Mystery picture
This is a picture I took recently while testing the homemade dark-field filter. Can you try guessing what it is? It is obviously part of something, but what?!
When you make your guess, check if you are right here.
Pollen in the Wind
November 2nd, 2009 by admin No comments »If you have a microscope and if you are getting bored of looking at algae and chasing paramecia, maybe you could try collecting pollen? Pollen comes in many different shapes and colors and with some practice you can learn to identify various types of plants by their pollen. Also, collecting pollen is easy – just shake a blossom over a microscope slide and you are pretty much done.
Even if there is not a single blossom in sight, you can still catch some pollen – without leaving your house. Take a piece of clear Scotch tape and attach it in such a way so part of its sticky side is exposed to the air. Leave it for several hours in the breeze and you will get plenty of pollen and other interesting stuff to look at.
One thing about pollen collected from the air is that the individual grains are often dried and shriveled. In this state it is very hard to see the actual shape of the pollen grain and identification is almost impossible. To see the real shape the pollen needs to be rehydrated. An easy way to hydrate pollen is to mix glycerine and alcohol. I’ve found that 1:1 mixture of glycerin and 50% isopropyl alcohol works just fine.
Put a drop of the glycerin/alcohol mix on a slide and carefully attach the Scotch tape over it. Stick it under the microscope, find a dry pollen grain, and start looking. After a couple of minutes you will see the grain slowly expanding. Here is a timelapse video that I’ve made of hydrating pollen:
Using a Scotch-tape-in-the-wind method you will catch not only pollen, but also trichomes, tiny scales from butterfly wings, dust mites, and of course a lot of dust. It can be a refreshing change from all these algae and paramecia…
Bad eyes, diffraction rings, and appreciating cheap optics
October 31st, 2009 by admin No comments »I am nearsighted at something like 2 diopters. Without glasses things become a bit blurry, especially in the dark. Here is a sketch I made a few years ago of what I see at night:
This is what I see without glasses
This is a somewhat enlarged version of the blob I see when I look at a remote streetlight in the darkness.
Not all the features of this image may be present at the same time. For example, the small dark spot that looks like a target is something that appears just from time to time, I guess when a minor particle in my eye goes at the exactly correct place.
This image shows how much inferior are our eyes to even the cheapest telescope. My eyes are not so bad as it may look from the picture. With glasses everything is just fine. Or at least looks like it’s fine…
But if this was a telescope, I’d burn the darn thing!
Making a Triode Vacuum Tube
October 30th, 2009 by admin No comments »An amazing video of manual fabrication of a triode vacuum tube:
For details, and to see what the lamp was used for, check this page.
Just pond scum…
October 30th, 2009 by admin No comments »Plants may look inert and passive to us but we just live at different timescales. Shake a vial of pond scum and let it sit for an hour. Take snapshots at regular intervals, speed them up, and this is what you will see:
(Full resolution video here.)
This pond scum is very much alive – and it is hungry!
One-Penny Darkfield Illumination Filter
October 29th, 2009 by admin 2 comments »
Brightfield
Darkfield
Look at these two microscopic images. Both are of the same specimen (a dust mite), both are taken with the same microscope and same camera. Yet, they look very different. The difference is in the way the subject is illuminated.
Most entry-level microscopes come with a single way to illuminate your specimen – bright field illumination. For many types of specimen this works just fine. But often you could get much better results and see much more details if you change the illumination. Click on both of these images to get the full-resolution version and you will see that the darkfield image not only looks better, but shows much more details that are almost invisible in the brightfield. Notice how much more you can see of the internal structure of the mite, and how better is the contrast of the feet.
If you want to try darkfield microscopy, you have two options: you could either buy a darkfield illuminator attachment (which will cost you anywhere between $50 and $1500), or you can try making one yourself (this one will cost you something in the range of one penny to a quarter).
