Cosmic Observer
@cosmicobserver.bsky.social
Just another fool. Also a physicist. I like holograms.
Witten spent a lifetime trying the understand the laws of Nature and now is writing lecture notes about everything he understood. What a man.
Introduction to Black Hole Thermodynamics
These notes aim to provide an introduction to the basics of black hole thermodynamics. After explaining Bekenstein's original proposal that black holes have entropy, we discuss Hawking's discovery of ...
arxiv.org
January 18, 2025 at 10:06 AM
Witten spent a lifetime trying the understand the laws of Nature and now is writing lecture notes about everything he understood. What a man.
Studying the universe is cool until you learn that it contains fermions. Isn’t that the proof that there is a creator who is utterly evil ?
January 17, 2025 at 7:24 PM
Studying the universe is cool until you learn that it contains fermions. Isn’t that the proof that there is a creator who is utterly evil ?
Happy new year stardusts
January 6, 2025 at 8:24 PM
Happy new year stardusts
I would not be happy without David Tong writing amazing lecture notes every year.
See his last banger here : www.damtp.cam.ac.uk/user/tong/ma...
See his last banger here : www.damtp.cam.ac.uk/user/tong/ma...
David Tong: Mathematical Biology
Lecture notes on Mathematical Biology
www.damtp.cam.ac.uk
December 21, 2024 at 5:27 PM
I would not be happy without David Tong writing amazing lecture notes every year.
See his last banger here : www.damtp.cam.ac.uk/user/tong/ma...
See his last banger here : www.damtp.cam.ac.uk/user/tong/ma...
Reposted by Cosmic Observer
I hate it here
December 12, 2024 at 1:03 PM
I hate it here
Teaching Black Hole shadows in GR today. What a great day !
December 9, 2024 at 11:30 AM
Teaching Black Hole shadows in GR today. What a great day !
Who are those people and why do they think that string theory is relevant for their workshop on sustainability and transition to clean energy ?
December 9, 2024 at 7:04 AM
Who are those people and why do they think that string theory is relevant for their workshop on sustainability and transition to clean energy ?
I am annoyed by the fact that many people work on « problems they know they can solve » rather than « problems they are interested in »
Ideally you would like to find the intersection of those sets, but the cruelty of job market makes some scientists shift on the first side, excluding the second…
Ideally you would like to find the intersection of those sets, but the cruelty of job market makes some scientists shift on the first side, excluding the second…
December 6, 2024 at 6:34 PM
I am annoyed by the fact that many people work on « problems they know they can solve » rather than « problems they are interested in »
Ideally you would like to find the intersection of those sets, but the cruelty of job market makes some scientists shift on the first side, excluding the second…
Ideally you would like to find the intersection of those sets, but the cruelty of job market makes some scientists shift on the first side, excluding the second…
Reposted by Cosmic Observer
A new CERN course, currently in its pilot phase, teaches particle physics basics online. The 16-part course is catered to high school students but available to anyone interested in learning about the fundamental questions in particle physics.
www.symmetrymagazine.org/article/new-... 🧪
www.symmetrymagazine.org/article/new-... 🧪
New CERN course teaches particle physics basics online
The 16-part course, currently in its pilot phase, is catered to high school students but available to anyone interested in learning about the fundamental questions in particle physics.
www.symmetrymagazine.org
December 3, 2024 at 8:46 PM
A new CERN course, currently in its pilot phase, teaches particle physics basics online. The 16-part course is catered to high school students but available to anyone interested in learning about the fundamental questions in particle physics.
www.symmetrymagazine.org/article/new-... 🧪
www.symmetrymagazine.org/article/new-... 🧪
Sometimes my students feel bad because they don’t remember some formula.
I cheer them up by confessing that I still have to draw the trigonometric circle to see for which values of the angle the cosine is positive.
I cheer them up by confessing that I still have to draw the trigonometric circle to see for which values of the angle the cosine is positive.
December 5, 2024 at 1:46 PM
Sometimes my students feel bad because they don’t remember some formula.
I cheer them up by confessing that I still have to draw the trigonometric circle to see for which values of the angle the cosine is positive.
I cheer them up by confessing that I still have to draw the trigonometric circle to see for which values of the angle the cosine is positive.
I promise I did not mean any harm
December 5, 2024 at 1:26 PM
I promise I did not mean any harm
Great thread !
In light of recent discourse, I'd like to mount my own defence of string theory (ST) as scientific practice as someone who's not a string theorist
Not being a professional, I might obviously get stuff wrong (so please correct me!) but at least nobody can accuse me of corrupt vested interests 🧵
Not being a professional, I might obviously get stuff wrong (so please correct me!) but at least nobody can accuse me of corrupt vested interests 🧵
December 5, 2024 at 1:13 PM
Great thread !
Reposted by Cosmic Observer
Reposted by Cosmic Observer
Dec 5 - Microcausality in Curved Space-Time
arxiv.org/abs/0709.1483
Causality is a central principle in physics, but how it manifests itself in quantum mechanical observables can be opaque. This paper provides a careful treatment of (some of) what it does and does not imply.
arxiv.org/abs/0709.1483
Causality is a central principle in physics, but how it manifests itself in quantum mechanical observables can be opaque. This paper provides a careful treatment of (some of) what it does and does not imply.
December 5, 2024 at 8:06 AM
Dec 5 - Microcausality in Curved Space-Time
arxiv.org/abs/0709.1483
Causality is a central principle in physics, but how it manifests itself in quantum mechanical observables can be opaque. This paper provides a careful treatment of (some of) what it does and does not imply.
arxiv.org/abs/0709.1483
Causality is a central principle in physics, but how it manifests itself in quantum mechanical observables can be opaque. This paper provides a careful treatment of (some of) what it does and does not imply.
Today I spent several hours trying to derive some equation in a paper. Turns out it was my paper from some years ago. Is this what getting old feels like?
December 4, 2024 at 4:02 PM
Today I spent several hours trying to derive some equation in a paper. Turns out it was my paper from some years ago. Is this what getting old feels like?
when Overleaf is back
December 3, 2024 at 5:09 PM
when Overleaf is back
when overleaf is down
December 3, 2024 at 1:58 PM
when overleaf is down
Reposted by Cosmic Observer
HISTORY OF PHYSICS
The history of Gauge Theories begins with General Relativity.
Hermann Weyl made in 1918 the first attempt to describe gravitation and electromagnetism within a unifying geometrical framework. His starting point was purely mathematical.
1/
The history of Gauge Theories begins with General Relativity.
Hermann Weyl made in 1918 the first attempt to describe gravitation and electromagnetism within a unifying geometrical framework. His starting point was purely mathematical.
1/
December 3, 2024 at 11:36 AM
HISTORY OF PHYSICS
The history of Gauge Theories begins with General Relativity.
Hermann Weyl made in 1918 the first attempt to describe gravitation and electromagnetism within a unifying geometrical framework. His starting point was purely mathematical.
1/
The history of Gauge Theories begins with General Relativity.
Hermann Weyl made in 1918 the first attempt to describe gravitation and electromagnetism within a unifying geometrical framework. His starting point was purely mathematical.
1/
That one postdoc in the collaboration
December 2, 2024 at 6:34 PM
That one postdoc in the collaboration
(Me in the confessional)
I like to open quantum chaos papers just to see their nice figures, knowing I will not understand a single equation.
I like to open quantum chaos papers just to see their nice figures, knowing I will not understand a single equation.
December 2, 2024 at 4:52 PM
(Me in the confessional)
I like to open quantum chaos papers just to see their nice figures, knowing I will not understand a single equation.
I like to open quantum chaos papers just to see their nice figures, knowing I will not understand a single equation.
Cool paper :
There are matrix integrals where saddle points correspond to geometries satisfying the Einstein GR equations.
The saddle points equations are formulated in terms of a gas of interacting particles.
Somehow these particles "build spacetime". Maybe we live in the matrix after all.
There are matrix integrals where saddle points correspond to geometries satisfying the Einstein GR equations.
The saddle points equations are formulated in terms of a gas of interacting particles.
Somehow these particles "build spacetime". Maybe we live in the matrix after all.
Einstein gravity from a matrix integral -- Part II
Using supersymmetric localization, we compute the partition function and some protected correlators of the polarized IKKT matrix model. Surprisingly, we find that the original IKKT model is different ...
arxiv.org
December 2, 2024 at 12:40 PM
Cool paper :
There are matrix integrals where saddle points correspond to geometries satisfying the Einstein GR equations.
The saddle points equations are formulated in terms of a gas of interacting particles.
Somehow these particles "build spacetime". Maybe we live in the matrix after all.
There are matrix integrals where saddle points correspond to geometries satisfying the Einstein GR equations.
The saddle points equations are formulated in terms of a gas of interacting particles.
Somehow these particles "build spacetime". Maybe we live in the matrix after all.
Could we just be happy about the fact that one can canonically quantize a 1D object moving through spacetime
And one finds a massless spin 2 state in the spectrum
And the operator that creates that state corresponds EXACTLY to a fluctuation of the spacetime metric
Quantum dynamical gravity !!
And one finds a massless spin 2 state in the spectrum
And the operator that creates that state corresponds EXACTLY to a fluctuation of the spacetime metric
Quantum dynamical gravity !!
December 1, 2024 at 5:05 PM
Could we just be happy about the fact that one can canonically quantize a 1D object moving through spacetime
And one finds a massless spin 2 state in the spectrum
And the operator that creates that state corresponds EXACTLY to a fluctuation of the spacetime metric
Quantum dynamical gravity !!
And one finds a massless spin 2 state in the spectrum
And the operator that creates that state corresponds EXACTLY to a fluctuation of the spacetime metric
Quantum dynamical gravity !!
This collaborator who is overly busy
November 30, 2024 at 10:07 AM
This collaborator who is overly busy