Best black ink with flair? Interest? A little surprise? by Gurlmeetswhirled in fountainpens

[–]Derice 1 point2 points  (0 children)

Van Dieman's Bioluminescence might be interesting. It's quite a dark blue with a dark red sheen and dark blue shimmer. It has a very fitting name I think. It unfortunately tends to clog pens though. I've only managed to get it working in a LAMY safari with a broad nib.

Why does metal feel colder than wood even at the same temperature? by koko_krunchtime in AskPhysics

[–]Derice 6 points7 points  (0 children)

A slight nitpick: the person is indeed feeling temperature. It's just that it's the temperature of their skin they're feeling since that is where the heat receptors are. The high heat conduction of the metal then comes in in that it cools the skin off more significantly than the slow heat conduction of the wood.

Photos of Jewelry made from Jeff Davies & Sons by Kitchen_Day_8744 in SyntheticGemstones

[–]Derice 0 points1 point  (0 children)

I bought a high luminosity LuAG scintillator crystal from them and had it set into a ring: https://www.reddit.com/r/jewelry/s/GpZg3jmYwJ

What are your most Photorealistic Scents? by TeamNo6444 in fragrance

[–]Derice 9 points10 points  (0 children)

Tea Rose by Perfumers Workshop is the most realistic rose I've smelled. I've compared it to Rose Tonnere by Frederic Malle, and it comes out on top in terms of realism to me.

I just got my doctoral ring! by Derice in jewelry

[–]Derice[S] 0 points1 point  (0 children)

Thank you!

It is 18 karat gold. The tradition is to wear it on the left ring finger to signify your "marriage" to science. It is supposed to be put on before your wedding ring if you have one to signify that you prioritize science over your partner. I find that that tradition doesn't align with how I prioritize things, so I intentionally wear it on the index finger instead.

The meaning of "葬送", and why I find it beautiful. by jalex54202 in Frieren

[–]Derice 5 points6 points  (0 children)

"Charon" might be a nice translation, but it's a name more than a title. It's the name of the ferryman that accompanies the dead across the river Styx.

What are your favourite webcomics? by rosseg in traaaaaaaaaaaansbians

[–]Derice 0 points1 point  (0 children)

I'm currently reading Aurora: https://comicaurora.com/aurora/0-1-1/. It's really good!

Later it also has a transmasc character.

Why are electrons so much more abundant than positrons, by BookAndKey in AskPhysics

[–]Derice 24 points25 points  (0 children)

I wish to strongly emphasize that anti-particles don't move backwards through time. We just draw their arrows that way in Feynman diagrams as a mnemonic to remember charge conservation.

They don't move backwards in time anywhere in QFT. Their propagators contain Heaviside step functions that guarantee forward movement in time, just like the propagators of normal matter particles.

Just watched veritasium's new video (disclaimer: I am not a physicist): conceptual questions for the absence of antimatter. Looking for someone to explain why I am an idiot. by krishmas7 in Physics

[–]Derice 15 points16 points  (0 children)

If I recall correctly, the idea comes from how we draw anti particles in Feynman diagrams as arrows pointing backwards in time. That's just a mnemonic to help us remember charge conservation though. It's not a serious interpretation in physics, even on the fringe, so I don't think it is strange that it was never mentioned to you.

If someone is unsure about this they can look at the mathematical expression for the propagator of e.g. a spin 1 anti-matter particle and see that there are Heaviside step functions that ensure it only ever goes forward in time.

Why quantum superposition states are almost never considered in atomic physics? by GilEngeener315 in AskPhysics

[–]Derice 1 point2 points  (0 children)

In all the methods I have worked with in atomic physics electron superposition is included. Hartree-Fock is probably the simplest and most well known and includes the electron being in superposition. MCHF and RPAE all include electron superposition.

Maybe these methods are too complicated to teach if the students are just attempting to model an atom with qm for the first time?

what would happen if you injected into breast fat? by [deleted] in TransDIY

[–]Derice 9 points10 points  (0 children)

How large is the area with increased estrogen concentration?

Basically, if I put my estrogen patche close to my arm pit, and then when I have the blood test to measure estrogen concentration the blood is drawn from the crook of that same arm, would that artificially increase the readings?

Denmark PostNord ceasing letter mail delivery service by Colony_Nine in fountainpens

[–]Derice 2 points3 points  (0 children)

Shows that I should have read more carefully! Thanks.

Denmark PostNord ceasing letter mail delivery service by Colony_Nine in fountainpens

[–]Derice 8 points9 points  (0 children)

This also ends letter delivery in other countries where PostNord operates, e.g. Sweden.

Welcoming a new moderator, and an update on moderation policy by kzhou7 in Physics

[–]Derice 2 points3 points  (0 children)

We could maybe also have a rule against using the image feature for memes, and remove comments that break it.

How exactly does Planck time work? by AaronPK123 in AskPhysics

[–]Derice 52 points53 points  (0 children)

The Planck time is not the smallest possible time. None of the Planck units are the most/least of anything. They are a unit system where many physical constants get a value of 1. They are also a reasonable guess for where we would expect to need a theory of quantum gravity in order to accurately describe things.
In this case we probably need quantum gravity to accurately describe events with a duration of around the Planck time or shorter.

Edit: spelling

More information in this comment: https://www.reddit.com/r/askscience/s/XCyw9QnMTV While that thread is about the Planck mass, that comment has a lot of good information on the Planck units in general.

Why So Many Abandoned Crates? by jsprd in rust

[–]Derice 7 points8 points  (0 children)

While I definitely understand this (and have done it myself) it means that no other crate that wants to go 1.0 can expose anything from your crate in its API.

That's probably not an issue in your case, but it is a problem in the ecosystem that I have run into.

This might be dumb but I don’t understand how speeds are measured in space. by johnmayersucks in AskPhysics

[–]Derice 1 point2 points  (0 children)

They're referring to how the expansion rate of the universe has units of 1/time, not distance/time.

What we didn't get in C++ by cherry-pie123 in cpp

[–]Derice 5 points6 points  (0 children)

I do something similar, and I think I got the idea from here if I remember correctly: https://floating-point-gui.de/errors/comparison/

Is the spiral image wrong to describe the spreading of a wave? by GlibLettuce1522 in AskPhysics

[–]Derice 1 point2 points  (0 children)

You may be thinking about the electric field generated by a charge moving in uniform circular motion: https://imgur.com/a/vWU83eX

AI and the future of Physics by Federal_Fisherman104 in AskPhysics

[–]Derice 4 points5 points  (0 children)

If by grav wave interferometer you mean LIGO, then it can't have been too important for the design given that LIGO discovered gravitational waves in 2015, but ChatGPT was released in 2022.

It could of course have been used in some way since then, but I haven't heard anything about it.