By showing children scientific curiosities, you can awaken the need to ask questions such as: why? how it's working? how it's done?
You can experiment in two ways: 1) in places like [EduPark] (http://www.edupark.gpnt.pl/) where professionals prepare the whole children's play program and 2) at home when you have more time, and you are not afraid of messing up.
One way to show your children experiments is to go to a research center. We were at a workshop called "Secrets of the Baltic". At the workshop, guide talked about animals which live in Baltic Sea, how salt level is changing and what depends on vegetation and why Baltic Sea is called the desert. We have seen the circulation process of water in the air - water reservoirs evaporates water, clouds are formed, and then the rain falls on the earth and everything evaporates again. We took part in experiments showing how the salinity of water affects the mass of water. In this experiment we had three liquids with different colors and different concentrations of salt in them, then we poured them into jar with a higher salt concentration. Later we pured water with smaller and smaller concentrations, and we had a bowl containing three-color liquid, where colors did not mix with each other. We also made a rainy cloud with shaving foam, blue liquid and water. It was very simple but quite spectacular experiment. In the dish we had water, then we added shaving foam on top of it, and then we slowly droped water droplets with blue dye. When shaving foam was already overflowing with blue liquid, blue droplets began to drip into clear water and it looked like rain. We also checked how pollution of beach influences water in the sea - even small amount of trash left after sunbathing can release dangerous substances through sand.
In the end we met student which spent too much time thinking about seas and oceans.
After workshop we went to exhibition organized for kids, where they could try lifting heavy bags of sand connected to different pulleys, check some optical illusions and play with other "physical" exhibits.
While at home, we like do simple experiments with our daughter, which does not require sophisticated equipment. We recently prepared a jar of water filled with salt, then a string was placed in the jar, and then we attached a button to it, so that the string would not flow on the surface. We left the jar in a easily accessed place and watched what happened every day. Today our jar and string look like this.
This experiment teaches patience and dealing with situation when not everything is immediately visible and we have to wait for results. It also gives us question: why salt stays on the rope? By evaporating water from the saturated solution, crystals begin to precipitate. The crystallization and evaporation takes longer, the larger the crystals are. If we wait longer, our salt will look more interesting. We can also see that the dissolution process can be reversible.
Our next experience was to create a Non-Newtonian fluid that is both solid and liquid. This fluid show unbelievable properties when we hit it: it behaves like a solid object and puts up a resistance. And when no force is applied to it, then it is in liquid form. After the joint preparation of such liquid, Ewa's fun took two hours. To prepare such fluid, all you have to do is to add some water to potato flour and check, from time to time, how created mass behave. The goal it to have fluid which allows to create the balls from our it and then those ball should "melt" in your hand.
Here I would like to recommend making "rain clouds" in home. On window, you should put the transparencies (so that there was not too much cleaning later), and then we put blue, black, green (and so on ...) paper on top of our play area. Next we have to put a cotton wool on the paper and spray it of watter. After a while, our cotton wool will be wet, and when the color paper underneath is wet, we will see a beautiful rain on the glass. If you used other colors than blue, then you will have beautiful colored rain.
I believe that, in every big city, you can find such workshops for children, so if you do not have the time or equipment at home, then you should go out and try to find something for yourself. It is good way to spend time with whole family. And there will be a lot o side effects such as more and more hard questions from your kids ;)