Shahn Majid

This will be my last regular post for a while because of Christmas and teaching three courses next term at my University. These past eleven posts, see here and here, have been my personal take on many of the topics covered in On Space and Time and its now time in this twelfth post to address the larger picture of the volume itself.

In fact the volume is about opening a genuine public debate on the true nature of space and time, starting with a public panel discussion on this topic in 2006 in Cambridge, England. Where this came from was my increasing unease about the portrayal of fundamental physics — quantum gravity in particular — as already solved by string theory when, in fact, theoretical physics is in need of fresh profound ideas and contact with experiment, when these are the most exciting and turbulent of times.

I also insist in the preface to On Space and Time that this debate needs to involve not only scientists but the wider public. The reason is that scientists’ ideas have to come from somewhere, from sitting around in cafes, from contemplation of art. We don’t know where the key revolutionary idea is going to come from. Put another way, to progress, scientists need now to see what Science is, which means they have to step outside it and see it in part as a non-scientist.

In particular, and this being Christmastime, I want you to ask yourself what does someone singing a Christmas carol have to say about quantum gravity? What does that person have in common with a theoretical physicist? What I think they have in common is contemplation of the infinite. I mean a sense of something bigger than ourselves. As a confirmed atheist I won’t call it God, but its a sense of awe at the Universe and a wonder about our place in it. My approach as a theoretical physicist is to use mathematics and the scientific method to explore the issue, while a carol singer is surely using other means to ‘connect’.

In fact it is only since the 17th century Enlightenment that Science somehow replaced religion as the font of physical truth. But the Scientific Method pioneered by Hooke and others replaced religious dogma, good, yet itself is based on certain assumptions and ways of doing things, of dividing knowledge into ‘theory’ and ‘experiment’, in other words some other dogma.

As a scientist I am 1000% committed to the Scientific Method but I see it as a particular way of exploring reality. One that we might now need to understand better by seeing it from the outside.

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Wisconsin Public Radio produces some of the best programming in the country, and I was delighted to hear from producer Jim Packard (also of Whad’ Ya Know? announcer fame) that Paul Kinzer would be a guest on Conversations with Larry Meiller.

Here’s a link to the interview >>

Kinzer is a Wisconsin astronomer and educator; author of Stargazing Basics, one of the most elegantly useful introductions to buying equipment and stargazing we’ve seen. That’s why we published it!

Shahn Majid

After last week’s imaginative speculation, I’d better tell you something concrete. How about the solution to quantum gravity that has been eluding us for some 90 years? Here it is … er … with one minor catch. We’ll have to suppose that spacetime is 3 dimensional, i.e. one time and only two space directions rather than three.

He's never heard of this "3rd spatial dimension"!

There is a tradition, starting I think with Edwin A. Abbott’s 1880 tale ‘Flatland’, where we suppose that we are not 3-dimensional beings but, let us say, ants, constrained to live forever on some two-dimensional surface. We tend to visualize a surface — imagine, say, the surface of a sphere or doughnut — within three dimensions, but don’t be fooled by that. That is just an aid to visualization. An ant crawling about on the surface, moving along ’shortest paths’ (the analogue of a straight line on a flat space) could fully map out the geometry of the surface without ever leaving it.

I am speaking here of the spatial geometry. We will assume that time is a further linear dimension, making spacetime 3-dimensional, mapped out as the 2-dimensional surface evolves in time.

Actually, we won’t assume any of this, since as I explained in previous blogs, there is no evidence of an actual spacetime continuum of any dimension. But we will take it as a commonly accepted starting point and then I will explain carefully where we have to make the quantum leap to throw all that away to get to actual quantum gravity. This will also give you a bit of insight into the guts of the way that scientific revolutions work in practice.

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Admittedly, there is some disconnect between myself, sitting at a desk in downtown New York City, and the tranquil, idyllic spires of Cambridge University. Cambridge University Press is a small part of the goings-on at the University. Having studied there, I have a stronger connection than many of my co-workers, who have never visited.

Even so, I caught news of an experiment this morning that struck me as very, well, Cambridge University.

That’s right: space bears.

These teddy bears were launched into the stratosphere via balloon from Churchill College. This was part of a Cambridge University Space Flight Science Club experiment, conducted by an aerodynamics student and a group of children as a way of getting them interested in science. The suits were made by the kids out of foil and plastic bottles, among other things, with sensors to monitor their temperatures and other forces.

So cool.

They even parachuted gently back to earth, landing about 50 miles from Cambridge.

Get the full story, and more pics, at The Daily Mail.

Over at Astronomy.com, the website and blog of Astronomy magazine, Daniel Pendick has posted a Q&A with one of our longtime guides to the heavens, Stephen James O’Meara.

This month, Cambridge University Press published Astronomy columnist Stephen James O’Meara’s latest book for stargazers, Observing the Night Sky with Binoculars. The book — billed as “a simple guide to the heavens” — is for beginners. This is a new direction for Steve, who has published several guides to observing deep-sky objects with telescopes. I asked him why he wrote the book and how readers could benefit from it.

Pendick: How did this book come about? When and how did you get the idea?

O’Meara: It happened after I completed my research-intensive Deep-Sky Companion trilogy (The Messier Objects, Caldwell Objects, and Hidden Treasures), followed by the extensive Herschel 400 Observing Guide. These are all deep-sky works largely to challenge telescope users.

I became aware of the need for a simple book to help pure novices get into our hobby. It’s something I’ve always wanted to do, but I didn’t get fired up to write the book until I learned that a friend of mine in Boston had bought a pair of binoculars and was trying to learn the night sky.

He was struggling with some basic concepts, and he would call and e-mail me with questions. I was enjoying helping him so much, that I thought I’d take what I was teaching him and share the knowledge.

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