The largest electrical grid in the U.S. has struggled to cope with an onslaught of data centers. Now, after an auction to add more generating capacity fell short, the grid’s operator, PJM Interconnection, has said it will cut off data centers and other large users during power shortages.

The decision arrives as the breakneck pace of data center construction has grid operators scrambling to generate power. Data centers are expected to use four times more electricity as they do today by 2035.

PJM won’t start curtailing supply until June 2027, and the cuts will only apply to data centers that are 50 megawatts or larger. The grid operator is running another auction for new generating capacity.

Similar to other demand response programs, which have existed for decades and typically include large users like manufacturers, the customers who have their power cut will be compensated. Such programs typically give customers advance notice, ranging from 30 minutes to a few days, depending on forecasted demand. 

The move will likely spur many new data centers — and potentially existing ones — to set up their own sources of on-site power. Those that don’t will probably rely on backup generators, which tend to be costlier to run and frequently more polluting. 

Many data centers favor diesel generators since the fuel is widely available and can be stored on-site. Federal regulations allow such generators to be used for up to 50 hours per year for demand response events, and up to 100 hours per year if including events like emergencies and maintenance.

This week, Vantage Data Centers came under fire for its apparent coordination with Virginia environmental regulators to cast doubt on a report that said diesel backup generators could contribute to tens of millions of dollars in annual health damages for people living near a 96 megawatt data center in Northern Virginia.

PJM has come under fire in recent months for the way it has managed new generating capacity and large new users, including data centers. The grid operator’s territory runs from Virginia to Illinois, covering 67 million customers. Over the last year, wholesale electricity prices have nearly doubled, and PJM’s independent market monitor blamed data centers for much of the increase. 

Physicists have been trying to measure the fundamental gravitational constant for well over two centuries. The current accepted value of big G, as it’s known, is 6.67430 × 10-11 cubic meters per kilogram per square second. It also has an uncertainty of ±0.00015 × 10^-11 m³/(kg s²). As far as constants of the universe go, that’s very uncertain.

Stephan Schlamminger recently completed a 10-year effort at the U.S. National Institute of Standards and Technology to replicate an earlier measurement of big G from the International Bureau of Weights and Measures, or BIPM (located near Paris) that’s notably higher than most measurements. He spoke with IEEE Spectrum about why it took so long to get a number—6.67387 x 10^-11 m³/(kg s²)—and why it’s notably lower than the BIPM result, to the tune of 0.0235 percent.

Why is it so difficult to measure big G?

Stephan Schlamminger: Gravity is very weak. When you were a kid, you probably played with fridge magnets, and it was a force you could feel. But if you have two coffee cups, you can try all you want—you can’t feel the force between them. It is there, but it’s so, so weak.

How did you attempt to measure big G?

NIST used a torsion balance with a fourfold geometry. This animation shows an exaggerated version of how the outer green masses gravitationally attract the inner blue masses.S. Kelley/NIST

Schlamminger: We used what’s called a torsion balance. The key idea in the torsion balance is that it decouples vertical gravity that you have from Earth from horizontal gravity, and that makes it sensitive to masses that are around the torsion balance but not the Earth below.

Ours had a fourfold geometry. It has a very thin torsion strip, then four cylinders in a “plus sign” arrangement. All of this is inside a vacuum. Outside, we have four larger cylinders that gravitationally attract the four smaller masses to them. If I move the outer masses just a tiny little bit, the plus sign will rotate, and we measure that angle that it moves. That angle is proportional to the gravitational torque.

Why try to replicate the BIPM value?

Schlamminger: We could move the field forward. The measurements have been plagued with inconsistencies, so by redoing an experiment, we hoped to shed light on the inconsistencies.

We did not find a smoking gun, so there’s no single reason why it’s different—our value versus their value. It’s still a big question mark.

What was it like spending 10 years on this?

Schlamminger: It’s a bit like herding cats. I’ve measured other fundamental constants, like Planck’s constant, and for most experiments, they have some sort of self-calibration built in. But with the gravitational constant, you have to keep track of every single mass that moves—where they are, how big they are, and weigh them.

How does your result compare to the rest?

Schlamminger: Our result is a little bit below the standard accepted literature value. I was disappointed because it doesn’t agree with the BIPM value, nor with the literature value. If there’s something wrong with the BIPM experiment, then the literature value—which includes that result—probably ought to come down a bit. But that is not for me to say. I think somebody else, independent, should figure out what the new mean value ought to be.

PayPal is seemingly still open to Stripe’s $53.4 billion takeover bid, just not at the price the latter had offered.

On the company’s Q2 2026 earnings call on Tuesday, PayPal CEO Enrique Lores didn’t fully shut down the idea of a deal, saying the company would consider a path that created “superior value” for its shareholders.

While that’s not the same as saying, “PayPal’s not for sale,” it still suggests the company doesn’t believe Stripe and Advent International’s current offer of $60.50 per share values it correctly, especially after the company reported better-than-expected profit and revenue, and said it had made progress on its turnaround strategy.

An analysis from financial services firm Cantor valued PayPal at closer to $70 per share. The company’s shares are currently trading at around $58.

PayPal reported adjusted profit of $1.38 per share, beating expectations of $1.28 per share. Revenue was up 5% year-over-year to $8.68 billion, above estimates of $8.47 billion. And adjusted free cash flow of $1.8 billion gives the company room to continue investing in its products and strategy.

That doesn’t mean PayPal would walk away from a takeover bid.

While Lores didn’t directly address Stripe’s offer, saying PayPal doesn’t comment on potential mergers or market speculation, he did acknowledge that a viable M&A bid would not be dismissed outright.

“If we see levers or a path that we believe would create superior value for our shareholders than executing our current strategy, we would, of course, carefully consider them,” he told investors on Tuesday.

PayPal is still busy with its AI-focused turnaround, which included a restructuring exercise to streamline its operations into three segments: checkout solutions and PayPal; consumer financial services (and Venmo); and payment services and crypto. The company has said it will generate additional cost savings as it embraces AI in areas like coding, customer service, support operations, and risk management.

Lores offered an update on this strategy on Tuesday, saying the company was “making good progress” on its plan to deliver at least $1.5 billion in gross run-rate savings over the next two to three years. He also said PayPal is on track to remove three organizational layers across the company, and is continuing to modernize its technology. This last bit includes migrating from its data center to the cloud, building a more modular and scalable architecture, and reducing platform complexity.

“We believe that executing the transformation strategy I have outlined will create significant value for shareholders. That remains our focus,” Lores said. “While there is still significant work ahead. I have strong conviction in our direction and in our ability to execute.”