Category Archives: Experiments

Q: When something falls on your foot, how much force is involved?

Physicist: There’s a cute trick you can use here.  It a falling object starts at rest and ends at rest, then it gains all of its energy from gravity, and all of that energy is deposited in your unfortunate foot. … Continue reading

Posted in -- By the Physicist, Experiments, Physics | 3 Comments

Q: How do we know that atomic clocks are accurate?

Physicist: It turns out that there is no way, whatsoever, to look at a single clock and tell whether or not it’s accurate.  A good clock isn’t so much accurate as it consistent.  It takes two clocks to demonstrate consistency, … Continue reading

Posted in -- By the Physicist, Experiments, Logic, Philosophical, Physics | 2 Comments

Q: What are “delayed choice experiments”? Can “wave function collapse” be used to send information?

Physicist: There are a lot of big claims made about entanglement, but there are two carved-in-stone facts that help cut through some of the more grandiose claims.  First, (maximally) entangled states always act exactly like a perfectly random state, until … Continue reading

Posted in -- By the Physicist, Entropy/Information, Experiments, Philosophical, Physics, Probability, Quantum Theory, Skepticism | 4 Comments

Q: Are there examples of quantum mechanics that can be seen in every-day life, or do they only show up in the lab?

Physicist: The weird effects that show up in quantum mechanics (a lot of them anyway) are due to the wave-nature of the world making itself more apparent.  What we normally think of as “particle behavior” is just what happens when … Continue reading

Posted in -- By the Physicist, Experiments, Quantum Theory | 17 Comments

Q: What does it mean for light to be stopped or stored?

Physicist: We’ve gotten a handful of questions since this was published and led to articles like this, this, and, this.  In a nutshell, some dudes in Germany (Georg Heinze, Christian Hubrich, and Thomas Halfmann) have found a method to shoot … Continue reading

Posted in -- By the Physicist, Computer Science, Entropy/Information, Experiments, Physics, Quantum Theory | 11 Comments

Q: How much of a direct effect do planets and stars have on us? Is astrology reasonable or plausable?

Physicist: Of the four forces: gravity, electromagnetism, nuclear-strong, and nuclear-weak, only the first two, gravity and EM, affect things over distances (at least, over distances larger than an atomic nucleus).  So, if the planets and stars have any direct influence … Continue reading

Posted in -- By the Physicist, Astronomy, Experiments, Physics, Skepticism | 7 Comments