@j_bertolotti@mathstodon.xyz
@j_bertolotti@mathstodon.xyz avatar

j_bertolotti

@j_bertolotti@mathstodon.xyz

Associated Professor of Physics at the University of Exeter.
Scientific visualizations (grouped under the hastag #PhysicsFactlet).
He/lui/on. All opinions are my own fault.

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davidrevoy, to random
@davidrevoy@framapiaf.org avatar

Too often

ZachWeinersmith, to comics
@ZachWeinersmith@mastodon.social avatar

Am I right??

Full comic here: http://smbc-comics.com/comic/apply

#smbc #hiveworks #comics #webcomics #science

mpesce, to random
@mpesce@arvr.social avatar

Now it can be told:

While doing some AI engineering work for a client, I developed a prompt - completely inadvertently - that reduced every AI chatbot to gibberish (except Anthropic's Claude 3). I then spent a week trying to alert the LLM vendors to this issue - and largely failed. There is no mechanism to report flaws in these models that are already deployed to billions of users. Read the whole story in @theregister

https://www.theregister.com/2024/05/23/ai_untested_unstable/

eniko, (edited ) to random
@eniko@peoplemaking.games avatar

what the fuck is an NPU and how do i avoid getting one

EDIT: ok got it thanks

ben,
@ben@peoplemaking.games avatar

@eniko Apparently "second GPU but worse and not for graphics" was found to not be catchy enough for focus groups, and marketing decided that "if bloatware was hardware" sent the wrong message.

Skepticat, to random
@Skepticat@mstdn.social avatar

You don't say...

Neuralink disclosed that their device has experienced a malfunction.

Parts of the brain implant have broken loose and are floating around inside the test subject's brain.
https://arstechnica.com/science/2024/05/elon-musks-neuralink-reports-trouble-with-first-human-brain-chip/

Glastomichelle, to random
@Glastomichelle@c.im avatar

To say I am blown away is an understatement, What a night! Glastonbury Tor and the Aurora...incredible.

NanoRaptor, to random
@NanoRaptor@bitbang.social avatar

This photo of an apple two-button two-handed mouse is banned in twenty three countries.

d_yellowlees, to random
@d_yellowlees@mastodon.online avatar

In academia everyone is a non specialist.

Researchers are extreme specialists, This actually means most people don’t know what they are on about. So when you are communicating your work to other academics remember.

They know their thing... not your thing.

testtubegames, to random
@testtubegames@mastodon.gamedev.place avatar

Science toy for today -> Evolution by Keiwando.

Draw the bones and muscles for your stick-figure creatures, and evolve them into better racers. Free and available on the web.

https://keiwan.itch.io/evolution

d_yellowlees, to random
@d_yellowlees@mastodon.online avatar

More pictures won't save your presentation

lots of images or busy images can be just as overwhelming as lots of text. It's about how much 'information' you are putting out not what form it's in.

Use simple visuals & words or take the time to go slow.

theropologist, to random
@theropologist@beige.party avatar

:bc: Attention Beige Party-goers! :bc:

A word about antisemitism, the state of Israel, and the war in Gaza

The war in Gaza has brought a lot of issues to a head and for the most part I have remained silent about specifics because my personal opinions should not be relevant to my job as a moderator. However, things at Beige Party have recently crossed a line where I felt I had to take action, and I feel it is my duty to explain what is informing my decisions on this matter.

Just a warning, this is going to be an extremely long post, so if you just want to know about the moderation policy you can skip to the end. It actually turns out to be quite simple.

First of all, I think it's important to explain where I'm coming from because this is a deeply personal issue for me. As a cis-hetero white male cloaked in all the undeserved privilege that entails I don't feel like it is my place to comment on most matters of identity, other than to recofnize bigotry where it occurs and enforce the site rules when something crosses the line. When I am unsure, I will seek out a trusted member of the affected community to get their perspective before I make a decision. In this case, however, I am a member of the community in question, and the issues of antisemitism, fascism, and genocide have informed my personhood basically since I have been a self-aware, thinking, feeling being, and have played a foundational role in forming my core morality and code of ethics.

I hate presenting this as if it were a set of qualifications, but I think it's important for you to know where I come from so you can understand my nuanced views on a very fraught and complicated subject.

I am part Jewish. I was not raised culturally or religiously Jewish, so I've never felt completely comfortable claiming that identity. However, I am Jewish enough for Hitler to have murdered two of my direct ancestors, and to have inherited the generational trauma of genocide. I am also part German, so I also understand the insidiousness of ethno-fascism and its inevitable consequences. There are a lot of words for it but ultimately, on a human level, it comes down to the murder of innocent people.

None of this is theoretical to me, or distant memories handed down to me over generations. I have a grandmother who is a living link to what it was like to grow up as a half Jewish girl in Hitler's Germany and to have a parent and a grandparent sent to a concentration camp to be murdered, and another parent jailed for trying to get their family out of a fascist country. This is all very real and present for me, and has been my whole life. It is in my bones.

Having said all that, let me go over some core principles that I have used to guide my moderation decisions when it comes to antisemitism and the actions of the government of the state of Israel:

Antisemitism is real and insidious and it has been for thousands of years. My definition of antisemitism is targeting Jewish people on the basis of their ethnic and/or religious identity. Like any form of bigotry it's targeting people based on who they are.

The state of Israel is a sovereign nation with all the rights and responsibilities of any sovereign nation that wishes to remain in good standing with the current world order. Disagreeing with the actions of the state of Israel or any members of its government is not antisemitism. Despite what the government of Israel claims it does not represent all Jews everywhere, and the very claim of ownership of an entire ethno-cultural group by a sovereign state is a mark of fascism. It's the very thing Hitler did to justify his crimes in Europe.

Zionism is a nationalist political ideology. It does claim religion as a justification but many political ideologies do. Nations rarly go to war over religion, but governments often use religion as a way to justify their wars. Being against zionism as a political ideology is not antisemitic, just as all Jews are not obligated to be zionists. Zionism as a political ideology dates to the 19th century. The first historical mention of the Jewish people dates back to 1220 BCE. Jewish people are quite capable of existing independently of zionism. They have for thousands of years.

Israel is an apartheid state. I think many will disagree with this statement, but there is no other way to describe the facts on the ground. They have kept the occupied territories in limbo for nearly 60 years specifically to disenfranchise the Arab population. The reality is that if you are born an Arab in Gaza or the West Bank you do not enjoy the full rights of a citizen of Israel, based solely on your ethnicity. That is apartheid. Acknowledging that fact is not antisemitism. The Jewish people are not responsible for this situation, the government of Israel is.

The state of Israel has, and continues to commit genocide. This is also going to be controversial, but I just can't see it any other way. International law is pretty clear on this. Even if an adversary is not abiding by international law, a state engaging in a military conflict has a responsibility to protect civilians. Collective punishment of the Palestinian people for the crimes of Hamas is a war crime, and it cannot be justified. Genocide was also committed in the initial wars of independence, where entire Arab villages were wiped off the map. This is not the same as saying Israel has no right to exist. I am an American of European ancestry, and as such, my very existence on this continent is the result of genocide. We can not hold people responsible for the crimes of past generations, but when we see genocide happening it is our responsibility as human beings to call it out. Doing so is not antisemitism. Again, these are crimes being carried out by the government of Israel, and despite what it claims, the government of Israel does not represent all Jewish people.

The government of Israel is sliding increasingly towards facism. It is ruled by a far-right nationalist coalition that is bent on consolidating power and dismantling democratic rule. Not only does the government of Israel not represent all Jews, it doesn't even represent all Israelis, as we have seen with protests against the legislation to weaken the supreme court. Again, as an American, I can relate. There are many things my government does that I don't agree with and there's very little I can do about it directly. Directing hatred against Israeli citizens for the actions of their government is wrong, as is holding the Jewish people as a whole responsible for those actions. However, being against the actions of an increasingly fascist state is not antisemitism.

Hamas is a terrorist organization that murders civilians to achieve its goals. It claims to represent the Palestinian people but it has no problem with putting them in harm's way to achieve their ends. The events of October 7th were reprehensible and should not be celebrated by anyone. Hamas saw their increasing irrelevance on the world stage so they committed genocide so that they could not be ignored. Part of their calculation was that the response by the government of Israel would be so severe that Hamas's crimes would quickly fade from the public discourse. They were right, and in doing so they offered up the lives of the people they claim to represent as an acceptable loss for their larger goal, which is the destruction of the state of Israel. Acknowledging Hamas's crimes does not negate the crimes of the state of Israel, both are responsible for their actions and there is no moral high ground here, only death, destruction, and the perpetuation of human misery.

That said, the facts on the ground are what they are. Israel exists and so does Palestine. Both have a right to exist because the people exist. Normal, everyday people, who want the same thing that anyone wants: Safety, security, the chance to just make it through the day and maybe the opportunity to improve their lives a little bit. Any government, organization, or ideology that simply wishes one of these groups of people out of existence is not operating in reality and is morally bankrupt. Furthermore, they are doing a disservice to the people they claim to represent by further perpetuating conflict, death, and human misery.

So that's a lot of words, and plenty for many different people to have problems with at least some of them. As a moderator I try to keep my personal beliefs and opinions out of moderation decisions and just stick to the rules as written. So much about the situation in Gaza has warped the discourse into a tangled mess, but ultimately I think the rules as written are sufficient to handle it.

Really, it's very simple:

  1. Targeting people based on who they ARE is against the rules

  2. Disagreeing with what people, organizations, or governments DO is not

  3. Advocating for violence against anyone for ANY reason is against the rules

In any cases where the rules seem to come in conflict with one another, my overarching principal is asking who has power in this situation, and who is in need of protection. When in doubt I always defer to those in need of protection.

I invite your thoughts on this subject, but please keep it civil and respectful. I am never one to claim that I have all the answers. Like most people, I am just trying to make sense out of a terrible situation so that I can hopefully do the right thing, or at the very least not cause more harm.

Thank you, and Beige-bless :bb:

d_yellowlees, to random
@d_yellowlees@mastodon.online avatar

How fit all your research into a short talk...

Don't.

You can't get 3yrs of work into 10mins, you just can't.
So focus up, have a clear point you want to make with this talk, get to it fast and end strongly.

You don't always have to tell everything you've done.

pills_ofscience, to random Italian
@pills_ofscience@mastodon.uno avatar

Condividete la notizia di #astrazeneca e rischio trombosi ma assumete ogni tanto farmaci per mal di testa, mal di schiena ecc? Questi farmaci hanno come effetto collaterale raro la trombocitopenia. Avete già chiesto la rimozione dal commercio di Voltaren, Oki e simili? In alcuni di questi farmaci oltre al rischio di infarto del miocardio, ictus ed evento letale, questo rischio di valori anormali nel sangue può interessare una persona su 10.000 e non qualcuna su milioni. 1/2
#MedMastodon

ZachWeinersmith, to random
@ZachWeinersmith@mastodon.social avatar

Yesterday I had one person say I'm too so pro-tech pro-capitalist and one person say I was trying to force a leftist ideology, and both were responding to A City on Mars. All I can say is I wish people would stop trying to find the hidden motive and just read the words as plainly written!

ColinTheMathmo, (edited ) to random
@ColinTheMathmo@mathstodon.xyz avatar

Re camera problems ...

Apologies to all ... problem solved.

I've vigorously unplugged and replugged all the cables multiple times, and now it seems to be working!

Bizarre!

I will delete this thread ... apologies to anyone who has lost any time over this.

j_bertolotti, to random
@j_bertolotti@mathstodon.xyz avatar

: The "Ashcroft/Mermin Project"
I will try to (likely very slowly) go through the classic textbook "Solid State Physics" by Ashcroft and Mermin and make one or more animation/visualization per chapter.
This will (hopefully) help people digest the topic and/or be useful to lecturers who are teaching about it. As with all my animations, feel free to use them.
The idea is that the animations are a companion to the book, so I will give only very brief explanations here.

j_bertolotti,
@j_bertolotti@mathstodon.xyz avatar

#PhysicsFactlet: The "Ashcroft/Mermin Project" Chapter 4: Crystal Lattices
Once we have the Bravais lattice, we can fully describe a crystal structure by specifying how the atoms are arranged around the lattice points (i.e. the "basis").

2D representation of how to combine a Bravais lattice and a basis to form a crystal structure. On the left the Bravais lattice (small gray dots) starts as a square lattice and becomes a triangular one. In the middle the basis (black dots), that starts as a single "atom", changes into two atoms, and then three atoms. On the right the resulting crystal structures.

j_bertolotti, to random
@j_bertolotti@mathstodon.xyz avatar

Not a #PhysicsFactlet, but a full beginner-friendly tutorial on how to use speckle correlations for imaging through a scattering medium, complete with a step-by-step guide on how to set up your first experiment and analyse the data:
https://arxiv.org/abs/2404.14088

dpiponi, to random
@dpiponi@mathstodon.xyz avatar

We have the millennium prizes in mathematics. There should be a similar prizes in computer science. Here's 5 problems I suggest for the list. Maybe they're too hard, I'm not sure.

  • Synchronizing audio and video streams.
  • Detecting an external display has been plugged in. Especially if that display is a projector.
  • Establishing that everything is correctly set up at the start of a video conference call. Especially verifying audio is working, and unmuted.
  • Bluetooth. Especially emulating the straightforward operation we can do with wired devices: unplugging from one and plugging into the other.
  • Printers. Making them work.
scottfgray, to random
@scottfgray@dice.camp avatar

“This machine kills AI.”

eniko, to gamedev
@eniko@peoplemaking.games avatar

"eni, did you just put the monty hall problem in your video game"

why yes, yes i did 😊

wishlist/more info about kitsune tails at https://kitsunegames.com/kitsunetails

a forest scene. the cat merchant, a humanoid cat wearing a fez, proposes a game where the player picks one door from 3, two have a single coin behind them, while one has a power up the player picks the leftmost door. the merchant helpfully reveals that the middle door contained a coin, and tells the player they can switch if they please the player switches and finds the power up. a golden chest appears and when bonked releases the power up, the scene ends

agbuckley, to random
@agbuckley@mastodon.social avatar

Brewdog's carbon-offsetting forest looks like a mismanaged disaster 😱 https://parkswatchscotland.co.uk/2024/04/14/brewdogs-dead-forest-and-the-dead-hand-of-scotlands-forestry-grants-system/

AnarchoCatgirlism, to MemeryAlpha

foone, to random
@foone@digipres.club avatar

I'm still broke, though I've got a temp job for now: they've not yet paid me, however, and I've had to pay something like 4k$ for two medications, and another 2k$ that was supposedly going to make the 4k$ free.

So any donations would be great. https://ko-fi.com/fooneturing

johncarlosbaez, (edited ) to random
@johncarlosbaez@mathstodon.xyz avatar

It looks like they've found protonium in the decay of a heavy particle! 🎉

Protonium is made of a proton and an antiproton orbiting each other. It lasts a very short time before they annihilate each other.

It's a bit like a hydrogen atom where the electron has been replaced with an antiproton! But unlike a hydrogen atom, which is held together by the electric force, protonium is mainly held together by the strong nuclear force. It's also much smaller than a hydrogen atom.

There are various ways to make protonium. One is to make a bunch of antiprotons and mix them with protons. This was done accidentally in 2002 during the first experiment that created antihydrogen. They only realized this upon carefully analyzing the data 4 years later.

This time, people were studying the decay of the J/psi particle. The J/psi is made of a heavy quark and its antiparticle. It's 3.3 times as heavy as a proton, so it's theoretically able to decay into protonium. And careful study showed that yes, it does this sometimes!

The new paper on this has over 550 authors, so I won't list them all. It also has a rather dry title - not "We found protonium!"

• Observation of the anomalous shape of X(1840) in J/ψ→γ3(π+π−), https://arxiv.org/abs/2310.17937

The idea here is that sometimes the J/ψ particle decays into a gamma ray and 3 pion-antipion pairs. When they examined this decay, they found evidence that an intermediate step involved a particle of mass 1880 MeV/c², a bit more than an already known intermediate of mass 1840 MeV/c².

This new particle is a bit lighter than twice the mass of a proton, 938 MeV/c². So, there's a good chance that it's protonium!

ct_bergstrom, to random
@ct_bergstrom@fediscience.org avatar

Total solar eclipse, April 8 2024.
Lake Champlain, Vermont.

Photo is the full frame, completely unedited, straight out of the camera. (Except for a modest reduction in image dimensions necessary to post to fediscience.)

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