Rights: The University of Waikato Published 17 September 2009 Download

In this video, Dr David Krofcheck reflects on his earlier years and how his experiences led him to a career as a particle physicist. He believes the universe to be a strange place and our understanding of it to date is very limited. “We are barely scratching the surface.”

As a physicist, he is concerned that, of all the energy in the universe, we can only account to date for 4%. “What is this dark energy that we know so little about?” he asks.

Point of interest
What do the symbols in the equation E=mc² stand for?


Chasing around rock quarries where I grew up in the US for fossils got me interested in the processes of how fossils were formed, the type of life that existed in my part of the world hundreds of millions of years ago and then the realisation that there was hundreds of millions of years ago. I started thinking about where did all this material come from in the first place, because you could find coal, and you could find all these wonderful chemical compounds. Well, where do they come from? Well, take it a step back farther, where did the atoms come from? Well, take that back a step, where did it all come from? And you end up thinking about the Big Bang. And for me, that’s what got me started.

What’s fascinating about the nuclear particle physics field is the universe is really just a strange place, because humans… our perceptions are very limited to very slow velocity. But actually, Einstein tells us that mass is energy and the faster you travel, the heavier you get, and this is something that really exists in the universe. And now we are finding out that the universe is so strange, we are barely scratching the surface of the universe of ideas and knowledge, and all of the matter that we’ve been talking about really only consists of about, what we think now is about 4% of the total matter of energy in the universe.

And for a physicist, it’s very embarrassing to sit here and say, “I don’t know what the other 96% of matter energy is – some kind of dark matter, some kind of dark energy.” Because not only is the universe expanding, we find it’s accelerating in its expansion, which means there is some kind of mysterious dark energy giving an extra push. Dark matter, dark energy – we only know 4% of that total – that’s us. But that 4% of matter, which is us, can now think about the other 96% and where it came from and what happened to it and what it is, and that is so exciting. That’s what I like.

NASA/courtesy of nasaimages.org./JPL-Caltech/R. Hurt (SSC)
Sam Heads