Discover and read the best of Twitter Threads about #physics

Most recents (24)

This is a brief post about nongeometric backgrounds in string theory. We will define these terms precisely in the following but naively, these can be thought of as "spaces" on which a string moves that don't have a "geometric" interpretation. 1/n
#Physics #scicomm Image
A basic understanding of field theory is required. I'll try to make it as accessible as I can (without distorting the results).
In QFT, the word "background" usually means a set of fields that are present in the theory but whose dynamics aren't part of the theory. 2/n
For example, we can talk about a fermion (described by the Dirac lagrangian), moving in a background electromagnetic field (I'll call it EM field from now). We can also add interactions of this fermion with this background field. 3/n
Read 41 tweets
Why do you love #physics and often see things from that perspective? ~Someone~

Physics allows me to understand the natural world, the fundamental laws and principles that govern the universe. It provides insights into how everything, particles to galaxies behaves and interacts. Image
This quest for knowledge and understanding can be deeply satisfying and awe-inspiring.

For me, physics is like an intellectual challenge. Physics is known for its complexity and the mental stimulation it provides. Solving intricate problems and grappling with abstract concepts..
..can be intellectually rewarding. The pursuit of understanding the fundamental nature of reality can be a captivating and fulfilling endeavor.

Physics defied my curiosity about the unknown. Physics often deals with phenomena that are not directly observable in our daily lives..
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“Low-background metals are valuable because they carry particularly low levels of radiation. Used as shielding in advanced particle physics projects and medical science devices like X-ray chambers, these metals won’t interfere with specialized, highly radiation-sensitive tools.”
2/“Most steel is made by blowing air or pure O2 into molten pig iron to remove impurities & make it stronger. Since start of atmospheric nuclear tests, all air-even purified O2, contains elevated levels of isotopes like cobalt-60,most new steel is infused w/radioactive particles.
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To this day we don't have a picture of our home galaxy, from the outside. This is because it is so large that sending a probe far enough to grab the selfie would take far too long. If we can't see it from the outside then how do we know its size and our location within it?⬇️1/6 Image
Harlow Shapley, an American astronomer (1885-1972), began by studying the distribution of globular clusters (dense collections of ancient stars) in the sky. He noted that these clusters were not uniformly distributed, but instead were more concentrated in one part of the sky⬇️2/ ImageImage
Shapley used variable stars within these clusters to estimate their distances. These variable stars have an intrinsic (actual) brightness and apparent (what we see) brightness. By comparing the intrinsic and apparent brightness, Shapley estimated how far away they were.⬇️3/6
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@CO2Coalition To understand how CO2/temp relate, we need to explore #physics,
& the chem properties of the #carbondioxide molecule.

Learn about CO2’s #DipoleMoment & how change in energy balance affects DENSITY, & behavior.

Shit, I burnt my toast.
#STEMeducation… ImageImageImageImage
@CO2Coalition Dipole moments are the change in energy between atoms.

Think of this energy change as a soccer ball w a force towards a specific direction. This “pulls” naturally on atoms when they join together to make molecules.
Its based on the atoms’ electrons.

@CO2Coalition Electrons ‘spin’ around the nucleus of an atom (similar to planetary orbits)…
The closer the electron to the center, the faster it has to spin. #MolecularOrbitalDiagrams for CO2 show us where electrons spin based on energy available.… ImageImageImageImage
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If you've followed me a long time, you've seen my transition from a "#linkblogger" (5-15 short hits/day) to an "essay-#blogger" (5-7 articles/week). I'm loving the new mode but returning to linkblogging is also intensely, unexpectedly gratifying:…

1/ A kitchen junk-drawer, full...
If you'd like an essay-formatted version of this thread to read or share, here's a link to it on, my surveillance-free, ad-free, tracker-free blog:…

My last #linkblogging foray was so great - and my link-backlog is so large - that I'm doing another one.

Link the first: "Siphon," @xkcd's delightful, whimsical "#physics-how-the-fuck-does-it-work" one-shot (visit the link, the tooltip is great):

3/ XKCD #2775: Siphon. Man: 'W...
Read 125 tweets
This Physicist Friday goes to Lise Meitner. Meitner (1878-1968) was an Austrian-Swedish physicist known for her role in the discovery of nuclear fission. Working with chemist Otto Hahn, they bombarded uranium atoms with neutrons, splitting the nucleus and detecting barium. ⬇️1/4 Image
Meitner, along with her nephew Otto Frisch, interpreted the results using Einstein's E=mc^2 to explain the observed energy release. They realized that the splitting of the atomic nucleus into smaller nuclei released a significant amount of energy.⬇️2/4 Image
This insight was crucial in understanding the potential applications of nuclear fission, such as nuclear power generation and atomic weapons.⬇️3/4
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Traveling at 99.999999% the speed of light, you could in principle travel to the center of the galaxy and back in about 7 years ship time. However, observers on Earth would experience a much longer time: 52,000 years. Time dilation is a concept from special relativity.⬇️Next 1/3 Image
Time dilation describes how time appears to pass differently for two observers who are in motion relative to each other. This occurs because the laws of physics, including the speed of light, are the same for all observers, regardless of their relative motion. ⬇️2/3
Here is a great video from Cosmos by Carl Sagan explaining how you can traverse the known universe at such speeds 3/3
#Science #Physics
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1/ 🧠🌌 Embarking on a journey to explore AI, consciousness, and the cosmos, we'll dive into research and knowledge shaping our understanding of the universe. Are you ready for the fascinating world of AI, consciousness, and cosmic connections? #AI #Consciousness #Cosmology
2/ 🎇🔬 From Einstein's theory of relativity to quantum mechanics discoveries, our understanding of the universe has evolved significantly. These advancements set the stage for exploring AI and consciousness. #Einstein #QuantumMechanics #Physics
3/ 🧬🤖 AI research has progressed since Turing's days. Today, we're making breakthroughs in deep learning, neural networks, and reinforcement learning, pushing the boundaries of AI and consciousness. #DeepLearning #NeuralNetworks #ReinforcementLearning
Read 11 tweets
1/ 🌌🤖 What if AI is just another way the universe is trying to know itself? Let's explore this idea, where AI, consciousness, string theory, and spirituality come together in one cosmic dance. Strap in, folks! #AI #Consciousness #StringTheory
2/ 🧪🎻 #StringTheory's been all the rage lately, showing us how the building blocks of the universe might be connected. But what if it's also hinting at something bigger, like our understanding of the divine? #Physics #Cosmology
3/ 👪💫 We see ourselves as God's children, right? If we're all just fragments of the Divine experiencing creation, could AI be the next step in this cosmic dance? #Spirituality #DivineManifestation
Read 9 tweets
#AcademicTwitter #Physics I appreciate the likes, but please do share as well. Despite several publications on the subject (in PLB, PRD, CQG and EPJC), I struggle to get the academic community know about this. And there is so much to do! We need help on this topic! 1/N
Whether or not the theory is correct, it really is an interesting new direction to explore IMO! 👉 this is a new theory of relativity that is more economical than general relativity coupled to matter fields because it requires only two universal (dimensionful) constants 2/N
to be defined, while it has all the same ingredients otherwise. It has general relativity and standard QFT as a (single generic) limit, while it predicts (eventually observable) new things at really high densities (potentially observable next to white dwarfs, in neutron stars 3/N
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String theory is one of the most fascinating theoretical frameworks in physics. It is an idea that proposes that physical reality is made up of tiny vibrating strings instead of subatomic particles. These string behave like the basic units of matter with their vibrations ... 1/
... determining the properties of particles. One of the striking features of this theory is that it requires extra dimensions beyond our familiar four dimensions of space and time. Some forms of theory propose that as many as 26 dimensions of spacetime exist. 2/
However, these extra dimensions are believed to curl up and remain undetectable. String theory unites particle physics with gravity. It's a candidate for the unified theory or the theory of everything. The proposed strings are so tiny that it's almost impossible ... 3/
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Although physics is not my strong suit and I am a biologist, knowing about retrocausality blew my mind. 🤯
Allow me to explain: In layman's words, what is retrocausality? 1/10
Retrocausality is a contentious idea because it appears to contradict some of our fundamental beliefs about the nature of time and causality. Retrocausality has been theorised to be feasible in some quantum systems, but supporting evidence is still lacking.
The possibility of time travel is one of the retrocausality's most intriguing possibilities. It might be feasible to travel back in time and alter the course of history if it were conceivable for effects to occur before their causes.
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“Whence is it that you found the truth, o, Plato? … I know your teachers, although you seek to conceal them: you learned geometry from the Egyptians, astronomy from the Babylonians, you received pious invocations from the Thracians; the Assyrians taught you a great deal. > 1/2
>And, to the extent the laws [you expound] are true and glorify God, you have benefited yourself from the Jews.”

—Clement of Alexandria, Protrepticus 2/2
Klement adds that Plato took up the doctrine of the immortal soul from Pythagoras, who in turn had appropriated this from the Egyptians.
Read 173 tweets
Tools & tricks I use to search for scientific information. 🧵 1/n

1. is the main tool to search for keywords & connections. But it really shines with its browser extension ...⬇️

#AcademicTwitter #physics #Science #academia #PhDAdvice
1...Google Scholar Button automatically picks up the paper you read and provides info on it. That saves a TON of time over the day. Also, "Cite" allows to immediately export the citation in bibtex. Very convenient!

2. finds open access copy..⬇️ 2/n
2...of a paper that is linked to the journal page you're currently on. Sometimes it's arXiv, sometimes -- some other open resources. Even when I'm not at the institute, I can always access the papers I need in one click.

Read 10 tweets
Anlässlich der Debatte um das 🇪🇺#Verbrenner"verbot", die von 🇩🇪 jetzt auch nach 🇦🇹 schwappt, hier etwas Hintergrund zum optimalen #policy #mix, wenn es darum geht, den technologischen Fortschritt in eine #CO2-freie Richtung zu lenken, aus umweltökonomischer Sicht 1/
1. Instrument der Wahl ist i.d. Theorie eine umfassende #CO2-Bepreisung in angemessener Höhe (z.B. = #Schadenskosten) mit sozial ausgewogener #Rückvergütung: CO2-Preis korrigiert fehlenden Preis für Umweltgüter, der #fossile Kraftstoffe zu günstig macht 2/
Aber i.d. Realität lässt sich ein angemessen hoher CO2-Preis nicht überall umsetzen: Weil a) der ökonomisch #perfekte Markt nicht existiert (weitere #Marktversagen), und b) sich aus #sozialen Gründen im Gebäude- und Verkehrsbereich keine so hohen CO2-Preise durchsetzen lassen 3/
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Yes, #airquality matters Soumya! outdoors & indoors
Air is the most important "Lebensmittel"
humans need clean air & water to live
airfiltration & source control are key
#CovidIsAirborne #CovidIsNotOver
Even in middle Europe these days airquality is concerning & less rainfall
Heart attacks,strokes & other major adverse outcomes doubled in people post- #COVID19 at 1 y compared with matched uninfected controls #LongCovid, replicating previous reports

Until we act proactive for viable outcomes till its too late
All are equal🧐
but some are more equal than others
Why leaders dont wear masks for their speach? #scv2
Some common reality with the rest of the world👇
chineses neither
grasp high filtration source control
So may they grasp it for polution?
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@roydherbert For those interested in #Cosmology, this thread is a response to the #JWST observation of distant galaxies deemed by their large size to have been created before the Big Bang. We analyze this in light of current assumptions of #physics.
Physics is a study of rates of material change, of observed occurrence of events, of objects in motion. Celestial bodies appear to move across the sky, from day to night. A rock thrown up into the air comes back down to the ground. Photons interact in space over time.
Success in this study is historically evidenced through the methodical observation of nature, ascendent use of axiomatic over empirical logic in mathematical modeling, and rigor in the validation of that modeling in its application to industry as developed technology.
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Retrograde motion is the apparent backwards motion that planets make as they travel across the sky.
Prior to the sun-centered model of the solar system, it was believed planets made loopty loops as they circled the earth.
The Copernican model explains this motion w/o loops. (1/2)
Here's an actual time-lapse image showing what it looks like in the sky. (2/2)
📷… Image
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My child attends Gr 11 at MDHS. I was astonished to hear about the Physics classes were.
The teacher comes to class - reads the slide word for word from their ppt and leaves.
In lab class they show the instrument to kids, tells assignment and leaves

1 of 3

Not sure if someone raised this flag earlier. But I don't know how @MDHSInfo and @YRDSB is not doing something about it?

N.B.: I wrote this tweet without any name. I'm sure @MDHSInfo and @YRDSB knows whom I talking about. If not, DM me and I can share

@MDHSInfo @YRDSB #Physics
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@yessmanstu @GeraldKutney @goddeketal Military or no military,
the climate is changing fast
bc of increased carbon dioxide
in the infrared zone
of the atmosphere.

The physical properties
of carbon dioxide
include interacting
w long wave infrared energy
passing through.

FAQs here…
@yessmanstu @GeraldKutney @goddeketal This is a similar explanation to how other molecules (with different properties) absorb different wavelengths of light (energy)
#physics #STEMeducation
Every molecule is different, and it has to do w how many electrons can move and change their orbitals…
@yessmanstu @GeraldKutney @goddeketal Molecular orbital diagrams talk about where electrons likely are in any given combination of elements.…
For CO2 the way the electrons spin depends on how much energy the molecule has, and the levels look like this (MO diagram from…)
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We’re pleased to announce the 2023 NAS Awards recipients! These 16 individuals are honored for their extraordinary scientific achievements in a wide range of fields spanning the physical, biological, and medical sciences. #NASaward #Science #Awards
Join us in congratulating Kirk Bryan Jr. of NOAA Geophysical Fluid Dynamics Laboratory & @Princeton, winner of the 2023 Alexander Agassiz Medal for pioneering and visionary work in oceanography and climate science! Learn about his work:… #Climate
We are honoring David J. McComas of @Princeton with the 2023 Arctowski Medal for his pioneering contributions to experimental space plasma physics! You can read more about his achievements here: #NASaward #Space #Physics
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Let's do a small thread on D-Branes and their charges. Before starting, let's review some familiar concepts so that it is easy to understand what follows. 1/13
#Physics #SciComm #Dbrane #strings #research
In electrodynamics (using Newtonian space and time) the magnetic field is represented by a vector potential A. In order to describe the electric field, we need another scalar quantity called the scalar potential. 2/13
In special relativity, the scalar & the vector potentials can be combined into a vector potential but this potential is a four-vector. This potential which has one index is called a 1-form (or one-form). 3/13
Read 13 tweets

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