Since various studies have suggested that insect biomass has declined about 75% in recent decades, one could say that there were four times as many insects. Large biomass losses also occurred in the time earlier (agricultural revolution, as e.g. described in Rachel Carlson's book 'Silent Spring'). The 75% loss refers to the latest decades only. How many insects were there around 1900 or before? Why is there so little data?
Seit verschiedene Studien nahegelegt haben das in den letzten Jahrzehnten 75% der Biomasse der Insekten zurückgegangen ist, kann man im Umkehrschluss sagen das es davor vier mal so viele Insekten gab. Große Verluste gab es in der Zeit davor auch schon (Agrarrevolution, wie z.B. beschrieben in Rachel Carlsons Buch 'Der stumme Frühling'). Der Verlust von 75% bezieht sich auf die letzte Phase. Wie viele Insekten gab es um 1900 oder davor? Warum gibt es so wenig Daten?
You may have tried this yourself, trying to photograph a nice landscape with the moon during the twilight hours in the evening or morning. For a landscape like this you need a tripod and a long exposure time. The moon being many times brighter needs a very short exposure time. In cases with such brightness differences you normally make an exposure series as shown here (with tripod!) and use high dynamic range techniques and exposure stacking which is nowadays quite straightforward to use. However with the moon and a bright planet (Mars, or Venus) below the moon this does not work for several reasons:
As I will explain here, there is a 'dirty' solution to this problem, which is not as realistic as exposure stacking, but gives a result that is quite true to the experience of the viewer. In short: the washed out moon needs to be cleaned (and not as bright), as well as planets and stars visible as stripes. From the end of the exposure series you copy in a layer and set it to blend mode 'lighten'.
This new Photoshop technique will allow you to remove any erratic, chaotic background patterns, caused by old printing machines ('random dotted pattern') or visible paper structures (fibers, depths), with the least possible blur. Note that there are various methods for recovering halftone prints from newspapers or color magazines (with the fast fourier transformation method) covered elsewhere. The images have in common that they show at the highest zoom a kind of chaotic leopard pattern. What you would like to do is to lighten the spots, and darken the background, so that they merge to a uniform color. The difficulty is to get a selection that is exactly right.
Many years ago I saw a "dark rainbow". A perfect bow, a dark curved band in the air, the same width and same shape as a normal rainbow. It was appearing in the south, where the dim sun also appeared, around 11:00 am. Later that day, my social network confirmed that others had seen this mysterious phenomenon as well. Mysterious indeed; nobody knew what it was or what could be the physical explanation! I contacted several meteorologists by email, but I never received an answer. All those years, none of the meteorological books that came in my hands provided a even the smallest clue... What could it have been?!!
