ask Ethan

"To be is to be the value of a variable." -Willard Van Orman Quine It's the end of the week once again, and the very end of our Year In Space 2014 Wall Calendar giveaway! So for this week's Ask Ethan column, after dipping into our question/suggestion box, I'm very pleased to let Vera from Italy know that her question was the winning one, as she asked: I saw the video you posted about  the variable star RS Puppis, by the Hubble Space Telescope, and I really would like a post about what exactly are variable stars. Thank you very much Ethan!! :-) So -- no burying the lede here -- there was a…
"It is by going down into the abyss that we recover the treasures of life. Where you stumble, there lies your treasure." -Joseph Campbell Ever since we created a question/suggestion box here, we've been deluged by far more excellent questions than one person could possibly answer, but that doesn't mean we aren't trying! For this week's Ask Ethan, our question comes from long-time fan and reader crd2, who asks: As we look at the furthest quasars we see they have supermassive black holes, as large as 109 solar masses. By what mechanism are they able to reach such large sizes over so short a…
"The results of my observation are best explained by the assumption that a radiation of very great penetrating power enters our atmosphere from above." -Victor Hess You might think of the largest and most powerful particle accelerators in the world -- places like SLAC, Fermilab and the Large Hadron Collider -- as the source of the highest energies we'll ever see. But everything we've ever done hear on Earth has absolutely nothing on the natural Universe itself! For this week's Ask Ethan, let's take a look at the simple question of our reader David Hurn, who asks: Ever since I was a young…
“If you see an antimatter version of yourself running towards you, think twice before embracing.” -J. Richard Gott III It may not occur to you that it's a special thing that the Earth and everything found on it is made of matter; it seems intuitive that it couldn't be any other way. And yet, the very laws of nature themselves haven't yet told us why or how the Universe is this way! For this week's Ask Ethan (and leave your own questions or suggestions here), our regular reader Michael Fisher wants us to get at the heart of this, asking: Is it true that in the early universe matter &…
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.” -Terry Pratchett It’s the end of the week once again, and so let's have a go at another Ask Ethan! Perhaps inspired by a great giveaway, there have been so many great questions pouring in (and you can submit yours here for four more chances to win), but this week’s comes from our reader and winner Brad (you owe me your email address, Brad), who asks, When an object is quoted as being 13.8 billion light years away is that…
"I wouldn't know a spacetime continuum or a warp core breach if they got into bed with me." -Patrick Stewart It's the end of the week once again, and so it's time for another Ask Ethan segment! There have been scores of good questions to choose from that were submitted this month alone (and you can submit yours here), but this week's comes from our reader garbulky, who asks: Why does gravity decrease the further away you are from the object? I've read that it does decrease with distance squared but not why it does this. This question seems so simple, and yet the answer -- to the limits of our…
"One of the most tragic things I know about human nature is that all of us tend to put off living. We are all dreaming of some magical rose garden over the horizon instead of enjoying the roses that are blooming outside our windows today." -Dale Carnegie Our new Ask Ethan segment has been really popular, and the questions and suggestions keep pouring in. It's your Universe too, and if there's something you want to know about it, you should ask! (So keep it up!) This week's question is one of the biggest of them all, and it comes courtesy of John L. Ferri, who asks, I have a difficult time…
"Galileo got it wrong. The Earth does not revolve around the Sun. It revolves around you and has been doing so for decades. At least, this is the model you are using." -Srikumar Rao It's the end of the week, so that means its time to take on another one of your questions from the question/suggestion box, and continue our ongoing Ask Ethan series! Even though there's a backlog of hundreds of questions, you should keep sending the new ones in, as all questions are fair game for any segment. This week's question comes from reader Brian Mucha, who asks us: Where did the sun and planets get their…
"I have just gone over my comet computations again, and it is humiliating to perceive how very little more I know than I did seven years ago when I first did this kind of work." -Maria Mitchell Well, it's getting close to the end of October, the Moon is waning towards its new phase, and -- at least in the northern hemisphere -- the days are getting shorter and the nights are lengthening. Is there anything unique on its way that's worth watching the skies for? In today's Ask Ethan column, our suggestion comes from longtime reader and commenter Sinisa Lazarek, who inquires: Since ISON comet is…
"If you are writing any book about the end of the world, what you are really writing about is what's worth saving about it." -Justin Cronin Well, it's Friday again, and that means it's time to dip into the question/suggestion box, and see what you've come up with for me. This week's Ask Ethan comes from our reader Michael Acosta, who wants to know about the end of the world. Not, mind you, the way the world is actually likely to end, but in a way that would be satisfying to an aspiring science fiction writer. In this wonderful science fiction book I am writing, there is a subplot involving…
"If you look for truth, you may find comfort in the end; if you look for comfort you will not get either comfort or truth only soft soap and wishful thinking to begin, and in the end, despair." -C. S. Lewis And yet, when you search for the truth, you often find answers that butt up against your sensibilities, your preconceptions, and even your very notions of common sense. Such is the case in this week's Ask Ethan, where longtime reader and commenter MandoZink asks: I have a question that has perplexed me for most of my life. Recently I sought out and re-read more expert explanations of the…
"Time is a sort of river of passing events, and strong is its current; no sooner is a thing brought to sight than it is swept by and another takes its place, and this too will be swept away." -Marcus Aurelius Every one of us does our best to come up with an accurate picture of reality, and that includes the Universe, from the smallest subatomic particles to the largest scales fathomable. But given how bizarre and counterintuitive some of our physical laws are -- even at a fundamental level -- this can be a daunting task for even those of us who are professional theoretical physicists. Image…
"I have an existential map. It has 'You are here' written all over it." -Steven Wright So just because the Ask Ethan series is becoming way more popular than I can handle -- I've got more than 200 questions that I'm sitting on by now -- doesn't mean you should stop sending your questions! There are some really good ones, and today's comes from Robert Plotner, who asks: When maps of the CMB are depicted, they are shown as a flattened ovoid. How does this correlate to our view of the sky which is a sphere? For example, a global map of the Earth is either distorted to show it in two dimensions…
"Observations indicate that the universe is expanding at an ever increasing rate. It will expand forever, getting emptier and darker." -Stephen Hawking Today's Ask Ethan comes to us via our question/suggestion box from reader MIUFish, who asks: I read something recently about some people who were doing work looking at the possibility that the mass of things has been decreasing, as an alternate explanation - or, perhaps, interpretation - to some of the questions regarding the expansion of the universe and so on. Is there any seriousness to this? Do you know anything about it? Here's what…
"The great oak of Astronomy has been felled, and we are lost without its shadow." -Subrahmanyan Chandrasekhar, on the passing of Jan Oort In our new semi-regular series, readers from all over the world (and in low-Earth orbit, too, because why not!) are invited to send in their questions and suggestions for a chance to have them answered here on this blog! Today, our question comes from Robert Meegan, who asks, Have any Oort Cloud objects been detected in situ, as opposed to when they whipped through the inner solar system as comets? I would presume that any detection would need to be…
"Education is an admirable thing, but it is well to remember from time to time that nothing worth knowing can be taught." -Oscar Wilde As many of you know, last weekend I launched a suggestion box here on the site, and I've been overwhelmed by the response: about fifty of you have sent something in to me in the first less-than-a-week of this alone! Image credit: Thao Nelson of http://mycredo.wordpress.com/. So, let's start answering them! There are more than enough excellent questions and suggestions to keep me busy for a long time, but with the new academic year starting up, one of them…