Category: 3. Business

LOS ANGELES — Math nerds and dessert enthusiasts unite to celebrate Pi Day every March 14, the date that represents the first three digits of the mathematical constant pi.

Representing the ratio of a circle’s circumference to its diameter, pi is approximately equal to 3.14159 — but its digits go on forever. In school, you might have used it to calculate the area of a circle or the volume of a cylinder. But the applications of pi are endless and part of every corner of our world.

The holiday was created in 1988 by Larry Shaw, a physicist at the Exploratorium science museum in San Francisco.

“He had a very open and expansive view of the world and saw an opportunity with this number, mathematical concept, to invite people into the joy of mathematical learning,” said Sam Sharkland, program director of public programs at the museum, who worked with Shaw before he died in 2017.

While it began as a small staff celebration featuring pie, it soon turned into a grand procession where hundreds of visitors marched around the pi shrine, each carrying a digit. Attendees often show up early to claim their favorite digit for the parade. One woman who has the symbol tattooed on her neck comes every year and marches near the front with a pi flag, Sharkland said.

The celebration begins at 1:59 p.m., signifying the next three digits of pi.

Here are a few ways pi is being used on the cutting edge of science.

Pi in outer space

In Artur Davoyan’s field of mechanical and aerospace engineering, pi is so fundamental that it would be hard to pinpoint one use case for it, he said.

Pi is part of “literally every single formula that you would use to do any calculation, like for spacecraft motion, for materials and how they work, or propulsion systems,” said Davoyan, a professor at the University of California, Los Angeles.

Anything that is round or has cyclical or repeating properties — such as radio waves — involves pi. Even squares or irregular blobs can be broken down into a series of progressively smaller circles and calculated using pi, Davoyan said.

Davoyan’s research looks at how to create new propulsion systems to send spacecrafts more quickly to the far reaches of the solar system to gather and send back information to Earth. He pointed to NASA’s Voyager 1 and 2, which launched in 1977 but didn’t reach interstellar space until 2012 and 2018.

To send a signal to those space probes, NASA must calculate Earth’s exact position in orbit around the sun and design antennas for communication using pi. Then scientists use pi once more when receiving and breaking down complex signals that are being beamed back to Earth.

“Say aliens send something to us, something that we don’t know how to deal with,” Davoyan said. “So the very first thing that you would do, you would try to split it into simple functions… and turns out that when you do this operation, you will naturally have pis in it.”

Tiny droplets of pi

Pi also comes up frequently when studying small amounts of fluids.

Dino Di Carlo, chair of the bioengineering department at the UCLA Samueli School of Engineering, conducts research that involves creating little particles out of polymers that act as tiny test tubes for cells. This is used as an important tool to examine cells closely and learn about their functions and what’s inside them.

The pi constant is used in calculating how to form those droplets, surface tension calculations that define how droplets can break up, and how researchers can control the size of those volumes, Di Carlo said.

Di Carlo is using this technique to find antibodies — small proteins that fight diseases in your body — that could block signals put out by cancer cells.

Pi is also an important part of calculations when looking at how liquids flow through tubes and barriers. One example is when the fluid sample slowly flows sideways in a take-home COVID-19 test.

Di Carlo used these properties to devise a new test for Lyme disease that can be completed in 20 minutes, rather than days or weeks like previously.

“As an engineer and scientist, (pi) is just a part of life,” Di Carlo said. “Maybe I’ve taken it for granted.”

Pakistan’s foreign exchange reserves have climbed to their highest level in four years, reflecting improved economic management and reforms introduced under the Special Investment Facilitation Council.

According to Adviser to the Finance Minister Khurram Shehzad, the country’s total foreign exchange reserves have risen to $21.6 billion. Out of this amount, $16.3 billion is held by the State Bank of Pakistan, while $5.3 billion is maintained by commercial banks.

Shehzad noted that the central bank now accounts for 76 percent of the country’s total reserves, a development that signals stronger monetary oversight and greater financial independence for Pakistan.

He further explained that the increase in reserves strengthens the country’s capacity to handle potential economic shocks and provides a more stable financial foundation. The higher level of reserves with the State Bank also highlights Pakistan’s improved financial safeguards and a gradually strengthening economic outlook.

US workers are still struggling with the cost of living despite Donald Trump’s campaign promises to fix the US affordability crisis.

The Guardian spoke to workers as an exclusive poll showed cross-party concerns about the Trump administration’s handling of the US economy.

Dawn Levie, 61, a postal service worker in Paulden, Arizona, said she’s lost thousands in earnings over the past year due to cuts to her hours, making it more difficult for her to afford basic necessities like paying for groceries and utility bills.

“It’s hard to describe how you feel when you can’t sustain your livelihood because your money is impacted,” Levie said. “You can’t pay bills, [and] creditors get mad. How do you tell them: ‘I just don’t have it?’”

The White House insists that the affordability problem Americans like Levie report doesn’t exist. At a rally in Kentucky earlier this week, Donald Trump told the crowd: “Inflation is plummeting, income is rising, the economy is roaring back!”

Though the positive sentiment will be a tough sell for voters in the upcoming midterm elections.

After helping Congress pass huge cuts to healthcare and food assistance programs, Trump is now pushing to remove minimum wage and overtime protections for some workers. And though seven out of 10 Americans said that tariffs have led to higher prices, Trump has only doubled down on more levies.

Far from feeling like the US is in a golden age, workers said rising inflation means their paychecks can’t keep up with prices.

“I know things are worse, because I’m living it and I feel it every day,” said Bryan Williams, 63, a home-care worker in Madison, Wisconsin, who is living paycheck to paycheck on $17.65 an hour. “It’s very hard trying to pay rent, pay your bills, buy food, gas and juggle which ones you can pay [and] which ones you can let go.

“[I] ask myself which one should I get, when I know I need both, or worrying will I have enough money to get back and forth to work until another payday? Or will I have enough money to pay my light bill?”

Vernice Thompson, 63, a retail worker in Williamsburg, Virginia, said that even though she receives social security benefits, housing still takes up half her income.

“Groceries have gone up. [The prices of] a lot of the foods that I like have gone up,” said Thompson. “I know the price of clothing too because I work in retail, and I haven’t seen any declines in the price of clothing.”

“Everything is going up,” she added.

Food prices were 2.9% higher in January compared to the year before and are predicted to increase by 3.1% over the next year. Data shows that the food insecurity rate spiked to 16% in November, up from 12.7% in January 2025.

Utility prices in the US also increased by more than 6% in January 2026 compared to a year prior.

More Americans are taking on debt because of the rising cost of necessities. Total household debt in the fourth quarter of 2025 reached $18.8tn, up by 4% since the beginning of the year. Delinquency for all types of debt rose 3.26% in the fourth quarter of 2025 compared to 1.7% in the same period of 2024. Credit card debt in the US by the end of 2025 hit a record $1.28tn.

Meanwhile, wages have stagnated for many workers. The 10% lowest wage earners, receiving on average $14.56 an hour, saw their wages decline by 0.3% when adjusted for inflation in 2025. The federal minimum wage of $7.25 an hour has remained unchanged since 2009 – the longest period without an increase since the federal minimum wage was enacted.

In comparison, higher-income Americans have been earning more than ever. Since 1979, high-end wages have grown twice as fast as low and middle wages.

“If people aren’t being paid a cost-of-living increase, or just the bare minimum of a cost of living increase, it’s hard to keep up,” said Crystal Franklin, 54, a US passport specialist and mother of three who lives in Dumfries, Virginia.

Franklin said she started taking the bus to work because of rising gas prices and is being more frugal at the grocery store. Yet she still has less room in her budget for entertainment and leisure expenses for her grandchildren.

“We’re not able to do what we used to be able to do because cost of living has gone up extremely high,” Franklin said.

US families have paid more than $1,700 in estimated costs due to the Trump administration’s tariffs from February 2025 to January 2026, with Trump announcing new tariffs to replace those struck down by the US supreme court last month.

At the same time, Republicans have been cutting down the country’s social safety net. Trump’s One Big Beautiful Bill Act that was passed last summer included massive cuts for the next decade, including over $1tn from Medicaid, $536bn from Medicare and $186bn from the Supplemental Nutrition Assistance Program (Snap).

In addition to these cuts, the White House is allowing Affordable Care Act subsidies to expire, which will raise health insurance premiums for 22 million Americans by an estimated 114%, from $888 a year to $1,904 in 2026.

Trump has also sought to cut pay for millions of low-wage workers. Last year, the president rescinded an executive order that raised the minimum wage for federal contractors to $15 an hour and gave annual raises to keep in pace with inflation, impacting more than 300,000 workers. The White House is also trying to remove overtime protections for nearly 4 million home-care workers who received median wages of $16.78 an hour in 2024.

“Things have been pretty tough in the last year,” said Williams. “I don’t believe anything Trump says because everything he promised us he was going to do did not happen.”

A spokesperson for the White House, Kush Desai, disputed the economic trajectory under the Trump administration.

“America’s economic trajectory under President Trump has been solid,” Desai said. “This week’s CPI report showed inflation continues to cool while the Administration’s tax cut, tariff, and deregulatory agenda continues to drive robust real wage and investment growth. Once we are past short term disruptions from Operation Epic Fury, America is poised to see even greater economic progress as the Administration’s trade deals, drug pricing deals, deregulatory efforts, and tax cuts continue taking effect.”

Owners of some Nissan Leaf electric vehicles are angry after the carmaker announced it would shut down an app that lets them remotely control battery charging and other functions.

Drivers of Leaf cars made before May 2019 and the e-NV200 van (produced until 2022) have been told that the NissanConnect EV app linked to their vehicles will “cease operation” from 30 March. This means they will lose remote services, including turning on the heating, and some map features.

Experts said they expected other drivers to experience similar problems in future as “connected cars” – vehicles that can connect to the internet – get older.

One driver and Guardian Money reader, Alan Clucas, said he was upset by the switch-off, adding that some of the affected vehicles were less than four years old. “I think Nissan should do better,” he said.

Talking about his seven-year-old Leaf, Clucas said the “most annoying thing will be not being able to smart-charge the car or remotely warm it up on frosty mornings”. He added: “We could previously check the charge levels from a mobile phone.”

Other affected motorists have been discussing the matter online. “Looks like going forward, only paid-for remote connectivity will be supported,” said one, adding that it was “amazing” that Nissan “only supported a core EV feature for seven years. Considering [an] average car can last for 12-plus years, that is shockingly bad.”

Another driver added: “My car is almost 10 years old now, but those with an early 2020 model won’t be too happy that their not-even seven-year-old car is having remote access removed with a month’s notice.”

Nissan faced criticism in 2024 when it dropped the first generation of Leaf cars after the switch-off of the UK’s 2G network. The carmaker said the latest move was because the app could not be “upgraded to support future enhancements”.​

In-car services such as climate control and charging timers would still be available through the infotainment system, Nissan said, but remote services and some map-related features would not.

Steve Walker from the motoring magazine Auto Express said the situation was a preview of what would happen when “today’s cars” get old.

“As modern cars that are even more reliant on connected services and updates than the Leaf age, it is likely that manufacturer support for their systems will drop away, too,” he said.

This could mean other features including navigation systems, touchscreen controls and even subscriptions for features such as heated seats, autonomous driving aids or extra engine power could stop working or be turned off further down the line, he said.

“Nobody wants to see cars rendered obsolete before their time,” Walker said. “The best way to minimise the environmental impact of cars is to build them to last. Software and digital systems need to be as durable and reliable as mechanical components.”

Benjamin Gorman, a senior lecturer at Bournemouth University, said the tech world was shifting towards software-as-a service (Saas) models.

“A good example is software like Adobe Photoshop – historically, you could buy it once and use it for as long as you liked, whereas now it typically requires an ongoing subscription,” said Gorman.

This worked well for things such as games and entertainment platforms, where people are used to subscriptions and shorter upgrade cycles, he said. However, it is more problematic when applied to expensive physical products such as cars, which people expect to keep working for a decade or more.

“I suspect we will see this issue more often in the coming years as vehicles become increasingly software-driven,” said Gorman. “We are seeing more manufacturers experiment with subscription fees for connected features … but it raises important questions about what consumers feel they should permanently own versus what they are effectively renting through software services.”