The Ultimate Guide to Determining Star Distances: Methods Unveiled

Stellar parallax is a method, using basic trigonometry, to determine the distance of stars within our galaxy. Using concrete and visual examples, I explain the methodology, why distance are defined in parsecs, and the limitation of the technique.
Thanks to Brett Atkins for the drone footage.
Thanks to Prof Geraint Lewis (University of Sydney) and Dr Luke Barnes (Western Sydney University) for their feedback.
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Пікірлер: 64

  • @dextersjab
    @dextersjab10 ай бұрын

    Clearest explanation of parallax and parsecs that I've found to date!

  • @ANDeoband
    @ANDeoband2 жыл бұрын

    I am a Physics teacher from Pakistan. I am genuinely inspired by you, owing to your extremely practical explanations. Unfortunately, I teach online. Had this not been the case, I would've taught my students the same way as you do.

  • @ldu97177
    @ldu971777 ай бұрын

    Can someone explain clearly how the parallax angle (p) is derived purely from the distance of displacement of the star against the faraway stars? If all I know if the distance of the earth to the sun, and the distance the star has seemingly moved against the background, how is that distance translated to the parallax angle? All that is said in the video is that after we measure the amount the star has moved against the background after 6 months, we know the angle. How do we determine the angle if all we see is a distance of displacement? We can’t see angles as such.

  • @theodoresweger4948
    @theodoresweger49485 ай бұрын

    Very minor, you ref to approximate and used the symbol for exact. very well done appreciate your work Thanks.

  • @bugpie9437
    @bugpie94372 жыл бұрын

    Amazing video. Helped me make sense of my college lecture. Thanks Paul!

  • @marquezedwards3108
    @marquezedwards31083 жыл бұрын

    Great explanation of parallax I’m 13 and I’m studying astronomy a lot and this is one of the last things I need to know and you simplified to make it less complex

  • @PhysicsHigh

    @PhysicsHigh

    3 жыл бұрын

    Great stuff.

  • @Abbu724
    @Abbu7242 жыл бұрын

    Awesome, outstanding, Marvelous, STUPENDOUS Explanation!!!

  • @PhysicsHigh

    @PhysicsHigh

    2 жыл бұрын

    Thanks

  • @globalification
    @globalification Жыл бұрын

    For the past 1 year I was trying to figure out the parallax method. Only after watching your video I am satisfied that I really understood. Thanks a lot. Very simple and detailed explanation. Could you please share the link of your video for other method? ( luminasity)

  • @DreaScarlett
    @DreaScarlett Жыл бұрын

    Well done lecture. You made it interesting.

  • @marisaelenenadiejamusiccom3974
    @marisaelenenadiejamusiccom39742 жыл бұрын

    In studying the subject I think it’s so much fun...Thank you for this video!

  • @aliahammedshawon9152
    @aliahammedshawon915211 ай бұрын

    Such an awesome explanation!

  • @gothicbump
    @gothicbump2 жыл бұрын

    Best video on this topic on KZread This detailed explanation is what I needed

  • @PhysicsHigh

    @PhysicsHigh

    2 жыл бұрын

    Thanks

  • @joserobertopacheco298
    @joserobertopacheco298 Жыл бұрын

    Amazing explanation!

  • @theodoresweger4948
    @theodoresweger494829 күн бұрын

    if I got this correct 50000 parsec would be 160 thousand light years that to me seems incredible. Thanks so much for the information.

  • @turquoisejpg5671
    @turquoisejpg56712 жыл бұрын

    Great video and explanations

  • @PhysicsHigh

    @PhysicsHigh

    2 жыл бұрын

    Thanks

  • @lawrencelee8995
    @lawrencelee89953 жыл бұрын

    What about the Sun’s Motion around the Galactic centre? While the Earth revolves half a circle around the Sun, the Sun itself has moved with respect to the galactic centre. If our target of observation is not moving at the same speed as our Sun so that any motion relative to the background stars are due to the Earth’s motion around the Sun, then the parallax measured will not correspond to a baseline of 2 AU, but 2 AU + the distance moved by the Sun instead. This problem has puzzled me for quite some time and I have no idea how to get it solved... Does this means that the method of parallax is applicable only to those stars moving in the same spiral arm as our Sun?

  • @matyaskassay4346

    @matyaskassay4346

    2 жыл бұрын

    I assume the distance the Sun and other stars move compared to each other during half a year is negligible. Note that it takes around 250 million years for the Sun to make a full circle around the galaxy.

  • @kevron01
    @kevron01 Жыл бұрын

    how do u measure the angle?!!?!?

  • @Ptoki1
    @Ptoki1 Жыл бұрын

    8:53 how do you measure that angle though

  • @daniels4338
    @daniels4338 Жыл бұрын

    We use parallax to determine that stars are extremely far away. To measure the parallax and determine the distance, we have to use as large of a baseline as possible because the stars are extremely far away..

  • @Last.Multiverse
    @Last.Multiverse Жыл бұрын

    Conclusion of the video: Great knowledge= Great Math

  • @mykytashvets8730
    @mykytashvets87309 ай бұрын

    How is it done to make the perdincular of the baseline to exactly go toward the star you want to measure the distance to? Do you measure the angle everyday for 365 days and then choose the pair of angles that are 6 months apart and have the same value?

  • @user-zd3vf5cp8z
    @user-zd3vf5cp8z3 жыл бұрын

    how do you know how much angle shifted by just viewing the star shifting...

  • @matyaskassay4346

    @matyaskassay4346

    2 жыл бұрын

    We measure apparent distances on the sky with grades. A full circle on the sky is 360°.

  • @arunkumartm137

    @arunkumartm137

    2 жыл бұрын

    Same doubt

  • @stephaniemcguire
    @stephaniemcguire4 ай бұрын

    How did you get 41.4 for the one side?

  • @RM-lu1kx
    @RM-lu1kx Жыл бұрын

    So we get a triangle with a base of 0,000316 Lightyear and a length of about 4,4 Lightyear, and that is for the nearest star. The shifting should be really really small right? And we have to assume stars are not moving. I cannot get my head around it.

  • @thaburninator0904
    @thaburninator0904 Жыл бұрын

    If we use this baseline measurement to check the distance of stars, how do we know our baseline measurement is good? Isn't measuring the distance to the sun difficult to do accurately, and if that baseline is off, would it result in...rough measurements? My brain is having a hard time with this one.

  • @PhysicsHigh

    @PhysicsHigh

    Жыл бұрын

    The diameter measurement is more than accurate enough for measurement. It’s approximately 300 million km. The uncertainty you talk of is minuscule at theses scales.

  • @profeluisegarcia
    @profeluisegarcia3 жыл бұрын

    The important point to be explained is HOW the small angle is measured

  • @matyaskassay4346

    @matyaskassay4346

    2 жыл бұрын

    you mean the parallax angle? I guess they just have to measure how much the star has moved compared to it's background stars. A full circle on the sky would be equal with 360°.

  • @goldeer7129

    @goldeer7129

    2 жыл бұрын

    I'm still trying to figure that out. I've made quite some research and the way the parallax method works is quite clear, but I still don't really grasp HOW we actually get the ANGLE. (Also the star is should not be making a right triangle as there's no reason to think it's exactly at the middle...)

  • @Ptoki1

    @Ptoki1

    Жыл бұрын

    did any of you figure it out yet?

  • @wailani3263
    @wailani32635 ай бұрын

    OOPS! My bad ! Diameter of earth's orbit, not of the earth. Of course earth's orbit is elliptical and the earth's position is not at the center of the ellipse, but in common parlance the radius is 93 million miles give or take ... because for a 1/2 of a base line, considering the change of position of the solar system in 6 months, is 2,2 trillion miles .. that makes the earth orbit diameter only 4 % of what the base line should be should actually be.. i guess making the star 96% farther from our solar system.

  • @realistic.optimist
    @realistic.optimist Жыл бұрын

    Try decaf

  • @brandaccount2178
    @brandaccount21783 ай бұрын

    How to find the angle as 1 parsec

  • @PhysicsHigh

    @PhysicsHigh

    3 ай бұрын

    Distance is 1 parsec when the angle variation (parallax) is 1 second (which is 1/3600 of a degree )

  • @lioncross9471
    @lioncross9471 Жыл бұрын

    Parallax you say? ....in brightest day ....

  • @bestytubeplaylists
    @bestytubeplaylists7 ай бұрын

    0:06 If you you knew what I know about them, 😒 you wouldn't want to even look at them.

  • @czealtamahawk1228
    @czealtamahawk12283 ай бұрын

    So how far is the sun from the moon? And....how big is the sun and the moon?

  • @wailani3263
    @wailani32635 ай бұрын

    BUT! You are going by earth's diameter. Have you forgotten that our solar system has travelled @ 500,000 mile per hour for 4380 hours(6 months)!!! ... So, earth's position in relation to that star has changed by 2 200 000 000 miles (forget the earth's diameter!) Whoa! Put that in your parallax and smoke it ... that star is not so very far away!!!

  • @klancyklancy7961
    @klancyklancy7961 Жыл бұрын

    This all wrong. How can you use a simply way to measure. The formula doesn't take into account how light travel through space it only takes into account how light travels through air. Also, it doesn't take into account how gravity bends light. It doesn't take into account the space time that is bending around the sun and earth. It doesn't take into account the temperature of space and how light travels through it. It doesn't take into account that after a certain point parallel lines are no longer parallel. It doesn't take into account the movement of any heavenly body or the rotation of the earth. This formula uses currency math (math used inside earths closed system, used for counting money, used to find area for square, doesn't take into account any force being imposed, all parallel lines are always parallel), it doesn't use language math (math which includes all forces being imposed, parallel are only parallel for a certain distance as long as no force is being imposed). In other words, you can't measure something like that using this equation because it doesn't take into effect any forces being imposed on the light that is traveling.

  • @klancyklancy7961

    @klancyklancy7961

    Жыл бұрын

    I just cant believe how you can past this as right.

  • @klancyklancy7961

    @klancyklancy7961

    Жыл бұрын

    Where is the speed of light traveling from the sun to the earth and the earth rotation in this formula D = (d/l)*L? Where is any of the forces being apply to the light of the stars we are looking at in this formula D = (d/l)*L? WHERE? WHERE? WHERE? WHERE?

  • @hokage774
    @hokage7743 жыл бұрын

    Without knowing trigonometry, you are wasting time here

  • @Elo-hv3fw

    @Elo-hv3fw

    3 жыл бұрын

    No. Without trigonometry, YOU are wasting time here.

  • @hokage774

    @hokage774

    3 жыл бұрын

    @@Elo-hv3fw how did you guessed that i have not studied trigonometry? 😂

  • @duckman12569
    @duckman125693 жыл бұрын

    I bet you have a very nice telescope

  • @PhysicsHigh

    @PhysicsHigh

    3 жыл бұрын

    Ha. Actually I don’t but wish for one. The opening shot was just done with dSLR and wide angle lens as time lapse.

  • @duckman12569

    @duckman12569

    3 жыл бұрын

    Could always go with a quality set of binocs, just sayin

  • @vincentmcardell8183
    @vincentmcardell8183 Жыл бұрын

    All your calculations are based on a stated distance from the sun to the earth but you don't tell us how we can know that this stated distance is correct. What if I had no knowledge of any distances to any of the celestial bodies? Tell me how I can calculate distances to the sun, moon, and stars beginning without any claims of known distances to them.

  • @PhysicsHigh

    @PhysicsHigh

    Жыл бұрын

    The distance to sun has been do a for a few centuries curious.astro.cornell.edu/about-us/41-our-solar-system/the-earth/orbit/87-how-do-you-measure-the-distance-between-earth-and-the-sun-intermediate

  • @vincentmcardell8183

    @vincentmcardell8183

    Жыл бұрын

    @@PhysicsHigh I am asking you tell us how we can measure the distance to the sun, not how we can take it on faith that others have it right.

  • @vincentmcardell8183

    @vincentmcardell8183

    Жыл бұрын

    @@PhysicsHigh You have measured that distance yourself, correct? You are not just taking it on faith that what you have been told is true, right?

  • @vincentmcardell8183

    @vincentmcardell8183

    Жыл бұрын

    All I am asking is that you show us how to begin from a point of having no measurements at all, and then taking our own measurements of what we see in the sky, before we get to the point of doing mathematical calculations. Can you do that?

  • @rap1df1r3

    @rap1df1r3

    Жыл бұрын

    @@vincentmcardell8183 I wouldn't expect any meaningful answer to that question, seeing how the distance has never actually been measured, only assumed based on a mathematical model.

  • @dickcastle
    @dickcastle2 жыл бұрын

    Pay attention in math class kids