Monday, October 10, 2016

Physics In "Doctor Strange"

Adam Frank, a physics professor at the University of Rochester, talks about being a consultant for the upcoming Marvel movie "Doctor Strange".

I suppose the biggest and most dicey issue that he had to deal with is how to deal with "consciousness", because as he stated, we actually do not have a concrete description of it. This is where many movies, and many pseudoscientists, allow themselves wide liberty at abusing the concept.

I will see "Doctor Strange" when it comes up, and I'll see for myself how the movie deals with this.


Thursday, October 06, 2016

Detecting Particles By Seeing Them Move Faster Than Light

No, this is not a topic on superluminal particles. Rather, it is an article on how we detect particles by using faster-than-light particles in a medium, i.e. by observing the Cherenkov radiation.

But photons only move at that perfect speed-of-light (c) if they’re in a vacuum, or the complete emptiness of space. Put one in a medium — like water, glass, or acrylic — and they’ll move at the speed of light in that medium, which is less than 299,792,458 m/s by quite a bit. Even air, which is pretty close to a vacuum, slows down light by 0.03% from its maximum possible speed. This isn’t that much, but it does mean something remarkable: these high-energy particles that come into the atmosphere are now moving faster than light in that medium, which means they emit a special type of radiation known as Cherenkov radiation.

The article listed several detectors that make use of this effect, but it is missing A LOT more. Practically all neutrino detectors use this principle (i.e. SuperKamiokande). Auger Observatory also looks out for these Cherenkov radiation.

But the part that I think should fascinate the layperson is when the speed of various things are listed, up to the most accurate decimal places:

It’s true that Einstein had it right all the way back in 1905: there is a maximum speed to anything in the Universe, and that speed is the speed of light in a vacuum (c), 299,792,458 m/s. Cosmic ray particles can go faster than anything on Earth, even at the LHC. Here’s a fun list of how fast various particles can go at a variety of accelerators, and from space:
  • 980 GeV: fastest Fermilab proton, 0.99999954c, 299,792,320 m/s.
  • 6.5 TeV: fastest LHC proton, 0.9999999896c, 299,792,455 m/s.
  • 104.5 GeV: fastest LEP electron (fastest accelerator particle ever), 0.999999999988c, 299,792,457.9964 m/s.
  • 5 x 10^19 GeV: highest energy cosmic rays ever (assumed to be protons), 0.99999999999999999999973c, 299,792,457.999999999999918 m/s.
 Just notice how much energy we had to put in to, say, the proton in going from 0.99999954c to 0.9999999896c. And then, notice how high of an energy cosmic rays have when compared to the LHC. If these types of collisional energy can create "catastrophic blackholes", we would be gone by now, thankyouverymuch!


Tuesday, October 04, 2016

Nobel Prize Goes Vintage This Year

Wow. While deserving, I didn't see this one coming because I thought the ship had left the harbor a long time ago.

The Nobel committee decided to dig deep and went back in time to award the prize to 3 condensed matter physicists for work done in the early 70's. This year's prize goes to David Thouless, Duncan Haldane, and Michael Kosterlitz.

In the early 1970s, Kosterlitz and Thouless overturned the then-current theory that superconductivity could not occur in extremely thin layers.
"They demonstrated that superconductivity could occur at low temperatures and also explained the mechanism -- phase transition -- that makes superconductivity disappear at higher temperatures," explained the Foundation. 
Around a decade later, Haldane also studied matter that forms threads so thin they can be considered one-dimensional.

Any condensed matter student would have heard of the Haldane chain, and the Kosterlitz-Thouless transition. These are textbooks concepts that are now widely used and accepted. It certainly took then long enough to decide to award the prize to these people.

I wonder if the Nobel committee is delaying the prize for the gravitational wave for another year to make sure it is verified, and to narrow down the people they award it to. Just like the award for the Higgs, there are several people, more than 3, that can easily deserve the prize.