Astronomy miscallaneous

Had 20 min during grocery shopping by the person who reports to me. Was reading Astronomy magazine. Some random findings from memory

Our galaxy is spiral. The outermost portion is 125000 light years from center.
Each galaxy has a black hole. I didn’t know that. I thought that the Universe came from big bang theory. When stuff escaped from one back hole.
The number of stars in a galaxy proportional to black hole Mass of each galaxy.

The CFL emits light that is found nowhere in our galaxy. While lack of infrared is good - no heating - the light being different may be damaging.

In summer we get plenty of natural light. So ok to use cfl. No heat emission. Good.

In winter we don’t get enough light. Plus incandescent light bulb emit heat. So heats home. So use those in winter. Clever.

Sorry - the issue was condominium free. Though I don’t condon it.

Re: Astronomy miscallaneous

every thing is a spiral.

What kind of black hole let stuff out ? :nono:

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My bad. I thought the same thing and was confused. How can there be an existing black hole within each galaxy? Maybe I read it wrong, Mr. Monk.

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once I saw the guy(on tv) who discover first black hole. It was amazing.
He sat infront of old style monitor night after night for 8 years.
Then he noticed a light distortion moving across give funky magnifying effect to its surrounding.
It was amazing. Some thing so powerful with such a small visual impact.

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^ 8 years! Good for him he found one.

Will try to read the same mag when we go shopping next weekend. And provide clarification.

Monkster is a Physicist.

Re: Astronomy miscallaneous

ohhh…interesting thread :k:

What is CFL?

Re: Astronomy miscallaneous

Old style light bulbs are banned in India. They have some new energy saver light bulb which is like curled neon tubes and emits white light while consuming very little energy. Those new light bulbs are called CFL here, they are also called energy saver bulbs.

PS. Quite expensive they are but they come with one year warranty.

Re: Astronomy miscallaneous

Kaka knows best.

To add to above - I think Compact Flouroscent Lamp? ( don't know how to go to the google without being the logged out)

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Mr. Monk

Subject: your post 5.
Reason did not reply with quote- The Monkster don't care to be quoted.

My bad. Use of "escaped from black hole ( dduring big bang) was my text.

Anyway, as promised, while my assistant was shopping, I took notes.

Reference: Astronomy (magazine) September 2013. P. 9. David Elder.

"Inside the galaxy's nucleus lies a dormant supermasive black hole that once was a massive giant".

 So each galaxy has its own black hole. Dormant - so doesn't grow anymore.nothing enter or escapes it?

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Same issue p. 34. Q/A format. David Inui.

There is " direct correlation between mass of a supermassive black hole and the stellar content of its host galaxy bulge"

Stellar content means amount of stars.

How to measure stellar content? One of 3 ways.

1) determine mass of Bulge ( bulge consists of stars).
2) measure light from stars
3) measure spread of random motion of stars due to the bulges gravitational attraction. Thiss also known as velocity dispersion.

Re: Astronomy miscallaneous

It has been found that method 3 best correlation. Larger the mass of black hole greater the velocity dispersion. Greater the number of stars.

For perspective milky way black hole mass 0.4 million ( tons?). Velocity dispersion 100 km / s.

M60 2 billion tons. 350 km per s.

Not sure if mass unit is tons. Didn't notes that.
Our milky way is puny compared to M 60.

Re: Astronomy miscallaneous

Why this correlation exists. Hypothesis: quasar feedback.

"When galaxies merge, their bulges all merge. New larger central black hole swallows lots of gas ( now Exxon popped to mind). Friction and radioactive processes cause material funneling toward BH to glow ss a bright quasar. The quasar glows till its powerful winds and jets heat up and/ or expel all the gas in the galaxy, so it cant make any new stars or feed the black hole. "

Ok so the BH stops growing. Kind of a dynamic equilibrium - fron Physical Chemists POV. ( do that is why Space is vacuum- all gases expelled).

Re: Astronomy miscallaneous

Nice thread.

BTW, Big Bang did not happen because of a black hole started spewing mass out of it. Big Bang happened, literally out of nothingness (more of this later, maybe).

Mass of black holes are usually measured in Sun Mass. So 0.4 could mean 0.4 times the mass of sun, but it seems pretty low for a black hole, especially the one that could be in the center of a galaxy

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^ Thanks! The low mass was confusing. Will clariffy this next Sunday after trip tyke grocery store.

Big bang is confusing. Could use your help. I recall you were a funda man on this topic.

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Good thread!

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Explain the nothingness

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I am no funda man, but love to read about such stuff.

Philo, Zero is nothingness, at least that much we all can agree. With that in mind, let me try to explain big bang.

Unlike chemical reactions that can be reversible or irreversible, all mathematical equations are reversible. Physics is nothing but math. When a matter particle and equivalent anti-matter particle hit each other, annihilation happens, meaning that with a burst of energy and emission of light (photon), the matter and antimatter particle vanish.

if A is matter, -A is anti-matter, P is photon and E is energy then,

A + (-A) = P + E
if we take all the right side to left side then
0 = -A + A + P + E
That means that from nothingness (Zero), a particle, anti-particle, a burst of energy and light can be produced.

  • What are the chances of it happening? Extremely rare, very close to zero, but still its a finite value, which means that over the period of very large amount of time, it could happen.
  • Can it always result in a universe? No. Many of the times, the energy produced is not sufficient and both particle and anti-particle can annihilate back into nothingness. So having a full blown universe out of nothingness is an extremely rare phenomena that nature my never duplicate.

Nature produced so many particle/anti-particle pairs that partcles formed the visible part of the universe. Some physicist believe that there is entire section of the universe that is formed out of antimatter.

I have dumb down the explanation not because you are not smart folk but I am not smart enough to keep it simple and short without over simplifying the explanation.

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If coincidences intrigue you, you may find this cool.

Was in the middle of reading "The Upanishads" by Eknath Easearan". I mark the page the old fashioned way, fold top corner - happened to be of page 121. Let me quote the first para

" in the wisdom of ancient India, the universe cam forth from the invisible and unchanging Reality like the uttering of a meaningful sound: mystical speech ( which is why the Vedas are thought of existing long before humans or anything else). It was not a Big Bang but a big Om; and it is with this image that the Upanishad named Chandogya, "the uprising of sacred song, " begins."

I was tickled by the coincidence.

Re: Astronomy miscallaneous

One question:

Is the Big Bang supposed to have occurred for each existing galaxy? Or for entire universe? Looks like the latter.

So several galaxies formed after Big Bang. Each with a black hole in the center? Sometimes galaxies merge (rarely). And form a more massive black hole? Whose size grows till equilibrium attained?

PS very nice explanation. Makes sense.

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Wow, our brains can't even grasp such abstract concepts. Were so limited.
Is there an accessible read on this?? Like a book.

PS rnt you a smart cookie tlk !!