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Deep space radio signal reaches Earth after 8B years

30 点作者 DocFeind8 个月前

7 条评论

tectonic8 个月前
One likely source of FRBs are magnetars, which are just absurd objects. We wrote about them in Orbital Index a little while ago (<a href="https:&#x2F;&#x2F;orbitalindex.com&#x2F;archive&#x2F;2023-03-15-Issue-210&#x2F;#magnetars" rel="nofollow">https:&#x2F;&#x2F;orbitalindex.com&#x2F;archive&#x2F;2023-03-15-Issue-210&#x2F;#magne...</a>):<p>These highly magnetized neutron stars—objects only ~20 km in diameter—have magnetic fields that may reach up to 1015 Gauss, a quadrillion (thousand trillion) times our Sun’s pitiful 1 Gauss. The energy density of just these magnetic fields (via E=mc2) is 10,000x the mass density of lead. Magnetars are a likely source of Fast Radio Bursts and can also emit giant gamma-ray flares—one flare, GRB 200415A, was seen to emit the same amount of energy as our Sun does over 100,000 years, but in only 0.016 s. We don’t really know how these flares form, but if they involve large mass motions, they could also produce gravitational waves, something LIGO and other gravitational wave observatories are watching for. Near a magnetar, “X-ray photons readily split in two or merge. The vacuum itself is polarized, becoming strongly birefringent, like a calcite crystal. Atoms are deformed into long cylinders thinner than the quantum-relativistic de Broglie wavelength of an electron (pdf),” resulting in a breakdown of anything resembling what we think of as chemistry. It’s believed that their magnetic fields decay relatively quickly over about 10,000 years, so magnetars are a transient state. We know of about 30 magnetars so far. Oh, and they may also have volcanoes (sort of).
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MilnerRoute8 个月前
I wanted it to be &quot;We&#x27;ve been observing your earth, and one night we&#x27;ll make a contact with you.&quot; Like in that 1976 song by the Carpenters...<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=tKkcPMNs4m0" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=tKkcPMNs4m0</a><p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=teBV0EoJJY8&amp;t=5s" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=teBV0EoJJY8&amp;t=5s</a>
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johnea8 个月前
Really interesting topic, not so great article.<p>Much better off reading the wilipedia page:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fast_radio_burst#FRB_220610" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fast_radio_burst#FRB_220610</a><p>In addition to the short summary of that specific event, it has a much more detailed treatment of the subject overall.
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1024core8 个月前
If these last only milliseconds, one must be really lucky to catch them, with the radio telescope pointing at the right direction at the right moment. Does that mean we miss the vast majority of FRBs, because we&#x27;re not looking everywhere at once?
FridayoLeary8 个月前
&gt;It turns out that visible matter — like stars, planets, and galaxies — makes up only about 5% of the universe’s total mass-energy content.<p>It always blows my mind how little we actually know. Everything we can observe and that science can describe is just a small fraction of what is actually out there. Since we don&#x27;t know what dark matter is maybe its possible that it is all around us, here on Earth. I find that slightly disturbing for some reason.
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orourke8 个月前
Not a series of prime numbers?
jasonvorhe8 个月前
It seems like most of these numbers are just completely made up.