It’s shaping up to be a huge week for space and physics news, with two major press conferences about the Universe announced for Thursday 29 June.
They may share a date, but they’re both very separate announcements, and from what we can tell, very distinct discoveries that will be shared with the public.
Speculation aside, both seem to concern advances that could change our fundamental understanding of how the Universe works, and it’s safe to say we’re pretty excited over here at ScienceAlert.
Let’s dive in and get up to speed with what we know so far.
Gravitational wave discovery
As we covered earlier this week, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) is coordinating a global announcement on Thursday 29 June 2023 at 1pm EDT (1700 UTC).
The update will shed light on research conducted by the International Pulsar Timing Array (IPTA) – a worldwide consortium of gravitational wave detectors: North America’s NANOGrav; the European Pulsar Timing Array; the Indian Pulsar Timing Array Project; and Australia’s Parkes Pulsar Timing Array.
Mark your calendars and get ready for a major announcement from the NANOGrav collaboration on June 29th! #nanograv
— NANOGrav PFC (@NANOGrav) June 21, 2023
As of now, they haven’t put out a whole lot of information on what the announcement will be about, but based on the groups involved we can speculate that this is going to involve the gravitational wave background, or GWB. Often referred to as the Universe’s background hum.
Detecting this background hum would be a huge deal as it would revolutionize our understanding of the earliest days of the Universe.
“For example, electromagnetic radiation does not provide a picture of the Universe any earlier than the time of last scattering (about 400,000 years after the Big Bang). Gravitational waves, however, can give us information all the way back to the onset of inflation, just ∼10-32 seconds after the Big Bang,” theoretical physicist Susan Scott of the Australian National University and the ARC Centre of Excellence for Gravitational Wave Discovery told ScienceAlert’s senior journalist Michelle Starr.
Teasing out this faint, background hum from all of the other ‘sounds’ in the Universe is incredibly challenging. But one of the most promising ways to find the GWB is using pulsar timing arrays.
Pulsars are a type of neutron star, the remains of once-massive stars that have died in a spectacular supernova, leaving just a dense core behind.
These rotating stars act like cosmic lighthouses, with their beams of radio emissions sweeping over Earth at precise intervals.
Gravitational wave ripples should, in theory, produce tiny irregularities in the timing of these pulsar flashes.
One pulsar on its own wouldn’t signal much, but a large number of pulsars all showing similar inconsistencies could represent the kind of gravitational waves we’d expect to see produced by the mass merging of black holes in the early Universe, as Michelle Starr explained.
This is exactly what the IPTA is looking for – and perhaps, what they found.
We’ll have to wait until Thursday to find out. But you can rest assured we’ll be sharing with you as soon as we know more.
Meanwhile, sit tight and wait here for their live stream.
Neutrino discovery
The second announcement on Thursday, which has erroneously been linked to the NANOGrav announcement on social media, is from the IceCube Neutrino Observatory built deep within the Antarctic ice.
Is it a coincidence, that there will also be an announcement on Icecube at the same date? https://t.co/tim2rK3inb
— Ole Streicher ????❤???? ???????? (@OleStreicher) June 22, 2023
This particle detector is searching for neutrinos; subatomic particles that are incredibly challenging to detect due to their lack of charge and a mass that’s virtually non-existent.
This specter-like ability to pass through our world en masse and unnoticed has earned neutrinos the nickname of ‘ghost particles’. It also makes them ideal subjects to study distant cosmic events as their path and characteristics remain relatively unchanged by their surroundings as they fly through space.
Neutrinos are emitted as a part of the beta decay process that turns neutrons into protons – which makes them one of the most abundant of subatomic particles in the Universe, with tens of billions hitting your fingernail every second without you ever noticing.
We’ve previously detected neutrinos from distant quasars, particle colliders, and even our own Sun. They’re even a candidate for the mysterious material known as dark matter.
We don’t know much about the announcement coming Thursday except that it’s definitely going to involve some kind of intriguing neutrino detection – and will have very little to do with gravitational waves!
The IceCube announcement will be livestreamed below at 2pm EDT (1800 UTC) on Thursday, 29 June 2023.
We’ll be watching live with you, and reporting on the results as we get them in!
