APOD and General Astronomy Discussion Forum
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Gravitational lenses don't have focal points in any conventional sense. They don't produce images.Qev wrote:Haven't there been proposals to use the Sun's gravitational field as a giant telescope lens? Not that a habitable planet could ever be that distant, since I think the focal point is out at >500 AU or something like that... :ssmile:
No, not at all. I just looked up the coordinates of WR104 and noticed it was close to the Ecliptic and the Southern Solstice. That was enough to pique my curiosity and to pose my somewhat silly question. At the time of asking, I was thinking that GRBs lasted for about the same duration as the corresponding supernova (making my question even sillier). I have since read that such GRBs only last for a few seconds to a few minutes. Quite amazing that such a short burst, from so far away, could potentially wreak so much havoc on us with no warning.neufer wrote:Nitpicker wrote:
For the sake of argument, if we imagine WR104 fires its jets at us directly, sometime in the next few years, say, and if we further imagine that it does so only within the precise window of a few hours around 22-23 December (when WR104 passes behind the Sun), would the Sun protect us?
- Ten hours of safety each year...just great
You weren't thinkin' of Haydn were you
That's my favorite evolutionary theory Geck. It acknowledges what the Earth's fossil record shows, which isn't the slow, gradual change in life forms first predicted by Darwin, but very long periods without much change broken (punctuated) by brief periods in which many new species make their first appearance.geckzilla wrote:The theory of punctuated equilibrium comes to mind.
Interesting. Friday the 13th will be on Friday this month. (Some will understand.)Psnarf wrote:Hmm, we're looking at photons that left the theater 8,000 years ago. We'd never know when the doomsday event occurred, so "Don't Worry, Be Happy!"
PS You'll recognize me as the guy in the lead suit.
It's not generally regarded as a good explanation for most of what we observe, although it certainly must occur sometimes. There's plenty of evidence in the fossil and genetic record for gradual evolutionary change. The appearance of sudden changes is probably better explained by the way fossils are preserved, with many regions and many times simply not represented in the record at all. In other words, punctuated fossil production fits the observations better than punctuated evolution.BDanielMayfield wrote:That's my favorite evolutionary theory Geck. It acknowledges what the Earth's fossil record shows, which isn't the slow, gradual change in life forms first predicted by Darwin, but very long periods without much change broken (punctuated) by brief periods in which many new species make their first appearance.geckzilla wrote:The theory of punctuated equilibrium comes to mind.
