Best of Last Week – World record for tabletop accelerator, mystery of Earth's water source and roller coaster strokes

It was a good week for physics as one team of researchers set a world record for a compact 'tabletop' particle accelerator—they used one of the most powerful lasers in existence to accelerate subatomic particles to the highest energies ever recorded for such a device, setting a new benchmark for what can be accomplished on them. Meanwhile, a team of physicists attempted to explain why some composite subatomic structures created at the Large Hadron Collider fell apart in unexpected ways during