The Large Hadron Collider accelerates protons to an energy of 7000 GeV, which is pretty impressive. (A GeV is a billion electron volts; the energy in a single proton at rest, using E=mc^2, is about 1 GeV.) But it requires a 27-kilometer ring, and the cost is measured in billions of dollars. The next planned accelerator is the International Linear Collider (ILC), which will be similarly grand in size and cost. People have worried, not without reason, that the end is in sight for experimental particle physics at the energy frontier, as it becomes prohibitively expensive to build new machines. That why it's great news that scientists from Lawrence Berkeley Labs and Oxford have managed to accelerate electrons to 1 GeV (via Entropy Bound). What's that you say? 1 GeV seems tiny compared to 7000 GeV? Yes, but these electrons were accelerated over a distance of just 3.3 centimeters, using laser wakefield technology. You can do the math: if you could simply scale things up (in reality it's not so easy, of course), you could reach 10,000 GeV in a distance of about a hundred meters. The LHC and the ILC won't be the end of particle physics. Even the Planck scale, 10^18 GeV, isn't all that big. In terms of mass-energy, it's only one millionth of a gram. The kinetic energy of a fast car is of order 10^16 GeV, close to the traditional grand-unification scale. (Why? Kinetic energy is mv^2/2, but let's ignore factors of order unity. The speed of light is c = 200,000 miles/sec = 7*10^8 miles/hour. So a car going 70 miles/hour is moving at 10^-7 the speed of light. The mass of a car is about one metric ton, which is 1000 kg, which is 10^6 grams, and one gram is 10^24 GeV. So a car is 10^30 GeV. [Or you could just happen to know how many nucleons/car.] So the kinetic energy is that mass times the velocity squared, which is 10^30*(10^-7)^2 GeV = 10^16 GeV.) The trick, of course, is getting all this energy into a single particle, but that's a technology problem. We'll get there.
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