prof-dr-ir

Yes it is quite surprising.

There is actually a simple way to obtain a force between two objects that does not decrease with distance: simply connect them with an (idealized) string. And it is indeed not entirely inaccurate to say that the strong force produces some kind of quantum mechanical string between two quarks.

Historically the study of exactly these strings for the strong force led to the idea of string theory. Only later was it realized that it can be useful as a theory of quantum gravity as well.

Do you maybe have a concrete suggestion for how you would rewrite it? Which parts do you think are not understandable for anyone attending, say, the annual Strings conference?

Excellent. Indeed, as you say already for the real numbers one could have chosen sqrt(9) = -3: after all, (-3)^2 = 9 just as much as 3^2 = 9. Taking into account this inherent ambiguity in the definition of the square root function becomes crucial when extending it to the negative numbers, as my example shows.

So, long story short: although not everyone agrees, personally I prefer to define the imaginary numbers by means of an entity i that obeys i^2 = -1, and avoid talking about "square roots of negative numbers" as the (otherwise fine) article does.

Hah! So if, as per the article, "imaginary numbers are square roots of negative numbers" then I am happy to report that:

1 = sqrt(1) = sqrt((-1) * (-1)) = sqrt(-1) * sqrt(-1) = sqrt(-1)^2 = -1

and all of mathematics collapses into a giant pile of logical nothingness. Ergo, imaginary numbers and mathematics cannot both be real.

UK politicians, especially those on the right, were never big supporters of the European Convention on Human Rights and often express their desire to circumvent it (see the linked Guardian article in another comment), or to remove its applicability from UK law altogether.

Supporters of human rights may find comfort in the fact that the UK is actually bound to the ECHR by various international agreements, including the Good Friday Agreement. This severely limits politicians' ability to scrap its applicability altogether, despite their repeated promises to the contrary. This excellent blog post from June summarizes all this well: https://davidallengreen.com/2022/06/oh-no-not-again-the-stor... .

Most recently the UK government introduced a "Bill of Rights". Despite its name, it changed little with respect to the applicability of the ECHR, but it does make it harder (again) for litigants to rely on the Convention in practice.

(Note that the ECHR, both the court and the convention, are completely separate institutions from the EU.)

Your point is clear but I do not think there is a need for such hyperbole (or for the exclamations).

I could not find a reference reliable enough to quote here, but I would be surprised if any major airport loses more than a few percent of checked luggage. So you will most likely not lose your luggage.

My advice would be to study mathematics. Or to find some other way to teach yourself to exclusively say or write things that are true. Then I think you will also more easily recognize when others do not.

This is not correct. The expectation value of the angular momentum along the x-axis might be zero, but the state itself simply does not have a definite angular momentum.

I like your example because it clearly shows the subtlety that the original comment by rssoconnor also misses. Energy, momentum, and angular momentum absolutely are conserved quantities. But if you prepare your initial state such that it does not have a definite value of these quantities then you cannot with certainty predict the measured value, either.

Thank you for your efforts but I am sorry to say that I am still not convinced.

The Protonmail link is not a primary source but let me dignify it with a response anyway. The authors of that blog post themselves admit that the resolution they link to "is non-binding and does not provide any specifics for new laws or regulations and, on the surface, seems fairly innocuous." They then go on to say how actually it is really dangerous, and the tone is very threatening, but their reasoning is simply not substantial enough to convince me.

I was sad to see that the EFF's very first link to a 'proposal' from the EU commission simply links back to Mr. Breyer's website. (But I am very happy with the letter co-signed by the EFF, which I think is well-written and a lot less alarmist.)

And once you do get to a primary source, in your third link, you can only make your case by rephrasing "security despite encryption", which I can happily interpret as being entirely in line with the direction suggested by the aforementioned letter, as "encryption they can access".

So I remain unconvinced, mainly because your "in other words" really do a lot of heavy lifting in your comment.

As you can easily check, Mr. Breyer's website has been at the top of HN multiple times in the past year or so, and invariably the comment section becomes an anti-EU pitchfork party based on nothing more than the linked text and various unhelpful stereotypes. Comments like yours, which justifiably ask for a primary source, have never been getting the attention they deserve.

So let me explicitly go against the grain here: I believe the linked text to be fear-mongering and I also believe that the EU will not "break secure encryption" (or make it illegal) in the foreseeable future. And if Mr. Breyer or anyone else would like to convince me of the alternative then please show me some concrete evidence first.

Perhaps we are just not smart enough? After all, you cannot teach a dog quantum mechanics...

If there was anyone who taught you this then they should be fired.

More constructively, principal among the many things wrong with your comment is the formula for the mean; sum_i p_i = 1, so sum_i p_i / n = 1 / n. The mean would instead be sum_i p_i x_i.

I think this comment is significantly more insightful than the article.

As for the thing you don't get: quantum mechanics means that the state space is actually discrete, which means there is no need to pass to a continuous distribution. And finiteness is not really a concern either: first of all it is not strictly necessary for the (Gibbs) entropy to be defined, and secondly the space state is actually often finite once e.g. the total energy in the system is fixed.

More precisely you say that we would save 23% of our heating expenses. But not all of our heating is from gas, and gas is not exclusively used for heating. So this is only a first step towards answering the original question.

I look forward to reading this recap of the training methods of an Olympic gold medalist.

That said, I think these sorts of books should be seen as valuable data for serious athletes, but never as gospel. To paraphrase my former coach: if Nils van der Poel would make a point of always practicing in a tutu, would you as well?

I am sorry for the snark, but do you always judge the presentation of a course based on ten sample problems listed on its website? Because if you do then you probably would not take any of my courses: the publicly accessible old exams also do not generally explain the course material very well...

It should by now be pretty clear that Tesla, like Uber before it, are taking the Lord Farquaad approach to self-driving: "Some of you may die, but it's a sacrifice I am willing to make."

It does not have to be this way, and these companies and their leadership deserve every bit of reputational damage they will get out of this.

The author is an undergraduate student, and judging from this list it appears that he has yet to encounter non-linear PDEs?

Besides the Navier-Stokes equations, which are already frequently mentioned, I would have very much liked to see Einstein's equations added as well.

Indeed. Sets are not doors, as the saying goes, because they can be open and closed at the same time.

Blaise Pascal needed a few sentences:

"When I consider the short duration of my life, swallowed up in the eternity before and after, the small space which I fill, or even can see, engulfed in the infinite immensity of spaces whereof I know nothing, and which know nothing of me, I am terrified, and wonder that I am here rather than there, for there is no reason why here rather than there, or now rather than then. Who has set me here? By whose order and design have this place and time been destined for me? The eternal silence of these infinite spaces frightens me."

The arxiv is a treasure, and such preprint servers not only streamline the academic debate but are also a necessary first step towards a future without for-profit academic publishers.

The arxiv moderators are like human spam filters. And as anyone who dealt with email should know, spam filters are essential for a platform to remain useful. I think the article puts undue emphasis on the few edge cases that invariably arise with any such filtering system.

And being a moderator is a thankless job indeed. The efforts of a moderator are largely focused on the absolute worst papers, and the job is therefore very different from being a referee or editor of a reasonable academic journal. So personally I would also focus elsewhere any efforts at increasing diversity in academic institutions.

for those wondering: a 120 kg bag, raised for 1 meter, could give you 1 W of energy for 20 minutes.

Sure. I am sorry to hear you have been insulted - my comment is not to be interpreted as a justification of rude online behavior.

By the way, what do you think of the tone of the other reply to my comment? (Did you perhaps see the now-deleted curse word at the end?)

Sorry but where did you see me defend the lack of investigation?

But you're incorrect? The lab leak theory is still widely considered to be an unlikely possibility.

And now I am reminded of the CmdrTaco option, and reminiscing about days long gone - certainly appropriate for New Year's day.

Then what is "quantum theory based on the real numbers"? I think your notion of "real amplitudes" cannot be the complete answer because the Schrodinger equation is linear, and complex linear algebra is just a special case of real linear algebra.

I looked at the appendix of the paper and their claim seems to hinge on some form of non-decomposibility of a certain tensor product state? It is the paragraph below equation A2.

More generally I got a bit frustrated reading the paper because the axioms of real quantum mechanics did not seem to be properly formulated.

Article 7 of the Charter of Fundamental Rights, which was adopted with the Lisbon treaty, reads (in its entirety):

"Everyone has the right to respect for his or her private and family life, home and communications."

On the short term a change to the treaties of the Union is not realistic, in my opinion. So I am afraid we might be stuck with having "to fight over and over again", using the above as a foundation. I guess I think of it as educating the politicians.

Fortunately the pro-privacy voices in the EU seem loud enough. For example, in this case the Belgian national privacy authority had already complained about the proposed law. And Germany seems to have adopted the right to encryption in its latest coalition agreement.

There are plenty of theoretical physicists who live to old age. As far as I can see, they all become increasingly irrelevant as they age. Scientific obscurity is all but guaranteed at around 80 years old, despite some people publishing until well after that age.

It is quite a sad future that awaits.

I would caution against getting your hopes up.

A milder variant might be nice, and on the longer term help resolve the pandemic.

On the short term, however, increased infectiousness may easily outweigh this. It is not hard to see the number of hospitalizations and deaths increasing, simply because of the larger total number of cases. Humanity will then generally try to mitigate this by stricter measures, and altogether we might end up with a rather nasty winter... again.