Density - Sixty Symbols

[tomaskvapil]

poor elephant

[lhrmeonom]

Will the density of water change if it is at different temperatures?

[pabloenis]

White dwarf? YOGSCAST!

[ArtypNk]

Oh Meghan.....

[DrNaturalPhenomena]

Thank you for the uploads "sixtysymbols", it is nice to see people spreading knowledge in a simple form, for everyone ready to learn and experience.

[HELLJUMP3R7]

Yeah it is Kg/m^3 not Kgm^2

[Brookskyar]

2:04 to 2:11 best :D

[adamjwal]

if we could figure out nuclear fusion and get to one on these neutron stars we could power the world untill the end of time with e=mc^2

[Aviatorsmith]

@adamjwal No.

[painxtreme]

@superdau I assume she would turn and fire chalk at you, inviting you to teach Density in today's class....it wont matter if you're right, never even act like you caught an Astrophysicist in error, especially first year. Between you and I, she could have said "meters cubed" or something else, to be correct, but the 2nd dimension keeps calling out to her.

[Eltron25]

wait, so a neutron star is more density than a black whole? i thought a black whole was the most density thing in the universe that even light can not escape

[TheGlenn9]

@Eltron25 yes a black hole is the most dense form of matter ,thats when an even bigger star collapses ,she just didnt mention it

[z0tx]

Saturn in a bathtub! She must have seen the Eyewitness series!

[visnevskiscom]

Stop filming interlaced! :)

[painxtreme]

@visnevskiscom decompress may be what you're hunting.

[visnevskiscom]

@painxtreme I mean - the video is converted from interlaced source without deinterlacing, making all sharp movements with horizontal stripes. I see no use to film interlaced for Youtube.

[Trouterr]

so when you dense something like a neutron star are the atoms staying the same size but are closer together? do scientists know how density works on those lvls? and will the neutron star begin to undense since there is no reason for it to be that dense? the gravity itself isnt making it that small right? so why doesn't it undense. (maybe uncompress is a better word.)

[Vejita12]

@Trouterr

The explanation is that gravity sqashes the atoms so that orbiting electrons are forced into a nucleus, the opposite charges of protons and electrons cancel each other out, thus the name, a neutron star. We have an idea of that kind of matter, its called a degenerate matter and there are a few types of it. It's gravity that holds it together, and we have no idea if a neutron stars "undense", but if they did by some strange phenomenon, it would take tens of billions of years.

[painxtreme]

@Trouterr decompress is the one you're looking for.

[VeryOxygen]

@kristijanadrian Well if I understood why I didn't understand something I would actually understand it...

[VeryOxygen]

@kristijanadrian I lost the meaning of your argument after you started discussing finding the perfect name of something tbh... And I think you've gone completely off topic with your probability analogy. However I just may not be able to follow your train of thoguht sorry. But I see what you mean about the renowned question 'what is "real"?'

[Sunderas]

@superdau duh...

[AntiProtonBoy]

Cute! Enough said. :D

[VeryOxygen]

In a sense does this video support the philosophical idea of atomisation, based on that atoms are more or less hollow inside and therefore, what we see and paramountly what we touch is not real, it is only how we perceive it, which, I suppose is based fundamentally on what we're taught growing up, such as the feel of shapes and household objects as infants?

[BenPsOhYeah]

I love that woman's accent and voice, sexy

[MarkArandjus]

2:57 OM

3:01 NOM

[runnybabbit12]

so what is the difference between a white dwarf and a neutron star?

[puncheex]

@runnybabbit12: White dwarf matter is called degenerate matter. In degenerate matter the electron shells have broken down, and what is left is a sort of ionic mush. There are a lot of attraction and repulsion spin forces so there is still considerable open space in degenerate matter, but not as much as normal matter.

Neutron star matter is called neutronium. It has been compressed so hard that the electrons are driven into the protons, producing neutrons. The matter is solid neutrons.

[puncheex]

... That is the final rest point of matter. If matter is compressed so far as to force neutronium to compress, the gravity of the neutronium cannot be countered by any known force; it collapses all the way to a zero dimension singularity, a black hole.

[runnybabbit12]

@puncheex so is a neutron star a singularity?

[puncheex]

@runnybabbit12: No. It is very dense, but it still has volume. A singularity, by definition, has no volume.  A neutron star is the last gasp of a material's internal strength holding back gravity; the black hole singularity happens when gravity wins that match.

[runnybabbit12]

so what is the difference between a white dwarf and a neutron star

[aeclipseguy1]

If a star was to collapse wouldn't Boyles gas law come into play? At like 1:28 ?

[puncheex]

@aeclipseguy1: To some extent it does - compression leads to increased temperature and decreased volume. But the effects are very non-linear, because the material is a plasma rather than a gas, and as a plasma there are a lot of other forces involved that keeps the gas from being "ideal". There's EM forces, various bonds, stickiness and raised viscosity, and so on. Finally, when gases condense into an object like a star, a lot of the heat has to do with potential energy release.

[xilin1983]

What is the density of a black hole? .... infinite??? XD

[puncheex]

@xilin1983: check.

[xilin1983]

@puncheex haha wow that's a crazy concept to grasp XD

I mean, the density is always scaling up in a black hole... but how can it be infinite? It always has more mass, but its not infinite right?

Do we say its infinite because of its singularity or because its impossible to measure it correctly due to its restless matter assimilation?

Thx for the reply, you seem to know a lot about this subject (I'm just a noob on the other hand XD)

[puncheex]

@xilin1983: Density is mass per volume. Mass is a constant, but in a black hole the gravity exceeds the ability to resist being crushed, so the crushing goes on and on until all the mass is crushed into a singularity - a zero dimensional point. Density is theoretically infinite, but of course no one has actually witnessed it, as this is hidden behind the event horizon. There are theoretical objections with this, as yet unresolved.

[NekuraCa]

One thing I've always wondered about white dwarf and neutron stars. If we could get a teaspoon of the material away from the object, would it stay in it's compressed state?

[pyropakman]

@NekuraCa : Great question!

[xilin1983]

@NekuraCa

I think not, simply because the immense amount of gravity needed to keep that in place would be lost (the neutron star itself), and it would be probably uncompressed somehow. IMO XD

[puncheex]

@NekuraCa: I think they would "evaporate" into regular matter. Free neutrons disintegrate with a half life of 15 minutes by beta decay, but they don't when bound. I don't know whether neutronium would be considered bound.

[CosmicRay137]

Is there any evidence of a neutron star using a change in quark (color or whatever you want to call it?)? I'd think with a neutron that would usually go lower energy by reverting back to proton's two up and one down so if they compress maybe go to the charm strange energy level? Also this Metallic hydrogen? They say you can't imagine it? I'd like to draw a picture!

[RoMMeL1337ak47]

i even had to look up how much a quadrillion is, im from sweden and there we use long scale so its always confusing to hear huge stuff like quadrillion witch in short scale is "only" 10^15 but in long scale is 10^24 so you almost never use it in swedish.

[Kowzorz]

The opposite of dense is sparse.

[Brookskyar]

yeah... should be kilograms per meter cubed

[blenderpanzi]

Why does neutron stars have magnetic fields when they are made of nothing but neutrons (no electrical charge)?

[chrisofnottingham]

6:10 220 million years  *o*

[ray123ification]

I come from Lun Density if thats of any use to anyone?

[frogiac]

She's pretty hot for youtube neutron star.

[xlrv1]

About "empty" - long ago I attended a lecture by John Archibald Wheeler in which he described a subatomic particle (don't ask, I was a history major) as "a bubble in the vacuum." So it's emptiness within emptiness. About Saturn - surely its density is not uniform; is there not a point where Saturn's core becomes solid (like Earth's) from the pressure?

[xlrv1]

Partial answer to my own question from Scientific American, May 2000, "Making Metallic Hydrogen", 84-90: "...Jupiter...is so massive that fluid hydrogen inside the gas giant is believed to be squeezed into metallic form." Saturn can't be that much lighter. Exo-geology revealed by exploring strata of old magazines!

[amnesiai]

how did we measure the density of a neutron star?

[calvinhobbesliker2]

We can measure mass by measuring its gravity and its volume by finding the radius and using the formula for the volume of a sphere.

[puncheex]

@amnesiai: Like black holes, we look at their gravitational effects on nearby stars, particularly in double star systems. If you can plot an orbit and assume a "normal" density for the other star, then you can compute the neutron star's density.

[HerrCaZini]

i heared form a dutch prof in astrophysics that its 6 hydrogen atoms per cubic meter

[puncheex]

@HerrCaZini: He apparently lives in a richer universe.

[bng44270]

At the risk of sounding completely uneducated, I have a question.

Since we've only been studying the finite attributes of the universe for the past 500 years at best and the life cycle of a start is a least 1 billion years, how is the life cycle of a star derived?

[Danukeru]

Very simply: we observe as many stars as possible. With billions of stars in only our galaxy alone, you can imagine how we can pretty much identify and categorise all the stages of a stars life.

[eltotoX]

I agree, except for the 'very simply' part.

[2882890]

This is fascinating stuff, thanks a million Nottingham uni for this information.

[lessofyou]

space is empty? what about dark matter & dark energy?

[ALAPINO]

The density quoted does not include the 'dark' portions.

[St00sh13]

They were talking about average density

[puncheex]

@lessofyou: It is unknown what they each ar at this point, so for the purposes of this video, they're ignored.

[kiwkee]

this one sizzled w/ great data

[Woad25]

Is it just me or is there *always* a police siren going off in these videos? :)

[Intskyste]

The university is opposite a hospital, so they are probably ambulances :)

[Woad25]

I suppose that would make sense :)

[Kargoneth]

I like how the video portion showing the neutron star displays gravitational lensing

[Acid113377]

don't wanna sound like a smartass, but I wouldn't cut the speaches of the two professors together, but show them one at a time. I got confused a few times and had to rewind =)

[asifyoucare41]

i remember wanting to take a basic astronomy class in college to get one of my science credits. someone told me that the astronomy class was too difficult for non-science majors. i think astronomy is accessible when it is explained well!! (like in these videos)

[desiredusername]

What is her accent? It sounds like "American living in the UK for a few years".

[Woad25]

She's Canadian living in the UK..she says Processes in a very Canadian way :)

[Tartrus1]

We say "processes" differently?

[Woad25]

Very much so :) Canadians make the O long whereas we Americans do away with the O and replace it with an "Ah" sound :)

[tiapon]

i love these videos but hate that guy at 1:28 cuz i mean WHY CANT HE SPEAK A LITTLE SLOWER? he's AlwAAYssS like this.

man!

[DeoMachina]

Aww don't be like that, he's just passionate about his field.

[RookieStudios]

shhH!! He's the best! he makes me so hyped up!

[puncheex]

@tiapon: Hey - don't feel like you can never watch it again after the first time.

[kongotech2]

5/5

[dhwanitchem]

Well Done!

[T1carus]

is there something on the ceiling at 1:22 ?

[2szymi]

yea, its number

[calvinhobbesliker2]

No, people point their eyes up when they're trying to remember something. The point them toward their brain.

[windowlicker1]

very good and entertaining as always.

keep them coming :)