For some of us, the idea of parallel universes ignites our wildest dreams. If there are other universes where certain events have different outcomes – where only one crucial decision goes differently – there may be some way to access them. Maybe particles, fields, or even humans could be transported from one to the other, allowing us to live in a universe that is better, in some ways, than our own. These ideas are also based on theoretical physics, from countless possible results in quantum mechanics, as well as the ideas of the multiverse. But do they have anything to do with observable, measurable reality? A statement has recently emerged claiming that we have found evidence of parallel universes, and Jordan Colby Cox wants to know what it means by asking:
There is an article floating around that claims that physicists in Antarctica have found evidence of a parallel universe. I find this very unlikely, but I wanted to be sure by asking you to address the truth of the story.
Let’s look and understand.
From a physical point of view, parallel universes are one of those intriguing ideas that are imaginary, fascinating, but very difficult to test. They first originated in the context of quantum physics, which is known to have unpredictable results, even if you know everything you can about how you set up your system. If you take an electron and shoot it through a double slit, you can only know the probabilities of where it will land; you can’t predict exactly where it will appear.
One remarkable idea – known as the very global interpretation of quantum mechanics – postulates that any results that may occur actually occur, but only one result can occur in each universe. An infinite number of parallel universes are needed to account for all possibilities, but this interpretation is as valid as any other. There are no experiments or observations to rule it out.
The second place where parallel universes arise in physics is from the idea of the multiverse. Our observable universe began 13.8 billion years ago with the hot Big Bang, but the Big Bang itself was not in the beginning. There was a very different phase of the universe that came before that created and gave rise to the Big Bang: cosmological inflation. When and where inflation ends, the Big Bang occurs.
But inflation does not end everywhere at once, and places where inflation does not end continue to inflate, creating more space and more potential Great Shores. Once inflation starts, it is virtually impossible to stop inflation from happening continuously, at least somewhere. Over time, more and more Big Bang appear – all interrupted by each other, giving rise to an innumerable number of independent universes: the multiverse.
The big problem with both ideas is that there is no way to test or limit the prediction of these parallel universes. After all, if we are left in our own universe, how can we even hope to gain access to another? We have our own laws of physics, but they come with a whole set of quantities that are always preserved.
Particles do not appear, disappear or simply transform; they can only interact with other quanta of matter and energy, and the results of these interactions are similarly governed by the laws of physics.
In all the experiments we have ever done, all the observations we have ever recorded, and all the measurements we have ever made, we have never found an interaction that requires something outside of our own, isolated universe to explain.
Unless, of course, you’ve read the headlines this week, announcing that scientists in Antarctica have found evidence of parallel universes. If that were true, it would be absolutely revolutionary. This is a spectacular statement that would show us that the universe as we currently think of it is inadequate and has much more to learn and discover than we thought possible.
Not only will these other universes be there, but the matter and energy from them will have the ability to pass to and interact with matter and energy in our own universe. Perhaps, if this statement were true, some of our boldest science fiction dreams would be possible. Maybe you could travel to the universe:
- Where did you choose the job abroad instead of the one that kept you in your country?
- Where did you face the bully instead of letting yourself take advantage?
- Where did you kiss the one who passed at the end of the night instead of letting them go?
- Or where did the event of life or death that you or your loved one encountered at some point in the past have a different outcome?
So what was the remarkable evidence that demonstrates the existence of a parallel universe? What observation or measurement was made that led us to this remarkable and unexpected conclusion?
The ANITA (Antarctic Impulse Transition Antenna) experiment – an experiment carried by a balloon that is sensitive to radio waves – discovered radio waves with a specific set of energies and directions coming under the ice of Antarctica. This is good; this is what the experiment is designed to do! In both theory and practice, we have all kinds of cosmic particles traveling through space, including ghostly neutrinos. While many of the neutrinos that pass through us come from the Sun, stars, or the Big Bang, some of them come from colossally energetic astrophysical sources such as pulsars, black holes, or even mysterious, unidentified objects.
These neutrinos also come with a variety of energies, the most energetic (surprisingly) being the rarest and, for many physicists, the most interesting. Neutrinos are most often invisible to normal matter – it will take about a year for lead to make a 50/50 shot to stop one – so they can realistically come from any direction.
However, most of the high-energy neutrinos we see are not produced from afar, but are produced when other cosmic particles (also with extremely high energies) hit the upper atmosphere, producing cascades of particles that also lead to neutrinos. Some of these neutrinos will pass through the Earth almost completely, interacting only with the outer layers of the Earth’s crust (or ice), where they can emit a signal to which our detectors are sensitive.
The rare events that ANITA saw corresponded to a neutrino coming through the Earth and producing radio waves, but at energies that must be so high that passing through the Earth without being able to be impeded should not be possible.
How many such events did they see? Three.
Did they have to come across Earth? No. The first two could be normal air shower tau neutrinos (one of the three types of neutrinos is allowed), while the third is probably just part of the experimental background.
In fact, there is unusual evidence that they are causing trouble coming through Earth: IceCube’s neutrino detector exists, and if high-energy tau neutrinos regularly cross Earth (and the ice of Antarctica), IceCube would finally see a signal, and, unequivocally, did not.
Scientifically, this means that:
- ANITA saw radio signals that it could not explain,
- their leading hypothesis was that high-energy tau neutrinos travel upward through the Earth,
- and this hypothesis was refuted by IceCube’s observations,
- teaches us that there is no astrophysical point source to create the particles that ANITA indirectly sees.
So where do parallel universes go into all this?
Since there were only three explanations for what ANITA saw: either there is an astrophysical source for these particles, there is a flaw in their detector or their interpretation of the detector data, or something very exotic, remarkable and outside the standard model (known as CPT Violation). ) happens. Some very good sciences have ruled out the first option (back in January), which means that it is almost certainly the second option. The third? Well, if our universe can’t break the CPT, maybe it’s coming from a parallel universe where the CPT is reversed: an explanation that’s as unlikely as it’s badly argued.
Remember: in science, we must always exclude all conventional explanations that do not involve new physics before resorting to breaking the game. Over the last decade, a number of remarkable allegations have been made, which have disintegrated in further investigation. Neutrinos do not travel faster than light; we found no dark matter or sterile neutrinos; cold synthesis is not real; the impossible “reactionless engine” was a failure.
There is a remarkable history here that pertains to good science. An experiment (ANITA) saw something unexpected and published their results. A much better experiment (IceCube) followed him and turned off their leading interpretation. I strongly suppose it is wrong with the first experiment and more science will help us discover what is really going on. For now, based on the scientific evidence we have, parallel universes must remain a science fiction dream.
Send your questions Ask Eaton at startwithabang at gmail dot com!