By William J. Furney
It’s not just a big world out there, but an enormous, gargantuan universe that’s so impossibly large — and growing — that it’s barely possible for humans to get their heads around the sheer scale of the galactic environment we are all inhabitants of.
And while there have been enormous strides in our understanding of the universe and what it’s composed of — even if no one has a clue how it came about in the so-called Big Bang — it turns out that we know precious little about its makeup at all.
A lot of the universe, it’s believed, is still evasive, with around 68% made up of dark energy that has no interaction with light and 27% dark matter, leaving a paltry 5% of what we can see in the heavens.
It’s a deeply sobering thought for a humanity that oftentimes thinks it knows it all.
To find out more about scientific undertakings in the quest for more expansive knowledge about the universe, I asked Steve Lamoreaux, professor of physics at Yale University, for his thoughts.
You’re using relatively small devices and instruments, as part of your HAYSTAC project, to try and detect dark matter — of the theoretical cold variety. How does this stack up against what CERN — home of the largest machine in the world, the Large Hadron Collider — is doing?
There is no comparison. CERN has become a sort of city-state, in the medieval sense. The yearly CERN budget for postage stamps is probably 100-1000 times the yearly expenditures on HAYSTAC. When Trump was elected president, there was fear that the US science budgets would be cut, so my funding was cut so much that I could only afford to support one graduate student at Yale and myself for one month of work a year.
I should mention that HAYSTAC is a collaboration between UC Berkeley, Colorado University/JILA — Joint Institute for Laboratory Astrophysics, which exists between CU and NIST Boulder. UC Berkeley supplies the microwave cavity, while CU designs and constructs the quantum limited receiver.
We bring it all together at Yale and make sure everything will be at a NASA level of reliability. The system must be able to run for months without failure — CERN projects have the same need, and that is probably the one point of comparison that makes sense in regard to engineering.
Getting the quantum receiver to work in the presence of a very large magnetic field was probably the biggest challenge. It took a new invention. CERN has problems like that;the difference is they have a team of crack engineers.
In studying the fundamental properties of the universe, what have you and your colleagues learned or unveiled so far?
We have set limits on a very narrow region of parameter space where the axion (a hypothetical subatomic particle), if it is the major part of the galactic halo dark matter, would be evident. The axion solves several problems in theoretical physics, and historically this has often been an indication that a path of inquiry might be useful, not a guarantee by any stretch of the imagination. Anything that is proposed to explain something has to be applicable to a broad range of observed physical phenomena. Saying something works here but not there means the theory is rubbish.
How close are we to finding out what dark matter and dark energy are, and if they exist at all? Are we solely relying on their gravitational effects so far, to give a clue to their existence?
You might remember that for gases such as ordinary air, you can relate pressure, volume, number of moles and temperature through PV=nRT. That is the equation of state for ideal or perfect gases.
There is an equation of state for the universe that includes the effects of dark energy, dark matter, and ordinary matter. This is built on the framework of General Relativity; so in that sense, we are relying on the gravitational effects but not entirely in the simple measuring of gravity within galaxies and using that to imply missing mass.
There has been speculation that perhaps Newton’s law of gravitation needs to be modified (MOND theories). Again, one has to look at a broad class of phenomena. Take the Pioneer anomaly that has really tested Newtonian dynamics at a level of precision that is almost unimaginable at length scales that are reasonably large. The equation of state is based on the measurements of the cosmic microwave background and distance/velocity of a specific type of supernova.
Those measurements imply dark matter and dark energy but don’t say anything much about the character. We also see galactic rotation curves that need dark matter — by the way, dark matter is really invisible matter. It does not interact with light or matter other than through gravitational effect.
In the 1980s through 1990s, there was a lot of work trying to figure out how galaxies formed. Nobody could figure out how this happened because there is not enough visible matter. Dark matter solves this problem also.
You could argue that these are all gravitational effects, but I think there is more to it.
What do you think dark matter might actually be? Do you have any hunch about it? There is some speculation in a recent CERN article.
When your tool is a hammer, everything looks like a nail. CERN can make high-energy particles and do precision experiments, and very impressively. One initial line of thinking was that dark matter is weakly interacting massive particles (WIMPs), because of something called the wimp miracle, because the properties of such particles fit well into the standard model.
The first experiment that was switched on to look for WIMPs showed that the miracle wasn’t. On the other hand, something called supersymmetry suggests that there could be all sorts of particles that might not interact with ordinary matter, at least not very much. So these types of experiments have been continuing and are reaching the point where neutrinos from the sun will be too much of a background to continue.
The axion strikes me as a very likely candidate.
Might it ever be possible to use dark energy as a power source?
Probably not. However, a driving force behind scientific investigation toward discovery is to make sure that what exists in nature can’t be used as a weapon. We know from history that the nation that does not lead in technology and scientific expertise ends up subservient to other nations. The problem is that you can’t pick and choose what you think is important, because you end up missing the new thing.
Do you believe that string theory, if ever proven, could explain the fundamental workings of the universe and reconcile general relativity with quantum mechanics? Or M-theory, which seeks to unite different versions of superstring theory?
Even if it did, the question would be then: What do these other levels mean? The onion has many layers of skin.
Is it possible there could be up to a dozen dimensions, as set out in these theories, instead of the four we currently believe only exist — length, width, depth and time?
In some sense, there are dozens of dimensions in quantum mechanics, as Hilbert space is multidimensional. So in some sense that is dealt with already, and has been since the beginning of the last century, if not earlier, in classical statistical mechanics.
But what is meant here is does the theory of relativity need more dimensions? The only way to know is to ask questions — form a hypothesis — and test it. If various theoretical venues can be brought together with string theory, unless there is a new predicted phenomenon that could be tested, the result would be academic and speculative.
What is your view of a multiverse, with many universes bound by “quantum foam”?
This goes back to [the previous question]. I’d ask the replica of myself in the next universe but he isn’t answering his phone.
Whether there’s just one universe, or an entire collection of them, what do you think they’re “contained” in — as in, does our universe have an edge, what is it expanding into and does it exist outside the realms of space and time?
We need to try to see the universe through our eyes, and not through our egos. Container is an attempt to force our common understanding onto something that is so foreign that we don’t have the language to really even discuss it. Some say that perhaps we are living in a computer simulation.
This idea is very old. The Greek philosopher Parmenides thought that motion was impossible and concluded that the physical world is an illusion, and Zeno was his student; so all of those paradoxes were in support of this.
Leucippus, and his student Democritus, came up with the idea of atoms to counter this philosophy. But most importantly, they constructed the Void in which atoms move. Shakespeare also went down this path — “all the world’s a stage.”
Do you believe there’s other intelligent life in our universe, and not so distant that we may one day make contact, or they with us?
“Other” is a loaded term here. Look at the Trump presidency, and poor Jacob Chansely in particular (The QAnon Shaman), who is defending himself by saying he prevented the theft of muffins from an office during the Capitol Insurrection.
I would ask if there is any intelligent life.
Seriously, we ask if reality is “real” — do we live in a simulation? — but is intelligence real? Do we have free will? I think people are prisoners to primeval thoughts, like not wanting to pay taxes and keeping America white, and will do destructive things like support Trump when it’s against their ability to survive in the long run.
On the other hand, there might be emergent intelligent life elsewhere. Given the ability of so-called intelligence to destroy itself, we could be on a horizon of hundreds and hundreds of civilizations popping up. Given that the laws of physics — hence the laws of chemistry and biology are the same everywhere — the timescale for the emergence of organisms able to ask if there are others in the universe should take about the same time. So the time is ripe. With that said, there could be a first. There might have been others that destroyed themselves.
Do you think it’s possible that Black Holes are ultimately the engines of new universes, resulting in “Big Bangs” when they get stuffed with too much matter, tearing the fabric of a universe and rupturing into a new space with all that material exploding out?
It seems there are some pretty big black holes and I know of no upper limit.
What’s the most surprising, or interesting, thing you can say about the universe as we currently know it?
The stability of matter. People talk about how mysterious and spooky Bell states are — action at a distance and all of that. On the other hand, why should the symmetry of the wavefunction of two atoms be important? If not for the Pauli exclusion principle, all the electrons in the atoms around us would collapse to the ground state and each kilogram of matter would give out as much energy as a small nuclear weapon.
Einstein said “imagination is more important than knowledge” and described himself as not especially brainy but intensely curious about the world — a quality Stephen Hawking also shared. So is it important in physics and all its various branches to have a vivid imagination, or can you get by solely with knowledge?
Hawking knew a lot more mathematics than Einstein ever did, but even during Einstein’s time, Hilbert commented that every schoolboy on the streets of Goettingen knows more about multidimensional calculus than Einstein does — yet Einstein had the vision and did the work.
Knowledge and imagination are both important, but we tend to imagine them as the same thing, or that knowledge is more important. I won’t let A students into my lab; give me a good C+/B- student any day. They can handle the unknown and open-ended projects much better, and can deal with failures that are numerous on the road to success.
You have a keen interest in quantum computing. Is it really the way forward with personal computers, and, if so, when do you think we might start to see them enter the mass market? What kind of things might we be able to do with such vastly more powerful devices than we can with today’s PCs?
There are a class of problems better suited for quantum computing, so I doubt we will ever have a computer based on quantum entanglement — after all, everything is quantum, so we need to specify what kind of quantum do we mean. Do we need quantum entanglement to watch cat videos on YouTube? Probably not.
And finally! What do you think of efforts to get to Mars and start human colonies there?
Why not do the moon first and learn how to live in an inhospitable environment? The atmospheric pressure on Mars is so low that it might as well be zero.
Mars is about half the diameter of the Earth and its gravitational field is so small that it cannot keep an atmosphere. So there’s an overall romantic misconception about turning Mars into something Earth-like.
We’d do better to think about how to reduce the density of Venus’ atmosphere. What’s needed is something like cyaniform bacteria that transformed the earth’s atmosphere into its present state. Maybe we can bioengineer something like that on Earth and send it to Venus. Of course, this would be a long project — billions of years — but now’s the time to start.
On the other hand, our sun is about halfway through its life; and at some time in the future, it will suffer core collapse and turn into a red giant with a diameter slightly larger than the Earth’s orbit.