# What is the least probable event ever observed? Quantum tunnels? **URL:** \ **Category:** Factual Questions\ **Created:** [May 30, 2018, 12:59pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126 "2018-05-30T12:59:10Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![BeepKillBeep](https://avatars.discourse-cdn.com/v4/letter/b/9e8a1a/32.png) [@BeepKillBeep](https://boards.straightdope.com/u/BeepKillBeep)\ **Post date:** [May 30, 2018, 12:59pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/1 "2018-05-30T12:59:10Z")
So I’m sure we’ve all heard about the notion that there is some probability that all the air in my room will suddenly be in the top, left corner of the room and I will suffocate. However, the probability of it occurring is so low that it never happens and never will happen. My (limited) understanding of quantum tunneling is that there is some chance that a particle can be on the other side of a barrier, and given enough energy it can be made to happen. I’m assuming that the least probable event ever observed is a quantum tunneling experiment. Is that so? And if so, what were the odds of it occurring? Please feel free to correct any of my flawed information. Also, I know there are some obvious political jabs that can be made here, for your own sake, I’d avoid making them. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [May 30, 2018, 1:02pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/2 "2018-05-30T13:02:21Z")
Defining probability is kind of tricky, though. I mean, if you have a few gazillion grains of sand on a beach, the chances that you will find them in the exact configuration you observe when you walk onto the beach are gazillions to one, but there they are. I’m not sure how you could define a “least probable event”. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [May 30, 2018, 1:23pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/3 "2018-05-30T13:23:33Z")
Pair-instability supernova are very rare, I believe only one has been observed … Las Vegas Golden Knights are the only team to reach the final playoff in their first year of operations … that’s gotta be a lower probability than quantainium tunneling … I’m tickled by your example … if we find within all the writings over the past 6,000 years a tale of how all the air in the room concentrated on the ceiling and suffocating the occupants … would we believe it? … under the threat of being accused of practicing witchcraft, would it even be recorded? … another problem with QM is that the act of observing it changes it’s behavior … like eyeglasses, they’re always around except when you’re looking for them … ---
**Author:** ![Hermitian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hermitian/32/470_2.png) [@Hermitian](https://boards.straightdope.com/u/Hermitian)\ **Post date:** [May 30, 2018, 1:50pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/4 "2018-05-30T13:50:17Z")
For sports, I’ve heard that Leicester winning the Premier league was incredibly improbable. It was like the Cleveland Browns winning the Super Bowl this year. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 30, 2018, 2:14pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/5 "2018-05-30T14:14:04Z")
Quantum tunneling happens a gazillion times a second. It [can be used](https://en.wikipedia.org/wiki/Tunnel_field-effect_transistor) [in electronics](https://en.wikipedia.org/wiki/Tunnel_diode). It is [what allows stars to burn](https://en.wikipedia.org/wiki/Quantum_tunnelling#Nuclear_fusion_in_stars). ---
**Author:** ![Iggins](https://avatars.discourse-cdn.com/v4/letter/i/b9e5f3/32.png) [@Iggins](https://boards.straightdope.com/u/Iggins)\ **Post date:** [May 30, 2018, 2:21pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/6 "2018-05-30T14:21:52Z")
I think the least probable event would be two completely identical games of Scrabble. 🙂 ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [May 30, 2018, 3:32pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/7 "2018-05-30T15:32:25Z")
> [@Hermitian](#): > > For sports, I’ve heard that Leicester winning the Premier league was incredibly improbable. It was like the Cleveland Browns winning the Super Bowl this year. > [@Iggins](#): > > I think the least probable event would be two completely identical games of Scrabble. 🙂 The catch in the OP is that this “least probable event” has to have been observed … it’s possible for a baseball infielder to be credited with an unassisted triple play without ever touching the ball … improbable indeed … and it’s never known to have happened … whereas a drive to the outfield and bouncing off the outfielder’s head and over the fence for a home run actually has happened {[YouTube](https://www.youtube.com/watch?v=QixQMUu4CKI) 1’17"} … ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [May 30, 2018, 4:25pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/8 "2018-05-30T16:25:01Z")
Given the thousands of interconnected items that have to work and the precise order and timing in which they have to work, I’d have to say putting humans on the moon and having them return safely has to rank as pretty damn improbable. The odds of doing it successfully six times, including four consecutively, have to be virtually impossible to calculate. Heck, even the ability to _fake_ a moon landing convincingly six times is pretty impressive. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [May 30, 2018, 4:28pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/9 "2018-05-30T16:28:15Z")
The “least probable event ever observed” may be the creation of a universe capable of sentience and self-observation, or indeed, even basic existence of physical objects as we know them. The so-called “fine tuning” of fundamental physical constants to create a universe in which stellar fusion, chemistry, and the gravitational accumulation of mass into planets, stars, and galaxies is so incredibly unlikely we could not reproduce it by chance permutation in the lifespan of our universe. This has led to a lot of errant specualation akin to creationism and the anthropic principle, but in truth if our universe were not this way we would not be around to notice so without any additional information any musing about special conditions is just idle woolgathering. Our universe could be but one of a countless number capable,of self-organizing systems using some analogue of chemistry, or it could be a unique confluence of possibilities. Or there could be some special reason the parameters are what they are that we just haven’t figured out. As noted above, quantum tunneling is not particularly improbable given the right conditions of pressure and temperature and drives fusion reactions in stars, certain types of electronic components (Esaki and resonant tunneling diodes, multijunction photovoltaic cells, Josephson junction superconducting magnetometers), and perhaps even more mundane reactions on Earth, albeit at levels not readily observable in nature. In fact, the rate of tunneling can be precisely determed on a statistical basis to a very high degree of precision. Stranger ---
**Author:** ![BeepKillBeep](https://avatars.discourse-cdn.com/v4/letter/b/9e8a1a/32.png) [@BeepKillBeep](https://boards.straightdope.com/u/BeepKillBeep)\ **Post date:** [May 30, 2018, 4:34pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/10 "2018-05-30T16:34:40Z")
Interesting replies so far. I’ll just add that this thought was prompted while I was out on my walk yesterday. While crossing a bridge I thought, I wonder what the odds are that the section of bridge I’m walking on would suddenly appear 10 feet to my right and I would plummet to me doom. Assured that it was safely quite low I kept going but I have to say this might be an example of ignorance being bliss. But it did get me thinking about what sort of low probability events have been observed. Now I was thinking more along the lines of low probability quantum events, but the replies so far have been great. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [May 30, 2018, 4:42pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/11 "2018-05-30T16:42:49Z")
> [@kunilou](#): > > Given the thousands of interconnected items that have to work and the precise order and timing in which they have to work, I’d have to say putting humans on the moon and having them return safely has to rank as pretty damn improbable. The odds of doing it successfully six times, including four consecutively, have to be virtually impossible to calculate. It can’t be that improbable given that moon landings happened repeatedly with only one recoverable mission failure. One could computer an _a posteriori_ distribution with a specified confidence level and estimate the likelihood of a particular mission or of five successful missions out of six. If you want to delve into the underlying reliability of individual subsystems or compnents it becomes very convoluted because we have no good way to credibly estimate reliability on many of them (and in particular the astronauts), nor to estimate latent defects that would reduce reliability estimates if we knew about them, but then that is why we have all of the testing, training, and “blizzard of paperwork” in the aerospace industry such that the actual reliability exceeds any presumably worst case estimate and that critical space systems are far more tolerant to unforeseen problems or latent defects than a facile design margin would require. Sending people to the moon was difficult and expensive, to be certain, but not especially improbable. Stranger ---
**Author:** ![Johnny\_Bravo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_bravo/32/493_2.png) [@Johnny\_Bravo](https://boards.straightdope.com/u/Johnny_Bravo)\ **Post date:** [May 30, 2018, 4:46pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/12 "2018-05-30T16:46:54Z")
Is any observable event more unlikely than [each of us?](https://www.huffingtonpost.com/dr-ali-binazir/probability-being-born_b_877853.html) Which I suppose holds true for any distinct living creature. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [May 30, 2018, 4:47pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/13 "2018-05-30T16:47:24Z")
> [@watchwolf49](#): > > … another problem with QM is that the act of observing it changes it’s behavior … The probability that a random Doper correctly uses apostrophes is vanishingly small. ---
**Author:** ![Hermitian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hermitian/32/470_2.png) [@Hermitian](https://boards.straightdope.com/u/Hermitian)\ **Post date:** [May 30, 2018, 4:54pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/14 "2018-05-30T16:54:33Z")
More random unlikely things: Edwin Booth, John Wilkes Booth’s brother, saved Abraham Lincoln’s son’s life in New Jersey a year or two before Lincoln’s Assassination. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [May 30, 2018, 5:00pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/15 "2018-05-30T17:00:07Z")
> [@BeepKillBeep](#): > > Interesting replies so far. I’ll just add that this thought was prompted while I was out on my walk yesterday. While crossing a bridge I thought, I wonder what the odds are that the section of bridge I’m walking on would suddenly appear 10 feet to my right and I would plummet to me doom. Assured that it was safely quite low I kept going but I have to say this might be an example of ignorance being bliss. But it did get me thinking about what sort of low probability events have been observed. Now I was thinking more along the lines of low probability quantum events, but the replies so far have been great. It should be understood that the action of quantum phenomena on macroscopic objects is essentially impossible under “normal” conditions (e.g. outside of a Bose-Einstein condensate or other coherent system). By definition, quantum phenomena are stochastic, and macroscopic objects are formed of many billions of individual quantum particles; the likelihood that all particles will suddenly change state in such a way that a macroscopic object like a bridge will suddenly disapper or change in location is so incredibly unlikely that it has never occurred in the life of the universe and will not if the universe lasts for trillions of years longer. In quantum mechanics this distinction is called decoherence, and it is what prevents macroscopic systems from behaving like a coherent quantum system, e.g. why Schrödinger’s Cat is not really a superposition of dead and alive states in the real world. It is sometimes better to live in blissful ignorance but in this case be assured in knowledge that disappearing bridges are no more likely than the entire universe spontaneously winking out of existence. Stranger ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [May 30, 2018, 5:09pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/16 "2018-05-30T17:09:32Z")
As mentioned, depending on how you define things, you can get pretty much as improbable as you want. However on this list of improbable physics events things that have been observed should be neutrino detection. A detector containing 65 tons of tetrocycline which had about 65 billion neutrinos passing through each square centimeter every second, measured a neutrino interaction about once every 50 days. ---
**Author:** ![BeepKillBeep](https://avatars.discourse-cdn.com/v4/letter/b/9e8a1a/32.png) [@BeepKillBeep](https://boards.straightdope.com/u/BeepKillBeep)\ **Post date:** [May 30, 2018, 5:33pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/17 "2018-05-30T17:33:40Z")
> [@Buck\_Godot](#): > > As mentioned, depending on how you define things, you can get pretty much as improbable as you want. However on this list of improbable physics events things that have been observed should be neutrino detection. A detector containing 65 tons of tetrocycline which had about 65 billion neutrinos passing through each square centimeter every second, measured a neutrino interaction about once every 50 days. That’s pretty cool. 🙂 ---
**Author:** ![BeepKillBeep](https://avatars.discourse-cdn.com/v4/letter/b/9e8a1a/32.png) [@BeepKillBeep](https://boards.straightdope.com/u/BeepKillBeep)\ **Post date:** [May 30, 2018, 5:37pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/18 "2018-05-30T17:37:17Z")
> [@Stranger\_On\_A\_Train](#): > > It is sometimes better to live in blissful ignorance but in this case be assured in knowledge that disappearing bridges are no more likely than the entire universe spontaneously winking out of existence. Well, that’s going to keep my up at night. 🙂 ---
**Author:** ![D18](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@D18](https://boards.straightdope.com/u/D18)\ **Post date:** [May 30, 2018, 6:06pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/19 "2018-05-30T18:06:18Z")
> [@watchwolf49](#): > > Pair-instability supernova are very rare, I believe only one has been observed … > > Las Vegas Golden Knights are the only team to reach the final playoff in their first year of operations … that’s gotta be a lower probability than quantainium tunneling … > > I’m tickled by your example … if we find within all the writings over the past 6,000 years a tale of how all the air in the room concentrated on the ceiling and suffocating the occupants … would we believe it? … under the threat of being accused of practicing witchcraft, would it even be recorded? … another problem with QM is that the act of observing it changes it’s behavior … like eyeglasses, they’re always around except when you’re looking for them … Nitpick - the [St. Louis Blues](http://www.thehockeynews.com/news/article/the-five-best-inaugural-seasons-by-expansion-or-relocated-franchises) made the Stanley Cup final in their expansion season. It wasn’t that remarkable accomplishment, however, because the NHL put the original six in one division and the expansion six in the other, so the playoffs were structured for one of the noobs to make it. ---
**Author:** ![Llama\_Llogophile](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@Llama\_Llogophile](https://boards.straightdope.com/u/Llama_Llogophile)\ **Post date:** [May 30, 2018, 6:10pm UTC](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126/20 "2018-05-30T18:10:55Z")
The final inning of game 6 in the 1986 World Series remains the most improbable thing I’ve ever personally witnessed. [Next page](https://boards.straightdope.com/t/what-is-the-least-probable-event-ever-observed-quantum-tunnels/815126.md?page=2)