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Pristine Big Bang Gas Found

JohnnyDanger Re:Isotopes != elements (220 comments)

There is probably a cloud containing nothing but radon (the heaviest elemental gas) somewhere in the universe as well, right? If that exists would it disprove the big bang, or would it simply have been there by chance for billions of years, just like this one could have been?

Hydrogen and helium isotopes (and a little bit of lithium and beryllium) are made in the Big Bang. Everything heavier is made in stars. So these pure clouds can exist only as long as there are no stars nearby to pollute them with heavier elements. Stars are common in the modern universe, which is why it has been so hard to find such clouds.

Radon in particular is made in supernova explosions (and by the decay of radioactives which were made in supernova explosions) and there is no natural mechanism to separate it back out from mixtures of supernova debris. So in a sense, yes, if a massive, primordial, pure radon cloud was out there, it would disprove the Big Bang theory's prediction of nucleosynthesis, which can only make light elements.

more than 2 years ago
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Nearby, Recent Interplanetary Collision Inferred

JohnnyDanger Re:Neat video, but not very accurate (88 comments)

The impact on Mercury which created the Caloris basin caused some wacky geology at the antipodal point to the collision. This is called "chaotic" or "weird" terrain. Link.

more than 4 years ago
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Dark Matter Discovered Near Solar System?

JohnnyDanger Bad summary. (179 comments)

The summary misinterprets the results.

The instrument detects high-energy electrons. They found an excess (only 70, but statistically significant) with a particular energy, which if they come from a galactic source (like a pulsar), that source must be within 3000 light years. However, the researchers can't find an appropriate source.

Alternatively, this could be due to annihilating dark matter---the energy spectrum matches some models---but that's not necessarily coming from a particular source.

more than 5 years ago

Submissions

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JohnnyDanger JohnnyDanger writes  |  more than 7 years ago

JohnnyDanger (680986) writes "A NASA press release details trouble with the Hubble Space Telescope over the weekend. From the release:

'NASA engineers are examining a problem related to the Advanced Camera for Surveys (ACS) aboard the agency's Hubble Space Telescope. On Jan. 27, the observatory entered a protective "safemode" condition at 7:34 a.m. EST. An initial investigation indicates the camera has stopped functioning, and the input power feed to its Side B electronics package has failed. The instrument had been operating on its redundant electronics since June 30, 2006, when NASA engineers transitioned from the primary, Side A, electronics package due to a malfunction... Science observations will resume this week using the remaining Hubble instruments: Wide Field Planetary Camera 2, Near Infrared Camera Multi-Object Spectrograph, and the Fine Guidance Sensors.'

The longer term prognosis for the ACS instrument is unclear."

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