Nobel Lecture: Kip Thorne, Nobel Prize in Physics 2017

Transcript

thank you can you hear me I'm so pleased to see so many of my like over goal colleagues here I just want to thank you for making me look so good I really think of myself as more of an icon for this collaboration and this nobel prize is really something that i accept as a representative of you who have made this great success in the end i would like... Read More

Summary

In this video, the speaker discusses the development of gravitational wave astronomy and physics. They highlight the three main efforts that have led to the progress in this field, which include the experimental and data analysis effort, the theoretical effort on understanding gravitational wave sources and waveforms, and the combined theoretical and experimental effort on quantum non-demolition. The speaker also discusses the future of gravitational wave astronomy, including the different frequency bands that can be studied and the potential to study moments of the universe.

Questions & Answers

Q: When did the speaker first become involved in the field of gravitational wave detection?

The speaker became involved in the field of gravitational wave detection during his time as a graduate student at Princeton in the period 1962 to 1965. He worked with John Archibald Wheeler and also had some interaction with Ray Weiss, who was a member of Bob Nikki's experimental gravity research group.

Q: What are the two types of waves that can propagate across the universe according to the laws of physics?

The two types of waves that can propagate across the universe according to the laws of physics are electromagnetic waves and gravitational waves. Electromagnetic waves are oscillations of the electromagnetic field that propagate through space, while gravitational waves are oscillations of the fabric or shape of space and time.

Q: How do gravitational waves differ from electromagnetic waves?

Gravitational waves differ from electromagnetic waves in several ways. While electromagnetic waves are incoherent superpositions of emission from individual particles and are easily absorbed and scattered as they travel through the universe, gravitational waves are produced by the coherent bulk motion of large amounts of mass or energy and are never significantly absorbed or scattered. Additionally, electromagnetic waves are oscillations of the electromagnetic field, while gravitational waves are oscillations of the fabric or shape of space and time.

Q: How do scientists study the shapes of gravitational waves produced by colliding black holes?

Scientists study the shapes of gravitational waves produced by colliding black holes by using numerical relativity simulations. These simulations involve solving Einstein's equations on a computer to compute the shapes of the gravitational waves. Numerical relativity simulations have been crucial in extracting the information carried by gravitational waves and inferring the properties of black holes and the distance to the sources.

Q: What is quantum non-demolition technology and why is it important in advanced LIGO?

Quantum non-demolition technology is a field of technology that deals with monitoring the motions of mirrors in gravitational wave detectors to a precision of 10^-17 centimeters. This precision is necessary to circumvent the Heisenberg uncertainty principle and deal with quantum fluctuations of the mirror motions. In advanced LIGO, this technology is crucial for accurately measuring and studying gravitational waves and observing human-sized objects behaving quantum mechanically for the first time.

Q: What are the four frequency bands in gravitational wave astronomy and what can they study?

The four frequency bands in gravitational wave astronomy include the low-frequency band studied by Lisa, where gravitational waves from giant black holes spiraling, colliding, and merging can be observed with high precision. Pulsar timing arrays can study gravitational waves from supergiant black holes using the timing of pulsars. Indirect imaging can be used to study the gravitational waves produced by a small black hole orbiting a large black hole, providing information about the geometry of space and time around the large black hole. Lastly, there is the hunt for unexpected kinds of massive central bodies using gravitational wave observations.

Q: What are some potential future discoveries in gravitational wave astronomy?

There are several potential future discoveries in gravitational wave astronomy. For example, it is predicted that gravitational waves from first-order phase transitions and amplification by inflation during the early moments of the universe could be observed. This would provide insights into the birth of the laws of electromagnetism, as well as the laws of quantum gravity governing the birth of the universe. Additionally, the comparison between gravitational waves with different periods and polarization patterns from the Big Bang could potentially reveal new information about the nature of the universe.

Takeaways

Gravitational wave astronomy and physics have made significant progress in recent years, thanks to the collaborative efforts of researchers and the development of advanced detectors. The study of gravitational waves has the potential to revolutionize our understanding of the universe, providing insights into the nature of black holes, the birth of the universe, and the laws of quantum gravity. With the future advancements and observations in gravitational wave astronomy, the possibilities for new discoveries and breakthroughs are incredibly exciting.