PDA

View Full Version : A bouncing baby pulsar

ToSeek
2002-Feb-13, 02:20 PM
First View of a Newborn Millisecond Pulsar? (http://www.spaceref.com/news/viewpr.html?pid=7401)

Russ
2002-Feb-13, 03:59 PM
I know I'm picking nits here but I'm going to dive in anyway.

They call this thing a "millisecond pulsar". In my line of work a millisecond is 1/1000th of a second. Yet in this article they say that the pulsar spins 246 times a second. Would that not make it a centisecond pulsar? It seems to me that it would have to spin 1000 times per second to be a milisecond pulsar. Did I get this wrong?

Wiley
2002-Feb-13, 04:17 PM
On 2002-02-13 10:59, Russ wrote:
I know I'm picking nits here but I'm going to dive in anyway.

They call this thing a "millisecond pulsar". In my line of work a millisecond is 1/1000th of a second. Yet in this article they say that the pulsar spins 246 times a second. Would that not make it a centisecond pulsar? It seems to me that it would have to spin 1000 times per second to be a milisecond pulsar. Did I get this wrong?

I shall attemped to defend this poor pathetic and picked upon nit.

Well, with an angular velocity of about 1550 rad/s, this gives a period of rotation 4.1 mS. It seems that to be classified as a millisecond pulsar the rotation period must between 1 and 10 mS. So an angular velocity between 100 and 1000 revolutions per second.

/phpBB/images/smiles/icon_smile.gif

Russ
2002-Feb-13, 06:02 PM
On 2002-02-13 11:17, Wiley wrote:

Well, with an angular velocity of about 1550 rad/s, this gives a period of rotation 4.1 mS. It seems that to be classified as a millisecond pulsar the rotation period must between 1 and 10 mS. So an angular velocity between 100 and 1000 revolutions per second.
/phpBB/images/smiles/icon_smile.gif

So if I read this correctly, a pulsar is a "millisecond pulsar" because its' rotation period is measured in milliseconds? Not because it pulses at 1000 times or more per second? (shakes head & gapes jaw) Well I'll be a dungbeetle! /phpBB/images/smiles/icon_eek.gif

Wiley
2002-Feb-13, 06:22 PM

Why are the wavelengths of "millimeterwaves" shorter than "microwaves"?

Russ
2002-Feb-13, 07:17 PM
On 2002-02-13 13:22, Wiley wrote:

Why are the wavelengths of "millimeterwaves" shorter than "microwaves"?

Ahem, harrumph: Welllll, the engineering unit called a "wave" can be divided into one million fractions known as microwaves. This is of course a greater length than a millimeter creating a condition whereupon you have millimeter waves being shorter than microwaves. (steps down from lecturn, removes morterboard, monicle & large, grey, handlbar mousache, puts on dunce cap) (whines) How the heck should I know?!

The deepest question in my book is: If a chicken & a half, can lay an egg & half in a day & half, how long would it take a grasshopper with a wooden leg to kick all of the seeds out of a dill pickle? Give your answer in furlongs per fortnight. /phpBB/images/smiles/icon_lol.gif

Hale_Bopp
2002-Feb-13, 07:22 PM
Here are a couple of more strange unit phenomena...

10^12 microphones = 1 megaphones

and my personal favorite...

2000 mockingbirds = 2 kilomockingbirds

/phpBB/images/smiles/icon_smile.gif

Rob

Russ
2002-Feb-14, 02:26 PM
On 2002-02-13 14:22, Hale_Bopp wrote:
Here are a couple of more strange unit phenomena...

10^12 microphones = 1 megaphones

and my personal favorite...

2000 mockingbirds = 2 kilomockingbirds

/phpBB/images/smiles/icon_smile.gif

Rob

/phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_lol.gif You guys crack me up! /phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_lol.gif

GrapesOfWrath
2002-Feb-14, 02:36 PM
On 2002-02-13 14:22, Hale_Bopp wrote:
and my personal favorite...

2000 mockingbirds = 2 kilomockingbirds

So howcome
52 cards = 1 decacards?

SeanF
2002-Feb-14, 02:38 PM
On 2002-02-13 14:22, Hale_Bopp wrote:

and my personal favorite...

2000 mockingbirds = 2 kilomockingbirds

/phpBB/images/smiles/icon_smile.gif

Rob

Not to mention that a thousand beers sold at a Minnesota Twins games is a kilobrew . . .

Russ
2002-Feb-15, 04:49 PM
Soooooo,....back to topic. Why is it that a pulsar that does not spin > 1000 rps is called a millisecond pulsar?

Maybe it's because we see both pole flashes and therefore it has to spin only 500 rps to have millisecond flashes. But that still leaves this one out in the cold as it rotates at 247 rps. So what's the deal?

Roy Batty
2002-Feb-16, 09:13 AM
On 2002-02-15 11:49, Russ wrote:
Soooooo,....back to topic. Why is it that a pulsar that does not spin > 1000 rps is called a millisecond pulsar?

I believe Wiley explained it above. Its classed as a millisecond pulsar because its Period of rotation is in milliseconds ie 1/274 =~ 3.6mS. If it spun at 100 rps or less then it would become a centi-second pulsar but if it spun at >1000 rps it would be a microsecond pulsar /phpBB/images/smiles/icon_smile.gif

_________________
N6MAA10816

<font size=-1>[ This Message was edited by: Roy Batty on 2002-02-16 04:18 ]</font>

Wiley
2002-Feb-18, 04:36 PM
On 2002-02-16 04:13, Roy Batty wrote:

On 2002-02-15 11:49, Russ wrote:
Soooooo,....back to topic. Why is it that a pulsar that does not spin > 1000 rps is called a millisecond pulsar?

I believe Wiley explained it above. Its classed as a millisecond pulsar because its Period of rotation is in milliseconds ie 1/274 =~ 3.6mS. If it spun at 100 rps or less then it would become a centi-second pulsar but if it spun at >1000 rps it would be a microsecond pulsar /phpBB/images/smiles/icon_smile.gif

I thought I did too! /phpBB/images/smiles/icon_smile.gif