Event Title: Instrumentation and Engineering in Astronomy
Date and Venue: 10 Oct 2024, at C301 VIT, Kondhwa Campus
Speaker: Ashish Mhaske Sir (B. Tech, M. Tech in ECE, Scientific officer at IUCAA)
Organizer: Antariksh Astronomy Club of VI
Introduction
The event was started by greeting the audience, Shravya Bhandary and Prajakta Joshi (Core Team Member @ Antariksh). They introduced the club by addressing various workshops, stargazing events, and internal talks done by the club.
Then the Speaker Mr. Ashish Mhaske (B. Tech, M. Tech in ECE, Scientific officer at IUCAA) joined the event along with Mr. Jameer Manur (Senior Researcher at IUCAA), and Prof. Milind Patil (Faculty Coordinator VIIT Pune).
The objective of the talk was to give insights into opportunities for Engineers in Astronomy and the role of Engineering in building and designing Instruments used for Astronomical research.
Overview of the talk:
During the talk, Ashish Sir discussed three types of communicators in Astronomy: EM(Electromagnetic) Waves, Particles, and Gravitational Waves. The speaker also covered the advanced technologies and instruments designed for these observations, such as radio telescopes, particle detectors, and interferometers.
They highlighted the vast opportunities for engineers in various fields of astronomy. He emphasized fields like mechanical and electrical engineering also play a crucial part in the construction and maintenance of observatories and space-based instruments.
The session concluded with an engaging Q&A.
Detailed Walkthrough
Ashish Sir started the discussion with the history of engineering in Astronomy, and how optical astronomy started when Gallio built an optical telescope back in 1609. Then they discussed Domains of Science which are Theory, Experiments, and Data analysis. The interrelation of these domains with each other was discussed. They explained how Theoretical physics evolved with time as one theory fails to explain certain phenomena, other theories come with practical models. They gave examples of how Newtonian physics failed to predict the orbits of Mercury, then Einstein came up with his Theory of General Relativity which helped explain these strange deviations from what Newton's laws predict. And then Newton’s Theory was updated with General Relativity, later general theory of relativity also failed to explain the merger of the Black Hole, and Sir gave the conclusion that Einstein’s theory is also incomplete.
EM Wave detectors: Then moving ahead they discussed Electromagnetic wave Detector, because of the opacity of the atmosphere, the atmosphere is not transparent to higher energy radiation like gamma rays, X-rays, and Ultraviolet rays, then in the Infrared spectrum, it is not possible from ground to detect these because of IR walls, the huge band of radio is available for ground-based radio astronomy, and then again because of the ionosphere waves with large wavelength reflect space. They showed images in Radiofrequency, Hydrogen line, Infrared, and optical for better understanding. Then they discussed that in the late 1880s, Heinrich Hertz set out to prove James Clerk Maxwell's theory that electromagnetic waves, including radio waves, travel through space. The experiment Hertz conducted was simple but revolutionary. He used a spark gap transmitter.
The role of Radio Astronomy in EM wave detectors was discussed. Starting with Carl Jansky while working at the bell lab for intercontinental communication an unexpected signal was getting received at a certain time of day, then it was found out that the source of the radiation was not local, but was from the center of the galaxy. Then continuing in discussion, they showed the interesting Atomic Hydrogen Line (20-40 MHz) detected by Horn Antenna. They discussed the working of a typical radio antenna and showed a short movie on how GMRT works. They gave some examples of Low-Frequency Radio Telescope (LOFR) like Square Kilometre Array (SKA), and ALMA (Atacama Large Millimetre/submillimetre Array).
Then moving toward other EM wave detectors, they described the Tera Hz detector (100-300 GHz), IR/optical Astronomy and also explained the basic construction of X-ray telescopes.
Particle detectors: Moving further in discussion they talk about how Particle detectors work. They gave reference to Sudbury Neutrino Observatory (SNO) located deep down in mine (To eliminate surface interference) in Sudbury, Ontario, Canada, and Kamiokande located in a mine in Kamioka, Japan. And the better version of these which is the IceCube Neutrino Observatory, located (2-3 Km deep) at the South Pole.
They also showed the image of a particle detector at IUCAA.
Gravitational Wave Detector: Continuing the further discussion on Gravitational wave detector they start with the general theory of relativity, the source of a gravitational wave is merging Black holes and merging Neutron Stars (Revolving Neutron stars which follows general theory of relativity), As the black holes approach each other, their gravitational fields intensify, causing significant distortion in spacetime. This distortion becomes increasingly pronounced as they near the event horizon. After the merger, a new singularity forms at the center of the newly created black hole. The distortion in spacetime around this singularity is extreme, the merger produces strong gravitational waves, these waves propagate outward at the speed of light and can be detected. They showed a movie visualizing the merger of black holes and the generation of gravitational waves having radiation magnitudes of about solar mass.
In 1960 scientists tried to detect gravitational waves but they failed due to insufficient sensitivity of the instrument, The Sensitivity required to detect gravitational waves is in the order of 4*10-18 meters.
LIGO (Laser Interferometer Gravitational-Wave Observatory): Which has 2 working observatories, LIGO Hanford and LIGO Livingston. LIGO uses a laser interferometer design consisting of two long vacuum chambers (each 4 kilometers in length) arranged in an L-shape. A powerful laser beam is split into two beams that travel down the arms, reflect off mirrors made of pure Silica, and return to a central beam splitter. When a gravitational wave passes through the detector, it distorts spacetime, causing a slight change in the length of the arms. This change is detected by measuring the interference pattern of the recombined laser beams.
In September 2015, LIGO made its first detection of gravitational waves from the merger of two black holes. This landmark event confirmed a prediction of Einstein's General Theory of Relativity. Also, gravitational waves detect the merger of Neutron Stars. This detection confirms the formation of heavy elements.
Sir tells of many upcoming projects like the LISA Pathfinder mission (Laser Interferometer Space Antenna) The primary goal of LISA Pathfinder was to test and demonstrate the technologies required for future gravitational wave observatories in space. And the INDIGO (Indian Initiative in Gravitational-wave Observations).
Conclusion From the Speaker:
Sir concluded by articulating the role of engineers in the field of astronomy. Sir addresses students that the technology we learn in the classroom is just the application in complex experiments. These experiments are the proof of theories. Also, there are so many opportunities for engineers in the field of astronomy. As astronomy is a multidisciplinary field engineers for all domains; Mechanical, Civil, Chemical and Electronics have opportunities. Sir addressed students to ‘Study with the point of curiosity, If you are interested in astronomy, you will find application of your study in it.’
Vote of Thanks
Harsh Jalnaker (Advisory Board Member, Antariksh) concluded the event by thanking Ashish Mhaske Sir and all the audience members who peacefully attended the event.
Q&A Session
During the event questions asked are:
1. Can we get the position of a black hole with gravitational waves?
Problem: How can we accurately determine the position of black holes in the universe?
Answer: Gravitational waves can help in determining the position of black holes. When two black holes merge, they create ripples in spacetime, which can be detected by observatories like LIGO. By analyzing these waves, we can infer information about the black holes, including their positions and movements.
Takeaway: Gravitational waves provide a new means of observing cosmic events that were previously undetectable with traditional electromagnetic observations.
Application: This capability enhances our understanding of the universe's structure and the dynamics of black hole mergers, contributing to fields like cosmology and astrophysics.
2. What steps is India taking in astronomy?
Problem: What is the current state of astronomical research and funding in India?
Answer: Science funding in India is relatively low compared to other countries, which limits research opportunities. To advance in astronomy, it is crucial to focus on innovation and optimize the use of existing resources.
Takeaway: Increased innovation and efficient resource utilization are vital for enhancing India's position in the global astronomy community.
Application: Students and researchers should seek to innovate within their projects, advocating for better funding and resources to support astronomical research.
3. What is the role of computer science and software engineers in astronomy?
Problem: Role of computer science and software engineers in astronomy.
Answer: All astronomical experiments generate large amounts of data. Software engineers and computer scientists play a crucial role in developing algorithms and tools to process, analyze, and visualize this data effectively.
Takeaway: The intersection of computer science and astronomy is essential for interpreting large datasets, enabling significant discoveries in the field.
Application: Aspiring engineers and scientists should consider careers in data analysis and software development tailored to astronomical applications, helping to bridge the gap between technology and research.
4. How can we observe dark matter?
Problem: What challenges exist in detecting and understanding dark matter?
Answer: The nature of dark matter remains unknown, making it difficult to observe directly. However, the rotation of galaxies provides strong evidence for its existence, as the gravitational effects of dark matter influence the motion of visible matter.
Takeaway: While dark matter cannot be directly observed, its presence can be inferred through its gravitational effects on galaxies and cosmic structures.
Application: Research focused on the properties and behaviors of dark matter can lead to advancements in both theoretical physics and observational astronomy.
