Author: John Timmer

Earlier this year, a group of Florida mayors that are dealing with problems caused by sea level rise sent a letter to the Republican presidential candidates that hailed from the same state. "We call on you to acknowledge the reality and urgency of climate change," the letter said. But Jeb Bush and Marco Rubio, both of whom have been ambiguous at best about that reality, ignored the letter.

With Bush since departing the race, it was left to Marco Rubio to field that request at last night's Republican debate in Florida. "Senator Rubio, the Miami mayor has endorsed you," moderator Jake Tapper noted. "Will you honor his request for a pledge and acknowledge the reality of the scientific consensus of climate change and pledge to do something about it?"

Rubio's response distilled down to "no," but he made a complete hash of its details.

Antarctica wasn't always the barren ice world that we now know. In the distant past, plate tectonics placed it at warmer latitudes. But more recently, even after it adopted its southern location, high global temperatures severely limited the ice on Antarctica. That started to change as the period known as the Eocene came to a close and global temperatures dropped. But the precise details of how the continent went white are a challenge to determine.

Now, a large international team of researchers has obtained a sediment core from just offshore of the East Antarctic ice sheet that captures key events in the glaciation of the continent. And because it provides relatively precise indications of when things happened, it's possible to line it up with other global records. Combined, the records indicate that there were two key transitions: one where an ice cap began to form and a second when it expanded to meet the ocean.

Both of these events appear to have been tied to the level of atmospheric carbon dioxide. And in each case, we've been on a path toward reversing them before the century is out.

In the US, electricity demand is growing very slowly, which means that capacity additions don't have to exceed retirements by much in order to keep the grid functioning. Tracking the comings and goings from the electric grid can help provide a picture of the country's changing energy mix.

We recently discussed the planned generating additions for 2016, which were dominated by renewables and natural gas; no new coal plants were expected. It appears that 2015's retirements were the mirror image.

The Energy Information Administration, which provides data on the US' electric grid, says 18GW of capacity were retired this past year, more than 80 percent of it coal-fired. More than 27GW of utility-scale projects will replace that this year. Note that much of the new generating hardware is wind and solar, which typically have a capacity factor in the area of 30 percent, while the plants they are replacing could have a capacity factor that's much higher, so it's not easy to have a direct comparison between the two.

The Wellcome Trust is one of the world's premier biomedical research and education organizations. As such, it has amassed a staggering collection of images, many of which it has made available for public use.

The image collecting isn't a thing of the past; it's an ongoing effort that brings new pictures in each year. And every year, the Trust convenes a panel of experts to choose the best images of the previous year. Each year features a mixture of objects from the sub-microscopic to the human-scaled, all focused on various aspects of biology and health.

Below, you'll find a selection of 2016's images that have been chosen for recognition.

When did the first stars and galaxies form? The earliest thing we can see in the Universe is the Cosmic Microwave Background, created about 400,000 years after the Big Bang. The event that created the CMB filled the Universe with neutral hydrogen, which efficiently absorbs most of the wavelengths of light we would normally use to detect the first galaxies. But their light gradually reionized this neutral hydrogen, bringing an end to the Universe's "dark ages."

By the time reionization was complete, however, there was already substantial population of galaxies (not surprising, since they were caused by the reionization). So, how do we find the earliest galaxies?

In the case of new results announced this week, the authors used a combination of the Hubble and Spitzer space telescopes to identify a candidate galaxy that was exceptionally bright and distant. Then they used the absorption of light by all that neutral hydrogen to determine that it dates from only 400 million years after the Big Bang, when the Universe was only three percent of its current age.

The Obama Administration's Clean Power Plan represents an attempt to use the Clean Air Act to limit the US' carbon emissions. But its roots trace back to a lawsuit filed during the Clinton administration and decided by the Supreme Court during the Bush years. Christine Todd Whitman, former governor of New Jersey, was in charge of the EPA when President Bush reneged on a campaign promise and announced he was giving up on any attempt to regulate carbon emissions.

Whitman has stayed involved in environmental issues and is now the co-chair of an organization called the CASEnergy Coalition, which is promoting nuclear power as one of the solutions for limiting our carbon emissions. She recently talked with Ars about climate issues, nuclear power, and those awkward Bush years.

Ars: You were in charge of the EPA when Massachusetts v EPA was moving through the courts. Had you already started looking into carbon emissions and the Clean Air Act?

For many of us, the term "robot" still evokes an image of R2D2 or a terminator-style collection of metal parts. But there's no reason to limit our construction materials to hard parts. A number of labs are working on soft-bodied robots and have shown they can do some rather interesting things, like squeeze through narrow spaces.

A team of researchers from Cornell and the Istituto Italiano di Tecnologia has taken a soft-bodied robot and made it glow. Their method of producing the light, however, has some interesting side effects: it allows the robot to determine how much it has flexed, and it makes the robot responsive to touch.

These days, "glow" is usually synonymous with "LED." But the authors used a very different technique, relying on what's called an electroluminescent phosphor—basically, something that glows when it's place in an alternating electric field. The phosphors (zinc sulfide, in this case) can be embedded in a silicone gel, making them stretchable and bendable. Different dopants in the phosphor will cause it to glow in different colors.

From nowhere, they appear as a sudden surge of power in the radio spectrum. Then, a few milliseconds later, they're gone—and as far as we could tell, they never come back. They've picked up the name "fast radio bursts," but nobody's entirely sure of what produces them. Follow-up observations have generally failed to find anything interesting in their direction, and the bursts didn't seem to repeat, leaving everyone who cares about these sorts of things a bit mystified.

One possible explanation for their one-time-only appearance would be that they're the product of a process that destroys the object that creates them. Thus, if they were produced by the collapse of a neutron star into a black hole (to give just one example), there'd be no way for that to happen twice.

But a new study suggests that at least one of them has repeated, which would take cataclysmic explanations off the table. There are enough differences between this burst and previously observed ones, however, to raise the question of whether there might be several processes producing similar surges in radio emissions.

Today, the US Energy Information Administration released data on planned additions to the US power grid this year. The year is notable because it will see the first new nuclear plant brought online in 20 years, contributing 1.1 GigaWatts to the grid. But that contribution will be dwarfed by renewable power sources, which together will account for nearly two-thirds of 2016's new capacity. And these numbers only count utility-scale solar, ignoring commercial and residential installations.

Part of the boom in renewables came because the tax incentives for their installation were in danger of expiring, so utilities rushed to get projects through the pipeline ahead of the end of the year. (The incentives have since been extended in the most recent budget deal.) This led to a phenomenal boom in solar, with 9.5GW of capacity expected to come online—more than the past three years combined.

Last year saw 8.4GW of distributed solar installed in the US (compared to 3.1GW of utility scale); given the continued slide in solar panel prices, that figure is likely to grow as well. Thus, the actual solar capacity installed next year may be double the EIA's estimates. California will see the most installations, with 3.9GW of capacity, followed by North Carolina (1.1GW), Nevada (0.9GW), Texas (0.7GW), and Georgia (0.7GW).

The particles known as quarks were suggested as a way of making sense of a large collection of particles that kept popping out of our atom smashers. While some particles, like electrons and neutrinos, are fundamental, others are composed of two or three quarks and a few gluons to hold them together. The familiar proton and neutron, for example, are composed of collections of three quarks.

But as far as we knew, three has been the upper limit for quarks in a single particle, so that's all our theories bothered to deal with. Over the past several years, however, evidence has been piling up that four- and even five-quark particles can be produced in particle accelerators. That data has led to a little theoretical confusion, as it wasn't clear whether these were single particles with all those quarks or a composite object composed of a combination of two familiar particles.

Now, researchers who worked on Fermilab's Tevatron have gone through old data and discovered that it too had produced evidence of a four-quark particle. This is the first four-quark particle to have each of its component quarks come in different flavors. And the particle's mass suggests that it's likely to be a single unit rather than a composite particle.