Spacetime geodesics (I).

Math, again, people!

A couple of posts ago I introduced myself to geodesics as free fall trajectories in curved spacetime. The problem with this description -one of them- is it's saying not enough. What I've learned since then about geodesics it's still not enough, but it's a step forward, so better than nothing.

This post was intended to solve geodesic equation for an easy case and show that spacetime nature depends on 4 coordinates -3 in space and 1 in time. The problem is the answer is not as straightforward as I expected. Let's see it anyway.

A geodesic is a curve. And like any curve, it can be described mathematically. General, index form is:

Leonard Susskind's GR lectures at Stanford.

I discovered Leonard Susskind because of the book "The black hole war". It was interesting and funny and the fact I was not able to grasp the last part of it -that holographic metaphore is disturbing-, didn't make me dislike it at all. I started to look at physicists more like human beings thanks to it. And that's saying a lot.

Before that, my only contact with physicists were close related hate-filled-relationships due to the fact engineering physics in Spain -the time I studied it, at least- were intended more to make an IQ selection than teaching actual interesting physics. I can blame no one for that. It's a consequence -one of the bad ones- of having a public university model. Good ones outnumbered bad ones, by the way. In the future, who knows.

 

Leonard Susskind a couple of years ago. From Stanford web.

What is happening at JSC?

Sorry for abandoning Math so soon. It is temporary, I promise. For the moment, I have to discuss another -possible- dead end. Which maybe it is not. I don't know yet. Media hype? Likely.

JSC stands for Johnson Space Center, which is one out of the 17 centers NASA has in the States.

I have heard some noise in the internet since September in sites like Gizmodo and Space.com about a JSC's scientist who claim feasibility of warping spacetime under certain specifications. Reliable science news, unfortunately, doesn't come from news sources, so I decided to wait a little before start looking for info.

Aerial view of JSC in 1989 -a long time ago, I know-. (Source: wikipedia)

Rotating superconductors. A dead end?

First time I heard about these, was back in 2006. And it seemed promising. It is a simple concept: Einstein says energy or matter warps spacetime. Why don't we modify matter in order to alter somehow spacetime?

Obviously, harvesting energy as I have pointed out previously is not going to be enough.

So, is it possible to have a "weird" state of matter which gives us more juice for warping porpuses? The idea is quite attractive, because Einstein was an open enemy of quantum theory, and this branch of physics has evolved a lot since Einstein's first days.

 

Experimental ARC Seibersdorf 2006 setup (photo from ESA web)