Astrophysics 公開
[search 0]
もっと

Download the App!

show episodes
 
Loading …
show series
 
In this episode we looked at how astrophysical simulations can never be completely realistic due to the sheer scale of the universe, and how computational astrophysicists have to work around that. Prof. Diemer also spoke about his project with a textile specialist, fabricoftheuniverse.org, which tries to visualise dark matter data in a unique ways,…
 
In this episode I speak with Dr Nevin on her work building a tool to recognise and classify galaxy mergers. She also talked about using machine learning and statistical tools in her work to assess how realistic fake galaxies can be to the ones observed. We also looked at some of the types of galaxies mergers present.…
 
In this episode I talk to Dr. Tacchella about how his research is looking for ways to explain the structure of galaxies, as well as why they come in many different forms such as spiral and elliptical galaxies. I also talk with Dr. Tacchella about the specific research he is doing, including some of the theories that exist that try to explain the ph…
 
A big part of Dr. Massara's research is studying the structure of the universe, and creating simulations to explain the irregularity of matter dispersal in the universe. In particular, we talked about her work observing the voids(A vast space in the universe containing very few galaxies) and how voids are where neutrinos can be indirectly detected.…
 
Dr. Evans is designing new technologies to improve advanced LIGO, a laser interferometer that detects gravitational waves. In 2019 he was awarded the New Horizons in physics prize for research on present and future ground-based detectors of gravitational waves. I talked to him about how he accidentally got into the field of astrophysics, and his wo…
 
A graduate of Columbia University in New York City, Gladys holds a Bachelor of Science degree in astronomy & physics. Gladys has conducted high energy particle astrophysics at various labs around the world, such as Nevis Laboratories and as part of the VERITAS collaboration. I talked with Gladys about her experience teaching at MIT, as well as some…
 
Dr Pat Scott leads the Gambit collaboration, a project with multiple theorists and experimentalists from around the world, is a project that aims to use the vast amounts of data available to test the likelihood of models beyond the standard model, which can be downloaded by anyone. I also talked to him about how he got into the field and his experi…
 
This lecture introduces an important concept related to the past and future of the universe: the Scale factor, which is a function of time. With reference to a graph whose coordinates are the Scale factor and time, the problem of dark matter is addressed again. Cosmological redshifts are measured to determine the scale of the universe. The discover…
 
Professor Bailyn begins the class with a discussion of a recent New York Times article about the discovery of a new, earth-like planet. He then discusses concepts such as epicycles, dark energy and dark matter; imaginary ideas invented to explain 96% of the universe. The Anthropic Principle is introduced and the possibility of the multiverse is add…
 
Reasons for the expansion of the universe are addressed at the start of this lecture, focusing especially on the acceleration of dark energy. Supernovae were the first evidence for the existence of dark energy. Two other proofs are presented. The first is the Cosmic Microwave Background, which is a form of electromagnetic radiation that is perfectl…
 
Professor Bailyn offers a review of what is known so far about the expansion of the universe from observing galaxies, supernovae, and other celestial phenomena. The rate of the expansion of the universe is discussed along with the Big Rip theory and the balance of dark energy and dark matter in the universe over time. The point at which the univers…
 
Class begins with a review of the mysterious nature of dark matter, which accounts for three quarters of the universe. Different models of the universe are graphed. The nature, frequency, and duration of supernovae are then addressed. Professor Bailyn presents data from the Supernova Cosmology Project and pictures of supernovae taken by the Hubble …
 
Class begins with a review of the issues previously addressed about the origin and fate of the universe. The role of gravity in the expansion of the universe is discussed and given as the reason why the rate of expansion cannot remain constant and will eventually slow down. The actual density of the universe is calculated using various methods. Fin…
 
Class begins with a review of magnitudes and the problem set involving magnitude equations. Implications of the Hubble Law and Hubble Diagram are discussed. Professor Bailyn elaborates on the Big Bang theory of cosmology and addresses controversial questions related to the age, development, and boundaries of the universe. The fate of the universe, …
 
Professor Bailyn returns to the subject of the expansion of the universe to offer explanations that do not require belief in the Big Bang theory. One alternative is a theory that, in the past, the entire universe was reduced to an "initial singularity," in which everything was much closer, and therefore denser and hotter. Since the universe is in c…
 
The third and final part of the course begins, consisting of a series of lectures on cosmology. A brief history of how cosmology developed into a scientific subject is offered. The discovery of dark energy, along with dark matter, played a crucial role in the development of cosmology. The lecture then discusses the discovery of spiral nebulae in 19…
 
The lecture begins with a question-and-answer session about black holes. Topics include the extent to which we are sure black holes exist in the center of all galaxies, how massive they are, and how we can observe them. The lecture then turns to strong-field relativity: relativistic effects that are unrelated to Newtonian theory. The possibility of…
 
Professor Bailyn begins with a summary of the four post-Newtonian effects of general relativity that were introduced and explained last time: precession of the perihelion, the deflection of light, the gravitational redshift, and gravitational waves. The concept of gravitational lensing is discussed as predicted by Einstein's general relativity theo…
 
Class begins with clarification of equations from the previous lecture. Four post-Newtonian gravitational effects are introduced and discussed in detail. The first of these is the so-called Perihelion Precession, which occurs when the major axis of a planet's elliptical orbit precesses within its orbital plane, in response to changing gravitational…
 
The lecture begins with a comprehensive overview of the historical conditions under which Einstein developed his theories. Of particular impact were the urgent need at the turn of the 19th century to synchronize clocks around the world; Einstein's position at a patent office; and a series of experiments that he himself carried out. In 1905 Einstein…
 
One last key concept in Special Relativity is introduced before discussion turns again to black celestial bodies (black holes in particular) that manifest the relativistic effects students have learned about in the previous lectures. The new concept deals with describing events in a coordinate system of space and time. A mathematical explanation is…
 
The discussion of black holes continues with an introduction of the concept of event horizon. A number of problems are worked out to familiarize students with mathematics related to black hole event horizons. In a longer question and answer session, Professor Bailyn discusses the more mystifying aspects of the nature of black holes and the possibil…
 
The lecture begins with the development of post-Newtonian approximations from Newtonian terms. Several problems are worked out in calculating mass, force and energy. A discussion follows about how concepts like mass and velocity are approached differently in Newtonian physics and Relativity. Attention then turns to the discovery that space and time…
 
The second half of the course begins, focusing on black holes and relativity. In introducing black holes, Professor Bailyn offers a definition, talks about how their existence is detected, and explains why (unlike in the case with exoplanets where Newtonian physics was applied) Einstein's Theory of Relativity is now required when studying black hol…
 
Class begins with a problem on transits and learning what information astronomers obtain through observing them. For example, radii of stars can be estimated. Furthermore, applying the Doppler shift method, one can find the mass of a star. Finally, a star's density can be calculated. A second method for identifying planets around stars is introduce…
 
The class begins with a discussion on transits – important astronomical events that help astronomers to find new planets. The event occurs when a celestial body moves across the face of the star it revolves around and blocks some of its light. By calculating the amount of light that is being obscured astronomers can obtain important information abo…
 
Professor Bailyn talks about student responses for a paper assignment on the controversy over Pluto. The central question is whether the popular debate is indeed a "scientific controversy." A number of scientific "fables" are discussed and a moral is associated with each: the demotion of Pluto (moral: science can be affected by culture); the discov…
 
The formation of planets is discussed with a special emphasis on the bodies in the Solar System. Planetary differences between the celestial bodies in the Inner and Outer Solar System are observed. Professor Bailyn explains how the outlook of our Solar System can predict what other star systems may look like. It is demonstrated how momentum equatio…
 
Class begins with a review of the first problem set. Newton's Third Law is applied in explaining how exoplanets are found. An overview of the Solar System is given; each planet is presented individually and its special features are highlighted. Astronomy is discussed as an observational science, and the subject of how to categorize objects in the S…
 
Exoplanets are introduced and students learn how astronomers detect their presence as well as the challenges associated with it. Physics equations are explained as well as their importance in the context of the course. A number of problems are worked out to get students used to dealing with large numbers in calculating planetary masses, interplanet…
 
Professor Bailyn introduces the course and discusses the course material and requirements. The three major topics that the course will cover are (1) exoplanets--planets around stars other than the Sun, (2) black holes--stars whose gravitational pull is so strong that even their own light rays cannot escape, and (3) cosmology--the study of the Unive…
 
Loading …

クイックリファレンスガイド

Google login Twitter login Classic login