Sal
@Sal@mander.xyz
- Comment on Self portrait 1 week ago:
This is fine ._.
- Comment on Is gravity instantaneous? 2 weeks ago:
OTOH my understanding of the speed of light in a medium is that it’s the result of photons being absorbed and re-emitted, and the speed of any individual photon is always exactly c.
I am an experimentalist and so if a theoretician reads this they will probably tell you that I am wrong…
I think that the description of a photon being “absorbed” and “re-emitted” could be used to describe the picture from the point of view of quantum field theory (which I don’t claim understand), because within this theory the photon/electron and even electron/electron interactions are mediated by photons that are created and annihilated during those interactions. Whenever the “photon” exists it will travel with speed c. As light travels through a material it is traveling as a wave of electrons influencing each other, similar to how water waves travel through water, and since these interactions of the electrons pushing each other are formally described by the photons popping into and out of existence I think one could correctly use the language of “absorbed” and “re-emitted”.
But personally I think that it can be a bit confusing, because the absorption and emission of light by materials is often used to mean something very different… Absorption more commonly refers to a resonant interaction in which a photon is destroyed and a molecule (or atom, or crystal, etc…) comes into an excited state. The molecule that becomes excited can remain excited for quite a long time (usually picoseconds - microseconds), and the re-emission of the light often comes in a completely different direction and even a different wavelength than the original photon. So using the language of “absorption” and “emission” in this context can also generate confusion,.
Personally when I imagine the propagation of light through a material I think about it in terms of the polarizability of the medium. When the light propagates through a medium, you don’t need a “photon”. The wave is being carried by the electrons oscillating (these are very small oscillations - unless you are using powerful lasers, then you reach the beautiful world of non-linear optics). The speed of propagation of this wave through the medium depends on how far the wave can travel through the material with every oscillation. There is a nice description of this semi-classical process in the Feyman Lectures: www.feynmanlectures.caltech.edu/I_31.html
gravity moves at the speed of light in a vacuum
Hmmm… Always? Maybe some funky things happen as the wave passes by a black hole.
- Comment on Maya warrior statue with serpent helmet discovered at Chichén Itzá 2 weeks ago:
That’s a really cool looking statue!
- Comment on Help identifying this? 1 month ago:
That is an interesting observation. I usually see them growing at 90 degrees but I had never really given this any thought. I will pay more attention to this when I see brackets. Thanks!
- Comment on Help identifying this? 1 month ago:
Thanks! :D
- Submitted 1 month ago to mycology@mander.xyz | 0 comments
- Submitted 1 month ago to mycology@mander.xyz | 0 comments
- Submitted 1 month ago to mycology@mander.xyz | 1 comment
- Submitted 1 month ago to mycology@mander.xyz | 0 comments
- Comment on Scarlet Caterpillar Fungus (Cordyceps militaris) 1 month ago:
Whaaat! No way! I have been actively hunting for these, but no luck yet!
- Comment on Anyone can help me ID? 1 month ago:
Ooh, I wasn’t aware of this, but you are right! From what I can find, the fungi belonging to this class tend to live in the tree passively and only transform into this form once the tree is weak and dying !
- Comment on Scarlet Waxcap (maybe?) 1 month ago:
Nice find!
- Submitted 1 month ago to mycology@mander.xyz | 2 comments
- Comment on Help identifying this? 1 month ago:
I can’t believe I didn’t notice that. Now I can’t unsee this.
- Comment on Lissotriton vulgaris 1 month ago:
Thanks!
- Comment on Deconica coprophila 1 month ago:
Could be - I am not 100% sure of the ID, Deconica coprophila is my best guess.
These mushrooms are very small though. Here is another photo where you can more clearly see how small they are:
- Comment on Deconica coprophila 1 month ago:
Yeah, these are tiny. Here you can see the size relative to a thumb!
- Comment on Help identifying this? 1 month ago:
Thanks! So far I agree, I think it is a beefsteak fungus. It seems to be an asexual “anamorphic” state.
- Submitted 1 month ago to herpetology@mander.xyz | 4 comments
- Submitted 1 month ago to mycology@mander.xyz | 5 comments
- Submitted 1 month ago to mycology@mander.xyz | 11 comments
- Submitted 1 month ago to mycology@mander.xyz | 0 comments
- Comment on Reliable mycology suppliers in EU 1 month ago:
In the Netherlands… I have experience with www.homegreen.nl and I can recommend their cultures (From them I have bought Lion’s Mane and King Stropharia).
I have bought Cordyceps off Etsy sellers, but unfortunately I can’t strongly any of them, because I have had really underwhelming fruits that looked like what one would expect from and old / sub-cultured strain.
In the Netherlands we have a website to report different species found in the wild. For Cordyceps militaris I can see that October is the most common month to find them (waarneming.nl/species/16371/statistics/), and in the map I can see the areas in which they are most commonly found: waarneming.nl/species/16371/maps/?start_date=2023…
So I am planning to go to a few hunting trips these coming weekends and hopefully I can find one in the wild… If I am not able to establish a wild culture, I think I will order from a vendor in the US, as there are a few Cordyceps breeders with a good reputation there. But i will keep an eye on this post in case anyone can recommend an EU Cordyceps vendor.
- Comment on Light sources for winter 1 month ago:
Personally I use E27 PAR (38 degrees) LED lamps, 17 watt power. I have a mix of 3000 K and 4000 K. The reason for these specific lamps is that I found them at a discount and so I bought a large amount. It is nice that they are somewhat directional, so I can aim them at specific plants.
I have a few different ways of hanging the lights by the plants. Most recently, I have set up a rack this way:
The lamp clamps I bought 12 off Ali-Express: nl.aliexpress.com/item/4000793927858.html
The rack is a simple light weight plastic rack that I found in a discount store for $12.
- Direct observation of geometric-phase interference in dynamics around a conical intersectionarxiv.org ↗Submitted 2 months ago to chemistry@mander.xyz | 0 comments
- Comment on Lets get some more content going! 2 months ago:
Cool! It’s like an antler coral forest.
I’ll go forage soon and make sure to bring you some nice pictures :-) I think it’s still a bit early for mushrooms in my area, though.
I’m not sure what is allowed here (no sidebar content?)
Ah, I’m sorry, that’s my fault 😅 I created a lot of communities at once and I never came back to properly create sidebars for all of them. My goal when I got started was to define the scope by creating communities about topics I find interesting… I will try to make some time to improve some sidebars. But, generally, I would say that if one is well-intentioned and not completely off-topic pretty much anything reasonable is allowed.
That said, if volunteers want to help moderate or take over a community, I’m always happy to hand over the reigns ^_^
- Comment on Shrooms - A place to discuss the growing, hunting, and the experience of magical fungi. 3 months ago:
Ah, actually, I responded thinking that you meant the /c/mycology community.
I’m not the creator/mod of the uncle_ben’s community, and the sidebar says “A community for the uncle ben’s mushroom growing technique.”, so I am actually not sure. I think it would be fine… Sorry!
- Comment on Shrooms - A place to discuss the growing, hunting, and the experience of magical fungi. 3 months ago:
Sure, what’s wrong with bird seed tech?
- Stability follows efficiency based on the analysis of a large perovskite solar cells ageing dataset - Nature Communicationswww.nature.com ↗Submitted 3 months ago to chemistry@mander.xyz | 0 comments
- Comment on Shrooms - A place to discuss the growing, hunting, and the experience of magical fungi. 3 months ago:
All fungi are magical ;)
The mycology community is more general in scope. Psychedelic mushrooms are not excluded, but there can be so much specialized discussion in that sub-category that is worth it having a more specialized community.
There is also the first community !uncle_bens@lemmy.ml dedicated to growing, but it is not very active.
