IQIS Lecture 1.1 - Probability amplitudes

[@admiralhyperspace0015]

Thank You, Thank You, Thank You. I watched your Royal Institute lecture and never saw someone explaining complex probability like you did. In Quantum Mechanics. I was always baffled where those probability axioms came from and you were the first one to address them. I wanted to.learn from you. And prayed you might have online lectures. This is jack pot.

[@shukailu6731]

Thank you Professor Ekert for this series. I read your paper on "Quantum cryptography based on Bell's theorem" and I would definitely love if you made more of these!

[@ArturEkert]

Will add few more lectures on quantum cryptography after I finish the basic course. Thanks for the suggestion.

[@asadraza3579]

Your lecture is great source of information I am doing Ph.D. in Quantum Cryptography this lectures help me alot. Thanks 👍

[@ulrichfekl5527]

This is an outstanding lecture series! Thanks, Dr. Ekert! Explanations are lucid, and the presentation is didactically brilliant (the light board works well, too). I learned a lot by watching all of it, and I put my comment on the first lecture (as opposed to the last), so more people see it. ((Here is the tiniest quibble, and I'm putting it into two brackets, because it is probably not so important at this stage: instead of saying "now in this ugly language of 'wave function collapse', which I really don't like, this is what happens..." [I'm paraphrasing here]: I do wonder if there could be further didactic advantage from introducing the multiverse and introducing it early))

[@chriswilloughby48]

Holy moly, I really enjoyed that.

[@christineliang4670]

Thank you so much! Professor Ekert! I like this topic.

[@ArturEkert]

So glad!

[@alexbos8211]

Why is the absolute value notation required when moving from probability amplitudes to probability - does the squaring not already account for negative values?

[@truebaran]

It does for real numbers but for complex taking squares is not enough for example i^2=-1 but the square may be even not real

[@alexbos8211]

@@truebaran Ah wow thanks a lot!

[@sophiac.700]

for the different routes of the same starting and ending states evolution, the \alpha_1 + \alpha_2 description is a bit less intuitive than guessing |\alpha_1|^2 + |\alpha_2|^2, could you explain a little more on this part? why does it require to be the same of the probability amplitudes rather than the sum of probability? thanks in advance

[@sophiac.700]

a counterexample in my mind is that if \alpha_1 = \alpha_2 = 1/\sqrt{2}, then \alpha_1 + \alpha_2 = \sqrt{2}. this is greater than 1, the probably |\alpha_1 + \alpha_2|^2 is also greater than 1. this seems wired

[@jakubczerski4265]

cholera, żałuję, że tak późno tutaj trafiłem.

[@jacobvandijk6525]

Would have been nice to hear where these prob.ampl.s come from?