Knocking on Heaven's Door - Lisa Randall [89]
We did realize, however, that whether or not black holes could ultimately be produced, other interesting signatures of strongly interacting particles at the LHC might provide important clues about the underlying nature of forces and gravity. And we would see these other signals of higher dimensions at lower energies. Until we see these other exotic signals, we know there is no chance for making black holes. But these other signals themselves might eventually illuminate some aspects of gravity.
This work exemplifies another important aspect of science. Even though paradigms might shift dramatically at different ranges of scales, we rarely suddenly encounter such abrupt shifts in the data itself. Data that was already available sometimes precipitated changes in paradigms, such as when quantum mechanics ultimately explained known spectral lines. But often small deviations from predictions in active experiments are preludes to more dramatic evidence to come. Even dangerous applications of science take time to develop. Scientists might be held accountable in some respects for the nuclear weapons era, but none of them suddenly discovered a bomb by surprise. Understanding the equivalence of mass and energy wasn’t enough. Physicists had to work very hard to configure matter into its dangerous explosive form.
Black holes could even possibly be worthy of worry if they could grow to be large, which calculations and observations demonstrated won’t happen. But even if they could, small ones—or at least the gravitational effects on particle interactions just discussed—would nonetheless signal the presence of a shift in gravity first.
In the end, black holes don’t pose any danger. But just in case, I’ll promise to take full responsibility if the LHC creates a black hole that gobbles up the planet. Meanwhile, you can do what my freshman seminar students suggested and check out http://hasthelargehadroncollider destroyedtheworldyet.com.
CHAPTER ELEVEN
RISKY BUSINESS
Nate Silver, the creator of the blog FiveThirtyEight—the most successful predictor of the results of the 2008 presidential election—came to interview me in the fall of 2009 for a book he was writing about forecasting. At that time we faced an economic crisis, an apparently unwinnable war in Afghanistan, escalating health-care costs, potentially irreversible climate change, and other looming threats. I agreed to meet—a bit in the spirit of tit for tat—since I was interested to learn Nate’s views on probability and when and why predictions work.
I was nonetheless somewhat puzzled at being chosen for the interview since my expertise was predicting the results of particle collisions, which I doubt that people in Vegas, never mind the government, were betting on. I thought perhaps Nate would ask about black holes at the LHC. But despite the by then defunct lawsuit that suggested possible dangers, I really doubted Nate would be asking about that scenario, given the far more genuine threats listed above.
Nate in fact wasn’t interested in this topic. He asked far more measured questions about how particle physicists make speculations and predictions for the LHC and other experiments. He is interested in forecasting, and scientists are in the business of making predictions. He wanted to learn more about how we choose our questions and the methods we use to speculate about what might happen—questions we will soon address more fully.
Nonetheless, before considering LHC experiments and speculations for what we might find, this chapter continues our discussion of risk. The strange attitudes about risks today