Which is the lowest-probability event ever recorded?

And the Higgs Boson? What are the probabilities of finding it?

Same answer-- 100% with the right equipment,* if* the Higgs Boson exists.

In the past several months CERN equipment thought to be capable has narrowed
the range of possibilities (IIRC energy ranges) for where it might be located.

You are right, and my 1000s was enough of an understatement
to count as a mistake.

Not wrong, just imprecise.

The male members of this forum (myself included) losing their virginity?

Hyuk hyuk.

Don’t worry. It will happen eventually, even for you.

I have heard the story told of Fort Sumter; I’m very sorry to be wrong about that.

Thomas Jefferson and John Adams, both on the 5 man drafting committee for the Declaration of Independence, and signers, died exactly 50 years to the day of the date, on July 4, 1826.

Uh, that isn’t that unlikely compared to other suggestions in this thread. It’s just a big coincidence, like:

A few possibilities:
-proton decay?
-a human living to 163 years age?
-getting hit by a meteorite?
-being revived after dying?

I don’t see where that one fits. Depending on the definition of ‘dying’, it either happens all the time or has never happened.

Sounds like the odds are pretty low that someone will invent nutrinovoltaic technology anytime soon.

There was an article in Harper’s a few months back that examined her techniques. It suggested that she was indeed gaming the system, and concluded with a blurb about her being either questioned by or in the custody of the FBI. So that one is a false improbability, but then again it demonstrates that statistical math has real-world applications.

A statistics professor of mine once remarked, “Statistically impossible events occur all the time.” Which indeed is the case. Consider the number of possible seating arrangements in a diner with 60 seats. Or a train with 60 seats. Or a staircase or patio made of 60 bricks. The number of combinations is 60! = 8.320987113 x 10^81, which exceeds the number of atoms in the universe. Any given arrangement is inconceivable. Yet there they are.

This is probably a good example of one of those things which is hard to define or quantify but that people feel they “know it when they see it”.

I don’t think “the current configuration of the universe” is a good choice. We need to differentiate between events that had to happen in some form but had many possible outcomes, from outcomes that seem meaningfully coincidental.

I guess it boils down to three possibilities:

  1. Repetition more frequent than statistically expected. Multiple lottery wins / lottery strikes / etc.

  2. Pattern more frequent - rolling 123456 on six die rolls.

  3. Unexpected frequency or locality of recurring events - successive meteors of a certain size within an unlikely time period or geographic area.

So, it the broad sense the question seems meaningless, but we cannot ignore the more personal sense of meaning to the human sense of coincidence or pattern recognition.

What? Statistically impossible events never occur. The arrangements in those examples you gave are both conceivable and possible. And if we’re assuming that the 60 bricks have been built into a patio, the probability of one of those arrangements existing is 1.

Following on this, it occurs to me that if the universe turns out to be determinate after all, then the probability of everything that ever happened is 1, regardless of how likely it may appear, which would make probability just one of our illusions.

Or, looking into the (deterministic) future, calculating probabilities could be viewed as a kind of ‘ignorance management’. What will happen is already a matter of fate, we just don’t know what it is, and a low-probability event occurring simply means we were especially ignorant of reality in that case.

But it seems paradoxical to ask questions about probability in a deterministic universe. I ought to feel much more robotic than I do if I am just a set of mechanical iterations passing through state A->B, shouldn’t I? The thoughts would then be also pre-determined, which would, ISTM, give them a different character. I don’t feel determined, which I guess doesn’t settle anything…

Actually, “ignorance management” is a good description of what probability is used for. We do in fact use probabilities in situations where something either is or is not already true, but we don’t, and perhaps can’t, know for sure whether it’s true. This happens, for example, when we say things about a population based on our observations of a random sample.

And even though it may seem paradoxical, I don’t have a problem with talking about probabilities of determined-but-unknown events. For example, I could deal you five cards face down and then, before either of us looks at them, calculate the probability that you have a royal flush.

As some have already noted, every time we shuffle a deck of cards, or throw dice many times in a row, or seat a large group of people, we are creating arrangements that are fantastically improbable. But we don’t consider most of the resulting arrangements as improbable because we don’t recognize them as special. After all, each time we shuffle a deck of cards, some arrangement has to happen. The probability of some arrangement is 100%. But there are arrangements we consider special, even though they are just as probable as any other: shuffling a deck of cards and ending up with the cards arranged numerically by suit; rolling “6” on a die many times in a row; seating 60 people and them ending up ordered by name; lightning striking the same person multiple times. So I would argue that the OP has a good question. Has anyone shuffled a deck of cards and ended up with the cards arranged numerically by suit? Has anyone been struck by lightning 10 times? There is some subjectivity involved, but not as much as you might think IMO. I like the OPs question.

I like the OP’s question too, but I like jackdavinci’s clarification even more.

It was a quip. As for the patio, if the bricks were all labeled with invisible ink, shuffled, and placed in a warehouse, most configurations on the patio-to-be would have preposterously low probability. I’m assuming that the relevant information set for this (conditional) probability does not involve somebody who has visited the warehouse or can read the invisible ink before the bricks are set in place.

If we use the know-it-when-we-see-it criteria, the fine tuned universe is probably the least probable event. Fred Hoyle compares “the chance of obtaining even a single functioning protein by chance combination of amino acids to a star system full of blind men solving Rubik’s Cube simultaneously”. Though perhaps there are better examples. The anthropic principle disallows this coincidence, which is why I used jackdavinci’s more subjective framework.

Slartibartfast: Come, your arrival on the planet has caused considerable excitement. It has already been hailed as the third most improbable event in the history of the Universe.

Dent: What were the first two?

Slartibartfast: Oh, probably just coincidences.