Astronomy/cosmology questions...

[Geo]

I meant within...

Just pullin'... 

-And I suspect that at that very closer range, the heat Jupiter radiates might be non-trivial, too.

Dunno. Jupiter radiates more energy then it receives from the Sun (at its current distance of course), but that's in the infrared.

[Buster's Uncle]

I thought that's what I said.

450 miles away is LEO or close, and Earth's environment wouldn't be improved by even a minor heat source added...

[Geo]

I think Earth's environment would already be wrecked by tidal forces before heat became a problem.

What interests me more is what would happen with Earth's 'husk' so to speak once the close encounter was over. Would it be sling into the Sun, or outer space? Or would the 'remains' become a satellite of Jupiter in one way or another (ring system, coalescing again into a sphere, although a molten one to start with,...).

[Buster's Uncle]

I'm sure you're right - probably ocean tides higher than Everest.

Depends on velocity and vector, ect.

[Lorizael]

Jupiter still gets most of its energy from the sun. It gets a little extra from the fact that it's still slowly contracting, which turns gravitational potential energy into heat. If Jupiter were the same distance from the sun as us, it would be at about the same temperature as us. It's also big, so it's capturing a large chunk of the sun's energy and redirecting a portion of it at us, but mostly in the infrared. We would not like that.

[Buster's Uncle]

Mystery of the universe's Cold Spot deepens – it's not a supervoid

[Buster's Uncle]

Pulsars, Not Dark Matter, May Be Responsible For Excess Gamma-Ray Glow At Milky Way's Centre

[Buster's Uncle]

Stephen Hawking and Others Pen Angry Letter about How the Universe Began
Hawking offers rare public opinion for which he's qualified

[Lorizael]

I'm trying to write blog posts more frequently, especially now that I'm not busy and have no excuses. To that end, if you guys have any questions about astronomy (and to a lesser extent, math and physics), fire away. If it's a quick question, you'll get a quick answer here. But if it's a question for which the answer can involve a story and some terrible MS Paint illustrations and maybe a bit of math (and I think it would be a fun thing to write about), I'll put together a blog post to answer it. I'll try to get posts out within a week or so, because my hope is that the pressure of someone asking me a question will nudge me into writing.

If this doesn't appeal to anyone here, oh well. If it does, cool, and thanks.

[Buster's Uncle]

...You know, there's quite a few science articles linked here in recent months that you could share reactions/thoughts about...

[Lorizael]

I had a feeling you might say that. If you notice, I tend to respond to direct questions but not to posted articles. Part of this comes from the fact that I tend to withhold judgment on cutting edge stuff in astronomy. I'm aware of how much I don't know and I'm not terribly interested in getting into the weeds about stuff where the best current answer is just that we have to wait for more data. What I like talking about most is (a) how we got to our current state of knowledge, (b) how astronomy gets done, and (c) what it all means. I like telling stories more than I like getting into debates, and questions are a good way to frame stories.

[Rusty Edge]

I'm trying to write blog posts more frequently, especially now that I'm not busy and have no excuses. To that end, if you guys have any questions about astronomy (and to a lesser extent, math and physics), fire away. If it's a quick question, you'll get a quick answer here. But if it's a question for which the answer can involve a story and some terrible MS Paint illustrations and maybe a bit of math (and I think it would be a fun thing to write about), I'll put together a blog post to answer it. I'll try to get posts out within a week or so, because my hope is that the pressure of someone asking me a question will nudge me into writing.

If this doesn't appeal to anyone here, oh well. If it does, cool, and thanks.

Okay. Here's one for you. It may or may not be cosmic. Is all energy the same in that it travels in waves, and we just perceive it differently as light or heat or sound or earthquakes, ( as examples) depending on frequency and amplitude?  Or is it particles, particles traveling in waves, or some of each ?

[Buster's Uncle]

I've never quite gotten why astronomy/cosmology thinks our observations tell us anything relevant about the mass of the universe within several orders of magnitude.  Stands to reason that there's a distinctly non-trivial amount of cosmic gas/dust and other non-radiating matter out there making estimations nothing but poorly-informed guesses...

[Lorizael]

Questions, cool. Thanks, guys. I'll get to them in a bit. In the mean time, here's a post on the cosmic distance ladder.

[Buster's Uncle]

As the best of our instruments have become far more refined in the last few decades, have there been any significant advances in the range of parallax measurements?  ISTR observations six months apart being good for measuring distance on the order of something 11lyrs.  Is that anything like it currently stands?