A Level Physics Revision: All of Cosmology | Parallax, parsecs, Doppler, CMBR, Hubble's Law

Поділитися
Вставка
  • Опубліковано 20 гру 2024

КОМЕНТАРІ • 69

  • @zhelyo_physics
    @zhelyo_physics  2 роки тому +12

    Hi guys! I have also filmed some past paper questions practice. Hopefully it is helpful! : )
    ua-cam.com/video/nuTdbYL8X0M/v-deo.html

    • @zoyajalal6433
      @zoyajalal6433 2 роки тому

      You have no idea how helpful your videos are....I'm so grateful....your way of explaining and covering each and every point is Just Amazing. Thank you so much. I've got my CIE A2 Physics tomorrow.

  • @mdarmanhossain2153
    @mdarmanhossain2153 2 роки тому +57

    I really feel like God sent you as an angel to help me with my exam 😭. Thank you so much!

  • @kxaie
    @kxaie 2 роки тому +21

    Fantastic video, helped alot, only thing is at the end with the section about dark matter, that section replayed.

    • @zhelyo_physics
      @zhelyo_physics  2 роки тому +5

      Glad you enjoyed it. Thanks for letting me know, will fix that 😀

  • @Vigilant69
    @Vigilant69 2 роки тому +10

    I'm super glad that you exist, love your explanation dear sir!

  • @DRMAOMMAIZEINNG
    @DRMAOMMAIZEINNG 7 місяців тому +3

    awesome video, really helped for my upcoming exams, which is starting with paper 1. One thing to point out is that you seem to accidently repeat the dark matter section twice, not sure if this was intentional or not.

  • @gjeraldh2989
    @gjeraldh2989 2 роки тому +6

    Thank you, it is helpful to revise after my lessons.

  • @Zecos
    @Zecos 8 місяців тому +4

    wow studying the big bang has made my belief in religion stronger!!!! it sounds soo stupid and even science cant explain the universe!! tysm physics ilysm :)

  • @enurih3543
    @enurih3543 Рік тому +1

    Thank you for this video! This was incredibly helpful!

  • @gautammorkhandikar394
    @gautammorkhandikar394 Рік тому +2

    do we need to know about the doppler effect or just the equation for doppler shift in OCR? Also are we expected to know red shift and blue shift?

    • @zhelyo_physics
      @zhelyo_physics  Рік тому +1

      the equation is given in the formula booklet, and you need to know how to use it, together with red shift/blue shift. Good luck revising!

    • @gautammorkhandikar394
      @gautammorkhandikar394 Рік тому

      @@zhelyo_physics thank you!

  • @nonviablegerm71
    @nonviablegerm71 7 місяців тому

    Absolute legend, thanks so much for the video!

  • @nadiaaaj6618
    @nadiaaaj6618 2 роки тому +1

    awesome. thank you so much. hope this helps me on on test next week

  • @bigboyali2312
    @bigboyali2312 6 місяців тому

    quick question! If hubble's constant a... constant, and if the age of the universe is 1 divided by hubble's constant does that mean the age of the universe is constant? frozen in time? or is hubble's constant isnt really a constant and just changes with time? in that case what would a hubble's constant against time graph look like?

    • @zhelyo_physics
      @zhelyo_physics  6 місяців тому

      such a great question!! Hubble's constant is not actually a constant....in time : ) Actually it is a constant in space meaning that it is the same at every location in the universe (so far as we can tell), but it's value is actually changing with time. Hope this helps, great question!

  • @neuropcs5879
    @neuropcs5879 2 роки тому +1

    Incredibly helpful! Thank you :)

  • @yana1067
    @yana1067 2 роки тому +2

    hi hi, a quick question that i kinda need clarifying, if we got asked a question on the big bang, would we need to know the time stamps? for example it was 380000 years after the big bang when the universe started to cool down, would the time have to be stated?

    • @zhelyo_physics
      @zhelyo_physics  2 роки тому +4

      I am gonna go with no. The spec doesn't explicitly state that you need to know the times, but you need to know the sequence.

    • @yana1067
      @yana1067 2 роки тому

      @@zhelyo_physics ohh okay thank you!

  • @kausarlolz
    @kausarlolz 6 місяців тому +1

    hi sir, do we need to know the time for the big bang processes? for ocr a

    • @zhelyo_physics
      @zhelyo_physics  6 місяців тому +2

      I’d revise it but not stress about it as paper 3 is typically more problem solving based. You never know though. Good luck tomorrow!

  • @videoharry_
    @videoharry_ Рік тому

    6:03 does Δλ/λ = -v/c rather than just v/c as you’ve put. In your “all of astrophysics” you put the former equation but in this you have the latter. I assume the former is correct?

    • @zhelyo_physics
      @zhelyo_physics  Рік тому +1

      So the two exam boards have chosen slightly different variations of the same equation.

  • @SorabeeZ
    @SorabeeZ 8 місяців тому

    do you need to know ab olbers paradox, open,closed,flat universe and their graphs and critial density for OCR A? ive seen it come up in topic questions but its not something we learnt in school.

    • @zhelyo_physics
      @zhelyo_physics  8 місяців тому

      Hi, they are not, they used to be on the OCR spec before 2017, however not anymore.

  • @justinlash
    @justinlash Рік тому +1

    i]s ]this sequence of big bang ]] enough for full marks

    • @zhelyo_physics
      @zhelyo_physics  Рік тому

      always depends what the question is asking, they are rarely on memory, typically they would throw in some specific data or something similar to comment on the question

  • @udayreddy3705
    @udayreddy3705 Рік тому +1

    hi sir i came across this formula where light years = 1AU/ 1 light year. Is this right ? And if so when is it really used?

    • @zhelyo_physics
      @zhelyo_physics  Рік тому

      never seen it before, it's not correct too I am pretty sure as the dimensions on the left (units of distance), don't equal the dimensions on the right. Where did you come across it?

  • @mikhaelhalbar417
    @mikhaelhalbar417 2 роки тому

    Amazing video thank you so much

  • @Allinone-nm2jh
    @Allinone-nm2jh 7 місяців тому

    thank you very much sir .

  • @xodusgraphicdesigns3384
    @xodusgraphicdesigns3384 Рік тому

    Thanks for the video really good, i like how you don’t put in useless info. Can you do a specific big bang video because the ocr exam i have done requires more info on the Big Bang. E.g the universe is hot and dense…

  • @hectorpearson3390
    @hectorpearson3390 Рік тому +1

    thank you for vid, gl ppl

  • @emmanuelige9889
    @emmanuelige9889 7 місяців тому

    Hi sir, do you agree with this statement or am I incorrect. If the lab wavelength is shorter than the measured wavelength then the object is moving away (Redshift), and if the lab wavelength is longer than the measured wavelength, then the object is moving closer (Blueshift).

  • @supersloths7052
    @supersloths7052 8 місяців тому

    Is this video for the AQA specification?

    • @zhelyo_physics
      @zhelyo_physics  8 місяців тому

      Nope - I have filmed the whole of AQA astrophysics here: ua-cam.com/video/5l787rt7cy4/v-deo.htmlsi=JsDOQS0-wAuwRLQM Enjoy!

  • @jameshosking8541
    @jameshosking8541 7 місяців тому

    Do I need to know the exact value of an astronomical unit?

    • @withtheflow8528
      @withtheflow8528 7 місяців тому

      If you're on the OCR A exam board it is in the formulae booklet

    • @Crimseno
      @Crimseno 7 місяців тому

      @@withtheflow8528 U got to remember the exact value for the astronomical unit for OCR A, its 1.5 x 10^11m. Idk bout the other exam boards.

  • @barnaby4232
    @barnaby4232 2 роки тому

    Does the AU value need to be remebered and do we not need to know the fate of the universe?

    • @zhelyo_physics
      @zhelyo_physics  2 роки тому

      Hi, which spec are you doing? For OCR I would remember the astronomical unit, the fate of the universe is no longer on the OCR spec though. If you are doing a different exam board it might be different

    • @barnaby4232
      @barnaby4232 2 роки тому

      @@zhelyo_physics yes I am doing OCR I assumed it was on the spec as it’s in the textbook, maybe it’s out of date

  • @jefferylarry-w5w
    @jefferylarry-w5w Рік тому

    do we need to know the mnames of the guys who invetend the background radiation theory.

  • @naturemc2
    @naturemc2 2 роки тому

    thanks!

    • @zhelyo_physics
      @zhelyo_physics  2 роки тому

      Anytime!

    • @naturemc2
      @naturemc2 2 роки тому

      @@zhelyo_physics if you add some historical information about how we get the hubble law and why parsec is useful and important. It would be great

    • @zhelyo_physics
      @zhelyo_physics  2 роки тому +1

      I agree! Thanks for the idea!

  • @jamiebarnes4804
    @jamiebarnes4804 2 роки тому

    awsome video really helped me a lot in understanding parsecs but just as a side note i think you forgot to convert nm to meters for the doppler shift or i could be completely wrong

    • @zhelyo_physics
      @zhelyo_physics  2 роки тому

      Hi, thanks! So with the Doppler Shift, because you are using change in wavelength/wavelength the units will cancel so no need to convert in a fraction. Hope this helps!

    • @jamiebarnes4804
      @jamiebarnes4804 2 роки тому

      @@zhelyo_physics ohhhhh I see cheers