter fat by mass). The fat is trapped in little bubbles so that it doesn't separate, and by shaking, you've done two things to break those bubbles. First, letting the cream sit at room temperature allowed bacteria (which normally is not desirable) to grow and produce lactic acid, breaking some of the bubbles. Shaking the cream smacks the bits of freed butter fat around, breaking more bubbles and freeing more butter, which feeds a nice loop of butter-churning goodness.

Your butter will not likely be very yellow: the yellow colour of butter comes naturally from beta carotene that animals get from grass.  Dairies that use grain-fed cows add the beta carotene directly into their butter to colour it. Goat's butter is naturally white: goats turn beta carotene into vitamin A.

We hope you like learning about the good things bacteria can do. But, be sure to come to Discovery Centre while our popular Grossology: The Impolite Science of the Human Body exhibit is still here so you can also learn about some of the other things bacteria does to our bodies, and why it can make us sick. Grossology is on now until May. 

For more great things to discover - visit the Discovery Centre on Barrington Street in Halifax, check out their website  or join them on facebook.     

For this activity you will need some containers, some water, a cold location, a pan and a metal spoon. Find a container (mould) shaped to your liking, fill it with water and then leave it in a cold spot - a freezer works, but the temperature outside can get much colder, which will speed up the process. As you might guess, this will eventually form a nice piece of ice in the exact shape of your mould. Great moulds range widely: from ice cube trays and yogurt containers to balloons or rubber gloves (though you’ll need to cut these away to remove your ice). Just make sure that your container has room for your ice to expand, because water gets slightly larger as it turns to ice (and therefore can break your mould if it doesn’t have room to stretch).

Now, take your cool-shaped block of ice, rest it in a pan (to catch melting water!) and sculpt it with a metal spoon and a cup of warm water (to keep your spoon warm). Use your imagination and scrape and melt your ice into nearly any shape you like. Upload your ice sculptures to our Facebook page!

There are two bits of science to be learned in this icy activity: first, the bigger the difference in temperature between two things, the faster they will come together (the warm one cools and the cold one warms). That means your ice will form faster the colder your day (or freezer), and melt faster the warmer your carving tool is. Secondly, ice sculptures look particularly cool because of how they catch the light: light bends a bit when it moves into and out of water, which makes a spoon look bent in a glass of water (try it!) and can make an ice sculpture seem like it’s glowing.

If you need a break from the cold – be sure to come to the Discovery Centre and check out our two new exhibits coming this month – Grossology: The Impolite Science of the Human Body and Let’s Go: Animals in Motion.  Both will be here until May.

For more great things to discover - visit the Discovery Centre on Barrington Street in Halifax, check out their website  or join them on facebook.