Tag Archives: Experimental gravity

Video: Hunting for gravitational waves using pulsars

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Louise Mayor

Louise Mayor is features editor of Physics World

As features editor of Physics World magazine, my search for stories to share with our readers takes me far and wide – from nuclear reactors to the quietest lab in the world. But sometimes I need look no further than the very office in which I work. That’s because I share my workplace with the staff behind nearly 70 journals published by IOP Publishing. So it was that one lunchtime earlier this year, I got chatting to Adam Day, publisher of Classical and Quantum Gravity (CQG).

Day began telling me about a method of detecting gravitational waves I’d not heard of before, and in no time at all I was hooked. First proposed in the 1970s, the method involves Continue reading →

Achieving resonance in the Advanced LIGO gravitational-wave interferometer

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Alexa Staley

Alexa Staley is a PhD candidate at Columbia University in the City of New York, and has been working as a graduate student at the LIGO Hanford Observatory in Richland, WA.

The next generation gravitational wave interferometers, known as Advanced LIGO, located in Hanford, WA and Livingston, LA have been installed and are in the process of achieving a sensitivity required for the first direct detection of a gravitational wave. The goal of their design is to measure a gravitational strain as small as 4×10–24/√Hz, requiring a length resolution of approximately 10–19 rms within a 100 Hz bandwidth. This high sensitivity demands multiple optical cavities to enhance the response Continue reading →

Testing the weak equivalence principle with atom interferometry in space

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Clifford Will

Clifford Will is the Editor-in-Chief of Classical and Quantum Gravity

The Weak Equivalence Principle (WEP) is one of the three pillars that support all metric theories of gravity, and testing it to high precision has occupied experimentalists for over 100 years. Although many successful tests have been performed, there is still room for new experiments (see this recent CQG focus issue on tests of WEP).

This paper describes in detail a concept called STE-QUEST for testing WEP in space. What makes this different from other space experiments, such as MICROSCOPE, due for launch in 2016, and STEP, still only a design concept, is that those experiments use macroscopic bodies, while STE-QUEST will use fundamentally quantum-mechanical systems: Bose-Einstein condensates of rubidium isotopes. Using atom Continue reading →