1

New Theories / Re: Could quantum mechanics be wrong?

« on: 17/07/2024 08:52:56 »

i cant help but spot the obvious here:

If you claim something is wrong with a theory, you're sort of obliged to point out what it is.

And pages later, you haven't. still. Nor has the team at the LHC, incidentally.

2

Physics, Astronomy & Cosmology / Re: why do a lot of people confuse between interference and diffraction?

« on: 23/06/2024 23:19:17 »

As usual, when I get access to a new AI model, I  check its understanding of topics I'm interested in.

AI with large-language models does not "understand" a subject. It is good at suggesting what words might be relevant and is trained to assemble meaningful sentences. That's about all it can do, search a large database which is a kind of dictionary, and string words together. It will make things up to try to impress you. (Ask that lawyer who lost their licence).

See if you can get one to understand French.

3

Physics, Astronomy & Cosmology / Re: How many spots are produced from Stern-Gerlach apparatus that rotates?

« on: 27/03/2024 01:23:47 »

It's my commentary on the first diagram, where z+ stream from first stage is maintained in second stage. Nothing changes into z-.

No that isn't what "happens".
Nothing about the spin state is "maintained in the second stage". Where is it maintained or "stored". You should realize, there isn't any room for this in the beams. You seem to be making a mistake about classical information; it isn't what most people think it is, although it is what (some) people say it is, which makes the stuff interesting.

4

Physics, Astronomy & Cosmology / Re: What is the Hopf gauge?

« on: 11/03/2024 22:17:25 »

I was once told, along with the rest of the class, that some people have difficulty with abstraction.

Well, maybe. I like to think that isn't really true, it's possibly more the case that people have difficulty thinking about a thing that requires a bit of focus. Some people pull engines and other bits of car apart, and put them back together.

Some people write software and have to stay focussed on the problem and finding solutions. Some people keep computers and software working in a useful manner. Some people design communications networks. I like to think those are skills I might have already, if I just look for them hard enough. I like to think it's about letting go of how important you or someone else thinks it is, and just do it because maybe you can. Maybe you should stop listening to people who tell you it's hard to do.

5

Just Chat! / Re: Is Category Theory the well of mathematical philosophy

« on: 01/03/2024 06:45:03 »

Mathematicians will always be keen to identify what their most fundamental mathematical objects must be.   Physicist's are keen to know what their most fundamental physical object or "atoms" would be, mathematicians are much the same.

Well ok. It does seem to be the case that Category Theory has been hailed a success. It isn't "there" yet, likely since nobody knows where "there" is. But I would say it's at least as successful as modern Information Theory, with it's languages and finite state machines to go with. That is, information entropy is also an algebraic entity, no surprise there really because information is not a continuous field. Ahem.

The continuous part of IT is about communicating the stuff, and the Categorists want IT to be understood as part of their lexicon. I don't see a problem. Someone tell me there isn't a problem (just kidding)

It is simple and Mathematicians are probably only working with and manipulating a very small class or category of structures, all built from what are probably just a small set of atomic objects.

Indeedly. I wrote down a really nice way to construct a tensor product of group algebras, the groups are the symmetric groups namely S₂, and S₁. This is the trivial case, so you start down the path of induction into larger symmetric groups. There is a vector space that uses an S₃ "distinguished" basis, i.e. you have the blindingly obvious (i.e. simple) {1,2}x{1} = {1,2,3}, a "set product", this is also pretty nice. Some permutation diagrams since I want the basis {1,2,3} and Perm{1,2,3}, the set of permutations.

All this is succinctly represented in some diagrams, with vertical and horizontal composition corresponding to inner "vector" and tensor multiplication, resp. with restrictions on the sets. You also invoke the categories Ind and Res as cocategories, it's like a one-page construction of a bunch of highly simplified mathematical thingies.

So yeah, let the good times roll

p.s. I didn't mention that it's been like the way I've kept my keyboard and guitar skills, through self learning. I'm self learning "higher" algebra, and discovering it isn't so hard. It is though, a bit like telling yourself to ignore that voice that says you won't do it.

6

Physics, Astronomy & Cosmology / Re: Why does vacuum affect frames of reference?

« on: 21/02/2024 22:25:22 »

Because somehow I can't stop myself doing it, I can point out that modern communications (actually since the telegraph) depend on the constant speed of light.

Imagine how hard it could be getting a working internet with all those optical fibres, if the speed of signal propagation varied around the globe. This is a rough kind of proof that c is constant.

footnote--it does vary because of changing gravitational potential, but this has a negligible effect, and besides, modern communication has robust error-detection/correction.

7

Just Chat! / My Jonny Clarke impersonation

« on: 18/01/2024 04:10:29 »

This is about a place that actually still exists. It's a suburb that was once basically a railway station and a big railyard.
You get the idea.

Evidently Frankton town

Frankton, Frankton, you're a load of bloody plankton.
Frankton, Wankton, I did not get thanked in,
Frankton.

My Dad once dranked in,
And I once banked in,
Frankton

The streets were manked in,
The Pub bloody stanked in,
Me account got blanked in,
Frankton.

Frankton, Wankton, don't get too skanked in;
You won't get bloody thanked in,
Frankton.

8

Physiology & Medicine / Re: Are Right Handed People Right Footed ?

« on: 16/01/2024 23:48:00 »

I'm right handed but bat left handed. I need left handed golf clubs and so did my father.

Sportswise I am "kak-handed". A tennis racket goes in the right hand, but a cricket or baseball bat is held to the left.

Incidentally I am hard to read in poker games, to more than a few people's mistake.

9

Just Chat! / Re: Trump's legal problems

« on: 11/01/2024 23:11:26 »

I don't know that one of Trump's legal problems (or, actually any of them) will be resolved should the Supreme Court decide that he has immunity from prosecution.

That would be despite any criminal liabilty and would have to apply to the sitting president. That the SC would rule in this way would be quite the shock to the system--a real kick in the head--since then, Joe Biden would get a licence to do whatever he likes.

So why not declare, under presidential authority, that political parties are banned? Every candidate for any office must be an independent. Then he orders the arrest of all Republicans under the pretext that they are members of an illegal political group. He sends Donald and his family to Gitmo. And so on.

With full immunity from prosecution. Unless the SC decides that Trump is the only man on the planet who can be trusted with it . . .

More popcorn please, miss.

10

Physics, Astronomy & Cosmology / Re: Are quantum systems dynamic?

« on: 07/01/2024 10:45:51 »

There's this astronomical effect called the Hanbury Brown-Twiss effect. Something about interferometry from optically distant light sources that you could look at, that might be connected to the question.

It's both classical (it's observed at radio frequencies I.O.W), and quantum (it involves "photon bunching"),

11

Physics, Astronomy & Cosmology / Re: What is a Fermion?

« on: 23/12/2023 17:40:27 »

I think you should know that quasiparticles, such as being disussed here, are quite common.

An electron in a vacuum isn't exactly the same thing as an electron in a copper wire or a transistor. Electrons are quasiparticles when they propagate in a physical medium.

12

General Science / Re: Yellow and Purple.

« on: 21/12/2023 06:29:03 »

I've noticed that you can choose a pair of colors and define a continuous line of color that varies smoothly between the two; for instance halfway along this line the two colors are mixed together in equal proportion.

You can do this with any two colors.

As to the emotional response we have to color schemes, that's another topic. Some people are more sensitive than others.

13

Just Chat! / Re: Are you a Dick?

« on: 20/12/2023 22:36:44 »

The meaning of varsigma is that it's an alternative way to write the greek symbol for sigma.
Alphabetic  variation is quite common across human languages.

The Latin VV for instance which became W.

14

Geology, Palaeontology & Archaeology / Re: Which came first - knives or caucasians?

« on: 21/10/2023 23:18:19 »

I think the original question has to lead to additional questions about human head hair.

Humans are primates; other primates don't have long hair growing from their scalps. Primates and other furry critters have a natural length--individual hairs stop growing and eventually are shed.

The OP is asking why do humans have this, and how isn't it a problem when it gets too long? When did we start grooming each other with knives or hair-cutting tools?

I found this snippet:

Humans and chimpanzees are very similar?genetically, behaviorally, physiologically. Underneath their fur, chimpanzees look sort of like human grandpas (only really, really buff).

But there's one big difference between chimps and humans that is curious once you think about it: Why don't chimps have hair? They have fur, sure, but why don't they have long flowing locks?

--https://www.smithsonianmag.com/smart-news/why-dont-chimpanzees-have-long-luscious-locks-1-180951387/

And why does animal fur seem to always grow to about the same length, while human hair keeps growing and growing?

Here, in a video answering fan questions, BBC Earth Unplugged's Maddie Moate and Simon Baxter explain that when it all comes down to it, human hair and animal fur are really the same thing. Just like chimpanzees, human hair will only grow to a certain length. This is obvious for arm and leg and back and other body hair. But it's also, more surprisingly, true for head hair, too.
Human head hair, like chimp fur, lions' manes and back hair, will only grow to a specific, individually determined length, says Today I Found Out. That length is determined, in part, by the length of your hair's anagen, or growth, phase.

    For the hair on your head, the average length of the anagen phase is about 2-7 years.  For your arms, legs, eyebrows, etc., this phase usually lasts just 30-45 days.  However, in extreme cases which are quite rare, some people have anagen periods for their heads as small as most people?s anagen phases for their arms and legs.  For these people, their hair never naturally grows more than a few inches long, presumably saving them a significant amount of money over their lifetime on barber visits. ;-)  The opposite is also true, with people whose anagen phase can last decades for their scalp hair.  Both of these extremes are very rare though.
 

--ibid

15

Just Chat! / What's the difference between fair and balanced

« on: 15/10/2023 22:45:12 »

If you type "fair and balanced" into google's search bar, most of the hits are about the journalistic meaning.

Given the situation in Israel, these two words might be seen in a different context.
All that aside, the more important context is the one I haven't mentioned: statistics.

Statistics is the backbone of scientific discovery (e.g. the Higgs boson, or its signal, in the data).

The simplest heuristic I have is a fair coin, with a balanced 'result' if I randomise it somehow, so I get a distribution of heads and tails. Ok, say I balance the coin on its edge, what does a fair coin have to say about that?

16

General Science / Re: Infinity...

« on: 29/09/2023 05:46:22 »

Only nothingness can be infinite.

Hmm.
Apparently, there are also different versions of nothing.

There's the nothing that you find inside an empty box, but an empty box isn't actually empty is it?

There's the nothing in a vacuum devoid of matter, but fields extend throughout the universe, so a vacuum isn't really empty either.

There's the empty set which is always empty, but the set exists, a set isn't nothing.

Also there's the nothing in the void space in Boundary Logic. This logic lets you create a boundary which immediately gives you a relation between the bounded interior and the rest of the empty space; you can impose true/false conditions such that you "recover" Boolean Logic. From nothing.
Actually, you do need some rules which look a lot like composition, you know, addition and multiplication say.

17

Technology / Re: Geeks shall inherit the earth

« on: 21/08/2023 20:55:33 »

I'll toss this into th' salad:

An anthropologist whose stuff I've read says that all human development (i.e. adaptation) is driven by need. If we don't need it we forget about it.

This anthropological rule of thumb explains why we didn't change much for tens of thousands of years, why we didn't develop better weapons for hunting or construct more permanent homes--we didn't need to. There was plenty of big game around and once you've figured out how to hunt and kill a certain species, it becomes knowledge that can be passed down; there's no need to change anything.

So what explains the rapid pace of tech changing. Almost as soon as it hits the shelves, newer and better stuff is in the pipeline. There's a learning gap; spend three years getting a tech degree and at least some of what you learn won't be, ah, needed anymore.

18

Plant Sciences, Zoology & Evolution / Re: Is religion killing us?

« on: 05/06/2023 20:47:26 »

"It would have been impossible for religion to exist before we had a society that was "rich" enough to support a bunch of preachers."

Ok. Your observation might need some actual history, though. As in, how did a society become rich? What constituted wealth during say, the early Neolithic before agriculture was around? How did hunter-gatherer societies become settled, or why did they?

19

Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 17/05/2023 19:59:12 »

In my world people have real problems and I get paid to understand and solve them with physics, chemistry, maths, brute force and duct tape. Very satisfying.

I would agree that hands on is more interesting than sitting around wondering what everything is, erm, is.

I personally find it frustrating when people don't seem to be able to question their own understanding or even admit they don't, nor does anyone else really, know that much about it after all.

Sure there is all that mathematics and a bunch of concepts, there are things that can go into bottles, and things that can't, but is that it? I shudder when I consider the possibility.

This other "discussion" (another forum) about what the word physical means, as opposed to what a physical thing "is", has  problem right off the bat. The universe is full of information, and we as observers decide what it means. Information isn't "encoded" with any meaning (at all).

Assume (ignore any objections here) that Hydrogen is a form of information. To us as observers the existence of this information leads us to theorise that it means stars, in the future. Hydrogen "by itself" tells us no such thing.

How useful is the "put it in a bottle" approach? What is a bottle, first of all?
Is it an entity, then what are its attributes? Is it an attribute because it's a particular shape, the material it's made of is the entity?

Then what does "in the bottle" mean? The material the bottle is made of is "in" the bottle a priori, and material has mass so mass is "in" the bottle. Now you struggle with what the mass of this bottle means, or with the difference between what the bottle is made of and what you can put in the ah, interior, whether this or that is an entity or an attribute--the bottle "has" mass, so it's an attribute of this thing you're calling a bottle.

What a headache.

20

Physics, Astronomy & Cosmology / Re: Talking about Physics

« on: 16/05/2023 02:09:12 »

On the other hand I'm embarrassed on behalf of my colleagues if they give you different answers to "what is a photon". It is a quantum of electromagnetic energy, modelled as a particle with zero mass. Anything else would have a different name.

Ok. I agree that most sources will say that a photon is a discrete particle or quantum of the electromagnetic field.
However, if you go to physorg or stackexchange, things are a bit less clear. It depends, apparently to a large extent, on how close you are to a photon as it were. Again with the near-field/far-field distinction, as to what a thing might appear to be.

And generally we represent photons and other particles in a diagrammatic way, and what the diagram looks like depends on the context. In electronics the electric field of some signal propagates at the speed of light; electronic circuits emit radiation in all directions. Photons don't really make sense at radio frequencies, even if radio signals are a whole lot of photons with long wavelengths.

Add to that, physics is by far a done deal, I guarantee there are quantum photon effects we haven't discovered yet, and we've discovered a lot that weren't predicted by any theory. So I think that's one way to gauge our understanding of quantum particles--how many discoveries have there been which were a "complete" surprise?

Given that such "new" quantum effects have appeared unexpectedly, what does that do to any quantum philosophy?
The philosophical problem might be connected to how the theories we have, don't tell us all that much in terms of what to expect. Unlike Newtonian mechanics which generally does.