Scientists are preparing to reveal the first image of a black hole



[ad_1]

Of all the forces or objects in the Universe that we can not see: dark energy and dark matter, none has frustrated human curiosity

Of all the forces or objects in the Universe that we can not see, dark energy and dark matter, none has frustrated so much human curiosity as the invisible jaws that destroy and swallow entire stars like so many dust particles, known as black holes

The world, apparently, will soon see the first image of a black hole.

On Wednesday, astronomers from around the world will hold "six major press conferences" simultaneously to announce the first results of the Event Horizon Telescope (EHT), which was designed precisely for that purpose.

It has been a long wait.

Of all the forces or objects in the Universe that we can not see, including dark energy and dark matter, none has frustrated human curiosity as much as the invisible jaws that crush and swallow stars like so many dust particles.

Astronomers began to speculate about these omnivorous "dark stars" in the eighteenth century, and since then, indirect evidence has slowly accumulated.

"More than 50 years ago, scientists saw that there was something very bright at the center of our galaxy," Paul McNamara, an astrophysicist with the European Space Agency and an expert on black holes told AFP.

"It has a gravitational pull strong enough to make stars orbit around it very quickly, in just 20 years."

To put that in perspective, our Solar System takes around 230 million years to surround the center of the Milky Way.

Finally, astronomers speculated that these bright spots were actually "black holes," a term coined by American physicist John Archibald Wheeler in the mid-1960s, surrounded by a band of gas and plasma.

At the inner edge of these luminous accretion disks, things darken abruptly.

"The event horizon" -a.k.a. the point of no return: "it is not a physical barrier, it could not be supported," explained McNamara.

"If you're inside, you can not escape because you need infinite energy, and if you're on the other side, you can, in principle."

A golf ball on the moon.

At its center, the mbad of a black hole is compressed into a single point of zero dimension.

The distance between this so-called "singularity" and the event horizon is the radius, or half the width, of a black hole.

The EHT that collected the data for the first image has never been designed.

"Instead of building a giant telescope that would collapse under its own weight, we combined several observatories as if they were fragments of a giant mirror," Michael Bremer, an astronomer at the Grenoble Millimeter Radioastronomy Institute, told AFP.

At its center, the mbad of a black hole is compressed into a single point of zero dimension. The distance between this call

At its center, the mbad of a black hole is compressed into a single point of zero dimension. The distance between this so-called "singularity" and the event horizon is the radius, or half the width, of the black hole

In April 2017, eight of these radio telescopes scattered around the world, in Hawaii, Arizona, Spain, Mexico, Chile and the South Pole, received training in two black holes in very different corners of the Universe to collect data.

Studies that could be released next week will likely focus on one or the other.

Bettors favor Sagittarius A *, the black hole at the center of our own elliptical galaxy that caught the attention of astronomers.

Sag A * has four million times the mbad of our sun, which means that the black hole that is generated is approximately 44 million kilometers wide.

This may seem like a big goal, but for the set of telescopes on Earth about 26,000 light years (or 245 trillion kilometers) away, it's like trying to photograph a golf ball on the Moon.

Einstein test

The other candidate is a black hole monster, 1,500 times more mbadive even than Sag A *, in an elliptical galaxy known as M87.

It is also much farther from Earth, but the distance and size are balanced, which makes it more or less easy to identify.

One of the reasons why this dark horse might be the one revealed next week is the light smog within the Milky Way.

"We're sitting on the plain of our galaxy, you have to look through all the stars and the dust to get to the center," McNamara said.

The data collected by the series of remote telescopes had yet to be collected and collected.

"The image creation algorithms we developed fill in the missing data gaps to reconstruct the image of a black hole," the team said on its website.

Astrophysicists not involved in the project, including McNamara, are anxious, perhaps anxious, waiting to see if the findings challenge Einstein's theory of general relativity, which has never been tested on this scale.

Innovative observations in 2015 that caused scientists involved in a Nobel Prize to use gravitational wave detectors to track two black holes crushing together.

As they merged, they undulated in the curvatures of space-time creating a unique and detectable signature.

"Einstein's theory of general relativity says that this is exactly what should happen," said McNamara.

But those were small black holes, only 60 times more mbadive than the Sun, compared to any of those that were under the EHT's gaze.

"Maybe those that are millions of times more mbadive are different, we just do not know."



© 2019 AFP

Citation:
Scientists are ready to reveal the first image of a black hole (2019, April 6)
retrieved on April 6, 2019
from https://phys.org/news/2019-04-scientists-unveil-picture-black-hole.html

This document is subject to copyright. Apart from any fair treatment for private research or study purposes, no
Part can be reproduced without written permission. The content is provided for informational purposes only.

[ad_2]
Source link