Discover and read the best of Twitter Threads about #Physics

Most recents (24)

Fact: Laser warning systems/active protection is becoming common.

Question: should/can we move away from using laser range finders to generate ballistic solutions?

I have some ideas (below).

Seeking thoughts and or a sanity check from #TankTwitter and or #Physics legends.
We know Laser Range Finders work.

They probably also aren’t obsolete yet. But the days of being able to fire the laser without fear of being detected are potentially coming to a close.

So what other options are there?
Passive Radar (pt 1/3)

These systems will *likely* become more common. Ranging is literally part of the ‘radar’ acronym so that part is solved.

BUT. Passive radar needs the target to be transmitting/something else to transmit to enable the passive radar to receive.
Read 9 tweets
1. “The Death of a Universe” -- Terrific talk this evening by Dr. Katie Mack (@AstroKatie) at @yorkuniversity. Here are a few highlights. This of course is the CMB, the faint microwave “echo” of the big bang. (cont’d) #physics #astronomy #cosmology (@YorkUScience)
@AstroKatie @yorkuniversity @YorkUScience 2. The big bang happened ~13.8 billion years ago. So what lies ahead? Could the universe collapse in a big crunch? Maybe – but as Prof. Mack explained, it's more likely that it will keep expanding. In fact, the universe is currently not only expanding but also accelerating...
@AstroKatie @yorkuniversity @YorkUScience 3. We seem to live in a universe with a non-zero cosmological constant. Right now, the CC appears small – but in the far future, the CC could come to dominate. That won’t end well! At best, in that scenario, we’re going to freeze to death in the dark...
Read 8 tweets
#Disclosure

Jack Sarfatti, world-renowned theoretical physicist, has published a paper theorizing some tech to manipulate gravity, pointing to the construction of an anti-gravity-driven vehicle.

VERY important. This goes in the direction of those recently revealed… (cont. >)
(< follows) … U.S. Navy patents with the same objects.

It looks like a pattern of disclosure.

Thanks to @svalvolatovalvo

#Disclosure #DarkToLight
#UFO #SpaceForce #physics
Read 3 tweets
Controlling the speed and trajectory of evolution with counterdiabatic driving -- a TWEETORIAL 0/n #evolution #mathonco #mathevo #physics #quantumcomputing biorxiv.org/content/10.110…
#Evolution is the most fundamental biological *mechanism - and drives change over time across all the kingdoms of life. We are getting better and better at *predicting* its outcomes, and *harnessing it* (directed evolution), but we haven't previously had any *control* over it 1/n
in work w\ @D4N__ we took advantage of sequential application of selective pressures in a math model to *steer evolution* & relied on taking limits (as time -> infinity) to understand where populations equilibrated in genotype space 2/n journals.plos.org/ploscompbiol/a… @PLOSCompBiol
Read 13 tweets
#GreatAwakening
Do we really know #Science & #Physics as well as we think? People like Dr. John G. #Trump did things had only been done by Nikola Tesla previously. Was #Technology #suppressed since the 19th century?

itgos.info/tv-J0yBou72Lz9…

#Learn... #QAnon #WWG1WGA #8kun #MAGA
Just who was Dr. John G. #Trump, uncle of @POTUS?
Read a profile of him from the #Journal - #Physics Today:

physicstoday.scitation.org/do/10.1063/PT.…

A daughter, Christine, same name as Julian #Assange's mother, has been partially obscured on the web.
#Learn... #QAnon #WWG1WGA #8kun #MAGA #KAG
Here is the #Obituary of Dr. John G. #Trump published by #Physics Today. Positive-ion #Accelerator? Was he the inventor of the #Proton-#Beam used in #Therapy today?
Clearly more than a big #electron #gun in his repertoire.
#DEW?

#Learn... #QAnon #WWG1WGA #8kun #MAGA #KAG
Read 5 tweets
The #phyphox app from @rwth_phyphox gives you direct access to the output of many #sensors in your smartphone. Next time you have a long ✈️flight, quantify turbulence or just check on your phone when the toilet rush is over. (Warning: #scicomm #physics thread ahead!👇) 1/n
Your #phone is full of #sensors (microphone, camera, temperature, GPS, light sensors, magnetometers,…), including air pressure sensors and accelerometers. The pressure at cruising altitude is about 80% of the pressure at sea level. 2/n
That’s why your crisps package expands after take-off and the empty plastic bottle appears auto-crushed after landing. The pressure sensor can be used to estimate elevation when being on earth. But it is so sensitive it feels when airplane toilets are flushed. 3/n
Read 9 tweets
Today's Applied Complexity Symposium begins with a panel on Computation and Complex Economies, feat. Rob Axtell, Joshua Epstein, @C4COMPUTATION, Blake LeBaron, John Miller, & @MelMitchell1

(Follow this thread for live coverage all day...)

#complexsystems #economics
4 Principles of Collective #Computation:

1 Ground truth (objective reality)
2 Effective ground truth (what we agree on, whether or not it is accurate)
3 #Information can be collectively encoded in #networks
4 Outputs are a product of collective dynamics

@C4COMPUTATION right now
"I think #economics really needs to adopt a generative framework with agent-based models of cognitively plausible software people...[and] we don't choose to fear."

- SFI'S Joshua Epstein (@GeorgeMasonU) on modeling emotions at today's ACtioN symposium:
Santafe.edu/action
Read 44 tweets
A running thread of things that @Twitter could do to unlock value for users. Will add to overtime. Please feel free to retweet and reply with your own, most of these below I have just taken and summarized from others. In no particular order. 1/♾ #JustKidding 🤔 or am I?
@Twitter I drafted a tweet on my phone but of course, can't access "draft's" on the desktop. So lets maybe start there. The desktop and @Tweetdeck version should be MORE robust than the mobile app not less. Tweetdeck, for example, has no bookmarks, emoji's, live video, polls, gif's, etc
@Twitter @TweetDeck There are SO MANY great meaningful quotes, threads, replies, and conversations that vanish into the Twitter ether, drowned out by hot takes, snark, and 280 character riffs on what some influencer or politician just did. Find a way to collect and resurface this treasure trove.
Read 80 tweets
1/ The Einstein Energy-Momentum Relation can be straightforwardly turned into the `Klein-Gordon Equation.` ✍🏽

Why’s that important?

The KG-Equation describes spinless particles of any charge! †
2/ If you use natural units (author’s note: ❤️) where ℏ = c = 1, and replace `E` and `p` for their quantum operators... ➡️
3/ You’ll find that the equation reduces to below.

Very serendipitiously, the *d’Alembertian* pops up and we can get a Lorentz-Invariant relativistic equation...
Read 10 tweets
So I'm at a physics conference this week in Lecce, Italy. Some of you wonder how that works given that I'm Deaf and probably don't know Italian Sign Language. Well... 1/N #deaf #interpreters #asl #access #physics
In most cases, I can just request ASL interpreters (yes, American Sign Language interpreters) months in advance. Who pays for it? Good question. That's something I've fortunately been mostly kept out of the loop on, rather than the discussions that happen at the conference! 2/N
But so we get terps set up months in advance, great. They're ASL, because I've barely had the chance to pick up any other language and it's my secondary mode of communication. ASL terps are hard to find in non-English speaking countries... UK too! UK uses BSL primarily. 3/N
Read 18 tweets
Modular, hierarchical, and information-processing:

Right now at SFI, biologists, physicists, neuroscientists, and computer scientists convene for a three-day workshop on Biological #Computation, organized by David Wolpert, @C4COMPUTATION, & @albert_kao.

santafe.edu/news-center/ne…
"A circular definition isn't worthless if the circle is big enough."

- @livcomp of @UNM at today's #biocomp workshop
"#Physics produces order through the minimization of #energy. Adaptive systems produce order through the addition of #information processing."

By why do biological systems compute, whereas classical physical systems apparently don't? @C4COMPUTATION on #function at #biocomp now:
Read 4 tweets
(Thread)

So frustrating to #know the answer to the question of how to formulate that #TheoryOfEverything #scientists say is the biggest unsolved problem in #physics, yet they don't even want to look at it:

tuks.nl/wiki/index.php…

Wave-particle duality a #mystery?
What I've found is rather astonishing:

The #mathematics used by #Maxwell are inconsistent.

He left the magnetic vector potential field [A] undefined and decoupled from the #medium thus creating #MaxwellsHole, which introduced an unwarrented #gauge #freedom in the model...
It is this #gauge #freedom thst led to the #hack known as #Quantum #Madness.

Really, it doesn't take a PhD to figure out that when you believe particles can exist at two places at the same time, you have a mental problem.

steemit.com/funny/@lamare/…
Read 20 tweets
"You don't see radio changing gradually and suddenly become radar. #Darwin's theory doesn't work for #technology, and we have to make a new observation."

- W Brian Arthur at SFI today

#evolution #innovation #invention
"Novel technologies are constructed from existing technologies. These offer themselves as components for the construction of further technologies."

- W Brian Arthur at SFI today

#evolution #innovation #invention #technology #engineering #design
Unlike the two-parent #inheritance typical to (but not ubiquitous among) #complex organisms, #technology inherits features from n parents - a "vast ancestral #network" more like horizontal gene transfer networks in #bacteria.

W Brian Arthur on sumulating #invention on a chip:
Read 18 tweets
"Life did not invent #DNA."

Experimental support for the #hotsprings hypothesis for life's origin: David Deamer of @ucsc on nucleic acid polymerization in the wet-dry cycling of Darwin's "warm little pond," powered by #geothermal. Lab results confirmed in #hydrothermal pools.
From "boring statistical partitioning" in the fission of early protocells to the complex #homeostasis-driven #mitosis of the cells we know - Doron Lancet of @WeizmannInstSci on the gradient between closure of #autocatalysis #networks to complex regulatory mechanisms of #biology.
"Life is an integrated nested network of dynamic #kinetic cycles."

Addy Pross emphasizes the importance of motion to the persistent forms of self-organizing #complexsystems at SFI today
Read 13 tweets
Oh, everyone is going crazy over this Simone Biles tumbling pass. You need some #physics physics to go with it? I got you covered.
1/ Here is the physics of a flip with a twist, it's about angular momentum.

wired.com/2016/08/physic…
2/ Once Simone is in the air, there is no external torque on her so her angular momentum vector must be constant. However, angular momentum and angular velocity DO NOT have to be in the same direction. I know, that's crazy.
Read 16 tweets
1. @ExtinctionR Having looked at some of your policies & grievances my advice to you as a scientist is to do your own research before you jump to conclusions; resist the temptation to go down a EnergyDeadEnd path before really appreciating after years of research life's realities
2. @ExtinctionR scenario has come about through a few scientists exaggerating #ClimateChange which is a natural phenomena that has occurred since Earth had an atmosphere; one of the variables keeping us warm is yes photosynthesising #TraceGas #CO2 as well as water vapour (clouds)
3. @ExtinctionR Earth's CO2 levels vary over time & currently only 0.041% or to make it sound larger 410ppm on average; at levels below 200ppm to 150ppm #photosynthesis ceases & all life relying on plants will die off.
Many other variables are involved with #ClimateChange e.g.Sun
Read 26 tweets
THREAD. In honor of the #Apollo50th anniversary of the moon landing, here is a thread of #physics posts related to space travel. @nasa @esaoperations @ESA_History
1/ I will start with my #physics #estimation - what would be like to ride a bike to the moon? How long would it take? How many sandwiches would you need to eat? More homework included.

wired.com/story/how-long…
2/ Video analysis of the lunar lander launching off the surface of the moon.

wired.com/story/the-phys…
Read 23 tweets
"If I were to write a textbook on #complexity, it would be structured like this..."
- SFI Pres David Krakauer starts off this morning at #CSSS19 #CSSS at @IAIASantaFe

#error #adaptation #universality #coarsegrained #math #theory
"If you talk about #intelligence and #stupidity, you talk about #communication and #policy. That is the natural place to start."

"If you've ever written a Lokta-Volterra #equation, you've drawn a perpetual motion machine. There's no #dissipation."

- SFI President David Krakauer
"Why #God is a bad #theory: it's not because it's not true; it's because it uses an infinite-dimensional process to explain low-dimensional phenomena."

- SFI President David Krakauer at #CSSS19 on #Ockham's Razor & why #Darwin's animal breeding metaphor backfired on #evolution
Read 7 tweets
Hey all, let us have a look at some basics of optics and light science today! #phdchat #Physics #optics
Let us look at some common objects that can be used to understand the nature of light rays. This includes mirrors and lenses. #phdchat #physics #optics
Light travels in a straight line. It is the most fundamental property of light. An obstruction on the path may only change its direction, else it travels in a straight line. #phdchat #optics #light
Read 40 tweets
Yesterday in #physics class, I had to have the discussion about learning vs. telling the answer. I got to use my favorite Karate Kid analogy - "wax on, wax off" to emphasize that sometimes you have to do tedious things to learn.

wired.com/2013/10/tellin…
2/ What happens when you just tell students answers? They have trouble learning complicated concepts. Personally, I love this (older) video showing students trying to explain the phases of the moon and the cause of seasons. It's great.
3/ Another point I mention to students.

If #physics was as easy as me just telling you the answer, I promise you I would do that. I'm not trying to make physics hard just for no reason. Physics is difficult on its own accord (and honestly, that's what makes it awesome).
Read 4 tweets
Here's a perspective on satellite mega-constellations that nobody has mentioned. (We are ALL tired of this, but I think this is interesting).

The real reason SpaceX is putting up a mega-constellation at this time is because of the laws of nature. It was inevitable.../1
2/ Many metrics of information growth show exponential growth. Examples: Moore's law, computer speeds, agents on the internet of things, sensors. See review here: ourworldindata.org/technological-…
3/ Even before humans existed, we see evidence of exponential growth in information. Consider the sizes of genomes. This plot has a slope of 1 on a log-lot chart, so this is exponential growth in DNA complexity. phys.org/news/2013-04-l…
Read 48 tweets
GCSE Physics Paper 1 Key Points thread

#GCSEs2019 #gcsephysics #aqaphysics #physics
Energy stores:
- Energy can be found in many forms. Learn them all:
- Thermal
- Kinetic
- Gravitational Potential
- Elastic Potential
- Chemical
- Magnetic
- Electrostatic
- Nuclear
Energy itself cannot be created or destroyed, only transferred from one form to another. This is much like money, for example if I give you £20, that £20 doesn’t disappear, it is just ‘stored’ by someone else.
Read 31 tweets
Here we go, time for my first thread about a new paper, out today on your local arXiv server! #sciencetwitter #physics #hepph #darkmatter #cosmology #earlyuniverse #plasma arxiv.org/pdf/1902.08623…
1/ Backstory: we've been looking for dark matter for a long, long time and we haven't found it. We're pretty sure it's a particle based on the concordance of evidence from a wide variety of astrophysical environments, but we're not sure what kind of particle it is.
2/ Since we've been looking pretty hard in a couple of particle mass ranges (most notably we've been looking for dark matter particles that are heavier than a proton) and since we haven't found it, folks are starting to wonder if other dark matter masses are possible/interesting
Read 21 tweets
Let’s talk about #lectures in HigherEducation
.@LangOnCourse alerts us to: When should we lecture in class? Excellent examples and analysis of the (positive) role of the lecture from @dgooblar chronicle.com/article/Is-It-#teaching #learning #lecture
.@mariosbham comments on "#Lectures: a much-maligned format which can be truly inspirational" #HigherEducation edudevelopmentbham.wordpress.com/2018/10/26/lec…
Read 48 tweets

Related hashtags

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just three indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3.00/month or $30.00/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!