fbpx
Connect with us

The Conversation

Quantum computers are like kaleidoscopes − why unusual metaphors help illustrate science and technology

Published

on

theconversation.com – Sorin Adam Matei, Associate Dean for Research, Purdue – 2024-06-14 07:38:17
This image could give you a better grasp of how quantum computers work.
Crystal A Murray/Flickr, CC BY-NC-SA

Sorin Adam Matei, Purdue University

Quantum computing is like Forrest Gump's box of chocolates: You never know what you're gonna get. Quantum phenomena – the behavior of matter and energy at the atomic and subatomic levels – are not definite, one thing or another. They are opaque clouds of possibility or, more precisely, probabilities. When someone observes a quantum system, it loses its quantum-ness and “collapses” into a definite .

Quantum phenomena are mysterious and often counterintuitive. This makes quantum computing difficult to understand. People naturally reach for the familiar to attempt to explain the unfamiliar, and for quantum computing this usually means using traditional binary computing as a metaphor. But explaining quantum computing this way to major conceptual confusion, because at a base level the two are entirely different animals.

This problem highlights the often mistaken belief that common metaphors are more useful than exotic ones when explaining new technologies. Sometimes the opposite approach is more useful. The freshness of the metaphor should match the novelty of the discovery.

Advertisement

The uniqueness of quantum computers calls for an unusual metaphor. As a communications researcher who studies technology, I believe that quantum computers can be better understood as kaleidoscopes.

Digital certainty vs. quantum probabilities

The gap between understanding classical and quantum computers is a wide chasm. Classical computers store and information via transistors, which are electronic devices that take binary, deterministic states: one or zero, yes or no. Quantum computers, in contrast, handle information probabilistically at the atomic and subatomic levels.

Classical computers use the flow of electricity to sequentially open and close gates to record or manipulate information. Information flows through circuits, triggering actions through a of switches that record information as ones and zeros. Using binary math, bits are the foundation of all things digital, from the apps on your phone to the account at your bank and the Wi-Fi bouncing around your home.

In contrast, quantum computers use changes in the quantum states of atoms, ions, electrons or photons. Quantum computers link, or entangle, multiple quantum particles so that changes to one affect all the others. They then introduce interference patterns, like multiple stones tossed into a pond at the same time. Some waves combine to create higher peaks, while some waves and troughs combine to cancel each other out. Carefully calibrated interference patterns guide the quantum computer toward the solution of a problem.

Advertisement
Physicist Katie Mack explains quantum probability.

Achieving a quantum leap, conceptually

The term “bit” is a metaphor. The word suggests that during calculations, a computer can break up large values into tiny ones – bits of information – which electronic devices such as transistors can more easily process.

Using metaphors like this has a cost, though. They are not perfect. Metaphors are incomplete comparisons that transfer knowledge from something people know well to something they are working to understand. The bit metaphor ignores that the binary method does not deal with many types of different bits at once, as common sense might suggest. Instead, all bits are the same.

The smallest unit of a quantum computer is called the quantum bit, or qubit. But transferring the bit metaphor to quantum computing is even less adequate than using it for classical computing. Transferring a metaphor from one use to another blunts its effect.

The prevalent explanation of quantum computing is that while classical computers can store or process only a zero or one in a transistor or other computational unit, quantum computers supposedly store and handle both zero and one and other values in between at the same time through the process of superposition.

Advertisement

Superposition, however, does not store one or zero or any other number simultaneously. There is only an expectation that the values might be zero or one at the end of the computation. This quantum probability is the polar opposite of the binary method of storing information.

Driven by quantum science's uncertainty principle, the probability that a qubit stores a one or zero is like Schroedinger's cat, which can be either dead or alive, depending on when you observe it. But the two different values do not exist simultaneously during superposition. They exist only as probabilities, and an observer cannot determine when or how frequently those values existed before the observation ended the superposition.

Leaving behind these challenges to using traditional binary computing metaphors means embracing new metaphors to explain quantum computing.

Peering into kaleidoscopes

The kaleidoscope metaphor is particularly apt to explain quantum processes. Kaleidoscopes can create infinitely diverse yet orderly patterns using a limited number of colored glass beads, mirror-dividing walls and light. Rotating the kaleidoscope enhances the effect, generating an infinitely variable spectacle of fleeting colors and shapes.

Advertisement

The shapes not only change but can't be reversed. If you turn the kaleidoscope in the opposite direction, the imagery will generally remain the same, but the exact composition of each shape or even their structures will vary as the beads randomly mingle with each other. In other words, while the beads, light and mirrors could replicate some patterns shown before, these are never absolutely the same.

If you don't have a kaleidoscope handy, this is a good substitute.

Using the kaleidoscope metaphor, the solution a quantum computer provides – the final pattern – depends on when you stop the computing process. Quantum computing isn't about guessing the state of any given particle but using mathematical models of how the interaction among many particles in various states creates patterns, called quantum correlations.

Each final pattern is the answer to a problem posed to the quantum computer, and what you get in a quantum computing operation is a probability that a certain configuration will result.

New metaphors for new worlds

Metaphors make the unknown manageable, approachable and discoverable. Approximating the meaning of a surprising object or phenomenon by extending an existing metaphor is a method that is as old as calling the edge of an ax its “bit” and its flat end its “butt.” The two metaphors take something we understand from everyday life very well, applying it to a technology that needs a specialized explanation of what it does. Calling the cutting edge of an ax a “bit” suggestively indicates what it does, adding the nuance that it changes the object it is applied to. When an ax shapes or splits a piece of wood, it takes a “bite” from it.

Advertisement

Metaphors, however, do much more than convenient labels and explanations of new processes. The words people use to describe new concepts change over time, expanding and taking on a life of their own.

When encountering dramatically different ideas, technologies or scientific phenomena, it's important to use fresh and striking terms as windows to open the mind and increase understanding. Scientists and engineers seeking to explain new concepts would do well to seek out originality and master metaphors – in other words, to think about words the way poets do.The Conversation

Sorin Adam Matei, Associate Dean for Research, Purdue University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

Advertisement

The post Quantum computers are like kaleidoscopes − why unusual metaphors help illustrate science and technology appeared first on .com

The Conversation

Supermassive black holes have masses of more than a million suns – but their growth has slowed as the universe has aged

Published

on

theconversation.com – Fan Zou, Graduate Student in Astronomy and Astrophysics, Penn – 2024-07-12 07:33:14
Most of the blue points in this sky survey image are accreting supermassive black holes emitting strong X-rays.
Fan Zou (Penn State) and the XMM-SERVS Collaboration

Fan Zou, Penn State and W. Niel Brandt, Penn State

Black holes are remarkable astronomical objects with gravity so strong that nothing, not even light, can escape them. The most gigantic ones, known as “supermassive” black holes, can weigh millions to billions times the mass of the Sun.

These giants usually live in the centers of galaxies. Our own galaxy, the Milky Way, contains a supermassive black hole in its heart as well.

So, how do these supermassive black holes become super massive? To answer this question, our team of astrophysicists looked back in time across the universe's 13.8 -year history to track how supermassive black holes have grown from the early days to .

Advertisement

We constructed a model of the overall growth history of supermassive black holes spanning the past 12 billion years.

How do supermassive black holes grow?

Supermassive black holes grow primarily in two ways. They can consume gas from their host galaxies in a process called accretion, and they can also merge with each other when two galaxies collide.

A black hole, shown as a dark dot in a swirling spiral of clouds.
An artist's illustration of an accreting supermassive black hole. The central black hole is black, while its surrounding gas heats up and shines to produce light.
Nahks Tr'Ehnl (Penn State)

When supermassive black holes consume gas, they almost always emit strong X-rays, a type of high-energy light invisible to the naked eye. You've probably heard of X-rays at the dentist, where they are sometimes used to examine your teeth. The X-rays used by astronomers generally have lower energies than medical X-rays.

So how can any light, even invisible X-rays, escape from black holes? Strictly speaking, the light is not coming from the black holes themselves, but from the gas just outside them. When gas gets pulled toward a black hole, it heats up and shines to produce light, like X-rays. The more gas a supermassive black hole consumes, the more X-rays it will produce.

Thanks to the data accumulated over more than 20 years from three of the most powerful X-ray facilities ever launched into Chandra, XMM-Newton and eROSITA – astronomers can capture X-rays from a large number of accreting supermassive black holes in the universe.

Advertisement

This data allows our research team to estimate how fast supermassive black holes grow by consuming gas. On average, a supermassive black hole can consume enough gas to amount to about the mass of the Sun each year, with the exact value depending upon various factors.

For example, the data shows that a black hole's growth rate, averaged over millions of years, is strongly connected to the mass of all the in its host galaxy.

How often do supermassive black holes merge?

Besides feeding on gas, supermassive black holes can also grow by merging with each other to form a single, more massive black hole when galaxies collide.

Supercomputer cosmological simulations can predict about how often these happen. These simulations aim to model how the universe grows and evolves over time. The countless galaxies flying through space are kind of like bricks, building up the universe.

Advertisement

These simulations show that galaxies and the supermassive black holes they host can undergo multiple mergers across the span of cosmic history.

Our team has tracked these two growth channels – gas consumption and mergers – using X-rays and supercomputer simulations, and then combined them to construct this overall growth history, which maps the growth of black holes across the universe over billions of years.

Our growth history revealed that supermassive black holes grew much faster billions of years ago, when the universe was younger.

Back in the early days, the universe contained more gas for supermassive black holes to consume, and supermassive black holes kept emerging. As the universe aged, the gas was gradually depleted, and supermassive black hole growth slowed. About 8 billion years ago, the number of supermassive black holes stabilized. It hasn't increased substantially since then.

Advertisement
Two small dark dots surrounded by gas clouds rotate near each other.
An illustration of a merger of two supermassive black holes.
Scott Noble (NASA GSFC)

When there isn't enough gas available for supermassive black holes to grow by accretion, the only way for them to get larger is through mergers. We didn't see very many cases of that in our growth history. On average, the most massive black holes can accumulate mass from mergers at a rate up to the mass of the Sun every several decades.

Looking forward

This research has helped us understand how over 90% of the mass in black holes has accumulated over the past 12 billion years.

However, we still need to investigate how they grew in the very early universe to explain the remaining few percentages of the mass in black holes. The astronomical community is starting to make progress exploring these early supermassive black holes, and we hope to find more answers soon.The Conversation

Fan Zou, Graduate Student in Astronomy and Astrophysics, Penn State and W. Niel Brandt, Professor of Astronomy and Astrophysics, Penn State

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

Advertisement

The post Supermassive black holes have masses of more than a million suns – but their growth has slowed as the universe has aged appeared first on .com

Continue Reading

The Conversation

Meteorites from Mars help scientists understand the red planet’s interior

Published

on

theconversation.com – James Day, Professor of Geosciences, of California, San Diego – 2024-07-12 07:32:55
A Martian meteorite in cross-polarized light. This meteorite is dominated by the mineral olivine. Each grain is about half a millimeter across.
James Day

James Day, University of California, San Diego

Of the more than 74,000 known meteorites – rocks that fall to Earth from asteroids or planets colliding together – only 385 or so stones came from the planet Mars.

It's not that hard for scientists to work out that these meteorites from Mars. Various landers and rovers have been exploring Mars' surface for decades. Some of the early missions – the Viking landers – had the equipment to measure the composition of the planet's atmosphere. Scientists have shown that you can see this unique Martian atmospheric composition reflected in some of these meteorites.

Mars also has unique oxygen. Everything on Earth, humans and the we breathe, is made up of a specific composition of the three isotopes of the element oxygen: oxygen-16, oxygen-17 and oxygen-18. But Mars has an entirely different composition – it's like a geochemical fingerprint for being Martian.

Advertisement

The Martian meteorites found on Earth give geologists like me hints about the makeup of the red planet and its history of volcanic activity. They allow us to study Mars without sending a spacecraft 140 million miles away.

A planet of paradoxes

These Martian meteorites formed from once red-hot magma within Mars. Once these volcanic rocks cooled and crystallized, radioactive elements within them started to decay, acting as a radiometric clock that enables scientists to tell when they formed.

From these radiometric ages, we know that some Martian meteorites are as little as 175 million years old, which is – geologically speaking – quite young. Conversely, some of the Martian meteorites are older, and formed close to the time Mars itself formed.

These Martian meteorites tell a story of a planet that has been volcanically active throughout its entire history. In fact, there's potential for Martian volcanoes to erupt even today, though scientists have never seen such an eruption.

Advertisement

The rocks themselves also preserve chemical information that indicates some of the major on Mars happened early in its history. Mars formed quite rapidly, 4.5 years ago, from gas and dust that made up the early solar system. Then, very soon after formation, its interior separated out into a metallic core and a solid rocky mantle and crust.

Since then, very little seems to have disturbed Mars' interior – unlike Earth, where plate tectonics has acted to stir and homogenize its deep interior. To use a food analogy, the Earth's interior is like a smoothie and Mars' is like a chunky fruit salad.

Two fume hoods with vials of sample under them.
Martian meteorite samples are prepared for analysis in a clean lab.
James Day

Martian volcano remnants

Understanding how Mars underwent such an early and violent adolescence, yet still may remain volcanically active today, is an area of great interest to me. I would like to know what the inside of Mars looks like, and how its interior makeup might explain features, like volcanoes, on the red planet's surface.

When geologists set out to answer questions about volcanism on Earth, we typically examine lava samples that erupted at different places or times from the same volcano. These samples allow us to disentangle local processes specific to each volcano from planetary processes that take place at a larger scale.

It turns out we can do the same thing for Mars. The rather exotically named nakhlite and chassignite meteorites are a group of rocks from Mars that erupted from the same volcanic system some 1.3 billion years ago.

Advertisement

Nakhlites are basaltic rocks, similar to lavas you would find in Iceland or Hawaii, with beautiful large crystals of a mineral known as clinopyroxene. Chassignites are rocks made almost entirely of the green mineral olivine – you might know the gem-quality variety of this mineral, peridot.

Along with the much more common shergottites, which are also basaltic rocks, and a few other more exotic Martian meteorite types, these categories of meteorite constitute all the rocks researchers possess from the red planet.

When studied together, nakhlites and chassignites tell researchers several things about Mars. First, as the molten rock that formed them oozed to the surface and eventually cooled and crystallized, some surrounding older rocks melted into them.

That older rock doesn't exist in our meteorite collection, so my team had to tease out its composition from the chemical information we obtained from nakhlites. From this information, we learned that the older rock was basaltic in composition and chemically distinct from other Martian meteorites. We found that it had been chemically weathered by exposure to and brine.

Advertisement

This older rock is quite different from the Martian crust samples in our meteorite collection today. In fact, it is much more like what we would expect the Martian crust to look like, based on data gathered by rover missions and satellites orbiting Mars.

We know that the magmas that made nakhlites and chassignites come from a distinct portion of Mars' mantle. The mantle is the rocky portion between Mars' crust and metallic core. These nakhlites and chassignites come from the solid rigid shell at the top of Mars' mantle, known as the mantle lithosphere, and this source makes them distinct from the more common shergottites.

Shergottites come from at least two sources within Mars. They may come from parts of the mantle just beneath the lithosphere, or even the deep mantle, which is closer to the planet's metallic core.

alt
The interior structure of Mars, with the sources of meteorites indicated.
James Day

Understanding how volcanoes on Mars work can inform future research questions to be addressed by missions to the planet. It can also scientists understand whether the planet has ever been habitable for life, or if it could be in the future.

Hints at habitability

Earth's active geological processes and volcanoes are part of what makes our planet habitable. The gases emanating from volcanoes are a major part of our atmosphere. So if Mars has similar geological processes, that could be good for the potential habitability of the red planet.

Advertisement

Mars is much smaller than Earth, however, and studies suggest that it's been losing the chemical elements essential for a sustainable atmosphere since it formed. It likely won't look anything like Earth in the future.

Our next steps for understanding Mars lie in learning how the basaltic shergottite meteorites formed. These are a diverse and richly complex set of rocks, ranging in age from 175 million years to 2.4 billion years or so.

Studying these meteorites in greater detail will help to prepare the next generation of scientists to analyze rocks collected using the Perseverance Rover for the forthcoming NASA Mars Sample Return mission.The Conversation

James Day, Professor of Geosciences, University of California, San Diego

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Advertisement

Read More

The post Meteorites from Mars help scientists understand the red planet's interior appeared first on .com

Continue Reading

The Conversation

Storytelling strategies make communication about science more compelling

Published

on

theconversation.com – Emma Frances Bloomfield, Associate Professor of Communication Studies, of Nevada, Las Vegas – 2024-07-11 07:26:49
A story that includes characters and focuses on what people care about can stand up to misinformation.
SDI Productions/E+ via Getty Images

Emma Frances Bloomfield, University of Nevada, Las Vegas

As a science communication scholar, I've always supported vaccination and trusted medical experts – and I still do. As a new mom, however, I've been confronting new-to-me emotions and concerns while weighing decisions about my son's health.

Vaccines are incredibly effective and have minimal risks of side effects. But I began to see why some parents may hesitate because of the flood of content, especially online, about potential vaccine risks.

Part of what makes vaccine misinformation persuasive is its use of storytelling. Antivaccine advocates share powerful personal experiences of childhood illnesses or alleged vaccine side effects. It is rare, however, for scientists to use the same storytelling strategies to counter misinformation.

Advertisement

In my book “Science v. Story: Narrative Strategies for Science Communicators, I explore how to use stories to in a compelling way about controversial science topics, vaccination. To me, stories contain characters, action, sequence, scope, a storyteller, and content to varying degrees. By this definition, a story could be a book, a article, a social post, or even a conversation with a friend.

While researching my book, I found that stories about science tend to be broad and abstract. On the other hand, science-skeptical stories tend to be specific and concrete. By borrowing some of the strategies of science-skeptical stories, I argue that evidence-backed stories about science can better compete with misinformation.

To make science's stories more concrete and engaging, it's important to put people in the story, explain science as a process, and include what people care about.

woman and man with arms around each other looking at burned out house site
Stories hit home more when they include human characters and not just forces of nature.
VladTeodor/iStock via Getty Images Plus

Put people in the story

Science's stories often lack characters – at least, human ones. One easy way to make better stories is to include scientists making discoveries or performing experiments as the characters.

Characters can also be people affected by a scientific topic, or interested in learning more about it. For example, stories about climate change can include examples of people feeling the effects of more extreme weather events, such as the devastating impacts of California wildfires on local communities.

Advertisement

Characters can also be storytellers who are sharing their personal experiences. For example, I started this article with a brief discussion of my personal vaccine decisions. I was not a hidden or voiceless narrator, but someone sharing an experience that I hope others can relate to.

Explain science as a process

People often think of science as objective and unbiased. But science is actually a human practice that constantly involves choices, missteps and biases.

At the beginning of the COVID-19 pandemic, for example, the medical advice was not to mask. Scientists initially thought that masks didn't prevent transmission of the SARS-CoV-2 virus that causes COVID-19. However, after additional research, medical advice changed to masking, providing the public with the most updated and accurate knowledge.

If you explain science as a process, you can walk people through the sequence of how science is done and why researchers reach certain conclusions. Science communicators can emphasize how science is conducted and why people should trust the process of science to provide the most accurate conclusions possible given the available information.

Advertisement

Include what people care about

Scientific topics are important, but they may not always be the public's most pressing concerns. In April 2024, Gallup found that “the quality of the environment” was one of the lowest-ranked priorities among people in the U.S. Of those polled, 37% said they cared a great deal about it. More immediate issues, such as (55%), and violence (53%), the economy (52%), and hunger and homelessness (52%) ranked much higher.

Stories about the environment could weave in connections to higher-priority topics to emphasize why the content is important. For example, stories can include information about how mitigating climate change can work hand in hand with improving the economy and creating jobs.

Medical provider faces woman and child, in discussion
A pediatrician is a science communicator, and so is a parent who talks about their own medical experiences.
SDI Productions/E+ via Getty Images

Telling science's stories

Scientists, of course, can be science communicators, but everyone can tell science's stories. When we share information online about health, or talk to friends and about the weather, we contribute to information that circulates about science topics.

My son's pediatrician was a science communicator when she explained the vaccine schedule and ways to keep my son comfortable after receiving vaccines. I was a science communicator when I spoke to others about my decisions to fully vaccinate my son on the recommended schedule, and how he is now a healthy and happy 9-month-old.

When communicating about science topics, remember to borrow features from stories to strengthen your message. Think about all of a story's features – character, action, sequence, scope, storyteller and content – and how you might incorporate them into the topic. Everyone can find opportunities to strengthen their science communication, whether it's in their jobs or in their everyday interactions with friends and family.The Conversation

Emma Frances Bloomfield, Associate Professor of Communication Studies, University of Nevada, Las Vegas

Advertisement

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post Storytelling strategies make communication about science more compelling appeared first on .com

Advertisement
Continue Reading

News from the South

Trending