Is the prediction of "The Three-Body Problem" coming true? The Milky Way may be losing dark matter

We all know that the ending of "The Three-Body Problem: Death's End" is that the universe's great god-level civilization zeroer declares the restart of the universe in the universe, but because the restart requires mass conservation, the multi-civilization micro-universes need to hand over the mass stolen from the big universe. Cheng Xin took the initiative to hand over the mass of the micro-universe and wait for the restart of the universe, but Cheng Xin still retains 5 kilograms of memory in the micro-universe. So whether the universe was successfully restarted, Liu Cixin did not write it, leaving us with endless reverie.

So, is it possible for the universe to lose mass? Is there any basis for Liu's prediction?

The answer is yes! A new study shows that the Milky Way appears to be losing some of its dark matter.

An international team of astronomers led by scientists from the Paris Observatory in France used data from the Gaia space telescope to estimate that the mass of the Milky Way is about 200 billion times the mass of the sun, only 1/5 to 1/4 of previous estimates. This study seems to indicate that the Milky Way is losing some dark matter, an invisible substance that accounts for about 85% of the total mass of the universe. The new research was published in the latest issue of the journal Astronomy & Astrophysics.

The Gaia space telescope has created an astronomical map of 1.8 billion stars in the Milky Way.

Image source: NASA official website

The Gaia space telescope has mapped the Milky Way's 1.8 billion stars, allowing researchers to estimate that the total mass of the Milky Way is only 200 billion times that of the sun, compared with previous estimates of about 890 billion to 1 trillion times the mass of the sun.

Dr. François Hamer of the Paris Observatory, an author of the study, explained that they calculated the mass of the Milky Way by observing its rotation curve. Essentially, the Milky Way is a spiral galaxy composed of 100 billion to 400 billion stars, which scientists believe are surrounded by a halo of dark matter. Although the 1.8 billion stars mapped by Gaia are only a small fraction of the total number of stars in the Milky Way, it is enough for researchers to calculate its accurate rotation curve.

The rotation curve of the Milky Way is different from other large spiral galaxies because it is not flat. Moreover, after the 1970s, scientists proposed a theory that large spiral galaxies must be surrounded by dark matter halos. The latest research shows that the rotation curve of the Milky Way begins to drop rapidly at the outskirts of the galactic disk, and the orbit speed of stars is slower than expected, which indicates that some gravity from dark matter is "absent."

The researchers said the Milky Way's rotation curve "may be due to the Milky Way's unusually quiet history": its last major merger occurred about 9 billion years ago, while other spiral galaxies merged about 6 billion years ago. In addition, this discovery may have far-reaching implications for understanding the Milky Way's 13 billion-year history, as it may indicate that the Milky Way has collided with other galaxies less often than its peers.

Author: Liu Xia Source: Science and Technology Daily