9 Things To Say About Quantum Physics That Will Make You Sound Clever At Parties
5. "The Energy Of The Universe Is Zero"
No, this isn't the reason why you're tired all the time, this is physics.
They say there's no such thing as a free lunch, that is to say, you can't get something for nothing. However, some physicists think that the universe itself may be the ultimate free lunch.
Given the amount of energy you can see around you, from the warmth of the sun's rays to the microwave heating up your lunch, not to mention that all matter is equal to energy as demonstrated by Einstein's most famous equation, you'd think that the amount of energy in the universe is an inconceivably large value.
This is not the case, however, as there is something in the universe cancelling it out.
To a physicist, matter, antimatter and light are all "positive energy", but many also think that the gravitational energy that radiates from positive-energy particles contains an equal amount of negative energy, thus bringing the sum total of energy on the universe to zero.
All this talk of positive and negative energy might sound a bit yoga-crystals-and-knitted-lentils, but it has come from some of the greatest scientific minds of our time, including the great Stephen Hawking.
So where does the free lunch come into it?
Well, the really cool thing is that this could have something to do with the creation of the universe.
In the quantum world, the spontaneous creation of energy from nothing is allowed, so long as it disappears again. Matter and antimatter particles are constantly forming and annihilating one another without violating the laws of the conservation of energy. However, it is thought that the negative energy loophole could be behind what scientists call "Inflation". If the positive-energy matter that is created is counterbalanced by negative gravitational energy, then it can exist without having to be annihilated, because the sum of its energy is zero.
This sudden, spontaneous creation of matter that doesn't immediately disappear is, to some physicists, a great explanation for how the universe began, and expanded at such breakneck speeds.
As is always the way with quantum mechanics, however, the talk of "creation", "balance", "matter" and "energy" is kind of just as way of putting it into terms that our brains can understand, sort of a trick to make the cosmological model work. That's not to say that it doesn't happen, but we are still at the stages of being able to describe the effects rather than the cause.