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-   -   Wacky news that makes you go "wtf?" (https://www.mersenneforum.org/showthread.php?t=12112)

retina 2015-03-03 07:51

[QUOTE=science_man_88;395124][URL="http://io9.com/how-big-is-the-biggest-star-we-have-ever-found-1684653072"]How Big Is The Biggest Star We Have Ever Found?[/URL][/QUOTE]Does the [strike]center[/strike] centre rotate faster than the surface? How far away would Earth need to be to be in the "goldilocks zone"? Or would the x-rays/UV kill us before we came close enough?

[size=1]I found a bigger one once, but then I lost it behind the couch. I'm such a butter fingers. :sad:[/size]

xilman 2015-03-03 08:26

[QUOTE=ewmayer;396880]The rotational speed needed to tear the star apart (i.e. at which centripetal acceleration exceeds the surface gravity) is bound to be far, far lower than any relativistically nontrivial rotational speed. I'll let you compute the former quantity as a fun exercise.[/QUOTE]Neglecting relativistic effects, the surface of a star with radius r rotating in time t is moving at 2πr/t. Plugging in the numbers for a millisecond pulsar (r=12000m, t=0.001s) results in a velocity of 7.5e7 m/ s. As c is 3e8 m/s, the equatorial velocity is c/4. Large enough for some relativistic effects to be important, easily measurable frame dragging for instance.

ewmayer 2015-03-04 22:22

[QUOTE=xilman;396883]Neglecting relativistic effects, the surface of a star with radius r rotating in time t is moving at 2πr/t. Plugging in the numbers for a millisecond pulsar (r=12000m, t=0.001s) results in a velocity of 7.5e7 m/ s. As c is 3e8 m/s, the equatorial velocity is c/4. Large enough for some relativistic effects to be important, easily measurable frame dragging for instance.[/QUOTE]

And the surface gravity of a ms pulsar compares how with that of a diffuse hypergiant?

xilman 2015-03-05 09:43

[QUOTE=ewmayer;397032]And the surface gravity of a ms pulsar compares how with that of a diffuse hypergiant?[/QUOTE]Ok, I recognize the context of your suggestion and took liberties. Nonetheless, my answer does show that relativity, special and general, is a very important consideration when thinking about the properties of neutron stars.

VictordeHolland 2015-03-05 14:14

I'm baffled by how little most people know about astronomy. You'd be surprised how few people can name the 8 planets in our solar system. If you tell them there is scientific evidence for a super massive black hole in the centre of our Milky Way galaxy, they are thinking you are talking SciFi, not to mention dark matter.

firejuggler 2015-03-05 14:39

what is pluto?

retina 2015-03-05 14:49

[QUOTE=firejuggler;397068]what is pluto?[/QUOTE]Take your pick.

[url]http://en.wikipedia.org/wiki/Pluto_%28disambiguation%29[/url]

It you believe those IAU folk it is not a planet, apparently. It forgot to "clear it's neighbourhood". Maybe we should give it broom when New Horizons arrives, to help it to sweep everything nice and clean.

chappy 2015-03-05 15:35

Pluto was big enough for your mom.

ewmayer 2015-03-06 03:52

[QUOTE=VictordeHolland;397066]I'm baffled by how little most people know about astronomy. You'd be surprised how few people can name the 8.[/QUOTE]

9 - you forgot Vulcan, which is too close to the Sun to be seen directly but which we know exists 'cos Einstein was wrong about the cause of the perihelion shift of Mercury.

(Re. Pluto, I never counted it ... too much of a Mickey-Mouse planetoid for my taste.)

firejuggler 2015-03-11 18:25

Utah to bring back death sentence by firing squad.
[url]http://abcnews.go.com/US/wireStory/utah-set-bring-back-death-sentence-firing-squad-29547807[/url]

ewmayer 2015-03-12 05:51

[QUOTE=firejuggler;397479]Utah to bring back death sentence by firing squad.
[url]http://abcnews.go.com/US/wireStory/utah-set-bring-back-death-sentence-firing-squad-29547807[/url][/QUOTE]

Messier, but arguably less botch-prone than electric chair, and perhaps even than lethal injection.

(Note the proposed law would only allow firing squad if lethal injection chemicals were unavailable 30 days prior to the execution date.)

Macabre though the subject may be, have there been any medical studies of the relative suffering of victims of the above methods? It might seem 'obvious' that getting hit by multiple bullets would be very painful, but many major traumas have the common theme that any perception of pain does not kick in until after the initial systemic shock has passed. If you're unconscious (from blood loss) in under a minute and never regain consciousness ... in that sense firing squad may be similar to death by guillotine.

Again, this is strictly within an 'if you must put someone to death' context - neverending 'death penalty or not?' debates belong in the Soap Box.

Note that the above debate is echoed in the MSM in a slightly different guise with great frequency: ISIS beheadings are 'barbaric', but Hellfire missiles blowing entire wedding parties - and rather more rarely, actual bad guys - to pink mist and rent limbs are described with sanitized lies like 'precision strikes'.


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