Friday, July 18, 2014

What would a brown dwarf look like?

I've been studying brown dwarf stars for almost three years now.  They are fascinating objects, more massive and hotter than planets but smaller and cooler than stars, with clouds of hot sand and molten iron vapor in their atmospheres.  They glow brightest at infrared wavelengths that the human eye can't see, and we usually study them at these wavelengths.  Recently, however, I've been working on a project studying them at the extreme red edge of the optical -- that is, at wavelengths near those that we can see (it turns out we can learn some unique information about their clouds at these wavelengths).  This has led me to produce an image something like what a human might see, if we could look at a brown dwarf through a powerful enough telescope (or get close enough).  It still isn't quite right, because it makes use of some information from light at wavelengths just a bit too long for our eyes to detect, but it's the closest that I know of to a true-color view of a brown dwarf:

The brown dwarf (called WISE 0819-0335) is the tiny red star in the center.  And that's the main impression a brown dwarf would make, if you could see one with your own eyes through a powerful enough telescope: it would be faint, and deep-red.  Has anyone done this?  I don't know, but I think not.  You'd have to put an eyepiece in one of the most powerful telescopes in the world (which normally use only electronic imaging equipment). Even then you'd only have a chance at seeing the very brightest brown dwarfs, and they'd probably be too faint for color vision -- you'd just see a faint grayish star.  We'd need even bigger telescopes (or better yet, a starship) to see this kind of view for real.

What if you could get really close to the brown dwarf -- close enough that it would appear not just as a red-hued point of light but as a huge orb out the windows of your starship?  It would still look deep-red, and unlike the Sun and most other stars seen up close, it would be dim enough that you could stare at it without hurting your eyes.  According to some of the latest research on brown dwarfs (including my own), it would probably have dramatic cloud features.  Thick, high-altitude clouds would glow only dimly, while through huge rents in them you would see down into the hotter, much brighter deep regions of the brown dwarf.  Powerful winds and possibly storms full of lightning would be constantly churning and shifting the glowing clouds.  It would be worth a journey of a few light years to see.

Thursday, July 10, 2014

The Late Unlamented Winter

Last winter was great and all... we had lots of good times.  But still -- thank God it's over, and three cheers for summer.

In summer you have to be careful about ticks.  Lyme disease is a serious concern here.  But not as serious as the road to Toronto back in February!

I sweat every day on my walk to work now.  But you can stand still outside and enjoy it.  Not so much on the walk when the picture above was taken.

A few nights ago, 9 year-old Petra came downstairs at about 10:30pm and told me that she and her brother had decided to sue me for not putting an air conditioner in their room. They have one now, thanks to a friend from church to whom I told this story... I wasn't trying for charity, honest, I just thought it was funny... but I am grateful for the air conditioner -- and that our house no longer looks like the above picture.

A couple of weeks ago we went boating.  Toward the end of the day the children were tired and I was a little warm, so I jumped off the boat to amuse them (forgetting to take my hat off).  The weather was a little different from when I took this picture back in February.

OK, so maybe that should be four cheers for summer.  Anyway, thank God for warmth and resurgent life and outdoor fun.  Winter is good too, and I will be ready for it to come back... maybe sometime in 2016.

Wednesday, July 2, 2014

Driving in D.C.

I spent last weekend in Washington, D.C. with my wife and our five children.  We were there as part of a larger family gathering to celebrate my father in law’s 60th birthday.  The celebration was very well planned (none of it by me!) and involved not only a nice dinner and cake but also visits to the National Mall and various Smithsonian museums.  You may ask what museums can hold the attention of five children with ages ranging from two months to nine years.  The answer is that the two-month-old doesn’t count, and you can keep the rest interested for quite a long time where there are a sufficient number of such things as rockets, space capsules, dinosaurs, and pickled giant squids.  The important thing is to move quickly from one exhibit to the next, and explain them each one in a brief and accessible way.  It’s rather exhausting for the parents, but it’s good mental exercise.

But all this, though more significant in the broad scheme of things, is only context for the real topic of this post: driving in D. C.  I did most of it, because I am slightly less stressed by dangerous driving situations, and because my wife is a much better navigator than I am.  I drove so aggressively that I was disturbed by my own conduct.  I didn’t understand why I was driving like this until my wife took over for a little while – and was forced off a highway exit she didn’t want to take by someone who accelerated to remain in her blind spot (I don’t think they were purposely malicious – just unobservant and unhelpful on a crowded road).  Anyway, I realized I was driving aggressively because other ways of driving didn’t work.

Still, I am painfully aware how thin the line is between aggressive and stupid.  I am alert and observant behind the wheel, and have excellent intuitive judgment of velocities and tolerances.  My quick, almost subconscious decisions are rarely at fault.  Nevertheless I intensely dislike suddenly realizing that I have staked thousands of dollars on a split-second decision whose rational basis I cannot articulate.  The fact that the decision was good does not comfort me – how do I know the next one will be?

The reader may be wondering why I have talked about staking money rather than the incomparably more serious risk of human lives.  The answer is that I drive with tight tolerances only when the stakes do not involve a high-momentum crash.  I risk totaling my car, not my children.  Nonetheless it is a car the children need, that I cannot afford to replace, and there could be some injuries even in a lower-velocity accident.

The most disturbing moment came when I pulled in front of a black pickup to make a left turn into a gas station on the way home. That was the only time I was honked at. I was making my intentions clear, but the driver of the pickup was not slowing down to let me in.  I saw that I had enough space, and I gunned the engine and took it.  It was only afterwards that I tried to estimate how close our rear bumper had come to the pickup’s front bumper and couldn’t do it.  Surely it was feet rather than inches… wasn’t it?  Why didn’t I let the left turn go, make a U-turn later, and come back?  The answer is that I was sure – intuitively, not rationally – that what I was doing would work.  I am not happy with answers like that.

There are other questions, though.  We needed the gas.  U-turns are dangerous too.  What would have happened if I had given up on turning there?

I have to recognize the uncomfortable reality that I cannot guarantee my family’s safety, even when I am literally at the wheel and it seems that I am most completely in control of it.  Much less can I guard effectively against other things: falling trees, malicious strangers, cancer, and the children’s own foolish decisions.  I have the responsibility to do what I can: to think carefully about how I drive, prune trees, and teach good decision-making.  Still the Proverb remains true: “Unless the Lord guard a city, the watchmen stay awake in vain.”  God promises care to his people, and I trust him.  The fact that he does not promise protection against any particular catastrophe troubles me.  But he promises his presence and care in both peace and disaster, and that must be enough.  We reached the end of the journey safely.  Why?  Because I am a good driver?  No. Because he is a good God.