In September 2015, some of the most sensitive instruments ever built made a remarkable discovery: the first-ever detection of tiny ripples in space and time, known as gravitational waves. Created by a pair of black holes spiralling towards each other and crashing together, the observed wave travelled through space at the speed of light until it was detected by two separate observatories here on Earth.
Now scientists are setting their sights on grander goals, hoping to observe the entire Universe, looking back in time to its very origin, with gravitational waves. In January 2024, the European Space Agency (ESA) gave the green light for an international team of scientists to begin building the largest gravitational wave detector ever built - only this time it will be in space. Its name is LISA, the Laser Interferometer Space Antenna, and it will revolutionise our understanding of the Universe.
Gravitational waves are ripples in space and time, similar to those formed on the surface of water when a pebble is dropped from a height. Gravitational waves, however, are caused by some of the most violent astrophysical events in the Universe, such as black holes smashing together. They were predicted by Albert Einstein in his general theory of relativity more than a century ago. According to theory, gravitational waves expand and contract spacetime itself. Everything, including you and me, will stretch and squeeze as a gravitational wave passes by. Thankfully, although gravitational waves are thought to be like tsunamis at the source, by the time they reach us here on Earth their effects are minuscule; so small, in fact, that gravitational waves produced by some of the most energetic events in the Universe are thought to only stretch and squeeze the entire Earth by a fraction of the width of an atom.
Shudders in spacetime
Denne historien er fra June 2024-utgaven av BBC Sky at Night Magazine.
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Denne historien er fra June 2024-utgaven av BBC Sky at Night Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
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Could We Find Aliens by Looking for Their Solar Panels?- Designed to reflect ultraviolet and infrared, the panels have a unique fingerprint
Researchers searching for life beyond Earth spend a lot of time thinking about what telltale signs might be detectable astronomically. Forms of unambiguous evidence for the presence of life on another world are known as biosignatures. By extension, techno signatures are indicators of activity by intelligent, civilisation-building life.
Antimatter- In our continuing series, Govert Schilling looks at antimatter, the strange counterpart to most of the matter filling our Universe
Particles and corresponding antiparticles are very much alike, except they have opposite electrical charges. For instance, the antiparticle of the electron - known as the positron - has the same tiny mass, but while electrons carry a negative electrical charge, positrons are positively charged.
Where Have All The Milky Way's Early Stars Gone?- Our Galaxy has a curious lack of pristine stars
The Big Bang produced a Universe filled almost exclusively with hydrogen and helium; all other elements - what astronomers call metals - were produced by stars, supernovae and everything that happens later. So if you can pick out a pristine star with no metals polluting it from among the billions in the Milky Way, then you are likely to have a star dating from our Galaxy's earliest days.
Inside The Sky At Night - Two years ago, exoplanet scientist Hannah Wakeford received some of the first data from the JWST
Two years ago, exoplanet scientist Hannah Wakeford received some of the first data from the JWST. In July's Sky at Night, we discovered what she's learned since then.
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Once-a-century solar storm is overdue
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The new era of human spaceflight
There's been a step-change in crewed space missions since the dawn of the 21st century. Ben Evans charts its course and looks ahead to future horizons
