We are not able to see Brownian motion in the milk/water. Is there more info on conducting this experiment? I can’t find anything online other than videos of what you should see. I’m not sure if it’s bad slide prep technique, or doing the experiment wrong, or a problem with the microscope. We can’t see motion at x40 or x100, and only see bright light at x400. I’d appreciate any tips, or pointers to online resources for similar experiments or more indepth explanations. Hard to troubleshoot with so little info. Thank you! We do love the series very much!!
Sorry not to get back to you until now. From what you describe, I think the problem is in the way you are using your microscope. Use the condenser to cut the light way down so that the background is only a light gray. Then carefully focus. Be sure you are focusing on the liquid under the coverglass. Get a rough focus with 40x, then go to 100x. Hopefully, this will give you something similar to what you see in videos.
I am very happy to see that you are (attempting) giving your kid(s) a first hand experience of this. Please let us know how it goes from here.