High Pressure



This last month there was a huge breakthrough in the field of high pressure physics. Harvard scientists got to experience seeing all of their hard work (spanning decades) pay off. They created metallic hydrogen and now get to carry it into the world to find out its applications. The Harvard Gazette has a very concise article about it and a schmancy video here.

The hydrogen molecule was placed under 495 gigapascals (GPa). The Earth’s core is estimated to be around 330-365 GPa. So, dang. That’s a lot of pressure. I had heard the usage of pascals (Pa) before but was unfamiliar with GPa. That amount of pressure may be too much for my tiny brain to wrap around. But I’m gonna try anyway!

To help me comprehend this, I referred to the International System of Units (abbreviated as SI). The prefix “giga” denotes a factor of 109. Meaning that each gigapascal is one billion pascals. A pascal is equal to one newton per square meter. The newton is a unit of force (also from the SI) which can be expressed as m·kg·s-2 where m=meter, kg=kilogram and s=second. It is giving one kilogram an acceleration of one meter of force per second per second. For my fellow Americans, it is equal to about 0.2248 pounds in a foot-pound-second system. Newton is force and pascal is pressure/stress and can be determined using N/m2.

Phew. So, the range of pressure put onto those molecules is still mind-boggling. But I find it to be at least comprehensible now. I also found 1 GPa can be described as about 9869 times the pressure of Earth’s atmosphere. Which, for a reason I do not know, also helped me come back from my “our universe is insanely complicated and I matter not” spiral (felt like I was watching How the Universe Works or something).

The jury is still out about whether or not the creation of metallic hydrogen was actually completed by the team at Harvard. But I remain optimistic that it has been done and we will get to see some exciting advancements come from it. Gotta stay positive!

Here’s an article about why we shouldn’t get too excited about the breakthrough.