Quantummechanica, Klassieke Fysica en Aliens

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Geest van Dirk
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Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

26 jul 2015, 11:33

Physicists Discover New Massless Particle; Could Revolutionize
Electronics & Quantum Computing

Posted By: Jolene Creightonon: July 25, 2015In: News, Physics Print Email
Afbeelding
Hasan pictured with a scanning tunneling spectromicroscope used to find the Weyl fermion. Danielle
Alio/Princeton University.

Physics may have just taken a new leap forward, as three independent groups of physicists have found strong
evidence for massless particles called “Weyl fermions,” which exist as quasiparticles – collective excitations of
electrons. Ultimately, this discovery is over 80 years in the making, dating back to Paul Dirac.

In 1928, Dirac came up with an equation that described the spin of fermions (fermions are the building blocks
that make up all matter). Within his equation, he discovered that, in relation to particles that have charge and
mass, there should be a another particle and antiparticle—what we know as the electron and (its antiparticle)
the positron.

Yet, there are more than one ways to skin a cat.

Other solutions to this equation hinted at more exotic kinds of particles. Enter Hermann Weyl, a German
mathematician who, in 1929, come up with a solution that involved massless particles. These became known
as “Weyl fermions.” And, for a number of years, physicists believed that neutrinos (subatomic particles that are
produced by the decay of radioactive elements) were actually Weyl particles. Yet, further studies, which were
published in 1998, indicated that neutrinos do, in fact, have mass, which means that they cannot be the
aforementioned Weyl particles.

But now, we have evidence that Weyl fermions actually exist.

Unlocking the Find

The research comes thanks to Zahid Hasan over at Princeton University, who uncovered these particles in the
semimetal tanatalum arsenide (which is referred to as TaAs). Hasan and his team suggested that TaAs should
contain Weyl fermions and (here is the important bit) it should have what is known as a “Fermi arc.” And in
2014, the team found evidence of such an arc.
Afbeelding
Artist's rendition via ChutterStock

But that’s not all, another team, led by Hongming Weng at the Chinese Academy of Sciences, found similar
evidence in an independent study that used the same methods. And Marin Soljačić and colleagues (hailing
from MIT and the Univeristy of China) have seen evidence of Weyl fermions in a different material, specifically,
a “double-gyroid” photonic crystal.

In this latter case, the team fired microwaves at the crystal and measured microwave transmission through it,
varying the frequency of the microwaves throughout the experiment. Through this process, the team could
map the structure of the crystal, allowing them to determine which microwave frequencies can travel through
the crystal and which cannot. In the end, this revealed the presence of “Weyl points” in the structure, which is
strong evidence for Weyl fermion states existing within the photonic crystal.

The Future of Physics

The significance of this find, quite literally, cannot be overstated. Hasan is clear to point this out, noting in the
press release that, “The physics of the Weyl fermion are so strange, there could be many things that arise from
this particle that we’re just not capable of imagining now.”

He goes on to note more specific applications: “It’s like they have their own GPS and steer themselves without
scattering. They will move and move only in one direction since they are either right-handed or left-handed and
never come to an end because they just tunnel through. These are very fast electrons that behave like
unidirectional light beams and can be used for new types of quantum computing.” Soljačić, the head of the
second study, adds that, “The discovery of Weyl points is not only the smoking gun to a scientific mystery, it
paves the way to absolutely new photonic phenomena and applications.”

Ultimately, it is believed Weyl fermions could be very useful, in that, because they are massless, they can
conduct electric charge much faster than normal electrons. Admittedly, this same feature is exhibited by
electrons in graphene. Yet, graphene is a 2D material, Weyl fermions are thought to exist in more practical 3D
materials.

Bron: http://www.fromquarkstoquasars.com/phys ... computing/" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;"
Laatst gewijzigd door Geest van Dirk op 27 nov 2015, 13:38, 3 keer totaal gewijzigd.
...... and that's what we mean by honey \:D/

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Geest van Dirk
Goalscorer
Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

27 nov 2015, 13:31


Link: http://www.youtube.com/watch?v=4Q-s4vyeffE

Als je er zelf over wilt lezen zonder een zweverige voice-over te horen :wink:

http://www.sciencealert.com/a-brand-new ... e-material" onclick="window.open(this.href);return false;"
...... and that's what we mean by honey \:D/

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vriend
Reservespeler
Berichten: 1891
Lid geworden op: 15 sep 2006, 23:38
Locatie: Alkmaar

21 jan 2016, 14:19

http://www.scientias.nl/ons-zonnestelse ... -planeten/

Hatsekidee. Alsof er een nieuw waddeneiland is ontdekt.
Morele winnaars zijn slechte verliezers.

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Jack
Technisch directeur
Berichten: 8350
Lid geworden op: 26 feb 2005, 12:07

25 feb 2016, 19:00


Link: http://www.youtube.com/watch?v=jZQedHhDW0k

Zwaartekrachtsgolven meten.
Glory Hunter

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Geest van Dirk
Goalscorer
Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

06 apr 2016, 21:58

...... and that's what we mean by honey \:D/

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Geest van Dirk
Goalscorer
Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

15 jun 2016, 21:21

Voor de tweede keer is er weer een detectie van gravitatiegolven gedaan. Het gaat om twee zwarte gaten die samenkomen, door om elkaar heen te draaien, en uiteindelijk een groter zwart gat vormen. 8)

https://www.facebook.com/LigoScientific ... 653145024/
...... and that's what we mean by honey \:D/

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Geest van Dirk
Goalscorer
Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

02 okt 2016, 13:07

...... and that's what we mean by honey \:D/

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Jack
Technisch directeur
Berichten: 8350
Lid geworden op: 26 feb 2005, 12:07

10 nov 2016, 16:40


Link: http://www.youtube.com/watch?v=ynRVnIh6wq4

Zwaartekracht is net zoiets als temperatuur. Het bestaat niet. Je ervaart de beweeglijkheid van moleculen als temperatuur. Zo is zwaartekracht ook.. ongeveer.
Glory Hunter

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differentcook
Barry
Berichten: 4176
Lid geworden op: 24 sep 2015, 23:08

10 nov 2016, 17:07

Merci Jack! Veel interessanter en belangrijker dan het geneuzel bij Geloof, Politiek & Racisme II
vi veri veniversum vivus vici

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Jack
Technisch directeur
Berichten: 8350
Lid geworden op: 26 feb 2005, 12:07

27 okt 2017, 20:10

Glory Hunter

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Jack
Technisch directeur
Berichten: 8350
Lid geworden op: 26 feb 2005, 12:07

17 dec 2017, 17:20


Link: http://www.youtube.com/watch?v=pE78AQqyDnA

Did Dinosaurs Build The Pyramids?
Glory Hunter

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Geest van Dirk
Goalscorer
Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

07 feb 2018, 10:18

Ik zet het maar hier: Fantastische prestatie weer van Elon Musk en zijn Space X organistatie


Link: http://www.youtube.com/watch?v=6s7T79m9_9A

Prachtige beelden van een livefeed:


Link: http://www.youtube.com/watch?v=aBr2kKAHN6M
...... and that's what we mean by honey \:D/

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differentcook
Barry
Berichten: 4176
Lid geworden op: 24 sep 2015, 23:08

07 feb 2018, 11:26

Ongelofelijk, de staande landing van die raketten!
vi veri veniversum vivus vici

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Geest van Dirk
Goalscorer
Berichten: 3809
Lid geworden op: 20 jan 2012, 20:51

20 feb 2018, 21:36

...... and that's what we mean by honey \:D/

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vriend
Reservespeler
Berichten: 1891
Lid geworden op: 15 sep 2006, 23:38
Locatie: Alkmaar

28 feb 2019, 11:54

Ik neem aan dat dit bericht gezien het topic onder 'Aliens' valt.
Morele winnaars zijn slechte verliezers.

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pAZcal
Basisspeler
Berichten: 2940
Lid geworden op: 17 mei 2006, 18:52
Locatie: Leiden

28 feb 2019, 18:15

vriend schreef:
28 feb 2019, 11:54
Ik neem aan dat dit bericht gezien het topic onder 'Aliens' valt.
:D

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