Events List for the Academic Year
Event Time:
Wednesday, January 16, 2019 | 1:00 pm - 2:00 pm
Event Location:
Henn 318
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2019-01-16T13:00:00
2019-01-16T14:00:00
Partners and Quantum Information Capsules
Event Information:
Where do entangled quantum systems store information in a total pure state? This question is nontrivial and interesting since the entanglement among subsystems delocalizes the information, and is significantly related to the information loss problem of evaporating black holes. So far, a common picture is that of a subsystem and its purification partner sharing the information quantum mechanically. For entangled multiple qubits in an arbitrary pure state, we introduce a new picture of a single qubit in the correlation space referred to as quantum information capsule (QIC), confining the information perfectly. Unlike the partner picture, in the QIC picture, by swapping the single-body state, leaving other subsystems untouched, the whole information can be retrieved out of the system. After the swapping process, no information remains in the system.
Event Location:
Henn 318
Event Time:
Monday, January 14, 2019 | 3:00 pm - 4:00 pm
Event Location:
Hennings 318
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2019-01-14T15:00:00
2019-01-14T16:00:00
Counting Stars: Developing Probabilistic Cataloguing for Crowded Fields
Event Information:
The depth of next generation surveys poses a great data analysis challenge: these surveys will suffer from crowding, making their images difficult to deblend and catalogue. Sources in crowded fields are extremely covariant with their neighbours and blending makes even the number of sources ambiguous. Probabilistic cataloguing returns an ensemble of catalogues inferred from the image and can address these difficulties. We present the first optical probabilistic catalogue, cataloguing a crowded Sloan Digital Sky Survey r band image cutout from Messier 2. By comparing to a DAOPHOT catalogue of the same image and a Hubble Space Telescope catalogue of the same region, we show that our catalogue ensemble goes more than a magnitude deeper than DAOPHOT. We also present an algorithm for reducing this catalogue ensemble to a condensed catalogue that is similar to a traditional catalogue, except it explicitly marginalizes over source-source covariances and nuisance parameters. We also detail efforts to make probabilistic cataloguing more computationally efficient and extend it beyond point sources to extended objects. Probabilistic cataloguing takes significant computational resources, but its performance compared to existing software in crowded fields make it a enticing method to pursue further.
Event Location:
Hennings 318
Event Time:
Friday, January 11, 2019 | 10:00 am - 12:00 pm
Event Location:
Room 309, Hennings Building
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2019-01-11T10:00:00
2019-01-11T12:00:00
Departmental Oral Examination (Thesis Title: “Precise Measurement of Rare Pion Decay”)
Event Information:
Abstract:
A precise measurement of the pion to positron or muon decay branching ratio provides a test of lepton universality incorporated in the Standard Model (SM) of particle physics. If a measurement is consistent with the SM, new constraints could be set on new physics. Most remarkably, a deviation could imply the presence of a new pseudo-scalar interaction whose energy scales up to O(1000 TeV) would enhance the branching ratio by O(0.1%). In some instances, these constraints can far exceed the reach of direct searches at colliders. This dissertation represents the latest experimental measurement effort by the PIENU collaboration. The current analysis presented in this thesis is blinded but includes the highest quality data portion available of around 3M π → e ν events. Furthermore, major experimental systematic problems have been solved, allowing for increased precision up to 0.12% in the branching ratio and up to 0.06% in test of lepton universality.
Event Location:
Room 309, Hennings Building
Event Time:
Thursday, January 10, 2019 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201
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2019-01-10T16:00:00
2019-01-10T17:00:00
Towards a more efficient model of particle physics
Event Information:
Grand unified theories envision the standard model of particle physics
as a piece of a larger system. However, in this talk we will ask the
opposite question: Could the standard model result from a set of
algebras much smaller than itself?
By the late 1930s, Arthur Conway knew that the complex quaternions (just
a 4 complex-dimensional algebra) could single-handedly encode the notion
of rotations and boosts, in addition to the degrees of freedom of
electric and magnetic fields, energy and momentum, fermionic spin and
chirality. Here we will demonstrate hints that the octonions might be
capable of similar feats in efficiency.
This colloquium is tailored so as to be as accessible as possible.
Students are more than welcome to attend!
Event Location:
Hennings 201
Event Time:
Thursday, January 10, 2019 | 2:00 pm - 3:00 pm
Event Location:
BRIM 311, Stewart Blusson Quantum Matter Institute, 2355 East Mall
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2019-01-10T14:00:00
2019-01-10T15:00:00
CM Seminar: Materials Informatics: the 4th paradigm Abstract
Event Information:
Materials informatics (MI) may be considered the 4th paradigm of scientific inquiry, in addition to experimental, theoretical and computational approaches. MI is made possible by the universal access to abundant scientific data, assisted by advances in software and machine learning (ML) to analyze the data. For materials problems with specific designing goals, physics-based indicators (or assumptions) are necessary to help narrowing down the informatics search. In this talk I shall present materials discovery by MI + ML, including 2D ferromagnets, solid state electrolytes, molecules for OLED, and possible high Tc superconductors. We conclude that backed by theory and first principles simulation, and eventually by experimental verification, MI + ML is a very efficient approach for materials discovery. Acknowledgements: work in collaboration with Dr. Eric Zhu (NanoacademicTech., Canada), Dr. Yifa Qin (HZWTECH, Shanghai, China), Dr. Zhongli Liu (McGill), Dr. Xianghua Kong (McGill).
Event Location:
BRIM 311, Stewart Blusson Quantum Matter Institute, 2355 East Mall
Event Time:
Monday, January 7, 2019 | 3:00 pm - 4:00 pm
Event Location:
Hennings 318
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2019-01-07T15:00:00
2019-01-07T16:00:00
The New Horizons spacecraft's encounter with the small Kuiper Belt object Ultima Thule
Event Information:
On 1st January 2019 the New Horizons spacecraft encountered a small body beyond Neptune named Ultima Thule. In this informal collquium we will cover the initial results that have emerged this week and provide background on the importance of the science that can be addressed.
Event Location:
Hennings 318
Event Time:
Thursday, December 20, 2018 | 2:00 pm - 3:00 pm
Event Location:
BRIM 311
2355 East Mall
Vancouver BC
V6T 1Z4
2355 East Mall
Vancouver BC
V6T 1Z4
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2018-12-20T14:00:00
2018-12-20T15:00:00
CM Seminar: Cavity Spintronics
Event Information:
Cavity spintronics (also known as spin cavitronics) is a newly developing, interdisciplinary field that brings together microwave and optical communities with researchers in spintronics and magnetism. The field started around 2014 when it was found that ferromagnets in cavities hybridize with both microwaves and light by light-matter interaction [1]. Since then, the emergence of cavity spintronics has attracted broad interest from groups studying quantum electrodynamics, cavity polaritons, optomechanics, superconductivity, plasmonics, and phononics. At the center stage of the topic is the physics of magnon-photon coupling: Via the quantum physics of spin-photon entanglement on the one hand and classical electrodynamic coupling on the other, magnon-photon coupling connects some of the most exciting concepts in modern physics, such as quantum information and quantum optics, with one of the oldest sciences on earth, magnetism.
This talk aims to provide an introduction to this new frontier of condensed matter physics to researhers working in magnetism, spintronics, quantum information, and microwave technologies. The talk starts with a historical review, tracing this new field back to some of the most courageous work in the history of magnetism, spintronics, cavity quantum electrodynamics, and polaritons. Recent experiments focusing on the development of new cavity-mediated techniques, such as coupling of magnetic moments, distant manipulation of spin current, qubit-magnon coupling, and conversion between optical and microwave photons, will be highlighted.
[1] Can-Ming Hu, “Dawn of cavity spintronics,” https://arxiv.org/abs/1508.01966
Event Location:
BRIM 311
2355 East Mall
Vancouver BC
V6T 1Z4
Event Time:
Friday, December 14, 2018 | 2:00 pm - 4:00 pm
Event Location:
Room 311, Brimacombe Building, 2355 East Mall
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2018-12-14T14:00:00
2018-12-14T16:00:00
Final PhD Oral Examination (Thesis Title: “A first principle study of the electronic structure of the bismuthates")
Event Information:
Examination Programme
Event Location:
Room 311, Brimacombe Building, 2355 East Mall
Event Time:
Thursday, December 13, 2018 | 2:00 pm - 3:00 pm
Event Location:
BRIM 311
Stewart Blusson Quantum Matter Institute
2355 East Mall
Vancouver BC
V6T 1Z4
Stewart Blusson Quantum Matter Institute
2355 East Mall
Vancouver BC
V6T 1Z4
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2018-12-13T14:00:00
2018-12-13T15:00:00
CM Seminar: The field theory of specific heat
Event Information:
The finite temperature field theory for condensed matter physics, based on the kernel of the evolution equation, was recently proposed. The field theory is scale-free formalism, so it denies the absolute scale of thermodynamic temperature and uses dimensionless thermal variables, which are defined by the group velocities of sound and the interatomic distances, combined with the defining constants of the New SI. The universal thermal functional is obtained and used to derive the specific heat of condensed matter. The field theory of specific heat predicts the fourth power of temperature at sufficiently low temperature instead of the Debye theory’s cubic law. Experimental data for various condensed matter systems, including diamond lattice crystals, glasses and even solid helium-4, confirm the quartic law. The range of temperature with the fourth order behaviour varies, so it is called the quasi-low temperature regime specified by the characteristic temperature and the dimensionless constant. The critique of the Debye theory of specific heat is given.
Event Location:
BRIM 311
Stewart Blusson Quantum Matter Institute
2355 East Mall
Vancouver BC
V6T 1Z4
Event Time:
Tuesday, December 11, 2018 | 12:30 pm - 2:30 pm
Event Location:
MCML 256, HR MacMillan Building, 2357 Main Mall
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2018-12-11T12:30:00
2018-12-11T14:30:00
Final PhD Oral Examination (Thesis Title: “Emergent Spacetime in Matrix Models”)
Event Information:
Abstract:
We study the noncommutative geometry associated to matrices of N quantum particles in the matrix models. The earlier work established a surface embedded in flat R3 from three Hermitian matrices. We construct coherent states corresponding to points in the emergent geometry and find the original matrices determine not only shape of the emergent surface, but also a unique Poisson structure. We prove that commutators of matrix operators correspond to Poisson brackets. Through our construction, we can realize arbitrary noncommutative membranes embedded in R3.
We further conjecture an embedding operator which assigns, to any (2n + 1) Hermitian matrices, a 2n-dimensional hypersurface in flat (2n + 1)-dimensional Euclidean space. This corresponds to precisely defining a fuzzy D(2n)-brane corresponding to N D0-branes. Points on the hypersurface correspond to zero eigenstates of the embedding operator, which have an interpretation as coherent states underlying the emergent noncommutative geometry. Using this correspondence, all physical properties of the emergent D(2n)-brane can be computed.
Many works have been done in exploring the geometry emerged from the matrix configuration, but they do not always produce consistent results. We apply two types of point probe methods and the supergravity charge density formula on the generalized fuzzy sphere S2so(4). Its tangled structure challenges the applicability of the probing methods. We propose to disentangle blocks of S2so(4) regarding the geometrical symmetry and retrieve S2so(4) as a thick two sphere with coherent layers consistently in three methods.
The Yang-Mills matrix model with mass term representing IR cutoff on the effective radius generates remarkable spherical solutions of the emergent universe, but it is unsolvable, unlike matrix models dominated by the Gaussian potential. By coarse-graining the dimension of matrices, quantum gravity is reproduced by the Gaussian model at the fixed point of dimensional renormalization group flow. We approach the unsolvable YM model by the same dimensional renormalization and discover a non-trivial fixed point after imposing the spherical topology. The fixed point might lead to a new duality between quantum gravity and the massive YM model in the continuum limit, and its existence also sets a density condition on the generalized fuzzy sphere.
Event Location:
MCML 256, HR MacMillan Building, 2357 Main Mall
Event Time:
Monday, December 10, 2018 | 3:00 pm - 4:00 pm
Event Location:
Hennings 318
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2018-12-10T15:00:00
2018-12-10T16:00:00
Goodnight, and thanks for all the planets
Event Information:
On 30th October, the Kepler spacecraft was powered down, initiating the final closeout sequence to cease operations. We'll pay homage to the mission by playing back some of the science highlights. We'll also consider Kepler's exoplanet legacy - what it leaves behind and what roles it yet has to play in the next era of exoplanet exploration led by TESS and JWST.
Event Location:
Hennings 318
Event Time:
Sunday, December 9, 2018 | 2:00 pm - 3:30 pm
Event Location:
LIFE building room 2201, 6138 Student Union Boulevard (UBC CAMPUS). The North Parkade is the closest parking lot to the LIFE Building.
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2018-12-09T14:00:00
2018-12-09T15:30:00
Magic? Or Physics? 2018 Faraday Science Show
Event Information:
WHERE: LIFE building room 2201, 6138 Student Union Boulevard (UBC CAMPUS). The North Parkade is the closest parking lot to the LIFE Building.
WHEN: SUNDAY, December 9, 2018, 2:00-3:30 PM
COST: FREE! (But bring non-perishable food items to support the Greater Vancouver Food Bank!) No RSVP required, though we recommend arriving 15-20 minutes earlier for good seats.
The Faraday Show is UBC's annual science show for children, presented by UBC Physics & Astronomy. This year join us to explore the scientific secrets behind magical wonders! Why would something roll uphill, not downhill? Can you make something moving away come back just by thinking? How can a plate float in mid-air, with no one touching it? How can we make things disappear, and reappear? We will explore these questions, and more, through lively demonstrations and hands-on activities. This show is for children of ALL AGES, and adults who are young at heart!
For more information please contact the outreach program at: outreach@phas.ubc.ca / 604-822-0596.
Event Location:
LIFE building room 2201, 6138 Student Union Boulevard (UBC CAMPUS). The North Parkade is the closest parking lot to the LIFE Building.
Event Time:
Sunday, December 9, 2018 | 2:00 pm - 3:30 pm
Event Location:
LIFE building room 2201, 6138 Student Union Boulevard (UBC CAMPUS). The North Parkade is the closest parking lot to the LIFE Building.
Add to Calendar
2018-12-09T14:00:00
2018-12-09T15:30:00
Magic? Or Physics? 2019 Faraday Science Show
Event Information:
WHERE: LIFE building room 2201, 6138 Student Union Boulevard (UBC CAMPUS). The North Parkade is the closest parking lot to the LIFE Building.
WHEN: SUNDAY, December 9, 2018, 2:00-3:30 PM
COST: FREE! (But bring non-perishable food items to support the Greater Vancouver Food Bank!) No RSVP required, though we recommend arriving 15-20 minutes earlier for good seats.
The Faraday Show is UBC's annual science show for children, presented by UBC Physics & Astronomy. This year join us to explore the scientific secrets behind magical wonders! Why would something roll uphill, not downhill? Can you make something moving away come back just by thinking? How can a plate float in mid-air, with no one touching it? How can we make things disappear, and reappear? We will explore these questions, and more, through lively demonstrations and hands-on activities. This show is for children of ALL AGES, and adults who are young at heart!
For more information please contact the outreach program at: outreach@phas.ubc.ca / 604-822-0596.
Event Location:
LIFE building room 2201, 6138 Student Union Boulevard (UBC CAMPUS). The North Parkade is the closest parking lot to the LIFE Building.
Event Time:
Thursday, December 6, 2018 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201
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2018-12-06T16:00:00
2018-12-06T17:00:00
The human voice, the erhu and the violin
Event Information:
The Western violin and the erhu, the Chinese violin, are at first glance, markedly different instruments, being apparently related only by their bows. The violin soundbox is made of spruce and maple, has a complex shape, and an asymmetrical interior. The erhu soundbox is a simple cylinder closed on one side by a pre-tensioned python skin and open at the other. However, delving into the vibro-acoustics of each structure, deep similarities emerge, both with each other and with that most ancient musical instrument, the human voice.
Acoustics is a field that tends to fall between the cracks of physics and engineering, and musical acoustics falls between the cracks of acoustics and music. Thus I will not assume any prior knowledge of the field.
Event Location:
Hennings 201
Event Time:
Thursday, December 6, 2018 | 2:00 pm - 3:00 pm
Event Location:
BRIM 311
2355 East Mall
Vancouver BC
V6T 1Z4
2355 East Mall
Vancouver BC
V6T 1Z4
Add to Calendar
2018-12-06T14:00:00
2018-12-06T15:00:00
CM Seminar: Muons for the Quantum Matter
Event Information:
A S=1/2 polarized particle, which may couple to the near-by electron is the simplest quantum mechanical object, as you may find in the standard text books. In reality, a particle called positive muon (µ+), provides such experimental observations. TRIUMF in the UBC south campus, which is also my home institute since this August, provides muon beams for material science research.
In the seminar this time, I would like to introduce some of my research work in which muons played important roles.
The subject involves phase diagram of iron pnictide superconductors [1], electrides [2,3] and wide gap semiconductors.
The muon characterization has the feature of a sensitive magnetic probe as well as a Hydrogen isotope which extracts its electronic state in the dilute limit.
[1] “Bipartite magnetic parent phases in the iron oxypnictide superconductor.” M. Hiraishi, S. Iimura, K. M. Kojima, et al., Nature Physics, 10, 300–303, (2014).
[2] “Cage electron-hydroxyl complex state as electron donor in mayenite.” M. Hiraishi, K. M. Kojima, et al., Phys. Rev. B., 93, 121201(R), (2016).
[3] “Electronic correlation in the quasi-two-dimensional electride Y2C”, M. Hiraishi, K.M. Kojima, et al., Phys. Rev. B. 98, 041104(R) (2018).
Event Location:
BRIM 311
2355 East Mall
Vancouver BC
V6T 1Z4
Event Time:
Wednesday, December 5, 2018 | 12:30 pm - 1:30 pm
Event Location:
Henn 318. 6224 Agricultural Rd.
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2018-12-05T12:30:00
2018-12-05T13:30:00
A Functional Approach to Soft Graviton Induced Decoherence
Event Information:
We consider the interaction between a matter system and soft gravitons. We use a functional eikonal expansion to deal with the infrared divergences, and introduce a "composite generating functional" which allows us to calculate a decoherence functional for the time evolution of the system. These techniques allow us to formulate scattering problems in a way which deals consistently with infrared effects, as well as being manifestly diffeomorphism invariant. We show how the asymptotic form of the decoherence functional can be written in terms of the infinitely many conserved charges associated with asymptotic BMS symmetries, and allow us to address the question of how much information is lost during the scattering.
Event Location:
Henn 318. 6224 Agricultural Rd.
Event Time:
Monday, December 3, 2018 | 3:00 pm - 4:00 pm
Event Location:
Hennings 318
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2018-12-03T15:00:00
2018-12-03T16:00:00
The Potential Habitability of Rocky Planets around Red Dwarfs: Stellar Drivers for Atmospheric Chemistry and Stability
Event Information:
ABSTRACT: High-energy photons and particles from stars regulate the atmospheric temperature structure and photochemistry on orbiting planets, influencing the long-term stability of planetary atmospheres and the production of potential “biomarker” gases. Rocky planets orbiting low-mass stars (M dwarfs) will likely be the first exoplanets directly probed for signs of life, however, relatively few observational and theoretical constraints exist on the high-energy irradiance from typical (i.e., weakly active) M dwarf exoplanet host stars. In this talk, I will describe results from an ongoing panchromatic survey (Chandra/XMM/Hubble/ground) of M and K dwarf exoplanet hosts. The MUSCLES* Treasury Survey combines UV, X-ray, and optical observations, reconstructed Lyman-alpha and EUV (10-90 nm) radiation, and next-generation stellar atmosphere models to provide realistic inputs for modeling the stability and climate on potentially habitable planets around red dwarfs.
Please join us for coffee, tea and snacks before the Colloquium in Hennings 318 at 2:45 pm
Event Location:
Hennings 318
Event Time:
Monday, December 3, 2018 | 10:00 am - 11:00 am
Event Location:
Hennings 318
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2018-12-03T10:00:00
2018-12-03T11:00:00
All-optical Field-free Three-Dimensional Orientation of Asymmetric-Top Molecules
Event Information:
Orientation and alignment of molecules by ultrashort laser pulses is crucial for a variety of applications and have long been of interest in physics and chemistry, with the special emphasis on stereodynamics in chemical reactions and molecular orbitals imaging. As compared to the laser induced molecular alignment, which has been extensively studied and demonstrated, achieving molecular orientation is a much more challenging task, especially in the case of asymmetric-top molecules. Here, we report the experimental demonstration of all-optical field-free three-dimensional orientation of asymmetric-top molecules by means of phase-locked cross-polarized two-color laser pulse. This approach is based on nonlinear optical mixing process caused by the off-diagonal elements of the molecular hyperpolarizability tensor. It is demonstrated on SO2 molecules and is applicable to a variety of complex nonlinear molecules.
Nat. Commun, 2018 (in press) DOI: 10.1038/s41467-018-07567-2
Event Location:
Hennings 318
Event Time:
Friday, November 30, 2018 | 11:00 am - 12:00 pm
Event Location:
Hennings 309
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2018-11-30T11:00:00
2018-11-30T12:00:00
Anomalous Dimensions for Conserved Currents from Holographic Dilatonic Models to Superconductivity
Event Information:
It is well known that the dimension of conserved currents is determined simply from dimensional analysis. However, a recent proposal is that what is strange about the conserved currents in the strange metal in the cuprate superconductors is that they carry anomalous dimensions. The basic model invoked to exhibit such behaviour is a holographic dilatonic one in which the field strength couples to the radial coordinate. I will show that the anomalous dimension in such cases arises from a fractional electromagnetism that can be thought of as a general loop-hole in Noether's second theorem. The general mechanism operative is a mass term in the IR that couples to the UV current. Such a mass that couples to the radial component of the gauge field introduces a breaking of U(1) everywhere except at the boundary. I will also show that even the Pippard kernel invoked to explain the Meissner effect in traditional low-temperature superconductors is a special case of the non-local action found here, implying that symmetry breaking is the general mechanism for fractional electromagnetisms. I will also construct the Virasoro algebra for such fractional currents and discuss the general implications for the bulk-boundary construction in holography.
Event Location:
Hennings 309
Event Time:
Thursday, November 29, 2018 | 4:00 pm - 5:00 pm
Event Location:
Hennings 201
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2018-11-29T16:00:00
2018-11-29T17:00:00
The Future of Cancer Medicine: Personal or Industrial?
Event Information:
Our characterization of cancer is advancing rapidly through the ever-increasing ability to make quantitative measurements of the cancerous tissues with new tools and technologies. These include continuously improving methods of sequencing the genome, advances in imaging that allow us to non-invasively characterize the biology of the disease in-situ, and the potential to integrate circulating biomarkers of response. The myriad of new signals that characterize the complex biology of cancer is compounded by the diversity of the human form. Characterizing the human ‘phenome’ – the detailed description of the patient and their biological state – is becoming critical for accurate prediction of clinical outcomes of a given therapy and is associated with the development of ‘precision’ or ‘personalized’ cancer medicines. Furthermore, the myriad of inputs to the decision-making process is challenging the capabilities of our human cognition and the healthcare system in general to deliver the new complex treatments with the precision required to realise the potential of these personalized therapies. Taken together, the traditional model of cancer medicine needs to be transformed from a fairly ad-hoc process of assessment, diagnosis, and treatment into something far more coordinated. Therein lies the paradox that ‘medicine must industrialize to personalize care’. Just as automation has allowed manufacturing to deliver highly customized products at scale, so too must medicine. The implications are important across all of cancer medicine and align with the need for improvements in patient safety, quality of care, clinical outcomes, and patient experience. The development of digital technologies will allow this transformation to occur and, if properly implemented, will not only advance care, but will also accelerate the pace of scientific discoveries required to make real progress against this disease.
Event Location:
Hennings 201