Ask any question you want about Physics

originally posted by: bottleslingguy
a reply to: Bedlam

"the spot's energy is isolated by the convective flows below" and you know that how?

Cosmic consciousness. I haz it like a cheezburger.

a reply to: Bedlam

Sound in an experiment bent light, dark matter is the spectrum

a reply to: Bedlam

Are you an expert or a YouTube pro watcher?

originally posted by: yulka
a reply to: Bedlam

Sound in an experiment bent light, dark matter is the spectrum

I'd like to say that made sense, but it doesn't, really.

originally posted by: bottleslingguy
a reply to: Bedlam

"the spot's energy is isolated by the convective flows below" and you know that how?

I don't know it with 100% certainty, but there is evidence to suggest this explanation. One clue is to see solar prominences associated with sunspots. It's apparent the prominences result from a magnetic field and they don't seem to be created by magnetohydrodynamic activity above the sun's surface, thus these features must extend below the surface of the sun:

Our sun

So if you project those prominences below the surface you get something like this:

Obviously it's not possible to go inside the sun to make measurements but it is possible to observe the prominences, the related sunspots, and the granulation on the sun's surface related to convection cells, and then use these observations coupled with our knowledge of physics to model what's happening beneath the surface.

Studying the sun is an area of active research and new observations will lead us to fine-tune our models to better match observation, but I haven't heard of any observations suggesting the sun is powered by electricity instead of nuclear fusion, though as the photo of prominences above shows there are certainly electromagnetic effects observed. We have a fair idea of what creates these effects but still have some details to work out and I'm sure our knowledge about how the sun works will continue to improve in the coming decades.

originally posted by: yulka
a reply to: Bedlam

Are you an expert or a YouTube pro watcher?

I haz a physics masters and a EE masters too. Also a MIC contractor.

Your question is...what is sound? This thing, what is it in itself, in its own constitution? What is its substance and material?

a reply to: Arbitrageur

The superconductivity was where I was heading. But no. I wasn't talking about adulterating or combining the hydrogen.
Followup question: Does it specifically require Herculean pressure, or can it acheive conductivity when supercooled? And have we ever cooled pure hydrogen to a solid?

a reply to: Bedlam

Nice

originally posted by: dragonridr

originally posted by: yuppa
I have to ask. how much wood can a woodchuck chuck fi a woodchuck could chuck wood? Explain how in psychics speak.

Groundhogs, aka woodchucks or whistle pigs though they aren't like pigs and eat anything especially wood they prefer green leafy things like grass leaves etc.However like beavers they will chew onto wood to make a burrough, (Yes ironically a wood chuck can chuck wood). They are a rodent of the Sciurid family. They live all over the US, and it's pretty common to see them along the side of the road (usually as roadkill, but sometimes you get lucky and see a live one.) well apparently when they said to chuck wood I'm guessing they meant chew? Though I know when I was a kid up chucking deffinatwly wasn't chewing. Now to the answer but at least next time ground hog day rolls around you know a lot about groundhogs.

Now the answer according to Cornell is about About 700 pounds. Compared to beavers, groundhogs/woodchucks are not adept at moving timber, although some will chew wood. (At Cornell, woodchucks that gnaw their wooden nest boxes are given scraps of 2-by-4 lumber.) A wildlife biologist once measured the inside volume of a typical woodchuck burrow and estimated that -- if wood filled the hole instead of dirt -- the industrious animal would have chucked about 700 pounds' worth.

Dragonridr, you are just fantastic.

a reply to: Arbitrageur

I have a question about the size of the universe and how it relates to a couple of other topics recently discussed.
Is the CMB a direct result of the energy released in the Big Bang/Bounce, trapped in the quark/gluon soup until reionization (approx. 380000 years later), or is it the result of some later interaction? For instance, could it be the result of the asymmetric matter antimatter destruction event?
If it is the result of either of these, is it reasonable to assume that it was originally in the extreme Gamma end of the spectrum?
Lastly, if so, can we not use the resultant red shift we see today to calculate the approximate expansion of spacetime from then until now, and roughly extrapolate the size of the universe based on that data?

a reply to: dragonridr

"No thong to expand into"
Is that like wearing a pair of grade 12 sexy underpants 3 kids and 10 years later?

My apologies, it just made me laugh.

originally posted by: pfishy
Does it specifically require Herculean pressure, or can it acheive conductivity when supercooled?

Everything but a vacuum has "conductivity" even if it's low, but if you mean superconductivity, for hydrogen that takes pressure.

And have we ever cooled pure hydrogen to a solid?

First done in 1899.

originally posted by: pfishy
a reply to: Arbitrageur

I have a question about the size of the universe and how it relates to a couple of other topics recently discussed.
Is the CMB a direct result of the energy released in the Big Bang/Bounce, trapped in the quark/gluon soup until reionization (approx. 380000 years later), or is it the result of some later interaction? For instance, could it be the result of the asymmetric matter antimatter destruction event?

We don't know enough about baryon asymmetry to explain why we ended up with matter instead of antimatter but still I think whatever happened in that respect is dated to before 380,000 years after the big bang. At about 379,000 years after the big bang is when neutral atoms formed, and when photons could travel longer distances, so that's when the CMB is dated. There were photons before that but they were interacting with the charged particles that existed prior to that.

If it is the result of either of these, is it reasonable to assume that it was originally in the extreme Gamma end of the spectrum?

No. While nothing is a perfect black body radiator, the CMB is pretty close with a current temperature of 2.7K, and it may have also been close to blackbody radiation profile at 380,000 years after the big bang, though it would have been much hotter then, maybe 3000K.

Lastly, if so, can we not use the resultant red shift we see today to calculate the approximate expansion of spacetime from then until now, and roughly extrapolate the size of the universe based on that data?

I don't see how that could be done. We correlate the redshift of distant galaxies to their approximate distances, so I can see why you'd ask this. However, the CMB isn't like a distant galaxy at a certain distance, it's everywhere. There's some at the distant galaxy and there's some nearby us.

Here's the correlation between redshift and LOS Comoving (type of distance measurement):
Distance measures (cosmology)


If you take the most distant object we've observed with redshift of 8.7, follow the 8.7 redshift up to the LOS comoving curve and you get a distance of 30 something billion light years distant, which is about right.

If you follow the CMB redshift z=1089 up to the LOS comoving curve you get something like 46 billion light years distant, which is consistent with our 46 billion light years comoving distance estimate for the radius of the observable universe, but redshift z=800 or redshift z=1600 would give about the same distance. Since doubling the redshift z from 800 to 1600 correlates to approximately zero change in distance, do you see why I say the redshift versus distance correlation is not useful in that range?

originally posted by: Arbitrageur
a reply to: KrzYma
You're in luck. Apparently when Goldhaber was 81 years old in 2005, he gave a presentation at the “50 Years of Antiprotons Anniversary Symposium” explaining how he did it 50 years earlier, so I'll let you read his explanation in his own words:

The Observation of Antiproton Annihilation by Gerson Goldhaber

Nice link. Thanks for sharing this.

a reply to: Arbitrageur

Your explanation makes perfect sense. Though I think I may have misstated my question slightly. It isn't necessarily red shift that I'm referring to, but the overall lengthening of the waveform from what it was originally to what it is now due to expansion. I know this is also a description of red shift, but since the CMB is universally pervasive, it isn't trying to measure distance. Merely the physical alteration of a given wavelength due to spacetime expanding the medium through which it's traveling. Though you did clarify that my assumption of the CMB originating an high frequency gamma isn't likely correct, so it's likely a moot point.

originally posted by: pfishy
a reply to: Arbitrageur

Your explanation makes perfect sense. Though I think I may have misstated my question slightly. It isn't necessarily red shift that I'm referring to, but the overall lengthening of the waveform from what it was originally to what it is now due to expansion. I know this is also a description of red shift, but since the CMB is universally pervasive, it isn't trying to measure distance. Merely the physical alteration of a given wavelength due to spacetime expanding the medium through which it's traveling. Though you did clarify that my assumption of the CMB originating an high frequency gamma isn't likely correct, so it's likely a moot point.

Well your right as the universe expands these wavelengths get longer. I guess the upper limit would be when it gets to the length of the universe strange thought huh.

a reply to: dragonridr
That is one hella low frequency.

originally posted by: Phage
a reply to: dragonridr
That is one hella low frequency.

Brings up something interesting though eventually entire civilizations wouldn't even see cmbr.

a reply to: dragonridr

Not without a hella wide antenna.
Now there is a basis for a science fiction story. A civilization too late on the scene. Sort of this in reverse:
www.amazon.com...

a reply to: dragonridr

I don't doubt that there are em frequencies propagating through the universe that we simply can't observe because we haven't bothered stringing an antenna out from Earth to L1. (Yeah, I know a space tether hasn't been successfully implemented yet either.)
But if these radically low frequencies could be interpreted, I wonder what information we could glean from them. Obviously not a wonderful data transfer speed, but the mechanism to produce these would be fascinating to learn about.

originally posted by: Arbitrageur

originally posted by: bottleslingguy
a reply to: Bedlam

"the spot's energy is isolated by the convective flows below" and you know that how?

I don't know it with 100% certainty, but there is evidence to suggest this explanation. One clue is to see solar prominences associated with sunspots. It's apparent the prominences result from a magnetic field and they don't seem to be created by magnetohydrodynamic activity above the sun's surface, thus these features must extend below the surface of the sun:

Our sun

So if you project those prominences below the surface you get something like this:

Obviously it's not possible to go inside the sun to make measurements but it is possible to observe the prominences, the related sunspots, and the granulation on the sun's surface related to convection cells, and then use these observations coupled with our knowledge of physics to model what's happening beneath the surface.

Studying the sun is an area of active research and new observations will lead us to fine-tune our models to better match observation, but I haven't heard of any observations suggesting the sun is powered by electricity instead of nuclear fusion, though as the photo of prominences above shows there are certainly electromagnetic effects observed. We have a fair idea of what creates these effects but still have some details to work out and I'm sure our knowledge about how the sun works will continue to improve in the coming decades.

.

What's wrong with this idea? www.youtube.com...