The Uncertainty Principle is NOT about 'Uncertainty'

The uncertainty principle was suggested by Werner Heisenberg in 1927. His version was only about position and momentum, but it's much broader than that. In fact, it happens anytime you model waves.
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COOL LINKS & SOURCES

MinutePhysics on Uncertainty Principle:

Veritasium on Uncertainty Principle:

SciShow on Uncertainty Principle:

Wikipedia:
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[akbarahmedchowdhury]

This channel is informative but yet so underrated. You are amazing, man. Keep up the good work 👍❤

[vinvinn]

I laughed really hard when he asked "where am i in the screen now?" 😂

[maazfaridi]

3 min video explained it better than 13 years of school and intermediate college ... damn you nick you are a wizard

[vinpandey]

You're definitely "the best teacher I never had". For me you're our online Feynman. Keep it coming Prof. Your understanding of subject matter is impeccable.

[samomuffucka]

Your videos are awesome. I'm so glad I found your channel. Keep up the good work!

[redist]

One of the hidden gems in Youtube. You sir deserve more likes and subscribers!

[WilliamJonesChess]

1:41 But where am I on the screen now? Everywhere!

Brilliant!

[Adragos]

Your videos are so fun and i learn more about quantum things that i love!

[priscillaallen]

Thank you! You just removed a splinter that has been spiking my mind for half a century. Purr

[arindam]

You should Be a professor or something!!!! :P

[proexcel]

Who is here because of Looking Glass Universe? 😂😂

[timwoodruff]

This is great stuff! I'm getting my 10 year old hooked on physics, and these passionate accounts of the weird whacky world of Lilliputia are super clear and easy to follow. Despite the ultra0complex subject matter, the video does a great job at helping to kick-starting my son's intellectual curiosity!

[RoguishlyHandsome]

Q. Where is the electron?
A. It's in there.

[Lucky]

For anyone wondering, here's an intuitive explanation of what a standard deviation is: Let's say we have the data set (1, 5, 8, 6, 10). The average of those numbers is 30/5=6. Now imagine we plot each of those data values on a number line along with the average value. Each data value will be some distance from the mean. Basically, the standard deviation is the average of those distances. However, to be technical, we actually _square_ each of those distances, average the squared distances, and then take the square root. So the standard deviation is the square root of the average _squared_ distance from the mean. I assume that's why Nick said it's complicated. The reason for this squaring and square rooting is that some distances will be positive and some negative (since some data values will be the left of the average and some to the right) and we need to eliminate this, otherwise the positive and negatives will cancel and we won't get an accurate picture.
So why not just take the absolute value of the distances and average them? Mainly for historical reasons. The "mean deviation" is the average of the absolute value of the distances and it's actually a better measure, but we've been using the standard deviation for so long now that we're kind of stuck with it, similar to how we're stuck with current being the flow of _positive_ charge while electrons have _negative_ charge. 🤷
What does this actually have to do with the uncertainty principle though? Well contrary to popular belief, uncertainty principle doesn't say that we can't measure the position to an arbitrary number of decimal places. You can measure it however accurately your equipment allows. _However, _ if you measure it again, you'll likely get a slightly _different_ value (you _could_ get the same value twice in a row, but if you did, it would simply be due to chance). If you do it several times, you get a data set that will have some standard deviation. Same thing for the momentum. You can measure it arbitrarily precisely any individual time (or as precisely as your equipment allows anyway), but if you do the same measurement several times, you'll have some variation in the data set which can be quantitied by computing the standard deviation. The uncertainty principle says that the product of these two standard deviations will always be greater than or equal to half of Planck's reduced constant.
What Nick meant about randomness, if I understand correctly, (Edit: Nick said he meant something slightly different than what follows, but that the description is accurate to how QM works. See his response below.) is that the variation between any two measurements is entirely random, but we see a low limit to this variation as we repeat the measurements over and over. Similar to how a coin flip is random, and hence we don't know ahead of time what the result will be, but we do know that, if we flip that coin an arbitrarily large number of times the proportion of heads to tails will get arbitrarily close to 1 (that is, there will be an equal number of heads and tails). It's theoretically possible, e.g. to get 1000 heads in a row, but it's _rediculously_ unlikely. Similarly, I think (though I may be wrong) that it's also theoretically possible to have a particular data set of positions and momentums that violate uncertainty principle, purely by chance, especially if the data sets are very small (i.e. only a few measurements have been taken). Is that correct Nick? Similar to how it's theoretically possible for the entropy of the universe to decrease, but it's just incredibly improbable?

[doodle]

wow a very great video it cleared my misconceptions about heisenberg uncertainty principal thanks alot

[andreaferro]

Finally a good explanation. People are giving wild interpretations out there, keep up the good job!

[Gratorist]

I'm bringing a "hi" from Looking Glass Universe. I also want tell you that you have gained a subscriber. You guys are great. Please continue making videos like that. They are being very useful for me as a highschool student who wants to be a physicist since I was a child. You (and other YouTube Education creators) helped me learn and improve my English as well. I'm very grateful to you for inspiring me in science. Making these kind of videos in my language (because there are none or too few) is one of my dreams and you are my idols. I hope you see the value you deserve as soon as possible from community. If this world won't going to an end soon, it's because of you. You are playing a huge role in saving the planet Earth. Just be aware of your importance in the lives of future's scientists. INFINITELY MANY THANKS!

[kovelamanas]

21 September 2014 is the upload date and today is 1st September 2024. 10 years back you had the same energy as you do today, so glad you keep doing what you do. This video is still relevant 😅 for people like me

[kanhunayak]

Sir your explanation and expression is mind blowing

[kronologie]

Yay! I finally got mentioned on a video!!!