Thanks for your reply. Aren't all systems, ultimately, closed, and that's why perpetual motion is impossible? But I agree. From a toy's point of view, or cool physics, relying on a battery is not very interesting, even though since 1840. In its favor, that is 179 years, so it gets huge points...
Perpetual motion is fundamentally impossible. But almost perpetual motion is possible.
The list of toys or devices designed to run for a very long time is short: crookes radiometer (photons, cheap), the drinking bird (heat engine, cheap), the Atmos clock (temperature, expensive), Beverly Clock...
Thanks! That makes sense, but if so, you'd think surfactants in 75% EtOH would have about the same effects they do in water. But, as near as I can tell, they don't. The solution has to stay at about 75% because these are museum specimens, and anything over say 90% will dehydrate the tissues...
A query about, I think, extinguishing surface tension in 75% EtOH:H2O.
I need to examine microscopically (~50x) specimens preserved and stored in the above medium, which I do by immersing them in dishes filled with the above, illuminating w fiber optics, and examining with a stereomicroscope...
Have tried placing slides a/o cover slips on top, obviously w/o bubbles, etc., but it does not markedly improve the image. To some extent it may also be a question of mag...high mag photos (~30-60x) are always a little softer. But it is still my impression that photos through liquid are...
Fundamental photo question:
Have noticed that, technical problems aside, photos in liquid are never on average as sharp as photos in air. Is this due to the RI of air v. e.g. water? If things are ca. 1.5, photo'ed in 1.00 air, that's quite a diff. Photo'ed in 1.33 water, less diff. If things...
It's usually a "bug" issue, as in small specimens of invertebrates and terrestrial arthropods. They range from soft to nearly indestructible. Most are <5mm, and some are < 1mm, especially the dissected parts. Because the contorted conformation of each specimen is unique, perforated saran or...
Solid-liquid yes, but biological, not mineralogical. Feasibility is indeed net over the gamut (literally), but haven't even got to first base.
You are right about flat glass slides--you can't pose the specimen correctly. Sand, the classical solution, is just great for precise positioning...
I work for the Smithsonian, and we are embarking on a very large, long project to image our most valuable specimens and to make that info available on the web (reduces loan requests, diffuses knowledge...).
These specimens are routinely stored in 75% EtOH, but can be immersed in other aqueous...
Another attempt to do this is at
http://resources.highett.cmit.csiro.au/RManasseh/a983/node3.html#SECTION00021000000000000000
and I see that the MgF2 ref pasted incorrectly. It is:
http://jchemed.chem.wisc.edu/journal/issues/2006/Aug/abs1170.html
That may be. I imagine intermediates are called for when you cannot alter the RI's of the two materials.
This is for a photomicrography application, so appearances matter greatly. Immersion oils, for example, match the RI of the glass objective very closely.
In my case, am photographing...
Thanks!
In other words, geometry matters. I gather that spherical objects minimize the problem of reflectance, so if cryolite, then cryolite spheres? Would be difficult to do, but perhaps in a rock polisher, at least all facets could be worn away to curved surfaces.
It is used to visualize...