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Comment Re:relative to what? (Score 1) 148

You should rest easy! It's been confirmed directly using planes and atomic clocks: as well as in observed ratios in muon detections from cosmic rays and in the operation of particle colliders like the LHC and at Fermilab. Also, interestingly, it is what is ultimately responsible for magnetic fields. The fact that you can stick these things to your fridge is a consequence of time slowing down and space shortening for charges in motion. It's fascinating.

Comment Re:A galaxy of what? Dark stars? (Score 1) 174

Because it's collision-less, there's no effective way for a cloud of mutually-attracting DM particles to lose energy other than gravitational radiation. Normal matter will collide and heat up (accretion disks), losing kinetic energy as well as potential, and coalesce into a smaller object. DM clouds, as I understand it, have a much larger timescale for collapse. They don't "clump" very fast.

Comment Re:My Hero (Score 1) 122

Wow --- blast from the past. I remember playing with a friend of mine in 9th grade at a local pizza joint. We each got good enough to roll it (I think that was level > 255) and play all day on a quarter each. That was really the way to do it since we got a break after each of us died. What a rush that game was.

Comment VPython (Score 1) 704

My 14-year-old has expressed a mild interest in programming, so I'm going to load up VPython for him to try. The language is easy to learn, and he can make things "happen" on the screen very simply. It's a first introduction to watching what happens in loops, conditional statements, and then graphics terms like textures, polygons, and lighting. Sounds like a perfect introductory mix. I would have loved such a thing when I was getting started.

Comment Re:Flash Sideways (Score 1) 955

Juliet said "it worked" and also "let's get a coffee sometime" because as she was dying she caught a glimpse of her "purgatory" meeting with Sawyer. It actually didn't have anything to do with the bomb.

Comment Re:collapse at any minute? (Score 1) 246

I'm having a hard time understanding the question. The universe expands at different speeds that depend on the distance from us. If you're asking about a collapse where all the objects are moving towards us at the exact same speed, and if that speed were the speed of light, then we wouldn't see them until they were right on top of us. But the physical model for that is difficult to imagine.

Comment Re:I love to be the first to say this... (Score 5, Interesting) 787

There are some factors you're apparently unaware of. The long-term trend over many decades is roughly 0.15C or so, but on the scale of a particular decade, roughly 4 main variables influence warming: CO2 excess, El Nino cycles, solar radiance, and aerosol cooling (volcanoes, say). Over the last 12 years we've had, in combination, a decrease in El Nino heating from a record 1998 (which is why many "skeptics" pick this year as a starting point) as well as a cooling cycle in solar radiation. They both operate on roughly the same timescale. Underneath that, the CO2 excess from humans contributes a fairly constant 0.2C per decade of warmth, which is why the last decade and a half have shown roughly flat temperature increases instead of the expected cooling. If you look at the temperature plots, you can see this "wiggle" happening on a regular basis. We'd then expect, over the next decade, to have rapidly increasing temperatures as all the warming factors are positive, then probably a flat profile after that. The long-term trend, as shown in the plots, is still rising.

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