Supernova Discovery Leads to Alien Search, Fast Neutrinos, And the Creation of Earth

This Week's Science Bits from SWTG

Supernova Discovery Leads To Alien Search

The new supernova SN 2023ixf in M101. Image: Florian Rünger, University of Potsdam

On May 19, Japanese astronomer Koichi Itagaki discovered a new supernova in the spiral galaxy M101, about 21 million light years away. It’s been given the catchy name SN 2023ixf and has now inspired a search for extraterrestrial life. The idea is that any half-witted being of whatever species out there would understand that a supernova makes astronomers on other planets look your way. So when the signal passes by the alien astronomer, they would send a signal out at that moment. From the time and location of the supernovae one can therefore calculate the locations from which we might receive the potential alien communication.

A team of astronomers just announced on the pre-print server arXiv, that they plan on using the Allen Telescope Array and the Robert C. Byrd Green Bank Telescope to do this search. A note underneath the pre-print says that collaborators are welcome, so if you’ve always wanted to search for aliens, this might be your chance. 

Earth Might Have Been Created Faster Than We Thought – And That’s Good News

According to researchers at the University of Copenhagen, Earth was created by the rapid accumulation of small pebbles in just a few million years, instead of the gradual collision of larger bodies over 100 million years, as previously thought. In a just-released study, they explain that this would mean water was already present in the pebbles that made up Earth, and not delivered later by comets or asteroids. Since water is a key ingredient for life (as we know it), the researchers say that this finding increases the chance of finding other habitable planets. Press release here. Paper here. 

Quantum Gravity from Neutrinos? Not So Fast

Image: Amelino-Camelia et al, Nature Astronomy (2023).

A paper that just appeared in Nature Astronomy claims that a bunch of highly-energetic neutrinos that arrived late from gamma ray bursts could be evidence for quantum gravity.

The idea behind the paper is an old one that superficially makes sense. If space-time had quantum fluctuations, that could impede how particles travel in a way that depends on the energy of the particle. These quantum-fluctuations are often referred to as “quantum foam.” The issue is that the energy of a particle depends on its motion relative to you. It is, as Einstein would have put it, observer-dependent. Such a space-time foam could therefore be used to define a preferred frame.

Not only is such quantum foam not a consequence of any consistent approach to quantum gravity and contradicts Einstein’s theories, it’s also in conflict with countless experiments that have looked for the existence of such a preferred frame. The only way to keep this idea alive is to postulate that, for some reason, the foam only affects particles for which we have very little data, such as, well, neutrinos.

In the paper, they tried to infer a trend in the arrival time of neutrinos that seem to be correlated with electromagnetic signals from gamma ray bursts. Even leaving aside the questionable motivation, there’s the issue that one doesn’t know the neutrinos actually came from the same source. The authors estimate that the trend they see has a chance of only 1% to have occurred by chance. I am highly sceptical that this estimate is accurate, but I doubt anyone has the energy to debunk this analysis.

In summary, I think we’ll not hear of this again, and it’s for the better.

Paper here. Press release here.