The other day, after a morning of learning about physics at a literary festival, my significant other and I went to a cafe. It was one of those terminally unhip places where tattered Christmas decorations are still up in May, and everything on the menu contains sundried tomatoes because the owners heard they are in this year.
We ordered drinks and split a giant chunk of something intended to be lasagne-esque. After trucking hungrily through the pasta-like substance, we came to the side salad. It was sparse and pitiful, garnish-sized, and dressed in what I can only assume was some kind of petroleum by-product.
Trouble was, as desperately hungry as we were, this mini-salad would not be speared. Our forks disappeared into its leafy fronds and came out unadorned. There was simply so much empty space in this salad, so much nothingness, that it could not be transported to our waiting mouths.
Having recently attended a lecture by Lawrence Krauss based on his new book A Universe From Nothing, this predicament took on an almost astrophysical significance. Turns out, empty space is not empty at all. Nothingness is never nothing. Particles zing in and out of existence all the time; theoretically, it would be possible for an entire universe to pop into existence in my living room as I type this.
In fact, Dr. Hawking, I was reminded of your famous assertion in A Brief History of Time that:
“What we think of as ‘empty’ space cannot be completely empty because that would mean that all the fields, such as the gravitational and electromagnetic fields, would have to be exactly zero... There must be a certain minimum amount of uncertainty, or quantum fluctuations, in the value of the field.” (112)
In other words, so-called empty space actually contains virtual particles, invisible so far to us, but measurable through the indirect effects they cause.
Stabbing fruitlessly at my almost-empty space salad, I realised: it was not the salad’s fault that its cavernous spaces did not give rise to instantly materialising sturdy leaves! Indeed, my fork was not probing into ‘empty’ space at all, but rather exploring loaded space, waiting for tomatoey particles to join around it. They fact that they didn’t might be evidence that I don’t fully understand the behaviour of particles; or perhaps it’s evidence that cafes need to develop more molecularly malleable foodstuffs.
Either way, I felt much better about my unforkable salad once I’d come home and created something equally hard to eat, but much tastier. I imagined its airiness might give rise to a spontaneously generated affogato for dessert, but alas, particle physics has some catching up to do before it meets my demanding standards.
In your honour, Dr. Hawking, I present the Almost-Empty Space Salad!
Almost-Empty Space Salad
Rocket leaves, or other spindly salad leaves
40g grated parmesan
1 yellow carrot
1 ½ tbsp butter
1 ½ tbsp flour
1C apple juice
Salt & pepper
Preheat the oven to 180C.
Thinly slice the tomatoes, and arrange them on a lined baking tray (leaving some space). Arrange the grated parmesan into four sparse discs on the baking tray. Place the tray in the oven and bake the cheese & tomatoes for about 5 minutes, or until the parmesan is melted and golden. Remove the parmesan rounds (they should stick in a nice neat, but stretchy, circle) and rest them on a plate in a single layer to crisp up.
Return the tomato slices to the oven and bake around another 30 minutes, until dried out but not blackened. Keep checking them, as the timing can be variable. When they’re dry and leathery, remove them and set aside to cool.
To make the carrot mousse, cook the carrots however you want (boil, steam, microwave, etc) until soft – just make sure to follow the laundry-day rule, and keep the colours separate. When soft, blitz each one separately in a blender or processor with a dash of apple juice to form a puree. Transfer your yellow & orange purees into medium sized bowls.
Meanwhile, melt the butter in a small saucepan, and add the flour. Stir for a minute or so, until it thickens up into a roux. Add the remaining apple juice (about ¾ cup) and simmer until thickened. Add the nutmeg, salt, and pepper. Divide the saucy apple mixture between the bowls of carrot puree, and mix each well. Spoon the mixtures into small dishes (crème brulee dishes work well) and bake at 180C until bubbling (around 30 minutes). Leave to cool, then refrigerate until really cold.
To serve, arrange the leaves, tomato slices, daubs of cold carrot mousse, and parmesan crisps on a plate. Stab ineffectually with a fork several times. Give up, and shove your mouth into the plate like a pig at a trough.
Or... like a particle hovering on the edge of a black hole. Ah, Dr. Hawking, you see what I did there?