Out of the Office
2:00 AM on the Kuuvik River in the Nunavik region of
northern Quebec. Photo courtesy of my friend,
Drew MacDonald.
Being the token astrophysicist in my social circles, I get a lot of questions from friends and family about what’s going on in the Universe these days. I try to use these questions as an outline to the posts I write for the QUEST web site.
As one example, I have written quite a few posts about dark matter because that is one of the most confusing topics to people, myself included. I also wrote a post on the dangers of gamma ray bursts from nearby supernova explosions after years of questions from my Incredible Hulk obsessed friend.
Recently I was asked “how large is the universe?” and “does a planet orbiting a black hole feel the increased gravity as that black hole grows?” Both of these are very complicated questions, and require quite a bit of explanation, making them the perfect fodder for future posts.
I’m away on vacation right now, paddling down the Kuuvik River, previously known in English and the Larch River and in French as the Rivière aux Mélèzes. A group of four, we are traveling this river in a wooden canvas canoe in the style of 19th century fur trappers and also of my old employer, Keewaydin Canoe Camp. This is one of the most remote rivers in the world, making internet access rather difficult.
Given that I’m so far off the grid right now, I’d like to take this opportunity to dig for some more cosmology fodder and ask the QUEST readers what questions they may have. Post your suggestion below and I’ll use it as material when I rejoin society.
Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and
development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.
Dear Dr. Kyle:
Yes, I have many burning universal questions. This one is a two-parter. Is there evidence that the universe’s rate of expansion is slowing down? And if so, does it allow us to infer what would happen if expansion stopped, i.e. would it put the universe in stasis or would it contract? This keeps me up at night, so I would appreciate any insights.
Thanks,
Randy Hyde
There’s been a recent debate in our local papers regarding Venus’ high planetary temperature being related to the dearth of carbon dioxide on the planet. Apparently Venus is much, much hotter than Mercury, even though Venus is twice as far from the sun. Could you explain a bit about our system’s planets and how they differ compositionally? What is it about the Earth’s composition of elements that makes it just right for 99% of the life on the planet? I say 99% because it seems 1% of the life is strange enough to exist in all sorts of harsh conditions.
Being the person who asked “how big is the universe?”, I will add a couple of related questions, just to give you enough to chew on.
Is there anything else out there besides the universe? If the universe is finite, then what exists where it ends? I find all this very hard to conceptualize in general. I’m still struggling with trying to understand the big bang. Maybe you could elaborate on what we all learned in high school on that one too.
Why is water clear? Where did all this water on our planet come from? Do you ascribe to the notion that it arrives on meteorites?
I have a two-part question about adaptive optics.
If one were observing the Moon at perigee through the 40″ refractor at Yerkes, how large would a cherry clafouti near the Moon’s equator have to be to be easily identifiable as a cherry clafouti, assuming clear conditions of observation.
And, how large would the clafouti have to be if observed through Yerkes’ 41″ reflector?
If the smallest clafouti sizes to be identifiable would be different for the two telescopes, can you explain why?
Thanks very much.
What is going on with this new exoplanet TrES-4? What is the difference between an exoplanet and a planet? How do they know that it is the biggest planet in the universe? How do they know it is 20 times Earth’s size?
Thanks and hope the flies didn’t torture you too much on the canoe trip.
I’m with Taron. If the universe is finite, what exists outside it? In other words, if I rowed a boat to the end of the universe, would I fall off the edge and be eaten by space monstors?
This question doesn’t keep me up at night, but sometimes it makes an afternoon nap impossible!
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