Author Archives: The Physicist

Q: In base ten 1=0.999…, but what about in other bases? What about in base 1?

Physicist: Yup! The “0.999… thing” has been done before, but here’s the idea.  When we write 0.9, 0.99, 0.999, 0.9999, etc. we’re writing a sequence of numbers that gets closer and closer to 1.  Specifically, if there are N 9’s, … Continue reading

Posted in -- By the Physicist, Math | 5 Comments

Q: How many samples do you need to take to know how big a set is?

The Original Question Was: I have machine … and when I press a button, it shows me one object that it selects randomly. There are enough objects that simply pressing the button until I no longer see new objects is … Continue reading

Posted in -- By the Physicist, Combinatorics, Math, Probability | 3 Comments

Q: Does anti-matter really move backward through time?

Physicist: The very short answer is: yes, but not in time-traveler-kind-of-way. There is a “symmetry” in physics implied by our most fundamental understanding of physical law, and is never violated by any known process, that’s called the “CPT symmetry“.  It … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics, Skepticism | 3 Comments

Q: How do we know that everyone has a common anecestor? How do we know that someone alive today will someday be a common ancestor to everyone?

The original question was: From biology and genetics we know that any group of living organisms had a mitochondrial most recent common ancestor (mitochondrial Eve): a female organism who lived in the past such that all organisms in this group … Continue reading

Posted in -- By the Physicist, Biology, Evolution, Probability | 3 Comments

Q: Are some colors of light impossible? Can any color of light be made?

Physicist: Just so we can talk about this using physics rather than poetry, for the sake of this article “color” really means “frequency”.  Light frequency is a bit more objective than color and includes things we can’t see (like ultraviolet). … Continue reading

Posted in -- By the Physicist, Physics, Quantum Theory, Relativity | 9 Comments

Proxima B!

Physicist: Good news!  There’s an Earth-sized planet in the habitable zone of Proxima Centauri, a star so named because it’s the closest star to Earth and it’s in the constellation Centarus.  This isn’t a question anyone asked, but I thought … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 13 Comments