Technologies

If The Universe Is A Hologram, We May Soon Gaze Into A Black Hole

A mind-bending theory called holographic duality could lead us into the universe’s deepest, darkest voids.

If you fell into a black hole, your journey might look something like this.

First, you’d stare into the rich, red event horizon of the abyss. Beyond this barrier, light cannot escape. As you get closer, your body would stretch out like chewing gum until it spaghettifies into the void. If you’re still conscious at this point, you’d peer out the entrance and watch a warped universe grow smaller by the second. That wouldn’t be your universe anymore. The black hole would be.

In all probability, though, you’d quickly be ripped to shreds.

Because of this absolutely horrifying disaster, we’ll likely never receive firsthand evidence of what lies within these cosmic mysteries. But in a paper published this month in the journal PRX Quantum, scientists are working toward the next best thing. They developed computing algorithms to help solve a mind-bending theory in physics called «holographic duality.»

In a nutshell, holographic duality suggests that the three-dimensional universe, like space inside black holes, is mathematically strung to the two-dimensional universe, like particle planes and magnetic fields. It basically presents the fabric of spacetime as a 3D hologram «projected» by 2D webs.

I know what you’re thinking. No, this wouldn’t be like the Star Trek holodeck. Unlike classic sci-fi holograms projected by light from a screen, holographic duality is bound by pure mathematics.

«It has not been proven formally, under the point of view of rigorous mathematics, but we know many examples where this duality actually works,» says lead author Enrico Rinaldi, a research scientist at the University of Michigan, based in Tokyo and hosted by the Riken Center for Quantum Computing and the Theoretical Quantum Physics Laboratory.

If holographic duality truly dictates the universe, scientists wouldn’t have to go inside a black hole to take a picture of it. Instead, they could study easy-to-handle 2D space around the beast, then extrapolate the 3D architecture lurking inside. «It is often the case that things difficult to compute on one side are easy to compute on the other side,» Rinaldi says. «That is why this duality is very important and useful.»

He compares the idea to having a dictionary where you can look up a word on one page and find its meaning on another. We just need some sort of index to bridge the 2D space-words with their 3D space-definitions — aka, the mathematical connection. And that’s precisely what Rinaldi’s algorithms are poised to do.

However, before we can use them to unlock the inside of a black hole, there are several, pretty trippy, steps to take. «The duality, as it is right now, applies to a specific spacetime, which is different from the spacetime of our universe,» Rinaldi says.

In other words, holographic duality is confined to a sort of alternate, theoretical world that scientists use as a sandbox.

A spacetime playground

1916 was a big year for physics. Albert Einstein had published the first of many papers that would forever alter the field: a holy grail chronicle of general relativity. Since then, the theory has earned a reputation for being unbreakable. I could go on forever about its spectacular consequences, but here’s the important part for holographic duality.

Suppose you have a trampoline and drop a soccer ball into it. The flat surface will morph inward, depending on where the ball settles. Now, add a tiny marble to the scene. It’ll fall along the trampoline’s curve and nestle next to the soccer ball.

In this analogy, the marble is you, the soccer ball is Earth and the trampoline is the intangible fabric of space and time — spacetime. According to general relativity, gravity is this «curve» we fall along until we’re planted on the ground.

In our universe — which, per experts, is known as the «de Sitter» universe — spacetime’s curvature is positive. That’s a problem. A positive model isn’t great for math equations, Rinaldi explains, especially when it comes to ultra high-dimensional ones. But there’s an easy fix. Scientists simply calculate stuff in a theoretical universe with negative curvature: the anti de Sitter universe. Then they translate their results back to our realm.

Fast-forward to the late 1960s. String theory is born.

Allowing for simplification, string theory says if you break down atoms, the building blocks of our universe, into elementary particles, then pulverize those into even smaller specks, and so on, you’ll eventually get to infinitesimal vibrating «strings.»

Presumably, these strings make up all we know: particles, fields, spacetime. If string theory is true, even you and I are made up of the wiggling bits. That’s why this concept is such a big deal. It might well be the closest we’ve gotten to a theory of everything. On the flip side, however, some physicists consider string theory a dead end because we still haven’t found concrete evidence for its premises.

But regardless, string theory requires unfathomable 11-dimension equations — as you might’ve guessed, that means it’s rooted in the anti de Sitter universe. And per Rinaldi, holographic duality relies on string theory. Thus, it’s also rooted in the anti de Sitter universe.

«Black holes we can investigate right now, with this duality, are not the same black holes that we imagine being out there,» Rinaldi says. «These black holes are a sort of mathematical playground that we can use to formulate this duality and test it.»

Simply put: In this mathematically ideal universe, Rinaldi is observing theoretical black holes to understand holographic duality. It’s like playing a game in tutorial mode before the real level starts. Our universe.

Getting to that level, though, is the crux of this whole procedure. «If we can do it for anti de Sitter,» Rinaldi says, «then we should be doing it for de Sitter.»

«The final goal is still to be able to describe gravity and black holes in our universe.»

The road into a black hole

OK, here’s where it all comes together.

First, a quick recap: Holographic duality can show us what’s inside a black hole because it suggests the 2D universe is connected to the 3D universe via mathematics. We just have to construct an index to bridge the two dimensions. But holographic duality is based on string theory. So, first, we have to make the index’s blueprints in our sandbox universe — the theoretical, anti de Sitter universe.

How do we make the blueprints? Well, Rinaldi says, start with the easier side. That’s the 2D half. But even though this side hurts less to think about, it isn’t that simple; we still need strong numerical methods to analyze it. «That’s what we’re doing,» Rinaldi says. «The numerical part.»

Think of the universe as a blanket knitted by strings that have a bunch of points. Rinaldi’s algorithms use quantum computing and deep learning to help calculate where these points are on the blanket and how they’re attached to each other. The goal is to sort of draw out the «strings» of string theory, then put them all together, like cosmic connect-the-dots.

However, the researchers are still in the proof-of-principle stage. They solved a few prototype points with their method, but these points don’t really represent anything. In the future, though, Rinaldi says the method can scale up to study complex points really present on anti de Sitter strings, including those relevant to anti de Sitter black holes.

Then, we’ll be on our way to making the anti de Sitter 2D-to-3D index that’ll reveal the insides of these theoretical black holes.

Then, if the index is precise enough, it can be translated to our true-to-the-bone, observable universe.

Then… we can use the final index to learn about the threatening insides of real, de Sitter black holes from the comfort of our homes and tucked away from terror.

A new theory of everything?

When you think about the steps Rinaldi and tons of other researchers are taking to realize the insides of a black hole — study prototype theoretical universe strings, scale up to learn about the full theoretical universe’s geometry, zero in on theoretical black holes, take all of that and filter the real universe through it, and probably more we can’t even comprehend — a jarring question might be… why?

Why does this all matter?

«We think we are very close to explaining the information paradox of black holes,» Rinaldi says. «If information goes inside a black hole, general relativity says, OK, whatever goes in is gone forever.»

But quantum mechanics, the other founding principle of our universe, says you cannot lose information. It says information is always maintained. Perhaps it can change, transform or adapt, but it cannot go away. So what’s happening to the information plunging into these massive space-borne voids?

«Stephen Hawking came up with this idea of the evaporation of a black hole and said ‘Look, actually there is stuff coming out of a black hole, it’s just slowly coming out’,» Rinaldi says.

But even those bits coming out don’t look like what went in. Stuff still seems lost in the process. «This is a very, very big problem in physics,» Rinaldi says. «And people are using the duality to understand that paradox.» If we can understand what’s inside, then maybe we can prove so-called lost information is actually, well, inside.

«Maybe it’s not lost, it’s just in a different configuration. It’s not particles anymore; it’s not spacetime anymore; it’s something else.»

Technologies

Wild Weather Ahead: Here’s How 2024 Is Shaping Up After the Hottest Year on Record

The climate crisis is impacting communities around the world. Here’s what to know about dealing with extreme weather in 2024.

We just lived through the hottest year since recordkeeping began more than a century ago, but before too long when we look back at 2023, it might not stand out as the pinnacle of extreme heat.

That’s because it’s unlikely to be the only hottest year that we experience. Our climate is changing, growing warmer due to the emissions from burning fossil fuels, and our weather is changing with it. It’s possible that this year may turn out to be hotter still.

In March, scientists from the EU’s Copernicus Climate Change Service said February 2024 was the hottest February according to records that stretch back to 1940. The news came on the heels of their report in early January that, as expected, 2023 was indeed the hottest year on record. Temperatures closed in on the critical 1.5-degree Celsius rise above preindustrial levels, after which we will see irreversible damage to the planet. These aren’t freak outliers: The extreme heat we’re experiencing is something we’ll need to be prepared to deal with on a much more regular basis, along with storms, floods and drought.

Later in March, the US National Oceanic and Atmospheric Administration issued its spring outlook, predicting that most of the continental US and Alaska will see above-average temperatures from April through June. The risk of flooding, it said, will ease during the three-month period because of «historically low winter snow cover» in large parts of the country.

A key trend highlighted by the US government’s Fifth National Climate Assessment, published in November, was that climate change is provoking extreme weather events across the country that are both more frequent and more severe. It pointed to an increase in heatwaves and wildfires in the West over the past few decades, the increased drought risk in the Southwest over the past century and more extreme rainfall east of the Rockies. Hurricanes have also been intensifying, as those who have found themselves in the path of a storm know all too well.

You’ll need to be prepared. Extreme weather is going to have a widespread impact on industry, society and individuals. Last year in the US there were 25 extreme weather events with losses amounting to over $1 billion that resulted in the deaths of 464 people. People lost their homes, saw personal property damaged or suffered mental and physical health issues.

Three months into 2024, we’re staring down the barrel of another potentially record-setting hot year. If there’s a silver lining, it’s that the US is now better prepared than ever and we know what steps you can take to better deal with these unwelcome events. When it comes to weather, forewarned is forearmed.

The US has been taking active steps. The Biden administration has provided funding to build resilient communities, and a new (as of September 2023) National Climate Resilience Framework, which should provide the US with a whole range of protections. These include conserving water resources, modernizing and strengthening the electric grid against weather and disasters and building infrastructure to protect communities and ecosystems from sea level rise, tidal flooding, hurricanes and storm surges.

At home and in your community, you can take steps, too, including preparing your home for wildfires and flooding and recognizing signs of heat-related health issues. This way, when wild weather comes calling, its impact on our homes, health and livelihoods is minimized.

Forecast 2024

Last year’s heat was no anomaly. It’s part of a long-term trend: The last 10 years have been the 10 warmest on record, according to NASA, with most of the Earth’s warming taking place over the last 40 years. Most forecasters are anticipating yet another year of extreme heat ahead.

«If we look at the forecast for the next three months in the long range, it’s suggesting that the trend that we’re seeing in baseline warming could continue, and so 2024 could rival 2023 for being the hottest year on record, which is very scary,» says Chloe Brimicombe, a heatwave researcher at the University of Graz.

Some of the extreme weather we experienced in the latter half of last year and will continue to experience in the first half of this year is a result of El Niño, a cyclical climate event that sees unusually warm ocean waters that has a knock-on effect of warmer temperatures and increased rainfall across the southern part of the US. For instance, temperatures in Death Valley, California, peaked at 128 degrees Fahrenheit in July, while forecasters predicted warmer temperatures in northern parts of the US stretching into February and a colder, wetter winter for Southern states.

While meteorologists are able to make long-term predictions about El Niño, other climate-related predictions are trickier. «All things told, we’re going to see an increased prevalence of heat events across the globe, but we can’t tell right now exactly where that will be,» says Andy Hoell, a climate scientist at NOAA.

What we do know, he adds, is that the climate crisis can compound events such as extreme heat or extreme rainfall to make them more likely or more severe.

In the past, it wasn’t always easy to draw direct links between extreme weather events and climate change. But huge improvements in attribution science (the ability to specifically identify emissions as the cause for unusually dramatic weather) in recent years have changed the game. The World Weather Attribution program, based at Imperial College London, has now completed nine studies on droughts, heatwaves, wildfires and heavy rainfall in North America. «Every study found that climate change made the event more intense and more likely,» says Ben Clarke, a researcher at WWA.

The speed at which climate scientists are able to identify human-caused climate change as the culprit for extreme weather has also dramatically improved. Last year alone, Climate Central was able to attribute record-breaking spring heat in the western US, and ongoing extreme heat stretching through the summer in Texas and Florida, to climate change as it was happening. «It’s much more impactful as far as our understanding of what climate change really is if we can make that connection in real time,» says Andrew Pershing, vice president of science at Climate Central, a climate science analysis non-profit.

Thanks to attribution science, we can confidently point to a heatwave we’ve experienced and say whether climate change played a role in making it happen. But it also helps us to recognize that extreme weather events we’re experiencing are part of a pattern – one that can’t be broken without tackling the root causes of the climate crisis. «Until the world moves away from fossil fuels and reduces emissions to net zero,» says Clarke, «extreme weather events in North America will continue to become more intense, more dangerous and more deadly.»

Even if you live in a region that hasn’t yet directly been impacted by a climate-linked weather event, you’re not off the hook.

«As the climate continues to warm, most areas will be at an increased risk of some types of climate-linked extreme weather,» says Russell Vose, chief of the Monitoring and Assessment Branch at NOAA’ National Centers for Environmental Information and one of the NCA’s authors. «Perhaps the best example is extreme heat – it can occur anywhere.»

He points to the scorching heat dome that descended on the Pacific Northwest in June and July 2021, which was unprecedented in the historical record. The unpredictable nature of such extreme heat means no regions are marked as safe.

In fact, a region that’s been lucky enough to not yet experience an extreme heat event is more likely to experience one in the future and suffer more greatly due to lack of preparedness, according to a study published by scientists from Bristol University last April.

Scientists are more concerned about the ability of people in areas that don’t usually get intensely hot to cope when their turn comes. «What worries me would be something in the Upper Midwest or the Northeast that just hasn’t had a major heat event for a few years,» says Pershing. «I think we kind of lose a little bit of that muscle memory.»

Weather’s unequal impacts

The weather might not discriminate when it comes to who gets hit, but that doesn’t mean its impacts are experienced equally by all groups across American society.

«Certain groups are simply more vulnerable to extreme events due to geographic, socioeconomic or demographic factors,» says Vose. He points to the extreme rainfall brought by Hurricane Harvey in 2017, which led to a large number of homes being flooded in Harris County, Texas, with a disproportionate impact on low-income Hispanic neighborhoods.

When a heatwave hits, it will feel hotter in high-density urban environments that are more likely to be occupied by people of color or people living in poverty than in more spread-out neighborhoods or rural areas. Then some are homeless and can’t access health care. They have little ability to protect themselves, no matter how much warning they get about an incoming heatwave. This makes these groups much more vulnerable to the health risks of extreme heat.

Heat researchers are extremely concerned about people who live in housing not resistant to warm temperatures, says Brimicombe, who points out that those who rent are especially at risk. «If you’re a tenant, you have less ability to adapt your house to extreme heat than if you’re a homeowner,» she says. «And that also means young families, because babies are vulnerable to extreme heat.»

Not only are economically disadvantaged communities in the US more susceptible to feeling the worst impacts of extreme weather, but they have also done the least to contribute towards the climate crisis in the first place. A study published last August revealed that the wealthiest households in the US are historically responsible for 40% of the country’s climate emissions.

Meanwhile, these same households have more tools at their disposal to protect themselves from the impact of climate-related weather events. In 2019, The New York Times reported that wealthy California residents were banding together to hire private firefighters to protect them from the impacts of wildfires.

The Biden administration is well aware that marginalized and minority groups are hardest hit by climate change, including extreme weather. At the beginning of his term, the president set up the White House Environmental Justice Advisory Council, made up of leading experts from the US climate justice community.

Last September the group published its policy recommendations urging the government to ensure climate disasters do not further or exacerbate harm to vulnerable populations and communities.

«Disaster relief should never be the cause of deepening inequality in any neighborhood, region, or Tribal community,» the council wrote in its recommendations. «When disaster hits, the goal of government should be that the people hit the hardest should emerge stronger and more secure than before, not the opposite.»

It recommended a number of measures that would help protect people in case of extreme weather including the creation of a low-cost national flood insurance and the establishment of a «Just Relocation Fund» that would provide communities hit by climate impacts with a relocation process based on a dignity framework with respect for their human rights.

The White House has yet to respond to the recommendations, but if it does act on them this would hopefully prevent a repeat of the aftermath of Hurricane Katrina in 2005, in which Black communities were allocated less money to rebuild their housing, resulting in a lawsuit against the federal government.

Through the Bipartisan Infrastructure Law and other initiatives, the Biden administration is investing heavily in adaptation, mitigation and resilience measures designed to protect all Americans from the impacts of climate-linked extreme weather. As with all funding, people may have to wait some time to feel the full impact of that funding. In the meantime, there are a number of steps you can take to keep yourself safe in the months ahead.

How to weather the weather, whatever the weather

Summer’s not so far off, meaning sizzling days are on the horizon.

Intense heat poses some scary risks to our health, including heat cramps, heat exhaustion and heat stroke, which can be life-threatening. It’s important to familiarize yourself with the signs so that you’ll recognize them in yourself and others, and can therefore seek medical attention if necessary.

Remember that heat is more likely to adversely affect older people, children and babies, and those with preexisting health conditions. There may be cooling centers or other well-air-conditioned places in your community where you can take refuge – if you do, consider taking elderly or vulnerable neighbors with you. «Look out for friends and families,» said Brimicombe. «Don’t be complacent.»

The British writer and fellwalker Alfred Wainwright is widely credited as coining the phrase, «there’s no such thing as bad weather, only unsuitable clothing.» Wainwright, who died in 1991, didn’t live through the kind of consistently bad weather we’re experiencing in this era of extreme heat, but that doesn’t mean we have nothing to learn from him. In the midst of a heatwave, it’s best to wear loose-fitting clothes in light colors, rather than black, which absorbs the heat.

Make sure you stay hydrated and try to spend as little time as possible outside in the sun. Try to block sunlight from warming your house, and consider buying reflectors to place in your windows that can help keep the heat out. At nighttime, take note of when it might be cooler outside than in, and use this to your advantage by opening doors and windows to let the internal temperature of your house regulate. Fans can be effective, but at very high temperatures they’re likely to just start pushing the hot air around – in which case you should, sparingly and without putting too much pressure on the grid, resort to air conditioning, or moving to your local cooling center.

Remember that global warming is worldwide, so the same heat warnings apply even if you plan to travel to other parts of the world over the summer. The heat waves that hit the US in the summer of 2023 also impacted areas of Europe, including popular vacation spots in the Mediterranean. Countries including Greece, Spain and Italy were all affected by wildfires that resulted in the evacuation of locals and tourists alike from some areas and islands.

The surge in Europe-bound American tourists that occurred in 2023 is expected to continue this year, but if you’re planning to be among them it’s important not to travel without comprehensive insurance. Likewise, if you’re traveling in the peak months of July and August, be prepared to adjust your itinerary in case of extreme heat to ensure you’re not putting your health at risk. This may mean spending more time indoors than you’d planned for the sake of your health.

For other types of extreme weather that may hit your property such as wildfires, storms or floods, it may be useful to have an evacuation plan. You should prepare an emergency evacuation bag, also known as a go bag or a bug-out bag. Don’t forget to plan for your pets. The National Fire Protection Association has a handy guide on how to prepare your home for wildfires.

One of the easiest but most important things you can do is keep an eye on long- and short-term weather forecasts. The silver lining for people in the US, says Pershing, is that the country has great weather forecasting capabilities and the channels to communicate incoming events to people so you can prepare. «The gaps are really whether you take it seriously yourself,» he says.

So for anyone who does take it seriously, be sure to read our tips on how to prepare yourself and your home for wildfires, hurricanes, floods and storms.

Here are some additional resources:

For even more details on natural disasters and how to prepare beforehand or respond after an event takes place, check out https://www.ready.gov/.

Correction, March 15: This story originally misstated the name of the National Fire Protection Association.

Technologies

SpaceX Calls Mission 3 a Success, Despite Losing Starship: How to Rewatch

On its third attempt, SpaceX launched its Starship and cruised into space, but lost the rocket after reentry to Earth.

SpaceX launched its third Starship mission on Thursday, with the space exploration company owned by Elon Musk forging ahead after the first two attempts exploded after takeoff. SpaceX considers those first two missions successful, thanks to the data it was able to collect, and the third mission was the most successful of the bunch.

Shortly before 9:30 a.m. ET Thursday, the company posted three words to the Musk-owned X social media site: «Liftoff of Starship!» A 36-second video showed the rocket engines igniting and then Starship rising amid a cloud of exhaust smoke and up into the sky.

But the rocket did not complete the round trip, as you can see by rewatching the full test flight. «The ship has been lost. No splashdown today,» Dan Huot of SpaceX communications said on the stream. «But we were able to get through some of the early phases of reentry.»

SpaceX quality engineering manager Kate Tice noted on the stream that SpaceX wasn’t intending to recover Starship anyway, and had been planning to crash it into the ocean.

Starship is arguably the most ambitious effort for Musk, who owns the satellite-based internet company Starlink along with X, EV maker Tesla and the neurotechnology company Neuralink. The Starship missions are critical to SpaceX’s — and Musk’s — goal of getting to and eventually settling the moon and Mars.

With a new flight trajectory and hopes for new data insights, the space company’s third mission may prove to be its most important yet.

When did the Starship mission launch?

Starship’s third mission launched on March 14. It had been pending favorable weather and a license from the Federal Aviation Administration.

How to rewatch Starship mission 3

SpaceX set up livestreams for watching the third mission. One was the SpaceX account on X, and another was the SpaceX third mission landing page. You could also watch via CNET’s YouTube channel.

You can rewatch the launch on X, on the mission 3 page, or via CNET’s YouTube stream embedded here.

What SpaceX achieved in Starship mission 3

SpaceX’s third Starship mission was designed to test whether the spacecraft can complete certain tasks. After liftoff, the company planned to open Starship’s payload door and transfer its propellant from one part of the vehicle to another. For the first time, SpaceX also attempted to relight its Raptor engine while in space, a test that could be critical for future missions as it eventually tries to propel Starship through space.

Starship took a different flight path this time around, and had planned to land in the Indian Ocean instead of the Pacific Ocean until it lost the vehicle after reentry. In a statement, SpaceX said that the new flight path was designed to maximize «public safety,» but the company didn’t discuss how.

The new flight path also paved the way for SpaceX to try «in-space engine burns,» a reference to the company attempting to reignite the Raptor engine in space.

«Huge congratulations to the entire team for this incredible day: clean count (glad the shrimpers could get out in the nick of time!), liftoff, hot staging, Super Heavy boost back and coast (and likely a couple engines making mainstage during landing burn!), clean ship ‘insertion’ and coast, payload door cycling and prop transfer demo (to be confirmed!), and ship entry!» SpaceX President Gwynne Shotwell posted on X following the launch, naming the successful components of the test.

The mission was slated to last for 1 hour, 15 minutes. Previous missions, if completed, would have lasted 90 minutes.

What happened in the previous missions?

April mission: Forced detonation

The first Starship mission launched in April 2023. Early on in the mission, the two stages of Starship — the reusable upper stage, called Starship, and its Super Heavy first-stage booster — were supposed to separate. That didn’t happen, and for safety reasons, the SpaceX team was forced to detonate the vehicle just 4 minutes into the mission.

November mission: Explosion due to liquid oxygen

In November 2023, Starship launched on its second mission. That time around, Starship was able to separate its two stages and it reached nominal first-stage engine burn. However, Starship exploded 8 minutes after launch when it tried to vent its liquid oxygen. Oddly, the explosion may not have needed to happen. Earlier this year, Musk said on a real mission carrying payload — meaning the materials a spaceship carries to perform its scientific mission — liquid oxygen wouldn’t be onboard.

«Starship’s second flight test achieved a number of major milestones and provided invaluable data to continue rapidly developing Starship,» the company wrote on its site. «Each of these flight tests continue to be just that: a test. They aren’t occurring in a lab or on a test stand, but are putting flight hardware in a flight environment to maximize learning.»

Corinne Reichert contributed to this report.

Technologies

iOS 17 Cheat Sheet: All Your Questions on the iPhone Update Answered

We explain everything from new features to upcoming updates.

Apple’s iOS 17 was released in September, shortly after the company held its Wonderlust event, where the tech giant announced the new iPhone 15 lineup, the Apple Watch Series 9 and the Apple Watch Ultra 2. We put together this cheat sheet to help you learn about and use the new features in iOS 17. It’ll also help you keep track of the subsequent iOS 17 updates.