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Backreaction: About
Research Fellow at the Frankfurt Institute for Advanced Studies

I am a physicist. More exactly, I am a theoretical physicist. People often wonder what a theoretical physicist does. You might not believe it, but most of the time I think. Sometimes, I scribble funny looking things with a pencil on a notebook. Processes like this usually involve lots of coffee and walking up and down the corridor.

I am working on physics beyond the standard model, phenomenological quantum gravity, and modifications of general relativity. You find more about my research on my homepage. If you want to know more about me, read my blog...
physics  blog 
1 hour ago by alligin
Memristor – The fictional circuit element
The memory resistor abbreviated memristor was a harmless postulate in 1971. In the decade since
2008, a device claiming to be the missing memristor is on the prowl, seeking recognition as a
fundamental circuit element, sometimes wanting electronics textbooks to be rewritten, always
promising remarkable digital, analog and neuromorphic computing possibilities. A systematic
discussion about the fundamental nature of the device is almost universally absent. This report
investigates the assertion that the memristor is a fundamental passive circuit element, from the
perspective that electrical engineering is the science of charge management. With a periodic table
of fundamental elements, we demonstrate that there can only be three fundamental passive circuit
elements. The ideal memristor is shown to be an unphysical active device. A vacancy transport
model further reveals that a physically realizable memristor is a nonlinear composition of two
resistors with active hysteresis.
physics  electronics 
1 hour ago by whitequark
Protecting the power grid: Advanced plasma switch for more efficient transmission -- ScienceDaily
low pressure, high voltage helium gas breakdown behavior for a plasma switch demonstrates 100 KV, might be able to do 300KV
inverter  high  voltage  DC  AC  conversion  plasma  switch  physics  research  technology  electricity  long  distance  transmission  hardware  electronics 
11 hours ago by asteroza
The Blog of Phyz: Be careful with your parabolic mirror

Let's say you you were into making solar ovens. Let's say that you decided a few years ago to make the best solar oven ever. Further, let's stipulate that you saw a nearly meter-diameter Direct TV antenna on the side of the road. An idea happened. You rushed to the local plastics store and bought highly reflective Mylar and glued it to the antenna.

Your solar oven was pretty amazing. While the hot spot wasn't super small, it was hot. Really hot. It can pasteurize a liter of water in 15 minutes.

And now you work at the Exploratorium and you think that you might bring it to work for grins. If you forget it in the back of the your Outback face up on a sunny day near the solstice, well, it can melt the molding in a fairly impressive way. I think I was lucky that my car didn't catch on fire.


You might be wondering how I could make such a mistake? I had a lot to carry into the Exploratorium, and the mirror wouldn't fit on the cart. I planned on coming back in a few minutes, but I got busy doing something else, and it slipped my mind. Coming back in the afternoon, I sat in the driver seat and looked into the rear view mirror.


Uh oh.


If you want to make your own parabolic mirror, you can find some excellent instructions here.

Marc "Zeke" Kossover"
classideas  optic  science  physics  mirrors  exploratorium  2018  humor  disasters  marckossover 
16 hours ago by robertogreco
AP Physics 1: The Exam | AP Central – The College Board
released free response exam questions and answer keys and commentary
ap  physics 
yesterday by menk
Einstein’s general theory of relativity
ONE hundred years ago, on November 25th 1915, Albert Einstein presented his freshly finished general theory of relativity to the Prussian Academy of Sciences. It was the outcome of nearly a decade's dedicated work. He showed that the theory solved a 150-year-old problem: each year, Mercury's closest point of approach to the Sun was moving forward more than it was expected to. In 1916, Einstein predicted that relativistic effects would cause the apparent positions of stars to change during an eclipse, as the sun bent the distant stars' rays. That prediction was proved right in 1919, in a widely publicised expedition
Economist  scientists  physics  theories 
yesterday by thomas.kochi
The Octonion Math That Could Underpin Physics | Quanta Magazine
New findings are fueling an old suspicion that fundamental particles and forces spring from strange eight-part numbers called “octonions.”
articles  math  physics 
2 days ago by gmisra

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