Imaging Black Holes with the Event Horizon Telescope
Andrew Chael, Princeton University
Friday, November 4, 2022 12–1 pm
Hegeman 107 The Event Horizon Telescope (EHT) is a network of eleven millimeter-wavelength radio telescopes that spans the globe from Greenland to the South Pole. Using the technique of Very Long Baseline Interferometry (VLBI), the EHT combines data from these telescopes to produce images with resolution comparable to that of a single telescope with the Earth’s diameter. The EHT has imaged both the supermassive black hole in the giant elliptical galaxy M87 and Sagittarius A*, the black hole in our Galactic Center. These images show rings of light produced by extremely hot, magnetized plasma with sizes very similar to that of the black hole's theoretical ‘shadow.’ Producing these images required years of painstaking calibration, validation, and imaging of EHT data, as well as new advances in numerical simulations required to model the turbulent plasma inflows and outflows around black holes. In this talk, I will discuss how the EHT obtained its images and how we use them to understand the extreme environments around supermassive black holes. I will also discuss how future advances in both EHT observations and theoretical simulations will both reveal the connection between supermassive black holes and extragalactic jets and enable more precise tests of General Relativity near the black hole boundary.Sponsored by: Physics Program.
For more information, call 845-758-6822, or e-mail [email protected].
Barringer House Kant’s metaphysical project is framed by his revolutionary claim that some judgments are both synthetic and a priori knowable: one must seek their justification independent of sense experience (i.e., they are a priori) and yet the meaning of such judgments cannot be grasped via conceptual analysis (i.e., they are non-analytic). Kant claims further that allmathematical truths have this distinctive character, and he came to this view by reflecting on mathematical practice. We will discuss how to understand Kant’s view of mathematical truth in light of the mathematics with which he was engaged.Sponsored by: Mathematics Program; Philosophy Program.
For more information, call 845-758-6822, or e-mail [email protected].
What’s Natural about 2.7182818… and How Fermat Invented Integration
Jeff Suzuki, Brooklyn College
Wednesday, November 9, 2022 12–1 pm
RKC 111 Everyone knows that calculus was invented by Newton. Or Leibniz. Actually, the real inventor was Isaac Barrow (Newton’s teacher), but Pierre de Fermat (1601–1661) solved all three of the main problems of calculus: finding tangents, extreme values, and areas under a curve. We’ll introduce Fermat’s method, then show how it leads to the familiar result that the integral of 1/x is ln x, and e as the base of the natural logarithmic function.
Jeff Suzuki was probably born indecisive, and double majored in history and mathematics with a concentration in physics. He avoided having to choose between them by writing a dissertation on the history of celestial mechanics. Since then, he’s done everything possible to avoid specialization, venturing into constitutional law, patents, and mathematics education, and as of this past weekend, is looking into the possibility of developing an open-world game based around mathematics.
For more information, call 845-758-6822, or e-mail [email protected].
Hegeman 107 Physicists use abstract mathematics to describe, and advanced technologies to probe, the physical world on spatial, temporal, and complexity scales unperceivable by the human body through ordinary perception. How, then, does a physicist – a living, breathing organism whose primary knowledge is rooted in the physical interaction of their body with the physical world – work with abstract objects and ground their understanding in the sensory impressions and emotional states that their body makes possible? In this talk, I will sketch out a research program that integrates artistic and intellectual practice to guide our approach to this question. My work is informed by the history and philosophy of science, theories of embodied and situated cognition, and Maurice Merleau-Ponty’s philosophy of phenomenology. My aim is to gain a more intimate understanding of the individual experiences of scientific inquiry and to explore their impact on collective research efforts in physics. Sponsored by: Physics Program.
For more information, call 845-758-6822, or e-mail [email protected].
RKC 111 In my talk, I consider the kinds of reasons that a mathematician has for believing in mathematical statements. Moreover, we investigate some of the epistemic concepts that are connected to these reasons, such as justification, mathematical justification, proof, formal proof, philosophical proof. This area is the battleground of the disputes between the philosophers of mathematical practice on the one hand, and the ‘traditional’ philosophers of mathematics on the other hand. I will argue for a middle road in this debate. Sponsored by: Mathematics Program.
For more information, call 845-758-6822, or e-mail [email protected].
Programmable Twist Angle and Strain Profiles in 2D Materials by Bending
Maëlle Kapfer, Columbia University
Friday, November 18, 2022 12–1 pm
Hegeman 107 The possibility to isolate atom-thick layer of material from a bulk crystal allows the design of structures with a wide range of properties. In particular, by twisting those single layer sheets, a periodic potential, called moiré potential, is superimposed over the lattice modifying the properties of the parent material. Twisted two-dimensional materials have generated tremendous excitement as a platform for achieving quantum properties on demand. However, the moiré pattern is highly sensitive to the interlayer atomic registry, and current assembly techniques suffer from imprecise control of the average twist angle, spatial inhomogeneity in the local twist angle, and distortions due to random strain. Here, we demonstrate a new way to manipulate the moiré patterns in hetero- and homo-bilayers through in-plane bending of monolayer ribbons, using the tip of an atomic force microscope. This technique achieves continuous variation of twist angles with improved twist-angle homogeneity and reduced random strain, resulting in moiré patterns with highly tunable wavelength and ultra-low disorder. Our results pave the way for detailed studies of ultra-low disorder moiré systems and the realization of precise strain-engineered devices.
For more information, call 845-758-6822, or e-mail [email protected].
Imaging Black Holes with the Event Horizon Telescope
Andrew Chael, Princeton University
Friday, November 4, 2022 12–1 pm
Hegeman 107 The Event Horizon Telescope (EHT) is a network of eleven millimeter-wavelength radio telescopes that spans the globe from Greenland to the South Pole. Using the technique of Very Long Baseline Interferometry (VLBI), the EHT combines data from these telescopes to produce images with resolution comparable to that of a single telescope with the Earth’s diameter. The EHT has imaged both the supermassive black hole in the giant elliptical galaxy M87 and Sagittarius A*, the black hole in our Galactic Center. These images show rings of light produced by extremely hot, magnetized plasma with sizes very similar to that of the black hole's theoretical ‘shadow.’ Producing these images required years of painstaking calibration, validation, and imaging of EHT data, as well as new advances in numerical simulations required to model the turbulent plasma inflows and outflows around black holes. In this talk, I will discuss how the EHT obtained its images and how we use them to understand the extreme environments around supermassive black holes. I will also discuss how future advances in both EHT observations and theoretical simulations will both reveal the connection between supermassive black holes and extragalactic jets and enable more precise tests of General Relativity near the black hole boundary.Sponsored by: Physics Program.
For more information, call 845-758-6822, or e-mail [email protected].
Barringer House Kant’s metaphysical project is framed by his revolutionary claim that some judgments are both synthetic and a priori knowable: one must seek their justification independent of sense experience (i.e., they are a priori) and yet the meaning of such judgments cannot be grasped via conceptual analysis (i.e., they are non-analytic). Kant claims further that allmathematical truths have this distinctive character, and he came to this view by reflecting on mathematical practice. We will discuss how to understand Kant’s view of mathematical truth in light of the mathematics with which he was engaged.Sponsored by: Mathematics Program; Philosophy Program.
For more information, call 845-758-6822, or e-mail [email protected].
What’s Natural about 2.7182818… and How Fermat Invented Integration
Jeff Suzuki, Brooklyn College
Wednesday, November 9, 2022 12–1 pm
RKC 111 Everyone knows that calculus was invented by Newton. Or Leibniz. Actually, the real inventor was Isaac Barrow (Newton’s teacher), but Pierre de Fermat (1601–1661) solved all three of the main problems of calculus: finding tangents, extreme values, and areas under a curve. We’ll introduce Fermat’s method, then show how it leads to the familiar result that the integral of 1/x is ln x, and e as the base of the natural logarithmic function.
Jeff Suzuki was probably born indecisive, and double majored in history and mathematics with a concentration in physics. He avoided having to choose between them by writing a dissertation on the history of celestial mechanics. Since then, he’s done everything possible to avoid specialization, venturing into constitutional law, patents, and mathematics education, and as of this past weekend, is looking into the possibility of developing an open-world game based around mathematics.
For more information, call 845-758-6822, or e-mail [email protected].
Hegeman 107 Physicists use abstract mathematics to describe, and advanced technologies to probe, the physical world on spatial, temporal, and complexity scales unperceivable by the human body through ordinary perception. How, then, does a physicist – a living, breathing organism whose primary knowledge is rooted in the physical interaction of their body with the physical world – work with abstract objects and ground their understanding in the sensory impressions and emotional states that their body makes possible? In this talk, I will sketch out a research program that integrates artistic and intellectual practice to guide our approach to this question. My work is informed by the history and philosophy of science, theories of embodied and situated cognition, and Maurice Merleau-Ponty’s philosophy of phenomenology. My aim is to gain a more intimate understanding of the individual experiences of scientific inquiry and to explore their impact on collective research efforts in physics. Sponsored by: Physics Program.
For more information, call 845-758-6822, or e-mail [email protected].
RKC 111 In my talk, I consider the kinds of reasons that a mathematician has for believing in mathematical statements. Moreover, we investigate some of the epistemic concepts that are connected to these reasons, such as justification, mathematical justification, proof, formal proof, philosophical proof. This area is the battleground of the disputes between the philosophers of mathematical practice on the one hand, and the ‘traditional’ philosophers of mathematics on the other hand. I will argue for a middle road in this debate. Sponsored by: Mathematics Program.
For more information, call 845-758-6822, or e-mail [email protected].
Programmable Twist Angle and Strain Profiles in 2D Materials by Bending
Maëlle Kapfer, Columbia University
Friday, November 18, 2022 12–1 pm
Hegeman 107 The possibility to isolate atom-thick layer of material from a bulk crystal allows the design of structures with a wide range of properties. In particular, by twisting those single layer sheets, a periodic potential, called moiré potential, is superimposed over the lattice modifying the properties of the parent material. Twisted two-dimensional materials have generated tremendous excitement as a platform for achieving quantum properties on demand. However, the moiré pattern is highly sensitive to the interlayer atomic registry, and current assembly techniques suffer from imprecise control of the average twist angle, spatial inhomogeneity in the local twist angle, and distortions due to random strain. Here, we demonstrate a new way to manipulate the moiré patterns in hetero- and homo-bilayers through in-plane bending of monolayer ribbons, using the tip of an atomic force microscope. This technique achieves continuous variation of twist angles with improved twist-angle homogeneity and reduced random strain, resulting in moiré patterns with highly tunable wavelength and ultra-low disorder. Our results pave the way for detailed studies of ultra-low disorder moiré systems and the realization of precise strain-engineered devices.
For more information, call 845-758-6822, or e-mail [email protected].
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