Archive for the ‘Cosmology’ Category

How Neutrinos Could Solve The Three Greatest Open Questions In Physics


(Starts With A Bang!) – Ethan Siegel:

A detailed look at the Universe reveals that it’s made of matter and not antimatter, that dark matter and dark energy are required, and that we don’t know the origin of any of these mysteries. …

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Detailed Universe


Is the Universe Infinite Or Finite?


(Starts With A Bang!) – Ethan Siegel:

Either possibility offers a tremendous existence, but philosophically, there’s so much more to think about. …

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Universes arise

Merging Neutron Stars Deliver Deathblow To Dark Matter And Dark Energy Alternatives


(Starts With A Bang!) – Ethan Siegel:

Don’t believe in dark matter or dark energy? Your view of the Universe just got a lot more difficult. …

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Merging Neutron Stars

Properties of Expanding Universes


(The Conversation) – James Geach:

The PhD thesis of perhaps the world’s most famous living scientist, Professor Stephen Hawking, was recently made publicly available online.

Given the complexity of the topic, “Properties of Expanding Universes,” you might benefit from a summary of its main result. …

Hawking has gone on to make further monumental contributions to cosmology and theoretical physics. Reading his thesis is an insight into an exceptionally creative mind – and the first steps of discovery in what has been a remarkable scientific journey. …

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Big Bang expansion timeline

The Big Bang Wasn’t The Beginning, After All


(Starts With A Bang!) – Ethan Siegel:

Why you can’t extrapolate back to a singularity. …

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Big Bang expansion timeline

Dark Matter in Black Holes


(Nautilus Cosmos) – Pedro Ferreira:

The elusive substance may not be a new kind of particle at all. … 142 dark-matter

Black Hole simulation at LMC

The Too-Small God


(Patheos::Excommunications) – Dave Cortesi:

Had I been born in another time and place, there are gods I could have believed in. In ancient Greece, I’m sure I would have been a devotee of the great Athena, and gone often to the beautiful temple on the Acropolis to worship.

Had I been born in India before 1800, I probably would have prayed often to Ganesha, the elephant-headed god of wit and wisdom. Born to a Native American tribe before the coming of the whites, I’d have felt close affiliation with Coyote, the trickster and storyteller.

But as it happened, I had the great good fortune to be born in a Western culture after the Enlightenment, and that placed a lower limit on the size of my God. …

patheos 2017/05 too-small-god

Galaxies in Hubble Extreme Deep Field

If the Universe is expanding, why aren’t we?


(Starts With A Bang!) – Ethan Siegel:

Space is getting bigger, but atoms, humans, Earth and our Milky Way stay the same size. How is this possible? …

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Is there a Center of the Universe?


(Starts With A Bang!) – Ethan Siegel:

Perhaps the Universe has a finite shape and a finite size, but if it does, that information is inaccessible to us. The portion of the Universe observable to us is finite, and that information isn’t contained within it.

What we’re sure of is that it’s expanding, it’s getting less dense, and the farther away we look, the farther back in time we’re able to see. …

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Two Micron All-Sky Survey (2MASS)

Fictional Multiverses Are Lame


(Nautilus Cosmos) – Shannon Stirone:

The multiverse movie that scientists usually rate the highest is Sliding Doors, wherein the simple act of Gwyneth Paltrow’s character missing her train creates a new branch of reality. We see the world play out as if she had or hadn’t missed her train. “That’s a pretty faithful story in terms of there is a crucial event that happened and things go two different ways,” physicist Sean Carroll says. “They don’t really interfere with each other in any way, but you follow the two parallel tracks.” … fictional-multiverses

Sliding Doors, 1998 film