Gravity records memories in space-time? Einstein’s “Gravitational Memory” can be real – we just don’t have the technology necessary to prove it yet, says new study.
It is considered one of the most fascinating theories of Albert Einsteinbut the famous physique could never prove it.
The concept of “Gravitational Memory”provided for in the general theory of Einstein’s relativity, suggests that the fabric of the universe is permanently altered by the passage of gravitational waveswhich ripple through spacetime when massive objects, such as black holes, merge. Suplens that the “memory” of old events such as the fusion of black holes can be recorded on this fabric by waves.
It is a theory that so far has not passed… well, of a theory – although gravitational waves have been detected.
However, a new study shows that the theory can be confirmed by future cosmic observations.
A team of theoretical physicists has proposed a new method for detecting these gravitational traces: to examine the Cosmic Background Radiation in Microwave (CMB), a fresh shine left by Big Bang.
This radiation has traveled through the space for thousands of millions of years, and takes with it possible marks of powerful gravitational waves of old events such as black hole mergers.
By analyzing changes in CMB temperature, the team expects not only to know the most violent and energetic events in the universe better, but also to say: Einstein was right.
“Since this is a direct prediction of Einstein’s theory of general relativity, his observation would serve as a confirmation of theory, such as the observation of gravitational waves by Ligo, Virgo and Kagra [o Detetor de Ondas Gravitacionais Kamioka] It has done! It can also be used as an additional tool for studying some astrophysical scenarios, as it may contain information about the type of events that generate memory, such as supernoves or collisions of black holes, ”said the study co -author Miquel Miravet-Lenés to the .
Gravitational waves and their effects
As general relativity tells us, gravitational waves are spacetime rods caused by the acceleration of massive objects. These waves travel to the speed of light, and when black holes spirala toward each other and merge, they generate gravitational waves that propagate through the cosmos.
Unlike the typical waves, which cross the matter without leaving a permanent brand, the gravitational waves have the ability to change the structure of the space-time itself. This permanent distortion means that the light that passes through the waves can be subtly altered.
The properties of the photons, or light particles, may reflect the memory of events passed from gravitational waves. The new study suggests that this lasting change can be observed in CMB, which would allow to track the gravitational influences of old cosmic events.
A window for the past
Research focuses on the way cosmic background radiation in microwave, present since the childhood of the universe, can contain the Black hole mergers that occurred a thousands of millions of years ago. These mergers, which involve the collision and fusion of massive black holes, can leave temperature variations in the CMB that reveal their gravitational signature.
“We can for example measure gravitational memory in a gravitational wave sign and have more information about the properties of the two black holes that produced this sign; What is the weight of these black holes or the distance from us, ”explains Kai Hendriks, another co -author of the study.
But the detection of gravitational memory in CMB is not an easy task. The expected temperature variations of these events are incredibly tiny – in the order of a trilionesimo of degree – so it is almost impossible to detect with current technology.
Instruments like the Planck J satelliteThey mapped the CMB in great detail, but the subtle nature of the gravitational memory signal will require more sophisticated technology to observe.
The investigators’ model provides that the gravitational waves of the old black holes would leave behind regions of hot and cold light in the CMB. These patterns would form a weak but discernible sign in the sky, offering a direct way to probe the cosmic events that shaped the universe.
And while the study offers a promising approach to the detection of gravitational memory, researchers notice that their calculations were based on Simplified assumptions. For example, they initially assumed that all fusion black holes had the same mass, when, in fact, black holes can vary greatly in size, from millions to thousands of millions of times the sun mass.
