Follow our progress with this video playlist: bit.ly/MessierObjects

Many, many thanks to Brady Haran, Drs. Gray, Merrifeld Moriarty, Copeland and all the other freaking brilliant folks putting these videos together. I've been reading popular books on science for almost 5 decades now, but I have learned more in the last 5 years than I did in all the years previous, thanks to videos like this one. I didn't just learn facts about M10 from this video, I learned something about how to think about the position of any object in the sky, which is a permanent benefit to me. Freaking priceless. If any of youse guys ever wander in the direction of Montana/Yellowstone, the door is open and I'll even put beer in the fridge before you get here (I drink it straight from the pantry, thank you) Thanks again for these!

Thank you so much for not cutting off the video before the Spirograph finished a complete cycle! I was waiting in anticipation

What a wonderful teacher Dr. Gray is!

Dr. Gray, you are one of the people that make me proud to be a Canadian.

I think Dr. Gray's accent is slipping back toward "Canadian". As a Canadian, I support this.

Talk about a cliffhanger ending. Excited for part 2!

Always great to see Dr. Gray featured in a video. More please.

1:35 it should be ".. how different that orbit is from a circle" not an ellipse. Nice Work! I love that visual representation with the hair tie.

More Dr Gray please.

After playing KSP for 3 years and watched great Scott Manley video, I managed to understand all the thing things that is being talk about here XD

That pattern is so beautiful.

im flabergasted that Brady didn't know what a spirograph was!

I want to hear the end about the rosette nebula!

This video is amazing. I really love how the material is presented so comprehensibly.

This video ended so abruptly, I'm surprised there isn't an Extras video.

Part 2 coming soon i hope? I always enjoy Dr. Gray's videos.She's like the James Grime of DeepSkyVids..AKA my favorite presenter.

My jaw dropped to the floor after witnessing what the spirograph can do. All hail Spirograph!!!!!!

Where is the rest of this video? Too bad it stopped so abruptly!!

Back in 1967 the spirograph had about a 1 year as a fad toy, another as a "New and Improved"" version then slowly made it's way to the science toy department of most science museums. There was a short time when every invitation or school valentine had to have a little spirograph doodle in the corner. Since Kenner bought it in 2012 there has been attempt to market it using a stickum like adhesive material to replace the pins originally used to fix the rings.

We want more!

Since starting to play Kerbal Space Program this orbital talk is second nature to me.

Spirograph is now on Brady's Christmas wish list. Would make fun footage for HI videos.

@ModJamesRandall

8 жыл бұрын

+Eric Wasatonic Or perhaps Brady's personal channel, imagine watching Dr. Gray make that drawing in 3000 fps! :P

Dr. Meghan, This is such a wonderful explanation of orbits. A bit advanced for my very interested 8 year old Granddaughter, but her M.D. Mommy can break it down in their astronomy studies. Thank you Meghan, and the rest of the DSV crew for this wonderful series. :)

I loved my Spirograph, I played with it for hours making intricate and ever-changing drawings. We also had Tinker toys, Erector sets and the entire Encyclopedia set.

Thank you for not cutting the completion of that rosette. Else I would of had to go and draw my own

I learnt alot from this video, including the name of the spirograph, I never knew what it was called.

My spirograph broke after about 1 minute when I was a kid. Way cheaper plastic than hers. Check out the old commercials from back to in the day. Ah the memories. Lite bright was also a fave

Amazingly interesting!

Dr. Gray would make a perfect Ripley

This video ended strangely, is there a part 2?

Why did the video get cut off?

Can you get one of the professors to play or review kerbal space program PLEASE!!

SPIROGRAPH!! That was what I was thinking when I saw the illustration on the paper. I'm glad my uneducated instinct was right. Its so very rare that it is.

Brady, you have been so nice to us recently, making part 2 available immediately. Why not this time?

why the cut to credits early?

I love her Hearthstone (Blizzard card game) necklace.

Yeah NOW I know what those contracts in KSP want from me...

Yay Dr Meghan!

SPIROGRAPH! Squeee!!!!! Love that!

@Peteminator

8 жыл бұрын

+rtpoe I loved those as a kid, well. I still do, they are fantastic

Huh. And I always thought the fifth element was _luuuuvvvvvvvvv_

Great explanation!

More videos with Dr Meghan please!

Yay, Dr Meghan Gray!

Feel sad for Brady. No childhood is complete without a spirograph.

@DanielDogeanu

8 жыл бұрын

+rwired My childhood wasn't complete either. :(

@TheOtherNeutrino

8 жыл бұрын

+rwired I had a deprived childhood then. Little me would've been seriously ecstatic with one of those.

@jerrylong381

8 жыл бұрын

I really loved my Spirograph, and Then I got a spectrograph!! Much more 3D.

Never knew what those spirographs were called. I used to love them when I was younger. Well, no I know what to get my niece for Christmas, thanks! :)

I assume there is going to be a part 2? What happened?

@btearspell

8 жыл бұрын

+Willumpie I assume Brady saw a spirograph for the first time in his life resulting in him drawing shifting ellipses for the next few hours

So a comet loses a little mass every time it dips into the solar system and circles the sun. A globular cluster loses a little mass each time it passes thru the galaxy.

I’m guessing having a cluster slide by is bad news for any planets orbiting stars at the intersection point…

i was obsessed with my spirograph as a child, and it was the first thought I had seeing that graph.

People how play Kerbal Space Program, besides undergraduate physics students, should also know about Kepler's laws of orbital motion.

@Tfin

8 жыл бұрын

+Kwin van der Veen Add _Kerbal Engineer Redux_, and you'll be able to see all these numbers. Of course, they mostly only apply to your spacecraft, since all the planets and moons are in very simple fixed orbits, mostly on a single plane.

So at what point does M10 switch to the red pen during its orbit?

"where all the dark matter is"???? why would all the dark matter be outside the galactic disk where the globular clusters are moving around in? Wouldnt we expect dark matter to be distributed relatively uniformly (albeit it in clumps)?

Brady, how do you not know what a Spirograph is?!

Just when it is getting interesting, the video stops...

@garetclaborn1399

8 жыл бұрын

+Ronald de Rooij ikr i was expecting a link to more spirograph explanations D:

@ronaldderooij1774

8 жыл бұрын

+Garet Claborn I spent weeks of my youth with Spirograph... Memories... But that was not my point, haha.

Did you know that there's a direct correlation between the decline of Spirograph and the rise in gang activity? Think about it.

@feilox

8 жыл бұрын

+sirkowski what u smoking bro i want some. There's s direct correlation between rich people & gang activity.

@sirkowski

8 жыл бұрын

Fa Vang It's from The Simpsons.

@7Somerset

8 жыл бұрын

I will

@sirkowski

8 жыл бұрын

7Somerset No you won't.

Why stop at this point...... Nooooooo Brady!

Please do a video about NGC 404 the ghost of Mirach.

I want this toy so badly...

@TheGreatBlackBird

8 жыл бұрын

Cawfee Dawg Haha, thanks!

I could watch these for hours. I just did, actually lol

So was it just Brady that didn't have a Spirograph, or were they just never a thing in Australia?

So, why leave us hanging, what aspect of general relativity is creating this change. Or is it to difficult to explain?

@sprites

8 жыл бұрын

+barnectar According to wikipedia, the acceleration of Mercury's orbit can be explained by the physical curvature of space from the Sun. I can't explain the theory of relativity though so for that I point you to someone smarter. Try looking into "Two-body Problem"

@bizzee1

8 жыл бұрын

+barnectar I'm guessing that time dilation due to gravitational fields is the cause of the procession of perihelion in Mercury's orbit. A planet's distance from the Sun varies during its elliptical obit and time varies along with it (closer to the Sun time passes slower for the planet).

@UnstableVolt

8 жыл бұрын

+barnectar The tl;dr version is because gravity is not really a force, but a description of the geometry of space-time. Mercury orbits not because there is a gravitational force as such, but because it's following the shape of space. As Mercury 'rolls' through the curvature of this space, the curvature it encounters is not exactly even, so it (Mercury) is skewed slightly each time. Since Mercury is so close to the sun, the curvature of space-time is quite large and the effect is noticeable. If you're quite well versed in maths and want a more satisfactory answer, I highly recommend L. Susskind's General Relativity lectures which are available for free on KZread. Really interesting and informative, but you will need decent algebra and calculus to get through it.

Why are the Globular Clusters only in a halo around the galaxy? Something I've always wondered. Why not part of the galaxy?

@filippobonaventura8801

8 жыл бұрын

+NeonsStyle because they are very old. they were born before the galaxy developed its disk structure.

@NeonsStyleHD

8 жыл бұрын

I knew that much, but it doesn't explain why they have not become part of the galaxy.

8 жыл бұрын

+NeonsStyle Why would they?

@NeonsStyleHD

8 жыл бұрын

Because over the eons of collisions with other galaxies, they would eventually be mixed. However they always form a halo around galaxies. Why?

how do you establish a reference plane, or is it just arbitrary?

@EcceJack

8 жыл бұрын

+Majoofi There are some conventions depending on what you are talking about, e.g. in the Solar System it's the ecliptic, in the Galaxy it's the galactic plane, for observations of binary stars it's usually "the plane of the sky", actually (i.e. the plane perpendicular to the line of sight). But in principle it's totally arbitrary. And the same for where you're measuring the longitude of the ascending node from. (source: I've finished a Master's in Astrophysics two months ago, where I spent about two weeks trying to wrap my head around the orbital parameters, how they change as you change the reference frame, and how the final orbits look like. It can get very confusing very easily :P)

@eltyo340

8 жыл бұрын

+EcceJack Gratz! I'm sure the hard work paid off :D

yeah, a lot of us were neglected children without ever having such amazing toys. cute how surprised she was to hear that.

M10 is 80 light years in diameter. What point within the cluster they use to calculate it's orbit. Or, on the galactic scale, 80 l.y. is insignificant?

@spamboli

8 жыл бұрын

+Enke796 i'm inferring from Dr. Gray's comment at the 15 second mark, that it's measured from the center of mass of the cluster

@ryandean3162

8 жыл бұрын

+Enke796 On a galactic scale, 80 light years might as well be a pointlike object, but of course they likely measure from their respective centers of mass.

Very interesting

upload more videosss

hm...the video really ended at the worst moment... what are those effects of relativity that are the only suited explanation for the ever proceeding shift of Mercury's elliptical orbit? - I'd be thrilled to learn that... now I am dissatisfied, after I liked the video so much, up until that point :(

@UnstableVolt

8 жыл бұрын

+PyrrhoVonHyperborea The tl;dr version is because gravity is not really a force, but a description of the geometry of space-time. Mercury orbits not because there is a gravitational force as such, but because it's following the shape of space. As Mercury 'rolls' through the curvature of this space, the curvature it encounters is not exactly even, so it (Mercury) is skewed slightly each time. Since Mercury is so close to the sun, the curvature of space-time is quite large and the effect is noticeable. I guess the best visual picture would be a marble rolling around the inside of a cone, but the surface of the cone being slightly unevenly sloped, so the marble takes a slightly different path each time (creating a pattern over many, many 'orbits'). If you want a truly satisfactory answer, you need to study general relativity. L. Susskind has a great series of lectures right here on KZread.

@PyrrhoVonHyperborea

8 жыл бұрын

Is it even true? - I mean: that this can only be described in Einstein's model of relativity? In fact, I'd challenge that(though I'd still have loved to hear your explanation on this. It's awful that I cannot hear your opinion of that!); ... if considering, that there is more mass to the system of reference that is our solar system, like the other planets and that bit of extra material retained in asteroids and such, it actually cannot be expected that the orbit of a planet like mercury, esp. as it is so close to the sun, could be perfectly elliptical. The sun only provides a little over 98% (afaik) of the mass of our solar-system, and the mass Jupiter makes up, already is big enough, that the mutual centre of gravity of those two objects is outside the radius of the sun itself (for all other planets, the centre of gravity isn't the centre of the sun either, but none of them have a centre of gravity outside the sun) ... this means, that the sun constantly _wobbles_ because of that tiny tug all the other planets have on that frame of reference, therefore a small, close planet like Mercury has to reflect that in it's orbit (more than any other planet in the system); as, when it is about to complete an orbit around it's host star, the centre of gravity it i bound to, has actually shifted a tiny bit, in regards *both (!)* to itself (Mercury) *and* it's host (Sol), and so it's trajectory (and in return: it's orbit) changes with it! Or, to put it more simple: the model of orbits as it was being presented here, didn't take into account, that the centre of gravity of our solar system (and any other complicated orbital system just as well) and the centre of the sun(/the centre of it's host star/the centre of it's most massive, central object), are neither aligned, nor can they be described in two positional values (or 6?), as there is a frame of reference (and interaction) between each planet and the sun, that intermixes with each other frame constantly, which means a constant battle of forces, of more than 2 _parties_ (i) ... (which, in turn, leads us to "relativity", as a somewhat better approach to the problem, but not as the only way to explain this). Or yet again in other words: the most basic problem lies within the idea of (strict!) heliocentrism, as it was only a partial improvement over the archaic, clumsy geocentric model! The sun is the centre of our earths frame of reference only to certain, relative degree. - to make it the centre of our frame of reference (i.e. to make it our frame of reference, as if it, itself, could not be effected in return (by all the other planets)) is off for about -1%- a very tiny percentage; thus, not even earth is following a perfectly elliptical path around it's "host star". The implications this has for climate-change and such could be interesting! (note: I am anything but a climate-change denier, so don't get the wrong idea here!) Again, this leaves us with relativity as a better approach, but not the only way of explaining this! - in the end, relativity is a model just as well as the force-concept was, that Newton provided us with! - even if it may be a better upgrade than the geocentric - > heliocentric advancement! - - - (i) And even if ... *even if* there was one sun and one planet only, all alone in a universe of their own, the planet would still exercise a tug to it's host in return, which would shift the elliptical orbit; though, in that scenario, the frame of reference (the frame of observation) is ambivalent to that, as relativity denies a hierarchy of direction (and thus position) so the wobble would mean squat to any observer in that universe (unless he becomes a planet of his own, and interferes with the balance he observes)

@PyrrhoVonHyperborea

8 жыл бұрын

+Mathew Cornelius Funny, that you - of all people - would say that, before I could make the addendum underneath ... esp. since you just copied exactly that thingy you just posted, from another answer (towards +barnectar) you gave further down below, an answer I had already criticized before making this stand-alone comment - as it lead me to make this decision post it as such...! I gotta wonder, if you didn't recognize that criticism, or if it's ghosted, because I edited it too many times / because it is too lengthy...

@PyrrhoVonHyperborea

8 жыл бұрын

*this decision, to post it as such

@UnstableVolt

8 жыл бұрын

The forces exerted by celestial bodies other than the sun are very minor. Far too little to effect Mercury's orbit by the amount observed. It also makes no sense under a Newtonian gravitational mode that these disturbances should give arise to an orbit like Mercury's is observed to be. I think since the time of Laplace (not 100% on that date) that people (chiefly Laplace?) had already calculated using perturbation theory that the effects of the solar system planets on each other was rather small and tended to almost cancel out over time. Thus, the inexplicable mystery of Mercury's orbit. It should also be said that the evidence for general relativity is overwhelming and that Mercury's orbit problem, though providing early evidence to Einstein that his theory was right, is a pretty minor piece of evidence in the great scheme of things and indeed, was deemed insufficient on its own to be proof of the theory. On climate change and orbits: The angle that sunlight passes through the atmosphere makes a much larger difference than the orbital difference. For instance, where I am living, our summer falls when we are almost at our furthest point from the sun.

How do we know what the milky way looks like from "above"... I've seen images of this, are they just simulations or interpretations?

@Hirobian

8 жыл бұрын

+gibbetify They are all pretty much interpretations, whether they are artistic or mathematically calculated and simulated. Even if we were to put all the information we have collected about space ( stars, position, etc.) we are still missing massive regions due to the galaxy itself being in the way (so we cannot see behind it from our position) and we have to extrapolate and guess. However, so far, our astronomers have determined in the 1990s that our galaxy is supposed to be a spiral barred galaxy (type Sbc). So even if we cannot see it from far a way, we can guess what it is supposed to look like, within a margin of error.

@gibbetify

8 жыл бұрын

+Hirobian thanks for that detailed and informative response! Everyone uses those images like it's matter of fact...

@gibbetify

8 жыл бұрын

Yea that would be fantastic!

@Hirobian

8 жыл бұрын

Seán O'Nilbud What do you mean by that?

"It's complicated "?

Obeys rosette nebula. What?

@dopplerduck

7 жыл бұрын

The write-up says: Correction: "Rosette orbit" not "rosette nebula"

so i've been doing astronomy since elementary with that toy? haha

1:40 ... How different is that orbit from a circle ....

WHATTT !! How was it obvious to Brady?

😎awesome!!!!!

Pretty easy if you played KSP

She schooled you Brady on the Spirograph :D

To me the Spirograph looks more interesting than M10.

Imagine of you took everything in space, and made it all disappear, so nothing of any mass existed. Then you placed a small pebble in this empty space, and another a light year away from it. Would gravity ensure that the pebbles would eventually enter in to an orbit around each other? Or would the gravitational attraction between the pebbles be so small that they would never meet up?

@oltner92

8 жыл бұрын

+Celtic Saint Disclaimer: Not an astrophysicist talking. Knowing the mass of each pebble and the distance they are apart with the law of gravity and the resulting motion equation you would get a finite amount of time until they meet. In cryptology the phrase "longer than the universe will be around" is quite common. Without having done the math for this problem I am pretty sure that it falls in that category. If you want to consider the expansion of space you have a problem since you just removed all the mass in the universe and we don't know the value of the cosmological constant (more: watch?v=nJsFsjSWYx0)

@aarond0623

8 жыл бұрын

+Andrea Tuccillo IDK if the OP meant for the pebbles to be stationary, but if they are not stationary, it would be very, very easy for one to reach escape velocity. If the pebbles are each 5 g, then the escape velocity for them would be something on the order of 10^-15 m/s, meaning that an elliptical orbit would be very unstable and easily disturbed. Any movement at all is likely to make the pebbles never meet.

@Groaznic

8 жыл бұрын

+Celtic Saint The premise is false -- if you ONLY have 2 objects, they will approach on straight trajectories and will meet and crash somewhere in between. There won't be any orbit or curved trajectory without a 3rd party around, or without initial speed.

@GreyFang9

8 жыл бұрын

+Celtic Saint Speaking from a point of limited knowledge, I was taught that everything with mass has gravity. In your hypothetical model, in the complete absence of another source of gravity (or indeed any other force at all) to alter the pebbles, they will invariably draw straight towards each other and collide.--no matter how long it takes. I'm guessing that the collision would be quite impressive since each pebble will have been accelerating for 2.9 trillion miles.

I want a spirograph

@grieske

8 жыл бұрын

+hadhad129 Download inkscape, and use the spirograph plugin (it shows up in the extensions menu). You're welcome.

so does the milky way orbit anything?

@cawfeedawg

8 жыл бұрын

+PMW3 I believe it is gravitationaly bound to the local group of galaxies which in turn orbit around a much larger group of galaxies.. but i'm nobody so check my facts because I can't be arsed.

@TFZoia

8 жыл бұрын

+Cawfee Dawg Pretty much it in basic terms, check CrashCourse's video about galaxies, part 2 I think, they cover the part about local group and galaxy clusters.

@ExperienceCounts2

8 жыл бұрын

+PMW3 According to the "news" this morning, the center of the universe is still Donald Trump. With an ego that massive and a inter-ear vacuum that hard it's natural focal point for the universe.It also explains where the septic tank pumping trucks go when they're full, but I'll leave that for Mr. Haran to document in his BigSeptic video series...

I need a spyrograph in my life

Goodstuff

Brady never had a spirograph? Gutted.

@Tfin

8 жыл бұрын

+Badatstuff Yeah. Mine was an earlier model. I never had that 3-ring part.

But what happened with mercury?

@ExperienceCounts2

8 жыл бұрын

+John Curran en.wikipedia.org/wiki/Tests_of_general_relativity#Perihelion_precession_of_Mercury

@TheFilbert13

8 жыл бұрын

+John Curran It is just so close to the sun that the elliptical orbit isn't very exaggerated.

I want that toy!

Thanks now I can edit my kerbal space program save file =D

This is easy for KSP players.

@timothyma7298

8 жыл бұрын

yeah hahahaha

kerbal space program taught me that, games can theach too!!

@rafaelalexie2417

8 жыл бұрын

+Marco aurelio Guerra Same here :)

I guess we know why it called the "ARGUMENT of Periapsis".

@kwanarchive

8 жыл бұрын

+Jerry Long Well, in programming languages, a variable of a function is supplied by arguments.

@jerrylong381

8 жыл бұрын

Thank you, I was being a bit of a smart, but I did find your video very interesting. I'm interested in astronomy and in the process of building a 12" Dobson telescope. At age 54

and elektrons orbit nuclei

@EvaVictoria1989

8 жыл бұрын

+Peter Timowreef Not in the same manner as things orbit each other in space. The planetary orbit model of the nucleus and electrons is no longer considered accurate : )

@manishy1

8 жыл бұрын

+Eva Upfold Aaaand really hasn't been since the 20th century :P Bohr's model is a lovely thing, but Heisenberg's is so much more pretty :3

@petertimowreef9085

8 жыл бұрын

***** Woah thanks Eva! For a minute there I thought Jupiter and an elektron were totally comparable.

@PetraKann

8 жыл бұрын

+Peter Timowreef in Quantum Physics things get a little bit hazy and fuzzy.

#scrunchiescience

does our galaxy generate it's own magnetic field?

@ronaldderooij1774

8 жыл бұрын

+Blake MacEwan Interesting question, but I am almost certain it does not. Galaxies are 99.99999% empty space.

@ddegn

5 жыл бұрын

I just typed the following into Google: *Does the Milky Way have a magnetic field?* Yes, out galaxy has a magnetic field. There is lots of other interesting stuff to be found on the subject.

@deepskyvideo the definition of eccentricity is wrong, it measure how far it is from being a circle, not how different it is from the ellipse.

@lcbp2009

8 жыл бұрын

Floris Groothof Nah it doesn't, ellipse has an eccentricity between 1 and 0, so if eccentricity measure how far it's from an ellipse then what would 0.5 e means? It's an ellipse, but 0.75 is also an ellipse, the number change but the object did not get further from being an ellipse. That's why the definition is how much further from being a circle because all circle has the same eccentricity which is 0.

@florisgroothof8617

8 жыл бұрын

Ah, I get it. Sorry, you're right.

She's pretty

No spirograph.. brother you missed out

Got 2 luv the math

Isn't the semi-major axis half the major axis?

Australia not having Spirographs is a perfect example of its well-established cultural bankruptcy.