What happens next? Scientists (including a consortium of researchers at the National Science Foundation’s Center for Matter at Atomic Pressures​​) are just starting to figure that out. They use a variety of tools (including some humongous lasers) to simulate planetary cores and see what happens. A few standout findings so far:

• Water can become a hot black ice that conducts electricity
• Hydrogen gas can be compressed down into a shiny metal
• Sodium (a soft, silvery metal at atmospheric pressure) can turn transparent

What happens under extreme pressures deep within planets also influences their ability to foster life. Check out our videos about the search for Earth-like worlds beyond our solar system:

• What we found when we went looking for another Earth
• How to find a planet you can’t see
• Here’s a closer look at another giant laser at the National Ignition Facility

This material is based upon work of and presented by the Center for Matter at Atomic Pressures (CMAP), supported by the National Science Foundation under Grant No. PHY-2020249. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of the National Science Foundation.

This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856, the University of Rochester, and the New York State Energy Research and Development Authority.

This video was prepared as an account of work sponsored by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof.

The confirmation of Supreme Court Justice Clarence Thomas, back in 1991, was a squeaker: 52 yeas, 48 nays — the narrowest margin in over a century.

The senators who voted to put him on the bench had won their most recent elections with a combined tally of 42 million votes. But the senators who voted nay were elected by 46 million. Thomas became the first Supreme Court justice to be confirmed by a bloc of senators who had been elected by a minority of voters.

Then it happened again. And again and again. The senators who confirmed Justices Samuel Alito, Neil Gorsuch, and Brett Kavanaugh received millions fewer votes than the senators who opposed their confirmations.

Ruth Bader Ginsburg’s replacement seems likely to join the ranks of these “minority justices.” Even if President Trump’s nominee, Amy Coney Barrett, wins the support of every Republican senator, including moderate holdouts like Lisa Murkowski and Susan Collins, all those senators combined received 13 million fewer votes than their colleagues across the aisle. 

If Barrett is confirmed, the Supreme Court will enter a particularly undemocratic new era. For the first time since senators were directly elected, a controlling majority of the Court will have been put there by senators whom most voters didn’t choose. (And, of course, the last three will have been nominated by a president who lost the popular vote by nearly 3 million votes.)

The Senate has always been one of the federal government’s least democratic institutions. Each state — big and small — gets two senators. That means Sen. Bernie Sanders of Vermont has as much say about who goes on the Supreme Court as Sen. Ted Cruz of Texas, even though Sanders represents about 600,000 people and Cruz represents 29 million. 

It also means the smallest 25 states, home to only about 15 percent of the US population, have as much power as the 25 biggest. And that’s not new; half the Senate has always represented about 15 to 25 percent of the population.

Yet for most of the Senate’s history, majority rule has endured. Traditions of civility and compromise, along with self-imposed rules like the filibuster, meant that most legislation was passed by a group of senators who represented a majority of the nation. Most Supreme Court justices were confirmed by large bipartisan majorities — like Ruth Bader Ginsburg (96 yeas, 3 nays).

But in the past few decades, things have changed. The nation has become more polarized, confirmation votes have become much closer, and Senate norms have been abandoned. 

At the same time, Democrats are increasingly concentrated in larger states, giving the GOP a leg up in the Senate. Democrats control a majority of seats (26-24) in the 25 most populous states. Republicans, however, have a much larger majority (29-21) in the 25 least populous states. Back in 1980, the average Republican voter had 6 percent more power in the Senate than the average Democratic voter. That advantage has grown to 14 percent.

This imbalanced Senate has created the least democratic Supreme Court in modern history.

We examine much more of the history of the unequal power of votes in America in our series Whose Vote Counts, Explained over at Netflix.