Ask a physicist anything. (8)

[essentialsaltes]

New Question:

What evidence is there left of the star that spawned our sun and solar system.

I'm not sure there was only 'the' star. A popular model is that the shockwave from a nearby supernova caused a preexisting cloud of gas to coalesce to form the solar system. That preexisting cloud was no doubt the remnant of some other star or stars that had exploded previously (and maybe also including some remnant gas that had never been a part of any star). So the matter that makes up the solar system could be mingled from several previous stars.

If the universe is just over 13 billion years old and the earth about 4.5 billion years old what would roughly be the timescale of this star's existence.

I don't think we could know for sure. I'm not an expert on this. Here are a couple links that might help:

Link

Metallicity

 

[Wiccan_Child]

I'm not sure there was only 'the' star. A popular model is that the shockwave from a nearby supernova caused a preexisting cloud of gas to coalesce to form the solar system. That preexisting cloud was no doubt the remnant of some other star or stars that had exploded previously (and maybe also including some remnant gas that had never been a part of any star). So the matter that makes up the solar system could be mingled from several previous stars.

Interesting, I hadn't heard that. The bulk of the material is still from a single prior star, though, yes?

 

[essentialsaltes]

Interesting, I hadn't heard that. The bulk of the material is still from a single prior star, though, yes?

I would imagine so, since the shockwave material will be spread out over the entire expanding sphere, but I really don't know.

 

[Justatruthseeker]

Yah well, I wouldn't put too much faith in current theory of novae. After 25 years they still can't get a supercomputer to model one that works. I would suggest this is because their constitution of what a star is, is incorrect, as well as to what they are, including how they form, etc.

http://images.nationalgeographic.co...glowing-pink-ring-supernova_25767_600x450.jpg

http://www.popsci.com/sites/popsci.com/files/images/2010/08/eso1032a.jpg

Because they are an electrical phenomenon in plasma, not a nuclear one.

http://www.holoscience.com/wp/wp-content/uploads/2007/04/supernova-diagram.jpg

Visible even on stars that have lit up their environment due to high electrical stress

http://2.bp.blogspot.com/-wZSVlKCfQ...AAALU/lhL77z9tVcE/s1600/plasmacomplexity2.jpg

http://25.media.tumblr.com/37767ec85579424e2ea8045b01fe4c03/tumblr_ms1p8gHyzs1rnq3cto1_500.jpg

And in nebula.

http://setterfield.org/ZPE-Plasma_model_clip_image002_0008.jpg

https://www.thunderbolts.info/tpod/2005/images05/051230bugnebula.jpg

http://www.thunderbolts.info/wp/wp-content/uploads/2011/08/boomerang_nebula_HST_480x531.jpg

And their ignoring electricity in space is why their computer simulations do not work at all.

 

[Zippy the Wonderslug]

Nevermind.

Sorry.

 

[Zippy the Wonderslug]

Okay. So I'm a bit old school.

Hopefully someone else here will be as well.

I'm trying to learn Google Spreadsheet and need a little help.

In BASIC language, I would like to try something like the following:

For A = 0 to 100 STEP 2
PRINT A
Next A

What is this mathematical concept called?

Is it just a function?

Also, could someone please give me an example or link on how to enter that into Excel?

I need the output in such a way that I can copy and paste it into another Windows program.

Thanks ahead!

 

[Elendur]

Okay. So I'm a bit old school.

Hopefully someone else here will be as well.

I'm trying to learn Google Spreadsheet and need a little help.

In BASIC language, I would like to try something like the following:

For A = 0 to 100 STEP 2
PRINT A
Next A

What is this mathematical concept called?

Is it just a function?

Also, could someone please give me an example or link on how to enter that into Excel?

I need the output in such a way that I can copy and paste it into another Windows program.

Thanks ahead!

Well that's simply the loop function, not really a mathematical concept but one of the most basic within programming / data science.

I've never used excel myself, but hopefully these links will be useful.

A link to use it within excel:
Excel VBA Loop - Easy Excel Macros

A link on how to export the excel data to text:
How to export Excel data to Text files in Excel?

If these are not what you were looking for, let me know. I'll see if I can dig some more.

 

[Zippy the Wonderslug]

Thank you so much!

Bookmarking both those sites right now.

 

[Sayre]

A serious question...

Are there genuine non-creationist scientists who question the existing theory of gravity? I often hear people say they don't think we've got it right, yet, but I've no idea if this is a widespread phenomena outside of debates concerning creationism.

Thanks

 

[Wiccan_Child]

A serious question...

Are there genuine non-creationist scientists who question the existing theory of gravity? I often hear people say they don't think we've got it right, yet, but I've no idea if this is a widespread phenomena outside of debates concerning creationism.

Thanks

Well, the current theory of gravity is Einstein's theory of general relativity, and it is held because it is stupidly accurate. But it contradicts quantum mechanics, and QM is more accurate than GR. They rarely interact, of course - GR is the mechanics of space and time, massive objects and high speeds; QM is the mechanics of tiny particles and tinier quantum efflusia. But they do talk to each other when there's something tiny and heavy - e.g., a black hole. QM says a black hole's core should be tiny but finite, GR says it should be infinitely small.

But to my knowledge there's no serious contender to Einstein's crown. I'm sure many scientists are trying - any scientists who upturns the status quo goes down in history, after all - but nothing thus far.

 

[Sayre]

Well, the current theory of gravity is Einstein's theory of general relativity, and it is held because it is stupidly accurate. But it contradicts quantum mechanics, and QM is more accurate than GR. They rarely interact, of course - GR is the mechanics of space and time, massive objects and high speeds; QM is the mechanics of tiny particles and tinier quantum efflusia. But they do talk to each other when there's something tiny and heavy - e.g., a black hole. QM says a black hole's core should be tiny but finite, GR says it should be infinitely small.

But to my knowledge there's no serious contender to Einstein's crown. I'm sure many scientists are trying - any scientists who upturns the status quo goes down in history, after all - but nothing thus far.

Hmm thank you. I am not well versed in physics or string theory.

 

[UnderstandForgive]

Other than dopplar shift observations of distant galaxies, what evidence is there to suppose the universe is expanding? for instance;

You look at light from a nearby galaxy, and then compare it to one far away, when you look at the light though a spectrometer you notice the light is red shifted.

The rate of expansion of the universe uses measurements of celestial clocks cephied 1a stars, the rate of the flashing of cephied 1a stars is roughly constant and there is a mathematical reasoning to suppose why the flashing of different Cephied 1a stars are roughly the same. It is noticed that for Cephied 1a stars further away flashes appear slower than ones nearby (I believe).

It is argued (poorly by many people arguing for the expansion of the universe that these are independent methods of verifying the expansion, when they not independent methods but both rely on Dopplar shift as their reasoning.)

It reminds me of that quote from Feynman. "An idea should not be confirmed by what that supposed it in the first place."

Both these methods rely on one concept Dopplar shift. So is there an independent means of verifying that these things are actually moving away from us that does not ultimately rely on Dopplar Shift? and do we use these methods?

(For instance, maybe you might be able to look out through a telescope and see that the angular diameter between time 1 and time 2 is different, which would be an independent means of verifying that these celestial objects are in fact moving away from us.) The method ought to be accepted on grounds of reason and not made to conform to an existing reasoning.

 

[Wiccan_Child]

Other than dopplar shift observations of distant galaxies, what evidence is there to suppose the universe is expanding? for instance;

You look at light from a nearby galaxy, and then compare it to one far away, when you look at the light though a spectrometer you notice the light is red shifted.

The rate of expansion of the universe uses measurements of celestial clocks cephied 1a stars, the rate of the flashing of cephied 1a stars is roughly constant and there is a mathematical reasoning to suppose why the flashing of different Cephied 1a stars are roughly the same. It is noticed that for Cephied 1a stars further away flashes appear slower than ones nearby (I believe).

It is argued (poorly by many people arguing for the expansion of the universe that these are independent methods of verifying the expansion, when they not independent methods but both rely on Dopplar shift as their reasoning.)

It reminds me of that quote from Feynman. "An idea should not be confirmed by the data that supposed it in the first place."

Both these methods rely on one concept Dopplar shift. So is there an independent means of verifying that these things are actually moving away from us that does not ultimately rely on Dopplar Shift? and do we use these methods?

(For instance, maybe you might be able to look out through a telescope and see that the angular diameter between time 1 and time 2 is different, which would be an independent means of verifying that these celestial objects are in fact moving away from us.) The method ought to be accepted on grounds of reason and not made to conform to an existing reasoning.

That they both use the mathematics of Doppler shifts doesn't mean they are the same, or the logic is circular. They are independent methods.

Take the case of radiometric dating. There are many phenomena that lend themselves to be dated by comparing isotope ratios, and these are all physically independant - the physical mechanism that allows organic things to be carbon dated, is completely unrelated to the physical mechanism that allows ancient rocks to be U/Pb dated. That they both utilise the same basic mathematics (dN/dt=kN, T[sub]1/2[/sub]=ln2/λ, etc) doesn't change the fact that they are still completely independent.

So even if there weren't non-Doppler-based methods of inferring the expansion of the universe, the two Doppler-based methods you mentioned are still fundamentally independent. That they both rely on Doppler reasoning is irrelevant, since the mathematics of Doppler shifts is quite simple.

To your question, I would point to COBE's map of CMB anisotropy as very good evidence of Big Bang cosmology, not to mention WMAP and Plank's more refined studies.

 

[UnderstandForgive]

Independent from dopplar-based reasoning, is there a method for determining how fast galaxies are moving away/towards us?

Also, I have always wanted to know the answer to this question, and I think it might have a kind of disappointing answer in GR.

I wanted to know whether space-time has some equivalency like mass and energy?

So say you take 1 cubic light-year, and you could turn it into mass or energy, how many photons could you get out of it? How much mass would that make?

 

[essentialsaltes]

I wanted to know whether space-time has some equivalency like mass and energy?

So say you take 1 cubic light-year, and you could turn it into mass or energy, how many photons could you get out of it? How much mass would that make?

Basically, no. Space and time are not convertible to matter in this way.

 

[UnderstandForgive]

Okay tried to explain why electric appliances in a bathtub, electrify the entire bathtub instead of just the space between the intervals, and I'm not sure if my reasoning was correct.

I told someone that the reason an electric appliance electrifies the whole bathtub rather than just the water between the two terminals is because of electromagnetic induction. I used Faraday's observation that "the electromotive force is equal to the negative of the change in magnetic flux" And I told him or her that an appliance with a DC current will not electrify the bathtub like an AC current appliance would, because the current changes sinusoidally. My reasoning is that the current generated from the electrons moving and changing directions would create a magnetic flux which would be changing -sinusiodially perpendicular to the electrons motion, and thus that change in magneticflux would cause other electrons to move sinusoidally and so on and so forth, until the entire bathtub is electrified.

Is my understanding correct? Is that why the whole bathtub is electrified? and is it also true that DC current does not do this (electrify an entire bathtub as it does with AC powered unit with the same amperage and voltage)?

 

[Wiccan_Child]

Independent from dopplar-based reasoning, is there a method for determining how fast galaxies are moving away/towards us?

Not to my knowledge. Theoretically, you could measure how fast a galaxy's angular diameter grows or shrinks.

Also, I have always wanted to know the answer to this question, and I think it might have a kind of disappointing answer in GR.

I wanted to know whether space-time has some equivalency like mass and energy?

It does not.

 

[Zippy the Wonderslug]

So I'm attempting to make my first ever stereogram on a drawing website.

What I have done so far is generate 5,000 random numbers that range from (34~134,63~660) and then use a mouse recorder to plot them all.

So it first will draw a 100x597 scattered image on the screen.

After this, I take those same 5,000 numbers but add 101 to the X position and redraw them all over again.

I'm currently just in the testing phase but was hoping I could get some pointers on what to do next.

I would eventually like to fill the entire screen like this.

I plan on using 4 more colors to give it more of that magic eye look by the way.

But what would be the next step to what needs to be done?

Do I use the same numbers again and keep repeating those to the right?

Do I generate new random numbers to continue?

Also, how far should these be spaced apart?

Right now I have it at 101 and while this is only the initial part of my project, I can already see the stereogram background.

Hope I made some sense here.

I could really use some mathematical advice.

Cheers.

 

[UnderstandForgive]

Just mess around with it and see which one you like best. Mess around with the numbers of random pixels, mess around with setting the range to take up the whole screen, and not just a 100x597 area. See what it looks like if you copy and paste the numbers and add just 101 to the x value. Just save and experiment that's the only way you'll know for sure what you like best.

 

[Zippy the Wonderslug]

Here's one.....

How on Earth is this thing even possible?

HUVr - The Future has arrived.