Genady

16 minutes ago, iNow said:

Would humans have done any better / worse? Probably the latter.

Details matter here. It depends. Which humans? How were they trained? What parameters were given for the analysis?

19 minutes ago, TheVat said:

people over 2000 miles away in Alice Springs could hear the explosion of Krakatoa.

And the pressure wave went around the world seven times!

5 minutes ago, TheVat said:

Added to my list, too. I was also introduced to famous eruptions in late sixties, partly by a cheesy US movie about Krakatoa (which Americans my age may recall had a humorous geographical error), and also a story about Pompeii. I remember my 12 year old mind being blown that people over 2000 miles away in Alice Springs could hear the explosion of Krakatoa.

The Pompeii story was well known and popular in the USSR. I guess it was "promoted" there thanks to the Russian painting, The Last Day of Pompeii - Wikipedia.

39 minutes ago, exchemist said:

That’s interesting. Seems the story of him being on death row is untrue. Also I was wrong about the number who died: 30,000 not 20, 000. Lacroix, who was among the first on the scene, took dramatic pictures of the aftermath which Holmes reproduced in the book, including the sinister “spine”, turdlike, of almost solid lava, which was extruded up to a height of I think ~ 100m afterwards, though it soon crumbled. It even glowed in the dark, creepily, for a bit, I think. You can visit Sylbaris’s cell among the ruins.

I found Martinique, being part of France, orderly and good to visit. I tried my first ti’ punch there - something I often make at home now in the summer. Needs rhum agricole, which I buy in France - Bacardi no good at all for it. We also tried sugar cane juice, on the beach. Very good and with far more flavour than I was expecting. (But you will know all this, being in the Caribbean yourself.🙂)

Martinique is a bit far from here, but the Collectivité de Saint-Martin is around the corner. I'll visit there at some time perhaps.

P.S. In fact, Martinique is close on the map - it's just more difficult to get there from here than to St. Martin, because of the Dutch part, Sint Maartin.

5 minutes ago, exchemist said:

Holmes also contained a dramatic account of the 1902 eruption of la montagne Pelée which destroyed st. Pierre in Martinique, which made a great impression on me. At that time, the term he used for what we now call a pyroclastic flow was une nuée ardente. I think it may have originated with that eruption.

Some years ago I climbed the mountain with my wife and son, as far as the 1st crater rim. Bizarrely, she was rung up by her uncle in Paris, just as we reached the ridge. He had no idea where we were.

The ruins of St. Pierre are a sombre reminder of the tragedy. 20,000 people perished. I think only three survived, one of them, ironically, a condemned convict in a deep cell in the prison, who subsequently earned a living by showing off the scars on his back from the burns.

They never had the heart to rebuild, establishing a new capital at Fort de France.

The story of that convict, with a bit more details (he was jailed again later) is mentioned in the Krakatoa book.

Ludger Sylbaris - Wikipedia

6 minutes ago, studiot said:

I have two copies of Holmes classic.

The first written I think written prewar which does not mention plate tectonics (though it did speculatte about continental drift) but it has so much useful information that is still correct that I keep it

The second from the late 60s when Holmes had becme a convert and rewritten many things, including adding early tectoniic material.

A really good modern book by Clive Oppenheimer from Cambridge University Press provides probably the most comprehensive history of eruptions on Earth.

Thank you. Added to the wishlist.

17 minutes ago, exchemist said:

I remember reading an account of this in Arthur Holmes's Principles of Physical Geology, as a teenager in the 1960s. At that time Anak Krakatau was quite small, still. Now, I gather, it has grown to adulthood and has even suffered a collapse rather like that of its parent, though not as dramatic.

Did it have an explanation of plate tectonics then?

... about this legendary but entirely unknown to me until now event. A good book, too.

Today, after going through about one third of this book, I learned that I don't care about English kings.

Just now, dimreepr said:

It might be a hologram, depending on one's perspective... 😉

Even in this case, it is not flat though.

2 minutes ago, Mordred said:

Lol there's some debate on whether math is a science or not.

Yes, I got used to it now although when and where I grew up, it was never a question.

2 minutes ago, studiot said:

As regards 'flat earth' , like so many things in nature, the issue is neither hard and fast nor clear cut.

As a rule of thumb in surveying and cartography th flat earth model is adopted for patches of the earth of less than 10km radius.

I disagree. You know exactly what I call "Earth" in my statement above. But you've changed the meaning of the word. It is a coincidence in English that the patches of the earth and the planet Earth are referred to by the same word. To avoid the language misunderstanding, I can clarify, "Earth, the celestial body, is not flat." It is a hard and fast truth.

11 minutes ago, studiot said:

It would also seem that the OP has lost interest.

Yes. And it is still in Politics.

6 hours ago, Mordred said:

It could also be argued there is no hard and fast truth in science. There is truth to the best of current understanding. Good example that everyone is familiar with in physics is Newtons laws of inertia. Everyone firmly believed the equations applied regardless of the measured objects inertia. Later findings showed its only valid for non relativistic inertia hence GR.

I also wonder why this thread is in politics.

I never know if math is considered science or not. If it is, then it is full of hard and fast truth.

Plus, regardless of the math question, isn't the statement "Earth is not flat" a hard and fast truth?

3 minutes ago, ahmet said:

when some effective/known people says something, others follow without questioning.

This is not true.

27 minutes ago, DimaMazin said:

a is arc of unit circle in radians. It shown on diagram.

OK, then [math]\frac{xy}{2}=\frac{1}{\sin 2\beta}[/math].

According to the drawing, the radius of the circle is 1.

2 hours ago, DimaMazin said:

I have mistaken because it correct only when à=Pi/4 .

You are correct only in the case too. Because green line is not tangenta to the circle in point [cos(a); sin(a)] . It is tangenta in other point.

You should've asked me, what is [math]\alpha[/math].

It is an angle between the green line and the axis.

7 hours ago, Markus Hanke said:

It should be noted that a simple curve (1D manifold) has no intrinsic curvature - the Riemann tensor vanishes identically in 1D. But it can of course have extrinsic curvature when embedded in a higher dimensional space.

The Riemann curvature tensor in one dimension does not vanish but rather is undefined. It has no components in 1D.

[math]\frac{xy}{2}=\frac{1}{\sin 2 \alpha}[/math]

14 minutes ago, KJW said:

I don't think a solution in terms of radicals includes infinitely nested radicals.

You are correct. It includes only a finite number of radicals.

On one hand, (notice the very last statement)

...

On the other hand,

[math]x=\sqrt[5]{2+5\sqrt[5]{2+5\sqrt[5]{2+...}}}[/math]

solves that polynomial.

What's wrong?

3 minutes ago, studiot said:

Nature has no requirement for a mathematical formula to describe a sequence.

Any such is purely artificial, but is in accord with an ordering of the set of all alkanes.

However Nature does present us with conundrums involving sequences such as chicken and egg, non commutativity

And that's why the OP question is misleading.

IOW, a waste of time.

P.S. I should've guessed so as it is in The Lounge and not in The Puzzles.

5 minutes ago, studiot said:

in increasing order of the number of carbon atoms

, for our convenience.

Another not Fibonacci:

328, 176, 105, 83, ...

What are the next terms?

14 minutes ago, studiot said:

How is this different from F_n = F_(n-1) + F_(n-2) ?

You're right. They are equivalent.

20 minutes ago, studiot said:

Methane, ethane, propane, butane, pentane for 1, 1, 2, 3, 5

This is not a meaningful sequence; the order is arbitrary.

It can be, e.g., [math]F_n=2F_{n-2}+F_{n-3}[/math].

1 minute ago, studiot said:

what other sequence(s) start of like fibonacci but diverge from this pattern further down the line ?

This is a different question, not the one in the OP.

2 minutes ago, studiot said:

This is an exercise in thinking out of the box.

I'm sorry you say this.