General Relativity and the Global Underscore

Dear Global Underscore participants,

I would love to share with you an aspect of the practice that is compelling to me.

I always love to tell people about Gravity Probe B... as it relates to the Global Underscore. This is fun and a little bit obtuse, but the relationship is there.

http://en.wikipedia.org/wiki/Gravity_Probe_B

Basically, Stanford University, NASA, and Lockheed Martin worked for years to measure the effects mass has on space according to Einstein's predictions in General Relativity.  The probe launched in April, 2004.

Imagine space is honey and the earth is in the honey of space; imagine there is a mysterious viscosity of space.  As the earth rotates around its axis, the space around it is dragged and warped by the mass of the spinning planet; perhaps the space twirls as honey would, above and below the planet, to make a tapered spindle of twisted space running off some distance in either direction along the axis of rotation.  An imaginary regular frame within space is distorted as the space's frame is dragged and so the phenomena is called "frame dragging".  The mass of the earth drags the frame of space with it.

Scientists collaborated, planning for over 20 years, spending $750 million dollars to measure how the axes of spinning gyroscopes in a probe orbiting the earth pointing to a star would dip and swerve; all of this to see how the gyroscopes would change, to see if they would follow Einstein's predictions.  And they did.  Einstein's ideas about frame dragging were confirmed by the probe's gyroscopes' axes.

The concept of Simultaneity was a crucial aspect of Einstein's thought experiments at the roots of the General Theory of Relativity.  Whether two events in different places can be said to happen "at the same time" was a question he insisted was crucial and is a question that scientists are still exploring.  Time and space has become spacetime.  In the dance, we deal with the spacetime and understand it intuitively, with our cells, with our nervous systems which is governed by the speed of light and the laws of physics (supposedly).  If you're traveling in a train car and two lightning bolts strike the front and back "at the same time" what does the observer perceive?

Our efforts to coordinate our dancing across spacetime have this feel to me; testing simultaneity.  It is a beautiful endeavor and something truly possible.  It does beg the questions of how "actually simultaneous we are" and of course this is not the point.

Our united intention to be simultaneous in our dancing the Underscore is beautiful and exciting.  And our efforts to feel simultaneity are much simpler, more human efforts than those of the scientists with their equipment.  In a way, as we dance, we are like the probe;  we are experiencing the realities the theory General Relativity points to, like the probe did. Thank you all for the vision of people all over the world dancing together in this way, coordinating through spacetime toward this end.

I am so excited to dance with you all!

And remember, theoretically, our mass warps space and when we spin around an axis we drag space with us.  Of course we don't have instruments to measure this minuscule distortion, but can we feel it?

happy Underscores!

b