Scotland’s Astronomer Royal Catherine Haymans believes observations of the universe don’t agree on its age, because the mathematical models aren’t quite right. She suspects our understanding of the dark universe may be an illusion.

Right, our best information about the universe tells us what the universe looked like right after the Big Bang. And from that data, we can come up with a model of what the universe should look like today.

But what we’re finding is that the universe that we observe isn’t quite what we expected. And (that) we can’t fully explain the universe that we’re observing today, means that we can’t trust it when it tells us how old our universe is. Just doesn’t add up.

Katherine thinks that although researchers have calculated how much of the dark universe is out there, they have little real idea of its impact.

We know that the stuff we’re made up of the earth, the moon, the sun, everything we can see in the universe, that accounts for less than 5% of it. The rest is dark. Two components, dark matter and dark energy.

Dark matter. That’s the kind of the big gravitational stuff that keeps everything bound in our universe together. And then its evil twin, dark energy, which appears to be causing the expansion of our universe to accelerate. Those are our three main ingredients, and we only understand 5% of it. So, you could picture this as an epic fail for science. We don’t understand 95% of our universe. But I like to think of this as a big challenge, because if we can understand that, then hopefully that will really revolutionise our understanding of everything around us.

To try and work out just how dark matter impacts the universe, Katherine investigates how it has evolved over time since the Big Bang.

So, this is a map of dark matter, spanning across the sky. Where you can see bright spots, that’s where there’s lots and lots of dark matter. And as the colour gets darker, that’s where there’s emptier voids, where there’s much less dark matter in our universe. And what we’re finding is not what we were expecting. We can see clumps, we can see voids, we can see that cosmic web-like structure. But it’s not exactly what we expected. It’s a lot smoother than predicted for what we should see today. That´s a bit of a problem … because it takes time for these dark matter structures to form.

Katherine has spent decades fine-tuning and finessing a dark matter map.

So, for about the last 20 years, I’ve been working to map out the invisible dark matter in our universe. This is our map of the north, we’ve got another map of the south. And whilst this is one of the largest dark matter maps that we’ve ever been able to make, it’s still quite a small patch of the sky. So, we might have been unlucky. This might have been just a weird patch of the universe that we’ve looked at, but it’s not exactly what we expected. And the fact that this is a lot smoother suggests that the universe is slightly younger than we first thought.

As yet, Katherine is unsure just how much younger, but her work continues.

• An Astronomer Royal (noun): the director of one of the royal observatories of Great Britain, who advises the king or queen on astronomical findings and information.
• A mathematical model (noun): a way of describing a process or system using a mathematical formula.
• To suspect (verb): to think or believe something is true or possible.
• The dark universe (noun): the part of the universe that consists of dark energy and dark matter, about 95%.
• An illusion (noun): an idea or belief that is not true.
• The Big Bang (noun): the large explosion that many scientists believe created the universe.
• To come up with something (phrasal verb): to suggest or think of an idea or plan.
• Fully (adverb): completely.
• To add up (phrasal verb): to make sense, to seem reasonable or likely.
• To calculate (verb): to use the information you have to estimate or predict something.
• To be out there (phrase): to exist.
• An impact (noun): a powerful effect.
• Stuff (noun): a substance, things; when you do not say exactly what it is.
• Made up of (phrasal verb): to consist of, to be made from different parts.
• To account for (phrasal verb): to form the total of something.
• Gravitational (adjective): relating to gravity, the force that attracts objects to each other.
• To be bound together (passive, phrasal verb): to be connected.
• A twin (noun): one of two very similar things.
• Expansion (noun): the increase in size of something.
• To accelerate (verb): to get faster.
• To picture something (verb): to consider or imagine how something looks.
• Epic (adjective): very big, huge.
• To revolutionise (verb): to completely change something so it is much better.
• To evolve (verb): to develop and change slowly.
• To span (verb): to extend or cross, describing the length of something.
• A spot (noun): a small area of colour that is different to the area around it.
• A void (noun): a large hole or empty space.
• A clump (noun): a group of something.
• The cosmic web (noun): a network of connected dark matter, believed by many astronomers to form the basis of the universe.
• Smooth (adjective): having a regular surface that is flat with no holes or areas that rise or fall.
• To fine-tune (verb): to make very small changes to make something work as well as possible.
• To finesse (verb): to improve something so it is as good as possible.
• To map out (phrasal verb): to plan or illustrate something in detail.
• Whilst (conjunction): although, despite the fact that.
• A patch (noun): a small area, often different from the area around it.
• Weird (adjective): strange or unusual.
• Slightly (adverb): a little.
• As yet (phrase): from the past until now.

In this text, there are a few examples of past modals of deduction. We use different modal verbs (+ main verb) to indicate how sure we are about something: must (certain about something), might/ may/ could (possible, but not certain), can’t/ couldn’t (certain that something didn’t happen, not possible).

To make a deduction about the past using a modal verb, use the form: modal verb + have + past participle

Examples in the text:

• … our understanding of the dark universe may be an illusion: this is a deduction about the present: may (modal verb) + be (main verb): we could be wrong about our universe, it is possible but not certain.
• So, we might have been unlucky: this is a deduction about the past: might (modal verb) + have + been (past participle): it’s possible that we were unlucky, but it’s not certain.
• This might have been just a weird patch of the universe: this is a deduction about the past: might (modal verb) + have + been (past participle): it’s possible that it was an unusual area of the universe, but it’s not certain.

https://learnenglish.britishcouncil.org/grammar/b1-b2-grammar/modals-deductions-about-past

https://www.englishpodcastscollected.com/wp-content/uploads/2024/04/BBC-Earth-Science-Are-we-wrong-about-our-universe.pdf

https://www.englishpodcastscollected.com/wp-content/uploads/2024/04/BBC-Earth-Science-Are-we-wrong-about-our-universe.docx