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"Never waste your time trying to explain who you are to people who are committed to misunderstanding you." -Dream Hampton Perhaps no word in the English language generates as much misunderstanding as the word theory. In scientific circles, this word has a very specific meaning that's different from everyday use, and -- as a theoretical astrophysicist myself -- I feel it's my duty to help explain exactly what we mean when we use it. In this week’s Ask Ethan column, I'm pleased to pull out of our question/suggestion box the question of Ripley, who asks: I often see that because there is no "100…
If you've ever put a pair of headphones in your pocket, you'll know how difficult it is to keep a long cord in a bundle without getting it hopelessly tangled and knotted. You'll also start to appreciate the monumental challenge that our cells face when packaging our DNA. At 2 metres in length, the human genome is longer than the average human but it needs to be packaged inside the nucleus of every one of our cells, each just 6 millionths of a metre long. How does it do it? One of the secrets behind this monumental feat of folding has just been revealed by research that reveal's the human…
Bret Underwood, a friend of mine from my time in Madison, WI, saw my post on String Theory, and took issue with my statement that it wasn't testable. I'm still standing behind what I said, but let's address what Bret has to say. I donât understand your argument above for why string theory is untestable. In fact, it seems to me you just outlined the best possible case for string theory! What you said above is that if I have a string theory construction of a phenomenon (say, the Standard Model or Inflation), which uses a set of parameters X, and makes some predictions, then I can find another…
Over the past few months, I have been asked a number of questions about String Theory and the Universe, including from readers Benhead and Mastery Mistery. But now Jamie, whom I'm going to marry later this year, has been asking me about it, and so it's time to write something about the scientific topic of String Theory. (Send in your questions now, because I'll answer them all this week if there's enough interest.) Let's start with this pair of questions: String theory has been around for over 20 years, and so far, there is not one shred of experimental or observational evidence in support of…