NEW YORK (AP) — Eggs are less likely to crack when they fall on their side, according to experiments with over 200 eggs.
What does this mean for the best way to crack an egg for breakfast? Not much, since a break around the middle is the best way to get the golden yolk and runny whites to ooze out.
But scientists said it could help with hard-boiling eggs in a pot: Dropping eggs in horizontally may be less likely to cause a stray crack that can unleash the egg's insides in a puffy, cloudy mess.
It's commonly thought that eggs are strongest at their ends — after all, it's how they're packaged in the carton. The thinking is that the arc-shaped bottom of an egg redirects the force and softens the blow of impact.
But when scientists squeezed eggs in both directions during a compression test, they cracked under the same amount of force.
“The fun started when we thought we would get one result and then we saw another,” said Hudson Borja da Rocha with Massachusetts Institute of Technology, who helped run the experiments.
The researchers also ran simulations and dropped eggs horizontally and vertically from three short heights up to 0.4 inches (10 millimeters).
The egg result? The ones dropped horizontally cracked less .
“The common sense is that the egg in the vertical direction is stronger than if you lay the egg down. But they proved that's not the case,” said materials scientist Marc Meyers with the University of California, San Diego who was not involved with the new study.
Scientists found that the egg's equator was more flexible and absorbed more of the energy of the fall before cracking. The findings were published Thursday in the journal Communications Physics.
Eggs are also usually nestled top-down into homemade contraptions for egg drop challenges as part of school STEM projects, which partially inspired the new study. It's not yet clear whether the new results will help protect these vulnerable eggs, which are dropped at much loftier heights.
It's a bit counterintuitive that the oblong side of an egg could hold up better against a tumble, said study co-author Tal Cohen with Massachusetts Institute of Technology.
Countless broken eggs show "the courage to go and challenge these very common, accepted notions,” Cohen said.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.
FILE - A hen stands on eggs inside her coop at at a farm in Glenview, Ill., on Friday, Feb. 7, 2025. (AP Photo/Erin Hooley, File)
SEOUL, South Korea (AP) — North Korea on Thursday displayed apparent progress in the construction of a nuclear-powered submarine, with state media photos showing a largely completed hull, as leader Kim Jong Un condemned rival South Korea’s push to acquire the technology.
North Korea’s official Korean Central News Agency said Kim visited a shipyard to inspect the construction of what the North describes as an 8,700-ton-class nuclear-propelled submarine, which the leader has called a crucial step in the modernization and nuclear armament of North Korea’s navy. The North has indicated it plans to arm the submarine with nuclear weapons, calling it a “strategic guided missile submarine” or a “strategic nuclear attack submarine.”
During the visit, Kim described South Korea’s efforts to acquire its own nuclear-powered submarine, which have been backed by U.S. President Donald Trump, as an “offensive act” that severely violates the North’s security and maritime sovereignty.
He said that the South Korean plan further underscores the need to advance and nuclear-arm North Korea’s navy, and claimed that the completion of his nuclear-powered submarine would be an “epoch-making” change in strengthening its nuclear war deterrent against what he called enemy threats.
The agency did not specify when Kim visited the shipyard but released photos showing him inspecting a huge, burgundy-colored vessel, coated with what appears to be anti-corrosion paint, under construction inside an assembly hall with senior officials and his daughter. It was the first time North Korean state media had released images of the submarine since March, when they mostly showed the lower sections of the vessel.
It was not immediately clear how close North Korea is to completing the vessel. But because submarines are typically built from the inside out, the release of what appears to be a largely completed hull suggests that many core components, including the engine and possibly the reactor, are already in place, said Moon Keun-sik, a submarine expert at Seoul’s Hanyang University.
“Showing the entire vessel now seems to indicate that most of the equipment has already been installed and it is just about ready to be launched into the water,” said Moon, a former submarine officer in the South Korean navy, who believes the North Korean submarine could possibly be tested at sea within months.
A nuclear-powered submarine was one item on a long wish list of sophisticated weaponry that Kim announced during a major political conference in 2021 to cope with what he called growing U.S.-led military threats. Other weapons were solid-fueled intercontinental ballistic missiles, hypersonic weapons, spy satellites and multi-warhead missiles.
North Korea has conducted a series of tests to develop some of those systems and recently unveiled a new naval destroyer, which Kim hailed as a major step toward expanding the operational range and preemptive strike capabilities of the country’s nuclear forces.
If North Korea obtains a submarine capable of operating stealthily for extended periods and launching missiles from underwater, it would be a worrying development for its neighbors, as such launches would be difficult to detect in advance. But there have been questions about whether North Korea, a heavily sanctioned and impoverished country, could get resources and technology to build nuclear-powered submarines.
Some experts say North Korea’s recent alignment with Russia — including sending thousands of troops and military equipment to support President Vladimir Putin’s war in Ukraine — may have helped it to receive crucial technologies in return.
While some analysts suspect North Korea may have sought a reactor from Russia, possibly from a retired Russian submarine, Moon said it's more likely that North Korea designed its own reactor, while possibly receiving some technological assistance from Russia.
During a summit with Trump in November, South Korean President Lee Jae Myung called for U.S. support for South Korea’s efforts to acquire nuclear-powered submarines, while reaffirming a commitment to increase defense spending to ease the burden on the United States.
Trump later said that the United States is open to sharing closely held technology to allow South Korea to build a nuclear-powered submarine, but it’s not immediately clear where and when the vessel would be built and how Seoul would get the nuclear fuel and reactor technology required.
In a separate report, KCNA said Kim on Wednesday supervised a test of a new, long-range anti-air missile that was fired toward its eastern sea. South Korea’s Defense Ministry didn’t immediately comment on the launch.
Tensions on the Korean Peninsula have worsened in recent years as Kim accelerated his military nuclear program and deepened alignment with Moscow following Russia’s invasion of Ukraine. His government has repeatedly dismissed calls by Washington and Seoul to revive negotiations aimed at winding down his nuclear and missile programs, which derailed in 2019 following a collapsed summit with Trump during the American president’s first term.
In this photo provided by the North Korean government, a test of a long-range anti-air missile is launched towards its eastern sea, as seen from an undisclosed location in North Korea, Wednesday, Dec. 24, 2025. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. Korean language watermark on image as provided by source reads: "KCNA" which is the abbreviation for Korean Central News Agency. (Korean Central News Agency/Korea News Service via AP)
In this undated photo provided Thursday, Dec. 25, 2025, by the North Korean government, its leader Kim Jong Un, with his daughter, inspects a nuclear-powered submarine under construction at an undisclosed location in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. Korean language watermark on image as provided by source reads: "KCNA" which is the abbreviation for Korean Central News Agency. (Korean Central News Agency/Korea News Service via AP)
In this undated photo provided Thursday, Dec. 25, 2025, by the North Korean government, its leader Kim Jong Un, third left, visits a shipyard as he inspects a nuclear-powered submarine under construction at an undisclosed location in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. Korean language watermark on image as provided by source reads: "KCNA" which is the abbreviation for Korean Central News Agency. (Korean Central News Agency/Korea News Service via AP)
In this undated photo provided Thursday, Dec. 25, 2025, by the North Korean government, its leader Kim Jong Un inspects a nuclear-powered submarine under construction at an undisclosed location in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. Korean language watermark on image as provided by source reads: "KCNA" which is the abbreviation for Korean Central News Agency. (Korean Central News Agency/Korea News Service via AP)
In this undated photo provided Thursday, Dec. 25, 2025, by the North Korean government, its leader Kim Jong Un inspects a nuclear-powered submarine under construction at an undisclosed location in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. Korean language watermark on image as provided by source reads: "KCNA" which is the abbreviation for Korean Central News Agency. (Korean Central News Agency/Korea News Service via AP)
