Connect with us

The Conversation

Nuclear fusion could one day be a viable clean energy source – but big engineering challenges stand in the way

Published

on

theconversation.com – George R. Tynan, Professor of Mechanical and Aerospace Engineering, University of California, San Diego – 2025-01-08 07:22:00

Inside the target chamber at the National Ignition Facility, where researchers work on getting higher energy outputs from fusion power.
Lawrence Livermore National Laboratory, Lawrence Livermore National Security, LLC, and the Department of Energy − National Ignition Facility

George R. Tynan, University of California, San Diego and Farhat Beg, University of California, San Diego

The way scientists think about fusion changed forever in 2022, when what some called the experiment of the century demonstrated for the first time that fusion can be a viable source of clean energy.

The experiment, at Lawrence Livermore National Laboratory, showed ignition: a fusion reaction generating more energy out than was put in.

In addition, the past few years have been marked by a multibillion-dollar windfall of private investment in the field, principally in the United States.

But a whole host of engineering challenges must be addressed before fusion can be scaled up to become a safe, affordable source of virtually unlimited clean power. In other words, it’s engineering time.

As engineers who have been working on fundamental science and applied engineering in nuclear fusion for decades, we’ve seen much of the science and physics of fusion reach maturity in the past 10 years.

But to make fusion a feasible source of commercial power, engineers now have to tackle a host of practical challenges. Whether the United States steps up to this opportunity and emerges as the global leader in fusion energy will depend, in part, on how much the nation is willing to invest in solving these practical problems – particularly through public-private partnerships.

Building a fusion reactor

Fusion occurs when two types of hydrogen atoms, deuterium and tritium, collide in extreme conditions. The two atoms literally fuse into one atom by heating up to 180 million degrees Fahrenheit (100 million degrees Celsius), 10 times hotter than the core of the Sun. To make these reactions happen, fusion energy infrastructure will need to endure these extreme conditions.

Fusion reactions fuse together two atoms, releasing enormous amounts of energy.

There are two approaches to achieving fusion in the lab: inertial confinement fusion, which uses powerful lasers, and magnetic confinement fusion, which uses powerful magnets.

While the “experiment of the century” used inertial confinement fusion, magnetic confinement fusion has yet to demonstrate that it can break even in energy generation.

Several privately funded experiments aim to achieve this feat later this decade, and a large, internationally supported experiment in France, ITER, also hopes to break even by the late 2030s. Both are using magnetic confinement fusion.

Challenges lying ahead

Both approaches to fusion share a range of challenges that won’t be cheap to overcome. For example, researchers need to develop new materials that can withstand extreme temperatures and irradiation conditions.

Fusion reactor materials also become radioactive as they are bombarded with highly energetic particles. Researchers need to design new materials that can decay within a few years to levels of radioactivity that can be disposed of safely and more easily.

Producing enough fuel, and doing it sustainably, is also an important challenge. Deuterium is abundant and can be extracted from ordinary water. But ramping up the production of tritium, which is usually produced from lithium, will prove far more difficult. A single fusion reactor will need hundreds of grams to one kilogram (2.2 lbs.) of tritium a day to operate.

Right now, conventional nuclear reactors produce tritium as a byproduct of fission, but these cannot provide enough to sustain a fleet of fusion reactors.

So, engineers will need to develop the ability to produce tritium within the fusion device itself. This might entail surrounding the fusion reactor with lithium-containing material, which the reaction will convert into tritium.

To scale up inertial fusion, engineers will need to develop lasers capable of repeatedly hitting a fusion fuel target, made of frozen deuterium and tritium, several times per second or so. But no laser is powerful enough to do this at that rate – yet. Engineers will also need to develop control systems and algorithms that direct these lasers with extreme precision on the target.

A piece of steel machinery in a physics lab.
A laser setup that Farhat Beg’s research group plans to use to repeatedly hit a fusion fuel target. The goal of the experiments is to better control the target’s placement and tracking. The lighting is red from colored gels used to take the picture.
David Baillot/University of California San Diego

Additionally, engineers will need to scale up production of targets by orders of magnitude: from a few hundreds handmade every year with a price tag of hundreds of thousands of dollars each to millions costing only a few dollars each.

For magnetic containment, engineers and materials scientists will need to develop more effective methods to heat and control the plasma and more heat- and radiation-resistant materials for reactor walls. The technology used to heat and confine the plasma until the atoms fuse needs to operate reliably for years.

These are some of the big challenges. They are tough but not insurmountable.

Current funding landscape

Investments from private companies globally have increased – these will likely continue to be an important factor driving fusion research forward. Private companies have attracted over US$7 billion in private investment in the past five years.

Several startups are developing different technologies and reactor designs with the aim of adding fusion to the power grid in coming decades. Most are based in the United States, with some in Europe and Asia.

A diagram showing a fusion reactor and all its components.
ITER is a fusion reactor planned to operate in France.
AP Photo/Claude Paris

While private sector investments have grown, the U.S. government continues to play a key role in the development of fusion technology up to this point. We expect it to continue to do so in the future.

It was the U.S. Department of Energy that invested about US$3 billion to build the National Ignition Facility at the Lawrence Livermore National Laboratory in the mid 2000s, where the “experiment of the century” took place 12 years later.

In 2023, the Department of Energy announced a four-year, $42 million program to develop fusion hubs for the technology. While this funding is important, it likely will not be enough to solve the most important challenges that remain for the United States to emerge as a global leader in practical fusion energy.

One way to build partnerships between the government and private companies in this space could be to create relationships similar to that between NASA and SpaceX. As one of NASA’s commercial partners, SpaceX receives both government and private funding to develop technology that NASA can use. It was the first private company to send astronauts to space and the International Space Station.

Along with many other researchers, we are cautiously optimistic. New experimental and theoretical results, new tools and private sector investment are all adding to our growing sense that developing practical fusion energy is no longer an if but a when.The Conversation

George R. Tynan, Professor of Mechanical and Aerospace Engineering, University of California, San Diego and Farhat Beg, Professor of Mechanical and Aerospace Engineering, University of California, San Diego

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

Read More

The post Nuclear fusion could one day be a viable clean energy source – but big engineering challenges stand in the way appeared first on theconversation.com

The Conversation

Trump’s executive orders can make change – but are limited and can be undone by the courts

Published

on

theconversation.com – Sharece Thrower, Assistant Professor of Political Science, Vanderbilt University – 2025-01-20 11:18:00

U.S. President-elect Donald Trump arrives for inauguration ceremonies in the Rotunda of the U.S. Capitol, January 20, 2025.

Chip Somodevilla/Getty Images

Sharece Thrower, Vanderbilt University

Before his inauguration, Donald Trump promised to issue a total of 100 or so executive orders once he regained the presidency. These orders are expected to reset government policy on everything from immigration enforcement to diversity initiatives to environmental regulation. They also aim to undo much of Joe Biden’s presidential legacy.

Trump is not the first U.S. president to issue an executive order, and he certainly won’t be the last. My own research shows executive orders have been a mainstay in American politics – with limitations.

What is an executive order?

Though the Constitution plainly articulates familiar presidential tools like vetoes and appointments, the real executive power comes from reading between the lines.

Presidents have long interpreted the Constitution’s Article 2 clauses – like “the executive power shall be vested in a President” and “he shall take care that the laws be faithfully executed” – to give them total authority to enforce the law through the executive branch, by any means necessary.

One leading way they do that is through executive orders, which are presidential written directives to agencies on how to implement the law. The courts view them as legally valid unless they violate the Constitution or existing statutes.

Executive orders, like other unilateral actions, allow presidents to make policy outside of the regular lawmaking process.

This leaves Congress, notoriously polarized and gridlocked, to respond.

Thus, executive orders are unilateral actions that give presidents several advantages, allowing them to move first and act alone in policymaking.

How have they historically been used?

Every U.S. president has issued executive orders since they were first systematically cataloged in 1905.

In March of 2016, then-presidential candidate Donald Trump criticized President Obama’s use of executive orders.

“Executive orders sort of came about more recently. Nobody ever heard of an executive order. Then all of a sudden Obama – because he couldn’t get anybody to agree with him – he starts signing them like they’re butter,” Trump said. “So I want to do away with executive orders for the most part.”

Little in this statement is true.

Obama signed fewer orders than his predecessors – averaging 35 per year. Trump issued an average of 55 per year.

Against conventional wisdom, presidents have relied less on executive orders over time. Indeed, modern presidents used drastically fewer orders per year – an average of 59 – than their pre-World War II counterparts, who averaged 314.

Executive orders have been used for everything from routine federal workplace policies like ethics pledges to the controversial 2017 travel ban restricting entry into the United States.

They have been used to manage public lands, the economy, the civil service and federal contractors, and to respond to various crises such as the Iran hostage situation and the COVID-19 pandemic.

Presidents often use them to advance their biggest agenda items, by creating task forces or policy initiatives and directing rulemaking, the process for formally translating laws into codified policy.

Limitations in their use

Why don’t presidents always issue executive orders, a seemingly powerful policy device? Because they come with serious constraints.

First, executive orders may not be as unilateral as they seem. Drafting an order involves a time-consuming bargaining process with various agencies negotiating its content.

Second, if they are issued without proper legal authority, executive orders can be overturned by the courts – although that happens infrequently.

Trump’s 2017 travel ban faced several legal challenges before it was written in a way to satisfy the court. Many of his initial orders, on the other hand, didn’t face legal scrutiny because they simply requested agencies to work within their existing authority to change important policies like health care and immigration.

Congress is another barrier, as they give presidents the legal authority to make policy in a certain area. By withholding that authority, Congress can deter presidents from issuing executive orders on certain issues. If the president issues the order anyway, the courts can overturn it.

Legislators can also punish presidents for issuing executive orders they do not like by sabotaging their legislative agendas and nominees or defunding their programs.

Even a polarized Congress can find ways to sanction a president for an executive order they don’t like. For example, a committee can hold an oversight hearing or launch an investigation – both of which can decrease a president’s public approval rating.

Congresses of today are equipped to impose these constraints and they do so more often on ideologically opposed administrations. This is why scholars find modern presidents issue fewer executive orders under divided government, contrary to popular media narratives that present executive orders as a president’s way of circumventing Congress.

Finally, executive orders are not the last word in policy. They can be easily revoked.

New presidents often reverse previous orders, particularly those of political opponents. Biden, for instance, quickly revoked Trump’s directives that excluded undocumented immigrants from the U.S. Census.

All recent presidents have issued revocations, especially in their first year. They face barriers in doing so, however, including public opinion, Congress and legal limitations.

Regardless, executive orders are not as durable as laws or regulations.

Constraints on Trump

Some of Trump’s executive orders, particularly those focused on the economy, will require legislation since Congress holds the purse strings.

Though Trump inherits a Republican House and Senate, their majorities are marginal, and moderate party dissenters may frustrate his agenda. Even so, he will undoubtedly use all available legal authority to unilaterally transform his goals into government policy.

But then again, these directives may be undone by the courts – or by the next president with the stroke of a pen.

This is an updated version of a story originally published on January 26, 2021.The Conversation

Sharece Thrower, Assistant Professor of Political Science, Vanderbilt University

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

Read More

The post Trump’s executive orders can make change – but are limited and can be undone by the courts appeared first on theconversation.com

Continue Reading

The Conversation

Neighbors and strangers pulled together to help LA fire survivors – 60 years of research shows these unsung heroes are crucial to disaster response

Published

on

theconversation.com – Tricia Wachtendorf, Professor of Sociology and Director, Disaster Research Center, University of Delaware – 2025-01-20 07:36:00

Neighbors fill and pass a bucket of pool water to help extinguish a spot fire in Pacific Palisades, Calif., on Jan. 9, 2025.

Brian van der Brug / Los Angeles Times via Getty Image

Tricia Wachtendorf, University of Delaware and James Kendra, University of Delaware

As wildfires swept through neighborhoods on the outskirts of Los Angeles in January 2025, stories about residents there helping their neighbors and total strangers began trickling out on social media.

Accounts of Hollywood stars clearing streets for emergency vehicles to get through and raising money for fire victims were widely circulated. But there were many other examples of less-famous people helping older neighbors to safety, and even showing up with trailers to evacuate horses.

Businesses, including fitness centers, opened their facilities so evacuees could shower or charge their phones. Organizations that routinely work with homeless populations quickly mobilized their members to help ensure people living on the streets and in camps could get to secure, safe locations away from the fires and hazardous air quality.

Disasters, by definition, overwhelm local resources, making civilian responders like these essential. Sixty years of research at the University of Delaware’s Disaster Research Center and by others examining the social aspects of disaster has repeatedly shown effective disaster management requires mobilizing community resources far beyond official channels.

Often the response happens through local groups that form in response to a clear need in the community and with shared skills and interests. And this is exactly what we are witnessing in Los Angeles.

Civilians helping often number in the thousands

The number of those who step up to help during disasters varies by event, but it can be tremendous.

Following the 1995 Oklahoma City bombing, over 6,800 volunteers worked with the Red Cross on the response. That same year, volunteers responding to the Kobe earthquake in Japan logged more than 1 million person-days of activity, a measure of the number of people times the hours they contributed.

Two people stand on rooftops with garden hoses as a home burns nearby.

People use garden hoses to try to prevent homes from catching fire in Altadena, Calif., on Jan. 8, 2025. Neighbors rushed to help neighbors as the wind blew burning embers into neighborhoods.

Mario Tama/Getty Images

In an in-depth study of the Sept. 11, 2001, World Trade Center attacks , we interviewed local residents who used their retired fireboat to pump water for the firefighters at ground zero. Operators of tug, ferry and tour boats in and around New York City immediately responded to quickly evacuate 500,000 people in the area from danger. In fact, the majority of the boats involved belonged to private companies. Other volunteers queued evacuees and organized supplies and rides to get people home.

Over 900 people, most acting in unofficial capacities, were awarded medals or ribbons for their efforts in just the marine response after the World Trade Center attack.

A survey of residents after the 1985 Mexico City earthquake found that nearly 10% of local residents volunteered in the first three weeks of the response. Following the 1989 Loma Prieta earthquake, in California, a survey of residents in Santa Cruz and San Francisco counties found that two-thirds of the public were involved in response activities.

A man standing behind a table with boxes of food hands a bag to a woman in line.

Local businesses are often quick to help in disasters. Greg Dulan, center, who runs a soul food restaurant and food truck, hands out hot meals to wildfire evacuees at a church in Pasadena, Calif., on Jan. 15, 2025.

Jason Armond/Los Angeles Times via Getty Images

However, much of the work local residents contribute during and after disasters goes unaccounted for in official reports.

There is no mechanism to quantify the full extent to which a neighbor or a complete stranger helps someone flee from peril. Yet when people are trapped and minutes count, research shows it is family, friends and neighbors who are already on the scene and are most likely to save lives. It’s often everyday citizens who also take on immediate tasks such as debris removal. Providing a phone, a car, a place to do laundry, or a little bit of elbow grease can fill a gap and let firefighters and other formal responders focus on critical operations.

Getting the right help to where it’s needed

Every study of a large-scale disaster conducted by the Disaster Research Center has revealed some level of emergent, informal helping behavior.

The lack of public understanding about the large number of local residents already involved, often including disaster victims themselves, can lead to an influx of outsiders eager to help. Their arrival can actually pose challenges for the disaster response.

When too many people show up, or when people try to operate outside their areas of expertise, they can put themselves and others at further risk. Communities often need supplies, but unsolicited goods of the wrong kind or at the wrong time can create more problems than they solve.

Several people wearing bright orange shirts rake debris into garbage cans on a residential street.

Local groups such as the Pasadena Community Job Center organize volunteers to send them where help is requested. This group is removing debris from streets in Pasadena, Calif., in the wake of the Eaton Fire on Jan. 14, 2025.

Zoë Meyers/AFP via Getty Images

So, what can you do to best support these local efforts?

Making a financial contribution to a trusted disaster response or local organization can go a long way to providing the support communities actually need. Organizations such as the American Red Cross or Feeding America, or local community-based groups that routinely work in the area, are often best suited to help where it’s needed the most.

Skilled help will be needed for the long term

Also, remember that disasters don’t end when the emergency is over. Survivors of the Los Angeles-area fires face years of confusing and frustrating recovery tasks ahead.

Offering help after the immediate threat has passed – particularly skilled help, such as experience in construction or expertise in managing insurance and FEMA paperwork – is just as important.

For example, after fires in 1970 destroyed hundreds of homes in the San Diego area, local architects, engineers and contractors donated their time and skills to help people rebuild. Their work was coordinated by a local architect and member of the Chamber of Commerce to ensure projects were assigned to reputable volunteers.

As we recognize the important ways that neighbors and strangers helped those around them, the broader community can support wildfire victims by responding to offering the right help as recovery needs emerge. Just about every skill that is useful in calm times will be needed in these difficult months and years ahead.The Conversation

Tricia Wachtendorf, Professor of Sociology and Director, Disaster Research Center, University of Delaware and James Kendra, Director, Disaster Research Center and Professor, Public Policy & Administration, University of Delaware

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

Read More

The post Neighbors and strangers pulled together to help LA fire survivors – 60 years of research shows these unsung heroes are crucial to disaster response appeared first on theconversation.com

Continue Reading

The Conversation

Astronauts on NASA’s Artemis mission to the Moon will need better boots − here’s why

Published

on

theconversation.com – Jesse Rhoades, Associate Professor of Education, Heath & Behavior, University of North Dakota – 2025-01-20 07:35:00

The lunar south pole’s terrain is rugged, and it can reach extreme temperatures.

Michael Karrer/Flickr, CC BY-NC

Jesse Rhoades, University of North Dakota and Rebecca Rhoades, University of North Dakota

The U.S.’s return to the Moon with NASA’s Artemis program will not be a mere stroll in the park. Instead it will be a perilous journey to a lunar location representing one of the most extreme environments in the solar system.

For the Artemis program astronauts, walking on the Moon will require new ways of thinking, the latest technology and innovative approaches to improve boot and spacesuit design.

The Apollo program’s journeys to the Moon 50 years ago were all to the milder, equatorial regions of the lunar surface, where the coolest temperatures reached -9 degrees Fahrenheit (-23 degrees Celsius).

In contrast, the Artemis missions are designed to take astronauts to the Moon’s extreme polar regions, where temperatures can reach -369 degrees Fahrenheit (-223 degrees Celsius). Apollo-era equipment designed for short-term stays in a moderate zone will not be enough for extended stays in this new, more hostile region.

At the University of North Dakota we focus on biomechanics, the study of human movement. Our research explores the effects of extreme environments on human movement patterns and gait, and our lab conducts research that we hope will one day help astronauts explore the Moon while protecting their body.

New boots for the Moon

Of all the equipment astronauts need to explore the Moon, one of the most critical pieces is the boots they’ll use for extravehicular activity – when they step outside their spacecraft and bounce across the lunar landscape. These boots have to hold up to the harsh environmental conditions unique to the lunar south pole.

A photo, shown from above, of an astronaut's boot and boot print on the lunar surface.

The Apollo program represents the last time humans stepped onto the lunar surface.

Edwin ‘Buzz’ Aldrin/NASA via AP

Since the lunar poles are much colder than other lunar regions, the boots will need to retain heat effectively. The current iteration of the lunar boot uses a rigid thermal plate, which is typically integrated into the sole of the boot. The plate is solid and does not bend or flex. These plates were not used during the earlier Apollo missions.

While it’s necessary to keep astronauts’ feet warm, this addition to the boot prevents the footwear from flexing. The stiff sole restricts the foot’s natural movement, specifically the joint at the big toe, called the the metatarsophalangeal, or MTP, joint. The MTP joint bends and flexes to facilitate normal walking and running gait patterns.

The windlass mechanism

As you walk, the MTP joint allows your big toe to extend forward. Extension of the big toe triggers a mechanism in the foot that converts the flexible landing foot to a ridged pushing foot when you’re about to push forward to step. This mechanism allows the foot to become rigid and support your body weight through your step. Kinesiologists call this mechanism the windlass mechanism.

The windlass mechanism helps propel your foot forward while walking.

The windlass mechanism isn’t well studied – particularly under lunar gravity. If this mechanism is vital for walking around on the Moon, it could be a problem that the boots keep an astronaut’s feet from bending.

There are a million little details that have to go right for a Moon mission to succeed – how much flex is in the sole of the boots explorers use is just one that could ultimately influence their health on the Moon.

While an astronaut should be fine over the short term – days or weeks – once astronauts are staying on the Moon for months, they could develop a foot injury that might affect other parts of the body.

Kinesiologists like to examine the human body as a kinetic chain. This is to say, if you hurt part of your lower body, your upper body takes on the load of many of its functions. An issue that begins in the foot may affect the way a person walks and stands, causing further injury up the kinetic chain, through compensatory mechanisms.

So, the kinetic chain describes how an injury in the lower body could cause chronic injury in several other joints further up the body.

As NASA works on sending astronauts back to the Moon, researchers will need to learn more about lunar gait to understand how the foot reacts while moving around under lunar gravity. What they learn will aid designers as they continue to perfect spacesuit designs.The Conversation

Jesse Rhoades, Associate Professor of Education, Heath & Behavior, University of North Dakota and Rebecca Rhoades, Researcher in Education, Health & Behavior, University of North Dakota

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

Read More

The post Astronauts on NASA’s Artemis mission to the Moon will need better boots − here’s why appeared first on theconversation.com

Continue Reading

Trending