Picturing Quantum Processes Updated 2025-07-16
Quantum Field Theory lecture notes by David Tong (2007) Updated 2025-07-16
Number of pages circa 2021: 155.
It should also be noted that those notes are still being updated circa 2020 much after original publication. But without Git to track the LaTeX, it is hard to be sure how much. We'll get there one day, one day.
Some quotes self describing the work:
- Perhaps for this reason Ciro Santilli was not able to get as much as he'd out of those notes either. This is not to say that the notes are bad, just not what Ciro needed, much like P&S:
In this course we will not discuss path integral methods, and focus instead on canonical quantization.
A follow up course in the University of Cambridge seems to be the "Advanced QFT course" (AQFT, Quantum field theory II) by David Skinner: www.damtp.cam.ac.uk/user/dbs26/AQFT.html
Porn image detection Updated 2025-07-16
Everipedia Updated 2025-07-16
History of Bitcoin Updated 2025-07-16
- 2008-08-18: bitcoin.org registered
- 2008-10-31: first public announcement at www.metzdowd.com/pipermail/cryptography/2008-October/014810.html by satoshi@vistomail.com
- 2009-01-03: Genesis block mined
- 2009-01-11: First block not mined by Satoshi
- 2009-01-12: First Bitcoin transactoin
- 2010-05-18: the first of Laszlo's pizzas at about $0.0045 / BTC
- 2010-07-17: first trade happes on Mt. Gox at $0.04951 / BTC: cryptopotato.com/10-years-ago-first-bitcoin-trade-on-mt-gox-for-0-05-per-btc/
- 2014: OP_RETURN goes live
History of Facebook Updated 2025-09-09
Facebook's original niche was college, and that was cool. Then it became this more diluted and irrelevant thing. If only they had added knowledge sharing to it, OurBigBook would have been done then and there.
From 2005: Four young internet entrepreneurs by CBS Sunday Morning
. Source. Machine translation Updated 2025-07-16
Open source machine translation Updated 2025-07-16
Peter Todd Updated 2025-07-16
Schrödinger picture Updated 2025-07-16
To better understand the discussion below, the best thing to do is to read it in parallel with the simplest possible example: Schrödinger picture example: quantum harmonic oscillator.
"Making a measurement" for an observable means applying a self-adjoint operator to the state, and after a measurement is done:Those last two rules are also known as the Born rule.
- the state collapses to an eigenvector of the self adjoint operator
- the result of the measurement is the eigenvalue of the self adjoint operator
- the probability of a given result happening when the spectrum is discrete is proportional to the modulus of the projection on that eigenvector.For continuous spectra such as that of the position operator in most systems, e.g. Schrödinger equation for a free one dimensional particle, the projection on each individual eigenvalue is zero, i.e. the probability of one absolutely exact position is zero. To get a non-zero result, measurement has to be done on a continuous range of eigenvectors (e.g. for position: "is the particle present between x=0 and x=1?"), and you have to integrate the probability over the projection on a continuous range of eigenvalues.In such continuous cases, the probability collapses to an uniform distribution on the range after measurement.The continuous position operator case is well illustrated at: Video "Visualization of Quantum Physics (Quantum Mechanics) by udiprod (2017)"
Self adjoint operators are chosen because they have the following key properties:
- their eigenvalues form an orthonormal basis
- they are diagonalizable
Perhaps the easiest case to understand this for is that of spin, which has only a finite number of eigenvalues. Although it is a shame that fully understanding that requires a relativistic quantum theory such as the Dirac equation.
The next steps are to look at simple 1D bound states such as particle in a box and quantum harmonic oscillator.
This naturally generalizes to Schrödinger equation solution for the hydrogen atom.
The solution to the Schrödinger equation for a free one dimensional particle is a bit harder since the possible energies do not make up a countable set.
This formulation was apparently called more precisely Dirac-von Neumann axioms, but it because so dominant we just call it "the" formulation.
Quantum Field Theory lecture notes by David Tong (2007) mentions that:
if you were to write the wavefunction in quantum field theory, it would be a functional, that is a function of every possible configuration of the field .
Bitcoin developer Updated 2025-12-25
Bitcoin miner inscription Updated 2025-12-25
Brazilian cuisine Updated 2025-07-16
Craig Steven Wright meme Updated 2025-07-16
TODO find the Shroud of Turin one.
- twitter.com/digitalnaut/status/1757464079076098212 vampire killed by cross of cryptographic evidence
DeepFloyd IF Updated 2025-07-16
ffplay Updated 2025-07-16
Scientific Autobiography by Max Planck translated by Frank Gaynor (1949) Updated 2025-07-16
Published as Scientific Autobiography and Other Papers by Max Planck translated by Frank Gaynor (1949) which also contained other papers.
This section refers just to the translation of Scientific autobiography by Max Planck (1948).
Search Wayback Machine by IP Updated 2025-07-16
useEffect Updated 2025-07-16 Cool data embedded in the Bitcoin blockchain Nelson-Mandela.jpg analysis Updated 2025-07-16
The toplevel transaction is 78f0e6de0ce007f4dd4a09085e649d7e354f70bc7da06d697b167f353f115b8e
The full concatenated payload contains the following ASCII characters:
8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba|396*8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba
575061146335bd57f2dc132112152d0eeea44cf187ea6a52ac02435a7e5bea44
674c7cc34ea44bb276c6caf76f2b28fa1597380ab6e6a6906076d8f7229ca5b3
8e2642416ad20924b43f51a633fa1c0a5ba8e4a7b631877db1c64540a42081c9
a3084018096b92af04df57b6116e01ff4b7c7e8bd228235ed49e23f4a2817029
39348722b841afa0c5b67e5af10839afe965ed1b24874e89336bea9fa4ef3091
tomSea & EMBIIOutput 2 is a change, so it contains no data and has been excluded. Change appear to be randomly placed in the list of output of the uploads, but they can be easily removed because they are the only output with a different value.
The newlines shown above are explicitly encoded as CR LF newlines with characters 0d 0a.
396 is the number of payload bytes between 396*8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba and the last txid 39348722b841afa0c5b67e5af10839afe965ed1b24874e89336bea9fa4ef3091, including newlines but exclusding the last line.Now let's inspect the transactions linked to from toplevel.
tx 8881a937a437ff6ce83be3a89d77ea88ee12315f37f7ef0dd3742c30eef92dba contains only payloads without any change. It starts with the following UTF-8 string with CR LF spaces;
"396\“There is nothing like returning to a place
that remains unchanged to find the ways in
which you yourself have altered.”
-Nelson Mandela
Nelson Rolihlahla Mandela was a South African anti-apartheid revolutionary, politician and philanthropist who served as President of South Afrd۽^2c'︨`ica from 1994 to 1999. -Wikipedia
Born: July 18, 1918, Mvezo, South Africa
Died: December 5, 2013This is immediately followed without any separator by a filename, and another size marker:then followed by all the
Nelson-Mandela.jpg?14400/14400 - len(Nelson-Mandela.jpg?) + len(/) JPEG bytes bytes, starting with the two JPEG file signature byte "FF D8".Further toplevel transaction payloads are then simply concatenated with the previous ones, until the last bytes of the image "FF D9" appears at the end of the payload.padded once again by an
00000430 d2 81 de 80 0c 52 f1 40 ea 29 68 03 ff d9 6f 6d |.....R.@.)h...om|
00000440 53 65 61 20 26 20 45 4d 42 49 49 00 |Sea & EMBII.|AtomSea & EMBII string fragment terminated by a NUL character. There are unlisted articles, also show them or only show them.