Why it’s hard for science to answer some basic questions

Science answers many questions but some questions test us because they are inherently difficult. They take us to the margins. Let’s look at some – why they are testing us:

To think big, theoretical astrophysicist Ethan Siegel discuss five puzzles of fundamental physics, any resolution of which “could unlock our understanding of the universe”. They are, how the universe began, what explains the mass of neutrinos, why is our universe dominated by matter, what is dark matter and what is dark energy? : About our matter-dominated universe:

More matter than antimatter permeates the Universe. However, known physics cannot explain the observed matter-antimatter asymmetry.

The Big Bang produced matter, antimatter, and radiation, with some more matter created at some point, leading to our Universe today. How this asymmetry arose or originated where there was no asymmetry to begin with remains an open question, but we can be sure that the excess of up and down quarks relative to their down counterparts antimatter is what allowed protons and neutrons to form. in the early Universe in the first place.

Ethan SiegelThe 5 Biggest Puzzles in Fundamental Physics” at think big (October 3, 2022)

No known science takes us behind the Big Bang when initial conditions such as the prevalence of matter have been established. Here we are in philosophy.

In another article, Dr Siegel talks about the fact that our two descriptions of the universe, general relativity and quantum physics, work quite well, but they do not work together:

We don’t understand how to calculate the behavior of gravity at high energy, at small scales, near singularities, or when quantum particles exhibit their inherently quantum nature. Likewise, we don’t understand at all how the quantum field that underlies gravity – assuming there is one – behaves in all circumstances. This is why attempts to understand gravity on a more fundamental level should not be abandoned, even if everything we do now turns out to be wrong. We have actually succeeded in identifying the key problem that needs to be solved to advance physics beyond its current limits: a huge achievement that should never be underestimated. The only options are to keep trying or to give up. Even if all our attempts ultimately prove fruitless, it’s better than the alternative.

Ethan SiegelThe fundamental problem of gravity and quantum physics” at think big (September 27, 2022)

It’s a particularly awkward discrepancy — not just because the two descriptions should work together — but because our universe gets along well even when they don’t.

Clocks in the sky.  time passes

And then there is time. Ask the BBC: “Why does time go forward and not backward?

Here’s the problem: when you zoom in to, say, a water molecule colliding and bouncing off another, the arrow of time disappears. If you watched microscopic video of this collision and then rewind it, it wouldn’t be obvious which way to go and which way to go. At the smallest scale, the phenomenon that produces heat – the collisions of molecules – is symmetrical in time.

This means that the arrow of time from the past to the future only emerges when moving backwards from the microscopic world to the macroscopic world – something Austrian physicist and philosopher Ludwig Boltzmann first appreciated.

Martha HenriquesWhy does time move forward and not backward?” at BBC (October 3, 2022)

Theoretician physician Carlo Rovelli notes that time is related to entropy, the increasing disorder in the universe:

“It’s not that the world is fundamentally oriented in space and time,” says Rovelli. It’s that when we look around us, we see a direction in which medium-sized everyday things have more entropy – the ripe apple fallen from the tree, the shuffled deck of cards.

Martha HenriquesWhy does time move forward and not backward?” at BBC (October 3, 2022)

We perceive time as flowing like a river, but it really isn’t. We are those that sink. And there’s no obvious answer to the question of why time only flows in one direction, except that our universe started out that way. Why? Again, back to philosophy. Somehow a spell has been cast or a decision has been made, but that may lie outside of science.

There is also the thorny problem that the mathematician Peter Cameron terms: “the breathtaking mystery of infinity:”

It has been so since the time, two and a half millennia ago, when Malunkyaputta submitted his doubts to the Buddha and demanded answers: among them, he wanted to know whether the world is finite or infinite, and whether it is eternal or nope.

Peter CameronInfinity: the question that cosmology cannot answer” at IAI News (September 23, 2022)

An infinity symbol in a man's hand against the sky and sun shine, business concept idea.

Infinity works well in math but not in the physical world where it descends into nonsense such as Hotel Hilbert, which is always full but can always accommodate more guests… This raises a question: is the world we live in a limited subset of an ideal world? Again, this brings us to the frontiers of philosophy. But we got there through math, not through mysticism.

In this sense, why can’t things just disappear forever? To Ars Technica, we are learning:

This double whammy of determinism and reversibility means that in physics terms, information must be preserved during any process. It cannot be created or destroyed – if we were to add or remove information willy-nilly, we would not be able to predict the future or read the past. Any loss or gain means that there would be either missing information or extra information, so all the physics would crumble to dust.

There are many processes that seem to destroy information, but that’s only because we don’t follow closely enough. Take, for example, the burning of a book. If I gave you a pile of ashes, it would seem irreversible: you couldn’t put the book back together. But if you have a powerful enough microscope at your disposal (and a lot of patience) and can watch me burning the book, you could – in principle at least, which is good enough – watch and follow the movement of each molecule in the process. You could then reverse all of these movements and interactions to reconstruct the book. Information is not lost when you burn a book; it’s just scrambled.

Paul SutterBlack holes can’t destroy information about what they swallow – and that’s a problem” at Ars-Technica (October 3, 2022)

In any event, the information is immaterial. The ideas in the burned (or saved) book can take many forms, including ideas that stay in your mind. Many of the most important things in our world are not material.

Siegel request pessimistically, “Is theoretical physics broken? Or is it just hard? When you don’t have enough clues to wrap up your detective story, you have to expect your educated guesses to be all wrong. It is fashionable today to speak of a “cosmology crisis” due to issues like these. But it’s a static crisis, if possible. In other words, things could go on like this indefinitely.

Will another discovery resolve the questions, as so often in the past? Or are we reaching the edge of the things science can tell us – the territory of “Why is there something rather than nothing”? We can only research and see what happens, as the questions science is meant to answer become more fundamental and deeper.

You can also read: A recent debate on the Big Bang: Pure politeness points to an upheaval. Takeaway: “Everyone would want to ditch the theory if there was a better alternative, nobody is married to the Big Bang theory.” Such sudden and widespread cosmological doubt is bound to have a major cultural impact, although it is too early to see how it will play out, for example, in science fiction.