Warped Passages - Lisa Randall [118]
What to Remember
Virtual particles are particles that have the same charges as true physical particles, but have energies that seem to be wrong.
Virtual particles exist for only a very short time; they temporarily borrow energy from the vacuum—the state of the universe without any particles.
Quantum contributions to physical processes arise from virtual particles that interact with real particles. These contributions from virtual particles influence the interactions of real particles by appearing and disappearing, and acting as intermediaries between the real particles.
The anarchic principle tells us that quantum contributions always have to be taken into account when considering a particle’s properties.
In a unified theory, a single high-energy force turns into the three known nongravitational forces at low energies. For the three forces to unify, they must have the same strength at high energies.
12
The Hierarchy Problem: The Only Effective Trickle-Down Theory
The highway is for gamblers, better use your sense.
Take what you have gathered from coincidence.
Bob Dylan
Ike Rushmore III came to an ignominious end when he drove his resplendent new Porsche into a lamppost. He was nonetheless happy in Heaven, where he could play games all the time. He was a gambling man at heart.
One day, God Himself invited Ike to a rather strange game. God told him to write down a sixteen-digit number. God would roll the heavenly icosahedral die. Unlike a normal, cubic die with six sides, this die had twenty sides, with the digits 0 through 9 written twice. God explained that He would throw this die sixteen times and construct a sixteen-digit number by listing the results, one after the other. If God and Ike came up with the same enormous numbers—that is, if all the digits matched in the correct order—God would win. If the numbers weren’t exactly the same—that is, if any of the digits failed to match—Ike would defeat God.
God began to roll. The first side that came up was the number 4. This agreed with the first digit of Ike’s number, which was 4,715,031,495,526,312. Ike was surprised that God rolled correctly, since the odds were only one in ten. Nonetheless, he was pretty sure the second or third number would be wrong; the odds of God’s rolling both numbers correctly in succession was only one in a hundred.
God threw the die for a second and then a third time. He rolled a 7 and then a 1, which were also correct. He kept rolling until, to Ike’s astonishment, He had rolled all sixteen digits correctly. The chances of this happening randomly were only 1 in 10,000,000,000,000,000. How could God have won?
Ike was a bit angry (one can’t get very angry in Heaven) and asked how something so ridiculously unlikely could have happened. God sagely replied, “I am the only one who could expect to win, since I am both omniscient and omnipotent. However, you must have heard, I do not like to play dice.”
And with that, gambling forbidden was posted on a cloud. Ike was furious (of course, only a little). Not only had he lost the game, he’d also lost the right to gamble.
By this point, you have hopefully learned quite a lot about particle physics and some of the beautiful theoretical elements with which physicists built the Standard Model. The Standard Model works exceptionally well in explaining many diverse experimental results. However, it rests uneasily on an unstable foundation that poses a deep and significant mystery, one whose solution is almost bound to lead to new insights into the underlying structure of matter. In this chapter we’ll explore this mystery, known to particle physicists as the hierarchy problem.
The problem is not that the Standard Model’s predictions disagree with experimental results.