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Roger's Equations

This blog is all about science and technology (with occasional math thrown in for fun). The goal of this blog is to try and pass on the sense of excitement and wonder I feel when I read about these topics. I hope you enjoy the posts.

Weyl Fermions

Posted July 27, 2015 9:37 AM by Roger Pink

I came across this article and thought I would pass it along. It's a great breakthrough, with powerful implications for computing.

Weyl fermions are spotted at long last

Evidence for the existence of particles called Weyl fermions in two very different solid materials has been found by three independent groups of physicists. First predicted in 1929, Weyl fermions also have unique properties that could make them useful for creating high-speed electronic circuits and quantum computers. In 1928 Paul Dirac derived his eponymous equation, which describes the physics of spin-1/2 fundamental particles called fermions. For particles with charge and mass, he found that the Dirac equation predicts the existence of the electron and its antiparticle the positron, the latter being discovered in 1932.

However, there are other solutions of the Dirac equation that suggest the existence of more exotic particles than the familiar electron. In 1937 Ettore Majorana discovered a solution of the equation that describes a neutral particle that is its own antiparticle: the Majorana fermion. Although there is no evidence that Majorana fermions exist as fundamental particles, Majorana-like collective excitations (or quasiparticles) have been detected in condensed-matter systems. Another solution of the Dirac equation - this time for massless particles - was derived in 1929 by the German mathematician Hermann Weyl. For some time it was thought that neutrinos were Weyl fermions, but now it looks almost certain that neutrinos have mass and are therefore not Weyl particles.

Now, a group headed by Zahid Hasan at Princeton University has found evidence that Weyl fermions exist as quasiparticles - collective excitations of electrons - in the semimetal tanatalum arsenide (TaAs). In 2014 Hasan and colleagues published calculations that suggested that TaAs is "Weyl semimetal". This means that TaAs should have Weyl fermions in its bulk and a distinct feature on its surface called a "Fermi arc". Using a standard technique called angle-resolved photoemission spectroscopy (ARPES), the team found evidence of a Fermi arc. The team then used a technique called soft X-ray ARPES to probe deeper into the bulk of the material, where it found further evidence for Weyl fermions in the form of "Weyl cones" and "Weyl nodes" - both of which were in agreement with the researchers previous calculations.

Article Continues Here

2 comments; last comment on 07/27/2015
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Pluto Flyby - New Horizons Just Finished Closest Approach

Posted July 14, 2015 9:17 AM by Roger Pink

Leaving Pluto - An Hour After Closest Encounter

After 3462 days in space, New Horizons has finally reached its closest approach to Pluto! Roughly an hour ago, it got within 7,800 miles of Pluto. Over the past few days and in the next few days, New Horizon will be working nonstop to gather as much data and images as it can.

In about 12 hours it will send that information home (or its signal will arrive home, I'm unclear on this detail). Soon after that we will get our first glimpse of Pluto in HD. To give you an idea of how furiously New Horizons is working right now, here is a sample of its work since midnight (these updates were provided by NASA):

00:06:21-New Horizons is taking 2 images of Pluto with LORRI from 383562.38 km away at est. resolution 1.9 km/pix. New Horizons is 31.8 AU from Earth.

00:07:10-New Horizons is taking 2 images of Pluto with LORRI from 382887.65 km away at est. resolution 1.9 km/pix.

00:07:59-New Horizons is taking 2 images of Pluto with LORRI from 382212.93 km away at est. resolution 1.9 km/pix. New Horizons is 31.8 AU from Earth.

00:08:48-New Horizons is taking 2 images of Pluto with LORRI from 381538.21 km away at est. resolution 1.9 km/pix.

00:14:17-New Horizons is taking an image of Pluto with MVIC Color from 377007.99 km away at est. resolution 7.5 km/pix. New Horizons is 31.8 AU from Earth.

00:19:07-New Horizons is taking an image of Pluto with MVIC Color from 373014.86 km away at est. resolution 7.4 km/pix. New Horizons is 31.8 AU from Earth.

00:22:46-New Horizons is taking 2 images of Kerberos with LORRI from ~360000 km away. New Horizons is 31.8 AU from Earth.

00:23:26-New Horizons is taking a spectrum of Kerberos with LEISA from ~350000 km away. New Horizons is 31.8 AU from Earth.

00:36:05-New Horizons is taking an image of Nix with MVIC Color from 328310.54 km away at est. resolution 6.5 km/pix. New Horizons is 31.8 AU from Earth.

00:39:16-New Horizons is taking 3 images of Nix with LORRI from 325691.61 km away at est. resolution 1.6 km/pix.

00:42:10-New Horizons is taking a spectrum of Hydra with LEISA from 373727.08 km away at est. resolution 23 km/pix. New Horizons is 31.8 AU from Earth.

00:50:00-7 hours to #PlutoFlyby Closest Approach. New Horizons is 347,501 km from Pluto!

00:53:26-New Horizons is taking an image of Hydra with MVIC Color from 364560.23 km away at est. resolution 7.2 km/pix.

00:56:13-New Horizons is taking 3 images of Hydra with LORRI from 362297.29 km away at est. resolution 1.8 km/pix. New Horizons is 31.8 AU from Earth.

00:57:03-New Horizons is taking 3 images of Hydra with LORRI from 361619.90 km away at est. resolution 1.8 km/pix.

00:57:53-New Horizons is taking 3 images of Hydra with LORRI from 360942.56 km away at est. resolution 1.8 km/pix. New Horizons is 31.8 AU from Earth.

00:58:43-New Horizons is taking 3 images of Hydra with LORRI from 360265.29 km away at est. resolution 1.8 km/pix.

01:02:52-New Horizons is taking 18 spectra of Pluto with Alice from 336873.78 km away. New Horizons is 31.8 AU from Earth.

01:20:00-New Horizons soon to be communicating with Goldstone 34 m (DSS-26) http://eyes.nasa.gov/dsn/dsn.html

01:35:00-New Horizons soon to be communicating with Goldstone 34 m (DSS-25) http://eyes.nasa.gov/dsn/dsn.html

01:49:41-New Horizons is taking 2 images of Charon with LORRI from 312464.78 km away at est. resolution 1.5 km/pix. New Horizons is 31.8 AU from Earth.

01:50:00-6 hours to #PlutoFlyby Closest Approach. New Horizons is 297,946 km from Pluto!

01:50:29-New Horizons is taking 2 images of Charon with LORRI from 311803.64 km away at est. resolution 1.5 km/pix.

01:50:00-New Horizons soon to be communicating with Goldstone 34 m (DSS-24) http://eyes.nasa.gov/dsn/dsn.html

01:51:17-New Horizons is taking 2 images of Charon with LORRI from 311142.51 km away at est. resolution 1.5 km/pix. New Horizons is 31.8 AU from Earth.

01:52:05-New Horizons is taking 2 images of Charon with LORRI from 310481.39 km away at est. resolution 1.5 km/pix.

01:57:59-New Horizons is taking radio uplink data with REX. New Horizons is 31.8 AU from Earth.

01:58:14-New Horizons is taking radio uplink data with REX. New Horizons is 31.8 AU from Earth.

02:05:00-New Horizons soon to be communicating with Goldstone 70 m (DSS-14) http://eyes.nasa.gov/dsn/dsn.html

02:23:04-New Horizons is taking radio reflectance data of Pluto with REX from 270644.06 km away. New Horizons is 31.8 AU from Earth.

02:23:19-New Horizons is taking radio reflectance data of Pluto with REX from 270437.66 km away. New Horizons is 31.8 AU from Earth.

02:28:14-New Horizons is taking radio reflectance data of Pluto with REX from 266378.70 km away. New Horizons is 31.8 AU from Earth.

02:28:30-New Horizons is taking radio reflectance data of Pluto with REX from 266158.55 km away. New Horizons is 31.8 AU from Earth.

02:35:46-New Horizons is taking radio reflectance data of Charon with REX from 274398.00 km away. New Horizons is 31.8 AU from Earth.

02:36:02-New Horizons is taking radio reflectance data of Charon with REX from 274177.85 km away. New Horizons is 31.8 AU from Earth.

02:44:14-New Horizons is taking radio reflectance data of Charon with REX from 267408.95 km away. New Horizons is 31.8 AU from Earth.

02:44:29-New Horizons is taking radio reflectance data of Charon with REX from 267202.61 km away. New Horizons is 31.8 AU from Earth.

02:49:08-New Horizons is taking an image of Pluto with MVIC Color from 249126.75 km away at est. resolution 4.9 km/pix. New Horizons is 31.8 AU from Earth.

02:50:00-5 hours to #PlutoFlyby Closest Approach. New Horizons is 248,411 km from Pluto!

02:53:50-New Horizons is taking 10 spectra of Nix with Alice from 215128.06 km away. New Horizons is 31.8 AU from Earth.

03:15:00-New Horizons soon to be communicating with Canberra 70 m (DSS-43) http://eyes.nasa.gov/dsn/dsn.html

03:15:00-New Horizons soon to be communicating with Canberra 34 m (DSS-45) http://eyes.nasa.gov/dsn/dsn.html

03:16:00-New Horizons soon to be communicating with Canberra 34 m (DSS-34) http://eyes.nasa.gov/dsn/dsn.html

03:22:05-New Horizons is taking a spectrum of Hydra with Alice from 245106.59 km away. New Horizons is 31.8 AU from Earth.

03:22:47-New Horizons is taking a spectrum of Hydra with LEISA from 244554.11 km away at est. resolution 15 km/pix. New Horizons is 31.8 AU from Earth.

03:36:05-New Horizons is taking an image of Hydra with MVIC Color from 234084.66 km away at est. resolution 4.6 km/pix.

03:39:28-New Horizons is taking 2 images of Hydra with LORRI from 231430.29 km away at est. resolution 1.1 km/pix. New Horizons is 31.8 AU from Earth.

03:40:17-New Horizons is taking 2 images of Hydra with LORRI from 230790.15 km away at est. resolution 1.1 km/pix.

03:41:06-New Horizons is taking 2 images of Hydra with LORRI from 230150.24 km away at est. resolution 1.1 km/pix. New Horizons is 31.8 AU from Earth.

03:41:55-New Horizons is taking 2 images of Hydra with LORRI from 229510.56 km away at est. resolution 1.1 km/pix.

03:42:44-New Horizons is taking 2 images of Hydra with LORRI from 228871.11 km away at est. resolution 1.1 km/pix. New Horizons is 31.8 AU from Earth.

03:43:33-New Horizons is taking 2 images of Hydra with LORRI from 228231.89 km away at est. resolution 1.1 km/pix.

03:48:56-New Horizons is taking a spectrum of Pluto with LEISA from 199789.59 km away at est. resolution 12 km/pix. New Horizons is 31.8 AU from Earth.

03:50:00-4 hours to #PlutoFlyby Closest Approach. New Horizons is 198,910 km from Pluto!

03:52:41-New Horizons is taking a spectrum of Nix with LEISA from 166944.23 km away at est. resolution 10. km/pix. New Horizons is 31.8 AU from Earth.

04:00:00-New Horizons' track ending with Goldstone 34 m (DSS-26)

04:02:39-New Horizons is taking an image of Nix with MVIC Color from 158804.46 km away at est. resolution 3.1 km/pix.

04:05:11-New Horizons is taking 2 images of Nix with LORRI from 156736.78 km away at est. resolution 0.78 km/pix. New Horizons is 31.8 AU from Earth.

04:05:59-New Horizons is taking 2 images of Nix with LORRI from 156083.94 km away at est. resolution 0.77 km/pix.

04:06:47-New Horizons is taking 2 images of Nix with LORRI from 155431.16 km away at est. resolution 0.77 km/pix. New Horizons is 31.8 AU from Earth.

04:11:06-New Horizons is taking a spectrum of Pluto with LEISA from 181514.76 km away at est. resolution 11 km/pix.

04:13:51-New Horizons is taking 2 images of Pluto with LORRI from 179248.28 km away at est. resolution 0.89 km/pix.

04:14:39-New Horizons is taking 2 images of Pluto with LORRI from 178588.97 km away at est. resolution 0.89 km/pix. New Horizons is 31.8 AU from Earth.

04:15:27-New Horizons is taking 2 images of Pluto with LORRI from 177929.68 km away at est. resolution 0.88 km/pix.

04:16:15-New Horizons is taking 2 images of Pluto with LORRI from 177270.40 km away at est. resolution 0.88 km/pix. New Horizons is 31.8 AU from Earth.

04:17:03-New Horizons is taking 2 images of Pluto with LORRI from 176611.14 km away at est. resolution 0.88 km/pix.

04:17:51-New Horizons is taking 2 images of Pluto with LORRI from 175951.89 km away at est. resolution 0.87 km/pix. New Horizons is 31.8 AU from Earth.

04:18:39-New Horizons is taking 2 images of Pluto with LORRI from 175292.66 km away at est. resolution 0.87 km/pix.

04:19:27-New Horizons is taking 2 images of Pluto with LORRI from 174633.44 km away at est. resolution 0.87 km/pix. New Horizons is 31.8 AU from Earth.

04:20:15-New Horizons is taking 2 images of Pluto with LORRI from 173974.24 km away at est. resolution 0.86 km/pix.

04:21:03-New Horizons is taking 2 images of Pluto with LORRI from 173315.06 km away at est. resolution 0.86 km/pix. New Horizons is 31.8 AU from Earth.

04:21:51-New Horizons is taking 2 images of Pluto with LORRI from 172655.89 km away at est. resolution 0.86 km/pix.

04:22:39-New Horizons is taking 2 images of Pluto with LORRI from 171996.74 km away at est. resolution 0.85 km/pix. New Horizons is 31.8 AU from Earth.

04:23:27-New Horizons is taking 2 images of Pluto with LORRI from 171337.60 km away at est. resolution 0.85 km/pix.

04:24:15-New Horizons is taking 2 images of Pluto with LORRI from 170678.48 km away at est. resolution 0.85 km/pix. New Horizons is 31.8 AU from Earth.

04:25:03-New Horizons is taking 2 images of Pluto with LORRI from 170019.38 km away at est. resolution 0.84 km/pix.

04:25:51-New Horizons is taking 2 images of Pluto with LORRI from 169360.30 km away at est. resolution 0.84 km/pix. New Horizons is 31.8 AU from Earth.

04:26:39-New Horizons is taking 2 images of Pluto with LORRI from 168701.23 km away at est. resolution 0.84 km/pix.

04:27:27-New Horizons is taking 2 images of Pluto with LORRI from 168042.18 km away at est. resolution 0.83 km/pix. New Horizons is 31.8 AU from Earth.

04:28:15-New Horizons is taking 2 images of Pluto with LORRI from 167383.15 km away at est. resolution 0.83 km/pix.

04:29:03-New Horizons is taking 2 images of Pluto with LORRI from 166724.13 km away at est. resolution 0.83 km/pix. New Horizons is 31.8 AU from Earth.

04:29:50-New Horizons is taking a spectrum of Pluto with Alice from 166078.87 km away. New Horizons is 31.8 AU from Earth.

04:32:31-New Horizons is taking 2 images of Charon with LORRI from 178279.45 km away at est. resolution 0.88 km/pix. New Horizons is 31.8 AU from Earth.

04:33:19-New Horizons is taking 2 images of Charon with LORRI from 177623.82 km away at est. resolution 0.88 km/pix.

04:34:07-New Horizons is taking 2 images of Charon with LORRI from 176968.26 km away at est. resolution 0.88 km/pix. New Horizons is 31.8 AU from Earth.

04:34:55-New Horizons is taking 2 images of Charon with LORRI from 176312.76 km away at est. resolution 0.87 km/pix.

04:35:43-New Horizons is taking 2 images of Charon with LORRI from 175657.33 km away at est. resolution 0.87 km/pix. New Horizons is 31.8 AU from Earth.

04:36:31-New Horizons is taking 2 images of Charon with LORRI from 175001.97 km away at est. resolution 0.87 km/pix.

04:37:19-New Horizons is taking 2 images of Charon with LORRI from 174346.67 km away at est. resolution 0.86 km/pix. New Horizons is 31.8 AU from Earth.

04:38:07-New Horizons is taking 2 images of Charon with LORRI from 173691.45 km away at est. resolution 0.86 km/pix.

04:39:07-New Horizons is taking a spectrum of Charon with Alice from 172872.51 km away. New Horizons is 31.8 AU from Earth.

04:41:55-New Horizons is taking a spectrum of Pluto with Alice from 156127.63 km away. New Horizons is 31.8 AU from Earth.

04:42:22-New Horizons is taking a spectrum of Pluto with LEISA from 155757.12 km away at est. resolution 9.7 km/pix.

04:50:00-3 hours to #PlutoFlyby Closest Approach. New Horizons is 149,473 km from Pluto!

04:55:36-New Horizons is taking a spectrum of Pluto with Alice from 144864.84 km away. New Horizons is 31.8 AU from Earth.

04:55:59-New Horizons is taking a spectrum of Pluto with LEISA from 144549.43 km away at est. resolution 9.0 km/pix. New Horizons is 31.8 AU from Earth.

05:11:51-New Horizons is taking an image of Nix with MVIC Color from 102629.49 km away at est. resolution 2.0 km/pix.

05:14:42-New Horizons is taking 6 images of Charon with LORRI from 143819.25 km away at est. resolution 0.71 km/pix.

05:15:16-New Horizons is taking a spectrum of Charon with LEISA from 143358.25 km away at est. resolution 8.9 km/pix. New Horizons is 31.8 AU from Earth.

05:25:09-New Horizons is taking a spectrum of Charon with Alice from 135328.69 km away. New Horizons is 31.8 AU from Earth.

05:26:15-New Horizons is taking a spectrum of Pluto with Alice from 119669.38 km away. New Horizons is 31.8 AU from Earth.

05:26:42-New Horizons is taking a spectrum of Pluto with LEISA from 119299.90 km away at est. resolution 7.4 km/pix. New Horizons is 31.8 AU from Earth.

05:40:45-New Horizons is taking a spectrum of Pluto with Alice from 107772.52 km away. New Horizons is 31.8 AU from Earth.

05:41:09-New Horizons is taking a spectrum of Pluto with LEISA from 107444.60 km away at est. resolution 6.7 km/pix. New Horizons is 31.8 AU from Earth.

05:50:00-2 hours to #PlutoFlyby Closest Approach. New Horizons is 100,194 km from Pluto!

05:57:13-New Horizons is taking 13 images of Nix with LORRI from 66612.933 km away at est. resolution 0.33 km/pix. New Horizons is 31.8 AU from Earth.

05:58:10-New Horizons is taking a spectrum of Nix with LEISA from 65875.190 km away at est. resolution 4.1 km/pix.

06:10:15-New Horizons is taking 15 images of Pluto with LORRI from 83646.234 km away at est. resolution 0.41 km/pix. New Horizons is 31.8 AU from Earth.

06:18:40-New Horizons is taking an image of Pluto with MVIC Pan Frame from 76792.463 km away at est. resolution 1.5 km/pix. New Horizons is 31.8 AU from Earth.

06:19:28-New Horizons is taking an image of Pluto with MVIC Pan Frame from 76141.986 km away at est. resolution 1.5 km/pix.

06:20:16-New Horizons is taking an image of Pluto with MVIC Pan Frame from 75491.696 km away at est. resolution 1.5 km/pix. New Horizons is 31.8 AU from Earth.

06:21:04-New Horizons is taking an image of Pluto with MVIC Pan Frame from 74841.597 km away at est. resolution 1.5 km/pix.

06:21:52-New Horizons is taking an image of Pluto with MVIC Pan Frame from 74191.695 km away at est. resolution 1.5 km/pix. New Horizons is 31.8 AU from Earth.

06:23:47-New Horizons is taking 12 images of Charon with LORRI from 88389.251 km away at est. resolution 0.44 km/pix.

06:24:37-New Horizons is taking a spectrum of Charon with LEISA from 87736.235 km away at est. resolution 5.4 km/pix. New Horizons is 31.8 AU from Earth.

06:38:15-New Horizons is taking a spectrum of Charon with Alice from 77151.533 km away. New Horizons is 31.8 AU from Earth.

06:40:11-New Horizons is taking an image of Charon with MVIC Color from 75668.123 km away at est. resolution 1.5 km/pix.

06:40:00-New Horizons' track ending with Goldstone 34 m (DSS-25)06:40:00New Horizons' track ending with Goldstone 34 m (DSS-24)

06:40:00-New Horizons' track ending with Goldstone 70 m (DSS-14)06:40:00New Horizons' track ending with Canberra 70 m (DSS-43)

06:40:00-New Horizons' track ending with Canberra 34 m (DSS-45)06:40:00New Horizons' track ending with Canberra 34 m (DSS-34)

06:43:00-New Horizons is taking 23 images of Pluto with LORRI from 56315.602 km away at est. resolution 0.28 km/pix.

06:45:03-New Horizons is taking a spectrum of Pluto with LEISA from 55474.326 km away at est. resolution 3.4 km/pix. New Horizons is 31.8 AU from Earth.

06:50:00-1 hour to #PlutoFlyby Closest Approach. New Horizons is 51,520 km from Pluto!

07:00:00-50 minutes to #PlutoFlyby Closest Approach. New Horizons is 43,609 km from Pluto!

07:05:05-New Horizons is taking a spectrum of Pluto with Alice from 39643.266 km away. New Horizons is 31.8 AU from Earth.

07:05:18-New Horizons is taking a spectrum of Pluto with Alice from 39475.307 km away. New Horizons is 31.8 AU from Earth.

07:05:25-New Horizons is taking an image of Pluto with MVIC Color from 39384.908 km away at est. resolution 0.78 km/pix.

07:10:00-40 minutes to #PlutoFlyby Closest Approach. New Horizons is 35,858 km from Pluto!

07:14:32-New Horizons is taking an image of Nix with MVIC from 22235.744 km away at est. resolution 0.44 km/pix.

07:17:48-New Horizons is taking 70 images of Pluto with LORRI from 30003.890 km away at est. resolution 0.15 km/pix. New Horizons is 31.8 AU from Earth.

07:20:00-30 minutes to #PlutoFlyby Closest Approach. New Horizons is 28,399 km from Pluto!

07:20:16-New Horizons is taking an image of Pluto with MVIC from 28206.280 km away at est. resolution 0.56 km/pix.

07:26:28-New Horizons is taking 130 images of Pluto with LORRI from 23859.780 km away at est. resolution 0.12 km/pix.

07:30:00-20 minutes to #PlutoFlyby Closest Approach. New Horizons is 21,536 km from Pluto!

07:31:05-New Horizons is taking an image of Pluto with MVIC from 20854.035 km away at est. resolution 0.41 km/pix. New Horizons is 31.8 AU from Earth.

07:40:00-10 minutes to #PlutoFlyby Closest Approach. New Horizons is 16,054 km from Pluto!

07:40:57-New Horizons is taking a spectrum of Pluto with Alice from 15661.488 km away. New Horizons is 31.8 AU from Earth.

07:43:07-New Horizons is taking 67 images of Charon with LORRI from 34200.236 km away at est. resolution 0.17 km/pix.

07:45:29-New Horizons is taking an image of Charon with MVIC from 33245.206 km away at est. resolution 0.66 km/pix. New Horizons is 31.8 AU from Earth.

07:49:57-Closest Approach to Pluto #PlutoFlyBy Go #NASANewHorizons!

07:50:47-New Horizons is taking an image of Pluto with MVIC from 13735.372 km away at est. resolution 0.27 km/pix. New Horizons is 31.8 AU from Earth.

07:53:19-New Horizons is taking radio reflectance data of Pluto with REX from 13981.327 km away. New Horizons is 31.8 AU from Earth.

07:53:34-New Horizons is taking radio reflectance data of Pluto with REX from 14022.327 km away. New Horizons is 31.8 AU from Earth.

07:57:15-New Horizons is taking radio reflectance data of Pluto with REX from 14947.896 km away. New Horizons is 31.8 AU from Earth.

07:57:30-New Horizons is taking radio reflectance data of Pluto with REX from 15031.013 km away. New Horizons is 31.8 AU from Earth.

07:58:17-New Horizons is taking a spectrum of Pluto with Alice from 15306.595 km away. New Horizons is 31.8 AU from Earth.

07:58:30-New Horizons is taking 60 images of Pluto with LORRI from 15386.759 km away at est. resolution 0.076 km/pix.

08:00:41-New Horizons is taking an image of Pluto with MVIC from 16282.704 km away at est. resolution 0.32 km/pix. New Horizons is 31.8 AU from Earth.

08:08:13-New Horizons is taking an image of Pluto with MVIC from 20323.226 km away at est. resolution 0.40 km/pix.

08:14:16-New Horizons Beginning Pluto Occultation Measurements #PlutoFlyBy

08:14:16-New Horizons is taking a spectrum of Pluto with Alice from 24247.777 km away. New Horizons is 31.9 AU from Earth.

08:15:30-New Horizons is taking radio reflectance data of Pluto with REX from 25094.810 km away. New Horizons is 31.9 AU from Earth.

08:22:18-New Horizons is taking radio reflectance data of Pluto with REX from 29958.281 km away. New Horizons is 31.9 AU from Earth.Next Observation

To see up to the moment New Horizons updates, go here.

11 comments; last comment on 07/19/2015
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Memcomputers

Posted July 13, 2015 9:31 AM by Roger Pink

Memory and Processing

The human brain both stores and processes information at the same time as opposed to conventional computers which store information in a dedicated location and move it back and forth as required by the processor(s). This back and forth leads to what is known as the "Neumann bottleneck", which is a major limitation for modern computers.

But what if computers could be built in such a way that they combined memory and processing similar to how our brains work? Such a computer would be able to avoid the Neumann bottleneck and would be capable of tackling problems beyond the capability of conventional computers. That's exactly what researchers are trying to do, creating what has been dubbed a "memcomputer".

Here is an interesting article I came across on hacked.com talking about the work:

RESEARCHERS DEVELOP FIRST WORKING MEMPROCESSORS, PLAN FUTURE ULTRA-FAST MEMCOMPUTERS

Researchers from San Diego and Turin have developed the first working "memcomputer" prototype, with brain-inspired "memprocessors" able to simultaneously perform computation and memory operations, which could open the way to ultra-fast future computers. The researchers, headed by Massimiliano Di Ventra, a professor of physics at the University of California, San Diego (UCSD), have published their work in Science Advances. The research paper, titled "Memcomputing NP-complete problems in polynomial time using polynomial resources and collective states," is freely available online.

Ultra-Fast Brain-Inspired Computing

Memcomputing, inspired by neuronal information processing in the brain, is defined as computing and storing information within the same units, interacting memory cells called memprocessors. The theoretical concept of memcomputing has been around for some time, but the researchers claim that theirs is the first working implementation. Traditional computers use separate computing and memory units, and therefore must shuffle a lot of data back and forth, which consumes power and time. The brain doesn't shuffle that much information, which is one of the reasons it's much more energy-efficient than current computers.

"To make a quick comparison: our own brain expends about 20 watts to perform 10^16 operations per second," Di Ventra explained to Popular Mechanics, while a supercomputer would require 10 million times more power to do the same number of operations. "A big chunk of that power is wasted in the back and forth transfer of information between the CPU and the memory." A memprocessor operates like a transistor, but also changes some of its physical properties, such as its electrical resistance, depending on incoming data and instructions. Therefore, a memprocessor can perform computation and data storage simultaneously.

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Here is an article from 2012 on the future development of memcomputers

7 comments; last comment on 07/14/2015
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New Horizons begins Flyby of Pluto - Daily Updates

Posted July 09, 2015 4:05 PM by Roger Pink

Pluto in HD

After a hectic week of scrambling which saw New Horizons go into safe-mode, everything appears to be back on track for its historic flyby of Pluto on July 14th. Indeed, the probe has officially begun its heavy lifting, officially entering "encounter phase", working around the clock taking measurements and images of Pluto and its largest moon, Charon.

The most recent image of Pluto released to the public is from 5,000,000 miles away. The image revealed a heart shaped lighter color area on the surface of Pluto (see image). Excitement is building as each new day should reveal ever more detailed images of Pluto's surface. On the 14th, New Horizons will pass within 8000 miles of Pluto, at a speed relative to Pluto of 14.6 km/s. From that point forward it will rush away into the Kuiper Belt.

To follow along with the progress of New Horizons, I recommend the following links:

NASA's New Horizons Page

John Hopkin's New Horizons Page

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8 comments; last comment on 07/15/2015
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Does Pluto Have a Giant Crater?

Posted July 01, 2015 8:36 AM by Roger Pink

New Horizons

It's an exciting time for space enthusiasts. The NASA probe, New Horizons, is just two weeks from its July 14th flyby of Pluto. Everyday new images arrive revealing more details of Pluto and its moons Charon, Nix, Hydra, Styx, and Kerberos (Nod to CR4 Member G.K. for possibly naming this moon). The images are already starting to surprise scientists. Charon appears to have a surprisingly dark pole. Pluto's moons* seem to tumble about chaotically. *Note - Pluto and Charon have more of a binary dwarf-planet arrangement than a traditional planet-moon arrangement. The other moons orbit the center of gravity of the Pluto-Charon binary (see image below). The center of gravity of the Pluto-Charon system is outside of the surface of Pluto.

The last month the ever improving images of Pluto have seemed...off. The dwarf-planet didn't seem to be completely round. At first scientists explained it was an optical illusion caused by the distance and the deconvolution method used to improve the images taken by LORRI on New Horizons. However, as the space probe gets closer and closer to Pluto, and the images sent back to us get better and better, it's starting to look like Pluto may have a gigantic crater that does indeed distort it's shape.

We wont have to wait long to find out for sure. In two weeks New Horizons will get as closer than 10,000 km to Pluto. Starting July 11th, the surfaces of Pluto and Charon will begin being mapped at 40 km (25 mile) resolution! Soon we will know for sure if the giant crater is real or some weird image processing effect. It sure looks real though in that June 29th image!

Approaching Pluto (LORRI Images)

Pluto-Charon Binary System

9 comments; last comment on 07/20/2015
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June 30th and July 1st - Venus and Jupiter Conjunction

Posted June 30, 2015 11:49 AM by Roger Pink

The Two Brightest "Wanderers" Meet

The last several weeks, the two brightest planets in the night sky, Venus and Jupiter, have been inching closer to each other in the night sky. At the beginning of June they were 20 degrees apart in the sky. Tonight and tomorrow night Venus and Jupiter will be less than a degree apart, having the appearance of a bright double star in the early evening sky. Here is an article from Sky and Telescope on the conjunction.

Venus and Jupiter: Together at Last

Anyone who pays even cursory attention to the evening sky has surely noticed that the two brightest planets, Venus and Jupiter, have been drawing closer together in the west in the evening twilight. At the beginning of June, the two planets were 20° apart in the sky, about twice the width of your fist held at arm's length. Week by week, Jupiter and the stars behind it have gradually slipped lower in the evening twilight. But Venus, due to its rapid orbital motion around the Sun, has stayed high up.

The resulting slow-motion convergence is setting the stage for a dramatic sky sight. The warm-up act came on June 19th and 20th, when the planetary duo was joined by a thin and lovely crescent Moon. Farther to their upper left, and fainter, was Regulus, the alpha star of Leo. (I was texting all my friends: "Go outside. Now. Look west!") -

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3 comments; last comment on 07/03/2015
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