How intelligent people before us were to discover such wonders, I am really humbled to learn these things.

2:15 This diagram is called H.R. or Hertzprung-Russell, which is useful to classify the stars upon their brightness, size, and heat, There is a common joke about the letters used to determinate which kind of star are we dealing with, our Sun, for instance, is a G2 class star, every letter is divided into 10 values, so, a G3 star is slightly different to our Sun, but, In University days, there was a mnemotechnic trick to remember those letters' order so they are O B A F G K M, which would stand for "Oh, Be A Fine Girl, Kiss Me..!

@RSClassicAngel

4 жыл бұрын

That's funny. I imagine they'll stop using that one soon.

@tori_gundo_

4 жыл бұрын

What if you are into guys, will that make it hard to remember 😜

@masterandservant8021

4 жыл бұрын

@@tori_gundo_ of course we do not...!

@horizonfilms3041

4 жыл бұрын

Thank you very much for this valuable piece of information 😍

@mobileoppressionpalace6728

4 жыл бұрын

Andrew Oh Beautiful African Fluid Gender Kind Muslim

Can you also make a video about how masses are calculated/measured in space?

@peasant8162

4 жыл бұрын

oh yes please

Feeling happy to be a member of this channel. i would love to support your hard work. This is simply the best space channel on youtube. In these holidays i hope you make more videos :)

much needed video thank you, and I can't tell how much i love your voice.

I never actually thought of this question.... Great vid

Very interesting! Thank you so much for this video. Loving your channel! Cheers.

You explained this with amazing detail that i can understand. Thank you.

An Astrum video on fridays makes an excellent start for the holidays.

I´m commenting here because it´s your newest video. I´m interested in Space since 3 years now, your videos are the best i have seen so far. You present the facts easy to understand for everyone, but also with great pictures and realy interesting graphs and comperisons. Great work.

I worked as an astronomer in a 100 year old program, measuring stellar parallax at the Leander McCormack Observatory in the mid 80's. Working with that beautiful Alvin Clark 26-1/4 instrument. Very interesting job. Photographing the target stars soon after sunset, or close to sunrise. We used glass plate film as it was dimensionally stable. After they were developed and dried, they went to the measuring room. Then much data entry.

I have learn't a lot with these's video's , they are very educational , thanks .

Happy Xmas Alex. What an amazing video

Excellent and informative upload, sir👍

Thanks for the video, would love to see more of these "how do they know" content

Thank you for making these videos...

your voice is soothing and calming thats why i watch u over others lol

Alex, your videos are literally one of the most well put together space videos on youtube, AND you upload so often! The visuals, the audio, your calm and collected voice, PLEASE never stop doing this!!!! By next year, you're gonna have so many subs its gonna be insane... Keep it up!

favourite space channel on youtube

@Ciech_mate

4 жыл бұрын

Agreed

@LunaticTheCat

4 жыл бұрын

He seems to make videos about every topic I would love to know about

@alexandermirdzveli3200

4 жыл бұрын

Agreed!

@dabu3

4 жыл бұрын

Mine too

@easley421

4 жыл бұрын

You guys need to check out John Micheal Godier. He has two channels. Event Horizon is the best because he brings on the smartest minds in space exploration and asks the questions we all want to know. His most recent video is a conversation with the WOW signal finder. Amazing.

Cepheid variable star changes in brightness depending on how bright it is. Lol love the channel, thank you for all the great enjoyable content.

This is the kind of video I hv been searching for 🙌🙏

I love how much your videos make me think. I've watched them all a few times each. I showed my wife this one but she didn't care for it 😂

@astrumspace

4 жыл бұрын

I'm guessing this may be more of a niche question haha

@Ciech_mate

4 жыл бұрын

@@astrumspace I love the fact that you replied to me lol, I feel like I'm a 14 year old girl and your bieber rn 😂😂

My method: Small stars: far enough Smaller stars: even farther out

@gt7984

4 жыл бұрын

accurate enough

@TheCbot88

4 жыл бұрын

GT 7 not really

@gt7984

4 жыл бұрын

@@TheCbot88 it was a joke

Thank you for that information.

Merry christmas to you and your and all your subscribers

@laurentstorchi290

4 жыл бұрын

Merry christmas to you Clive Five

I love this channel. Trying to incorporate some of these awesome production values, into my videos.

Awesome!!

Great background sounds

I have wondered, thanks

Sometimes I get tired of listening to space related videos, because of the vastness of it, its infinite size, the idea that the big bang creating the universe because of its expansion blah blah blah but I love Astrum as he explains it in simple words by mind can understand. Gosh it is so possible, there are others on other solar systems in our galaxy and other galaxies.

Great stuff as usual; very well explained with excellent graphics and editing. After such shameful brown-nosing I'd like to put in a request... any chance of doing a video on HD 140283, popularly known as the "Methuselah Star"? It's fascinating in itself and it does bear upon the science involved in measuring age/distance of stellar objects.

@astrumspace

4 жыл бұрын

Check this out kzread.info/dash/bejne/aqWVzLtxg8jNftI.html

@sumeriansumer1622

4 жыл бұрын

@@astrumspace , Please watch on the GLOBEBUSTERS KZread channel: US FE Court Case Withdrawn Citing it is Impossible to Prove Globe Earth!

@radeee87

4 жыл бұрын

@@sumeriansumer1622 You mean "Bob the 15 degrees per hour drift" and "Jeran the interesting"? =)

@libertyresearch-iu4fy

4 жыл бұрын

@@sumeriansumer1622 If you can explain how the solar analemma works, I might think you know something. Otherwise, forget it.

Alex you made my Christmas and Happy Christmas 2 U

What grade of improvement with the parallax method could we gain, if we would launch 2 probes to Neptune orbit (opposite to each other)?

Merry Christmas Alex!

thank you

With the rocket technology we've currently got, forget about ever trying to cover those vast distances in space. Excellent video.

You gave me the answer to a question I didn't know I had

108k views is an outrage. This video should have 100 million!

Thanks man

ASTRUM ADVICE NEEDED: today I had a think, I dont know if this is already a theory but could at least some terrestrial planets be objects that originated in the kyper belt and beyond and just got sucked into the centre of the solar system while the gas giants were forming? This would change a lot of things, I dont see a reason why it couldn't, what do you think?

If anybody wants an even more in-depth lesson on this should look up David Butler's "How Far Away Is It?" series here on KZread. I need to speed him up to at least 1.5x speed because he talks slow, but he makes such amazing educational videos.

Hey Make video about our nearest neighborhood star

What about measuring redshift and using Hubble's law ? I thought this is the main method for really far objects. However, after seeing video, it seems it depends on supernova method for calibrating Hubble's constant.

I couldn’t quite understand the meaning of this statement at 3:38: “A Cepheid Variable is a very special type of star that changes in brightness periodically depending how bright it is”. 1. Because it is referred to a star, does that mean “Cepheid Variable” a name of a star? 2. Can it be said an object “changes its brightness depending how bright it is”? Does it make sense? Wouldn’t that be tantamount to saying “So and so is a very special type of darkness that changes its darkness depending how dark it is”? Or, “So and so is a very special type angle that changes its angles depending how angular it is”?

@user-pk9qo1gd6r

4 жыл бұрын

Cepheid variables are a type of variable star (named after delta Cephei, the first reported such star) which have a relatively high frequency in their variation (on the order of months usually, but it can get as short as a few days or even hours: compare that to our Sun which has a cycle of about 11 years). The particularity of these stars is that their frequency is related to their absolute magnitude (which is what he meant by "changes its brightness depending on how bright it is" which I agree is not phrased very clearly), so by knowing such a star's pulse frequency you can figure out its absolute magnitude with good accuracy, and by comparing it to its observed apparent magnitude you can work out its distance. I studied cepheid variables as a school subject a while ago so don't hesitate if you have any questions, and yes I do agree that the wording was bad but I hope it makes sense to you now!

@danielbelayneh8823

4 жыл бұрын

@@user-pk9qo1gd6r Thank you so much for the absolutely perfect explanation! Yes, with your expert explanation, it now definitely made sense to me. Thanks a lot again; I really appreciate it. I’m also very grateful for your offer in encouraging me to ask if I have further questions. I now know where to look for when and if I have one. With great respect and appreciation!

@cjay2

4 жыл бұрын

Why don't you just look it up on Wikipedia? Take you 2 seconds.

Thanks

You show the main sequence stars diagram. But there are multiple sequences available. How do astronomers know, which to pick?

2 days ago I was discussing with someone about the distances , that they measure it, scientists or nasa says and we believe.... And today here it is., The video I wanted. Love from 🇮🇳❤️❤️INDIA. I WATCH UR EVERY VIDEO IN 1080P OR 4K . especially those highres ones. All the best

I'm glad scientists and mathematicians found a way to measure distances in light years.

@astrumspace

4 жыл бұрын

They prefer parsecs, LY are for us plebians in reality 😂

@kirbymarchbarcena

4 жыл бұрын

@@astrumspace Uh-oh, the Romulans are coming for ya!

Guys from asia! We will be able to witness an annular solar eclipse on 26th Dec (4"30 AM UTC 10 AM IST)! Looking forward to it!!

Thank you for this informative presentation. The idea is to use the best indicator of distance, thus minimizing the approximation. Of course, then there is also the spacetime relativity conundrum! 🤔😑

nice

thanks for very informative gift video in my birthday

@ali-k643

4 жыл бұрын

Happy Birthday dear.

KZread is not notifying me about your vids even tho I have the bell on

@69Solo

4 жыл бұрын

Maybe it's on silent mode? 😤

@schopenhauer5427

4 жыл бұрын

@@69Solo no, bc notifications from SciShow are working just fine

Thumbnail already gave the answer

That thumbnail. Brilliant.

in ancient times, there were some people trying to figure out how to find the distance to far away objects, a man named Pythagoras came along and said "try angles" who subsequently died in an attempt trying not to run the hypotenuse of a right triangle through a bean field. surely he must have known he and the men pursuing him would destroy someone's hard earned crop.

Makes me so depressed ill never be able to see other stars, world's and galaxies in real life 😔

@PookieQDB

4 жыл бұрын

Andy E, welcome to the club ☹️

@MrKroxan

4 жыл бұрын

A lot of time went to waste thanks to the religious people during the middle ages.

@RagdyAndy

4 жыл бұрын

@@MrKroxan yeah totally! A holes set us back years cos of their fairytales

@arc46789

4 жыл бұрын

@@MrKroxan that's such a primitive and uninformed view of history. Its precisely those people who enabled science.

@arc46789

4 жыл бұрын

You can see other stats by looking up.

You said the colour of a star (and so its place in the main sequence) tells us how bright it would be if it was nearby, and so we can then calculate, from its dimness, it's distance. But surely the SIZE of a star influences its relative brightness? Two stars of the same colour might have one twice as big as the other, and so twice as bright? Wouldn't that mean the distance calculation could be wrong by twice the number of miles etc I realise colour (and subsequent place on the main sequence) tells us SOME info re what possible size range a star may be, but surely there are some stars of colour X twice the size of similarly coloured ones? Am I missing something? Does anyone here know the answer?

@user-pk9qo1gd6r

2 жыл бұрын

In this case, brightness means the total amount of energy released by the star inependently of its size. By comparing that value to its observed brightness you can work out its distance, and only from then on infer its size.

yes

Doesn't the parallax method rely on the notion that the stars don't move relative to our sun? How do we know that the changed position of the star in the 2 observations is only a perceived shift and not partly an actual shift? Or is there another way to calculate the actual motion of stars relative to our son and correct for it when observing the perceived shift or something?

@user-pk9qo1gd6r

3 жыл бұрын

The actual motion of a star traces a corkscrew motion, which is a combination of parallax motion and proper motion (the translational motion of the star relative to the solar system). Separating the two is actually quite easy in practice. The only component of the star's motion that isn't known is the radial velocity (how fast it mvoes towards or away from the solar system), but this can be deduced through precise measurements of redshift in the star's spectrum.

How do we know the actual physical size of stars ?

It’s such a shame we were born too early to ever reach any of these things

@My_NameJeff

4 жыл бұрын

I personally think we'll never be able to teach any of those things no matter how advanced we get

@aguywithananimeprofile8950

4 жыл бұрын

Even at the speed of light ,those things are far beyond our reach

@dreamyrhodes

4 жыл бұрын

Unless we invent something like Warp drive or jump gates with wormholes, we will never even get close. And even if we could reach lightspeed, all the radiation in our universe would just burn our head off because due of doppler blueshift and bending of spacetime, the microwave backround radiation would become hard gamma radiation hitting us in a narrow cone from our front so we'd need huge lead plates shielding our ship from that high energetic radiation. So nope, we are quite locked on our little rock here. Maybe we can reach Mars but further away in any acceptable timeframe? nope.

@chrome9455

4 жыл бұрын

atleast you were born late enough so you can know that these places exist

@darth856

4 жыл бұрын

@@dreamyrhodes but if we could send unmanned space probes at near light speed to other star systems, that would be the next best thing at least

talking about parallax made me think ... what if we put a telescope in orbit around jupiter and measure parallax from there. it would be a long-term experiment 6 years (half of jupiter's year) plus the time it takes to build it and get it there. at 5 times earth's diameter, it means more accurate measurement of more stars, and maybe we can use the data to refine other distance methods.

Whilst I find space information endlessly interesting I can't help but think it's mostly pointless because of the massive distances involved. Unless we can invent or discover what is essentially space magic to break laws of physics we are in reality confined to this solar system. It's not like there isn't enough opportunity here anyway.

@andymouse

4 жыл бұрын

Sadly very true.

@rickpeters8204

4 жыл бұрын

You don't actually have to break physics, this is is what the proposed alcubierre drive does, it shrinks the fabric of space time in front of it while simultaneously expanding the fabric of space time behind it, so essentially you'd be in the middle 'never moving at greater speeds than light'.

@LordArioh

4 жыл бұрын

It's not pointless at all. By exploring other worlds we can better understand our world. And sometimes find answers to some cosmology questions. And ofc, our generation is just opening the doors for the next ones to come with more advanced technology. Leaving them as much information about where they can look forward to explore, what problems they have to overcome etc. Tho I see your frustration, as we will never be able to be there ourselves and as for 99.999999% of individuals not even leave our tiny planet in the next generation or so.

@tonywells6990

4 жыл бұрын

@@rickpeters8204 The Alcubierre drive does actually 'break physics' since you need magical negative mass to make it work and a magical handbrake to make it stop.

@jamiesaggers235

4 жыл бұрын

@@tonywells6990might seem magical to us now but I dare say modern computers and space ships would have been classified as mythical fantasy and invoking magic only a hundred years ago.

🤔 One question how sure are we of the Speed of light? I mean it's possible that outside our solar system light travels faster than c. It's also possible that it's slower. I mean when light enters the atmosphere it slows down when it enters glass it further slows down. We are not sure if our solar system os filed with an invisible fluid that we cannot detect yet that slows down light. So our light year measurements could be entirely wrong.

@eclipse369.

6 ай бұрын

light has no speed, same as sound has no speed whats actually being measured is the rate of propagation of the medium on earth for sound that would be the atmosphere reacting to the pressure changes your bones create when vibrating when you "speak" for light most call the medium the ether/aether, be like living in an endless ocean but not realizing it

Thanks for this vid. But what are we measuring? The distance to the visible light is not where the star is anymore.

@andymouse

4 жыл бұрын

yep

Simple answer in one word: Trigonometry.

So do think there will be a the expanse season 5

@1:30 How does this work if things aren't fixed? In the car scenario, a house & hill aren't moving, only the car. In space everything is whizzing around, so where the stars were 6 months ago is not where they are today. We're not even in the place.

@user-pk9qo1gd6r

4 жыл бұрын

You're right, stars show two types of movement: parallax (which is the amplitude of their circular motion, which gives away how far out the star is) and proper motion (which is how far the star moves across the sky, and corresponds to how fast the star is moving sideways relative to the solar system). There is also radial motion but this one is harder to detect. Most stars have negligible proper motion compared to their parallax, but some very near stars have very high proper motion and can be seen moving across the sky from year to year (Barnard's star is a great example). basically, stars move in circles that slightly change position year after year, giving a spring like motion across the sky, the study of which can give both the distance and the velocity relative to the solar system.

Can you explain lensing.....isn't this also a method of calculating distances?

@astrumspace

4 жыл бұрын

I'll add lensing to the list of potential future questions... It's a very interesting topic!

Your so pleasant to listen to, I always look forward to your uploads mate

The problem with measuring distant stars arises from the erroneous use of redshift due to doppler or and expanding universe idea. None of those redshift-expansion models give a coherent rate of expansion. This is mainly due to the fact that redshift has been shown by studies of refractive index, flux density, and GPS, to be due to flux density or back-emf, and not due to doppler. The light emitted is due to the flux density in the area where the vibration originates, and not due to doppler. Once we reconfigure these expansion models, and redshift based upon flux density and not doppler, especially for quasars, we will get a steady universe expansion rate of zero, and will get a better idea of the distances to these distant objects.

@jamiesaggers235

4 жыл бұрын

Did you actually watch the video?

@JoeDeglman

4 жыл бұрын

@@jamiesaggers235 I think you can deductively figure out that I have watched the video, based on the fact that I have pointed out that he is describing the erroneous redshift model, that mainstream claims they can use to determine the age and speed of a galaxy and quasar. Such determinations cannot be made. Halton Arp has shown such a model and expansion to be false. Yet the mainstream still uses that erroneous model. You can tell that I have watched the video, by the fact that I have described why the model he describes is wrong.

@jamiesaggers235

4 жыл бұрын

@@JoeDeglman there were numerous different methodologies used to measure different distances so it didn't rely on just redshifting. Even if you are correct and redshifting is alot less accurate than currently relied upon it doesn't alter any of the other measuring techniques. I am confused as to why you think the expansion rate of the universe should be zero.

1 light year should be called 1 never never year

planing on a trip? well send us a postcard when you get there. Oh, and watch out for the variations in the vacuum of space, it's not uniform you know. things may be closer than you think and the trip may be longer.

The vastness of space is quite incomprehensible, it’s so mind blowing

@damarisburrimccolgan8989

4 жыл бұрын

My brain just automatically read your comment in Jellal's voice^^

Would not the parallax give us different constellations then? In the beginning video showing closer objects moving faster than the farther objects. Closer objects where in different positions constantly to further objects. Never providing same picture. Where as we see the same constellations no matter what year and only where we are on earth. Thanks.

@user-pk9qo1gd6r

2 жыл бұрын

The yearly change to constellation is real, but the change is so small that you will never ever notice it with the naked eye: only precise enough telescopes can detect the change.

Woow

I wonder how bad future generations will see us when the real space exploration begins and what we consider to be reality now turns out to be a fairy tale, as well as the dragons that the ancients drew on their maps when they began to sail the seas.

The SWAG method is used for this

How is the parallax system possible if our sun is revolving around the center of our galaxy?

@scorcherbrimstone8480

4 жыл бұрын

1) literally every other star in the galaxy is also revolving around the center of the galaxy. 2) the sun takes about 230,000,000 years to complete a single orbit. 3) given the parallax method requires a 6-month wait, this means the sun would have completed ~0.0000002% of it's orbit relative to when the first observation was made. The changes in apparent position due to the star's movement through the galaxy is negligible at best in human timescales.

@davidallison9880

4 жыл бұрын

@@scorcherbrimstone8480 Thank you for the reply Scorcher. Do they not assume background stars remain stationary or perhaps more to the point , light from background stars remain stationary? When they do this measurement for one particular star, I was wondering if they get the same parallax measurement for that star, year after year, against the same background stars? I suspect they do. If the background stars don't change over time, would this not imply the light from background stars is slowly moving?

i lear to mecher is whit e O colombus sfeer drop , and disten teers an apecehet the butiy

Here trying to learn how to find distances of galaxies for class lab, Lab instructions very unclear and i'm supposed to use a ruler somehow

Everything has already happened out there ..perhaps it's already over...

I think inverse square law makes star light imposiblle to travel(see) over distances astronomers say they are traveling.. Wiki:/// an approximate threefold increase in distance results in an approximate ninefold decrease in intensity of radiation( /brightnes) so imagine how bright is a star that we can see from earth 100 milion Light years away if we look at it from 1 lihjt year away....I would say those brightneses are imposiblle...

@galvanaut7119

4 жыл бұрын

The brightness can never reach zero no matter how bright the origin is nor how far it travels. Try the math with any value of your choosing.

Hey Astrum i dont know if you are born in switzerland or moved to switzerland thats why i speak ine nglish right now: how do they know which star/planet it is in the sky directly? i mean they dont have a nametag on them ;D

@mr.zelice6924

4 жыл бұрын

@Q.E. D Ah ok, thank you for the answer

I wish in 2050 the measurement will be - it is 1 second to get to Alpha Centauri

Alex, where are you from.🙏🇦🇺👍

@sarfarazahmed2022

4 жыл бұрын

He is from Mars. For your information

@Retriever_YT

4 жыл бұрын

UK

@alextiganus8373

4 жыл бұрын

@@Retriever_YT me too

Salutations fellow physics fanatics!

But how do you get the diameter of the earth's orbit?

The greatest trick the universe ever played on intelligent beings was not being able to transverse it. My belief there is intelligent life out there but it's very difficult to impossible to master but there has to be few. Great video thanks!

@wanderingquestions7501

4 жыл бұрын

Alien A says, “Scheesh those humans are violent”. “And they are destroying their own planet!! Don’t they know they need their planet to survive”, Alien B replies. “All they produce is garbage and pollution”, adds Alien C. Alien A asks, “Why do they ignore the well being of their habitat”? “Recon reports there is nothing more important then money to the humans”, answered Alien B. Then the Galactic Alien Council surmised, “Then it is agreed. We will continue the quarantine of the human’s planet otherwise they’ll ruin the whole neighborhood. Maintain the information embargo and sanction all communications w/ Earth. Let the recon continue so we are ready to salvage the planet and other species”. Agreed”, they reply in unison..... Alien A asks,”What is money”?

@geemanbmw

4 жыл бұрын

@J LA my sentiments exactly.

@geemanbmw

4 жыл бұрын

@J LA agreed

According to no mans sky, you just need to buy to corresponding color warp drive to reach other stars. NASA just needs to follow this method. Yup yup

Long ruler 🤷🏻‍♂️🤪🥳

@NeuteredSmurfs

4 жыл бұрын

Let's do this 📏

I think the universe have no end. So there is infinity other lives in the universe.

3:41 wat

If you are lookin at something that's 1 billion light years away, how do you know there there,if it takes the lite ,1billion years to get to your eye.

@GregorShapiro

4 жыл бұрын

It most certainly IS NOT "THERE" it has it's own proper motion and has moved (as have we - the observers). It WAS in that DIRECTION a billion years ago and it WAS in that evolutionary state a billion years ago. Astronomers know this and everyone should revise their idea of "simultaneous" according to the einsteinian model.

@marks7386

4 жыл бұрын

Ye ,the lite would be spiraling, a different direction all togeather. If it ,and it does, take billions of years to get to our telescope eye

@marks7386

4 жыл бұрын

WHAT were looking at,,,,,,isn't even there

@GregorShapiro

4 жыл бұрын

@@marks7386 What 'lite'? What do you mean be 'spiralling'? or 'togeather'?...

How do we know those stars are standard candles? Because some dead guy said they were so we better do what he says.

@beta_cygni1950

4 жыл бұрын

You either didn't watch the video (this was explained) or you missed the point. Either way... whoops.

Parallax.. Not to be confused with Buffalax Girly mannnnnn...girly man

Your parallax numbers aren't correct. Hipparcos measured parallax out to about 200 parsecs. Gaia's reach is much further. It is obtaining measurements accuraye to 10% out to 30K ly. It's true though that earth based observations are limited to about 400 ly, primarily due to the unsteadiness of the atmosphere.

@astrumspace

4 жыл бұрын

Wow thanks for sharing that, I knew Gaia was impressive but didn't realise it was such a beast. It's probably worthy of its own video at some point

@pipertripp

4 жыл бұрын

@@astrumspace ,oh yeah. Gaia is amazing. You can even download the data yourself. There's a query language for getting just the info you want. Love the channel, BTW. Just needed to point out howmuch parallax measurements have improved. The key is getting above the atmosphere.

@astrumspace

4 жыл бұрын

@@pipertripp I am familiar with Gaia data as every so often I go on Zooniverse and their Planet 9 Hunter thingy. I find it pretty fun tbh, my wife can't see why haha

Why don't you SAY standard candle ?

Hello!I'm here! I have a lot of interest to study and make videos about space. But I can only study about space, but cannot make videos because I am 10 years old.