Recent content by Andy Resnick

This is the last sample in the 'phonolite theme' that started back at sample #250: I don't know if this is a different rock from the same location as the three previous Fen 35 samples, it could even be a sample made in 1971 from the same rock used in 1969. In any case: Potassic-fenitized...

The optics aren't that complicated- just imaging through crossed polarizers. The way colors are generated is a little tricky, but basically result from what is left when a narrowband portion of of the illumination spectrum is rejected (because of the 'retardance' of the material). The poster...

If you removed all matter in the universe (other than the spinning bucket), why do you think the surface of the water would still be curved? In any case, it's a highly interesting thought experiment that seems to require the existence of an absolute frame of reference. The paradoxes of...

Agreed- I have never seen anything like that.

Posting a day early this week: This is (presumably) the 3rd thin section from the same rock: a potassic fenitized phonolite. The unique feature in this sample are the two large K-feldpsar phenocrysts exhibiting both perthic and poikilitic textures in the upper right. At higher magnification...

My attempt at describing the thin section (phrased as a prompt): "I am trying to identify metasomatic process and also classify a thin section sample. This rock is a fenitized phonolite from the Fen complex. Aphanitic intergranular groundmass is a disordered collection of dark green-brown...

First, the images. Then, a description and discussion: Fenitized Phonolite, Fen Complex. Aphanitic groundmass is a disordered collection of dark green anhedral pyroxene grains mixed with a combination of needle-like K-feldspar laths and anhedral quartz. The anhedral quartz...

Region of the night sky centered on NGC 6820, taken during summer: (deets: Nikon Z7 + Nikkor 105/1.4 @ f/2.8 on Losmandy GM-8, 30s subs 19.5 h total integration, stacking &tc. AstroPixelProcessor) There are many photogenic deep-sky objects in this field of view- Brocchi's cluster/NGC 6802...

There's no clear answer to this question because you did not specify the relationship between x0 and x1. For example: are they separated by a spacelike or timelike interval? Edit- also, you need to clarify how the detection works. For example, detecting a photon means destroying the photon...

Altered (fenitized?) trachyandesite, Fen complex. Mesocratic. Groundmass consists of vaguely trachytic K-feldspar within two different matrices; both are granular and identification is tricky. I think the darker matrix consists of interstitial green pyroxene and some carbonate, while...

(Message reply didn't add the quote, Im replying to post #4) Yes, a point detector would almost never detect the position of a particle. But sometimes it does. Like I said, it depends on what information you are expecting from a measurement. Surely, you would agree that an array of...

Ergh... I stayed up way to late to try and image the Falcon 9 lunar impact. TL;DR: didn't see anything happen. Firstly: (Nikon Z7 + 800/5.6 nikkor @ f/8, 1/160s, ISO 200) Here's where the plume would have been (300%), had I seen it: But I did get nice images of Rupes Recta (200%...

I got to spend a sunny afternoon practicing macro (55mm MicroNikkor) and tilt-shift photography (Vivitar 135/3.5), both are lenses I inherited, but this is the first time (for me) using a 135mm lens. Some macro shots, all @ f/11, 1/1600s, auto ISO, images cropped as I see fit: Hairy...

I guess it depends on what information you hope to obtain- a point detector does not cover all positions, but then your location measurement is simply 'yes' or 'no' (of course, since you set the position of the detector, you also know the position value). Similarly, a momentum measurement can...

Heavily altered tinguaite (fenitized trachyandesite), Fen Complex. Groundmass consists of trachytic K-feldspar laths (with a high concentration of inclusions), green pyroxene (heavily eroded), and carbonate (likely calcite). Forgot to add scale bars this week :( Trachytic texture is more...