Keep watching the Sky at Night, the world's longest running tv science programme. Thanks, BBC.

I'm beginning to get hooked on Astronomy again, after watching a few of Chris' talks. Thanks Gresham , nice work.

Thanks so much for these excellent lectures Dr Linott and Gresham College. What a wonderful time to be alive when this knowledge exists, and when it can be presented to a general audience both in person and electronically throughout the world (and beyond?). Looking forward to future talks.

I love this guy. ❤ & all your physics lectures.

Thank you for an enjoyable and informative series of lectures on a fascinating subject.

@chrislintott1

21 күн бұрын

My pleasure! Back next year

just a marvelous presentation and presenter. Thank you

Excellent. Keep up the great work. More please.

This talk isn't about the first stars, or the early universe, it's an introductory overview of modern astronomy.

Outstanding lecture.

Before the famous ''Sky At Night'' presenter Patrick Moore died, he groomed and introduced his successor Chris Lintott into his old role. A very worthy successor indeed!

@K1lostream

17 күн бұрын

Unfortunate choice of verb….

@agxryt

3 күн бұрын

Groomed might be the worst word to pick here lol

Always enjoy Chris' talks. Thanks to all the team involved for making this happen!

11:15 Our favourite ex-planet always finds a way to come up in these talks.

@chrislintott1

18 күн бұрын

Was very pleased to get it into a lecture on the CMB!

This was a fantastic talk, thank you.

@PetroicaRodinogaster264

14 күн бұрын

my brain hurts though when they talk billions of light years. But it makes anything that happened in the last million yrs on this planet seem like yesterday to me.

@GlassEyedDetectives

14 күн бұрын

@@PetroicaRodinogaster264 The fact that we can imagine it and wonder is enough for me, let alone try to explain it! 😁

Thank you Chris

Don't ever stop Chris 👍🤗

since the refraction index of all transparent material is the difference in density between mediums. and the mass in the universe was less densly packed together at the start. then wouldn't the difference in density over time be reflected in the light from the early universe. if the speed of light is constant.

At the risk of sounding simplistic, I would suggest that the question "what is the universe expanding into" is difficult to answer is because it is based on a false premise. A better question may be "what is there when the universe isn't?"

@chaosking911

10 күн бұрын

I love when a suggestion is a thought experiment in irrelevant nitpicking. 10/10.

What a magnificent way of explanation! I loved it. Thanks. One thing that came into my mind is that, if the expansion rate of the universe as explained, then, will there be a time when the maximum distance of our observable universe is going to come to an end? I guess you got my point!

@chrislintott1

21 күн бұрын

Because the expansion is accelerating, the fraction of the universe we can see is actually dropping. Which is slightly mind boggling. If nothing changes in the far future we will only be able to see our own galaxy

if the space itself expanding it remains the question, what is space? what does it expanding to? where the extra space coming from? it appears that another layer of existance could be wrapped around our 3D world. or magic

Nice tv

if we see the past farther and further with distance, how can we draw the lovely looking map of supergalaxies and all the network of clusters? it is like a google map compiled from historical photos , older and older as we go away from the centre. how reliable any conclusion from it?

@chrislintott1

18 күн бұрын

Yes, if you go far enough then you are indeed comparing the past to the present. The map I showed is about a billion years across in travel time, which is small enough that we tend to consider that all the present day.

@petersq5532

17 күн бұрын

@@chrislintott1 thank you for your answer. in that range it appears uniform. so the question remains that for how long you can extrapolate this result.

I like the theory that the universe is contained within a black hole we could never escape it but stuff might be able to fall in from out side

Trying to work out how the Great Magician pulled off the greatest trick of all.

If the Universe is expanding, how come Andromeda will collide with the Milky Way?

we experience a faster expanding universe. but as this lecture pointed it is an illusion. the speed of the expansion is the same but more bits are expanding at the same time. so the later contraction does not go against the observation. it is not fundamentally contradictive.

1. Any 'objective' observation places the observer outside the subject system, so your reply to the question 'what is the cosmos expanding into' must surely apply to any observation. 2. Quantum theory shows that particles and waves behave differently when observed. Could this phenomenon account for the Hubble tension? Thanks for clear explanation and presentation.

Can somebody please elucidate on the idea that gravity travels at the same speed as light. Gravity travels??

@bipolarminddroppings

22 күн бұрын

It's not an idea, it's an established fact. The speed of light is a misnomer, it should properly be called the speed of causality. It falls out of maxwells equations and also out of special and General relativity. We know it's true because we have measured gravitational waves. We have 2 observatories on opposite sides of the earth, they detect the waves at slightly different times, we calculate the difference and get the speed of light. If you want to know more you really need to go Google it.

@chrislintott1

21 күн бұрын

Yes. In relativity, there’s a speed of gravity! If the Sun disappeared, it would take eight minutes for the Earth to ‘notice’.

@georgenorris2657

21 күн бұрын

@@chrislintott1 but at the same speed? are light and gravity somehow then connected to one another? at the same speed indicates a complex relationship of some sort doesnt it?

@cleon_teunissen

20 күн бұрын

@@georgenorris2657 The connection is not so much with each other, but with the background that allows light and gravity to exist: spacetime. The upper limit to speed is not a specific property of light, nor a specific property of gravity, it's a property of spacetime. On Aug. 17, 2017, the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo detected, for the first time, gravitational waves from the collision of two neutron stars. The event was not only “heard” in gravitational waves but also seen in light by dozens of telescopes on the ground and in space. This event has been given the name 'GW170817', that will allow you to find more information about it. The event occurred 130 million lightyears away. The light produced (in the wake of the gravitational event) started arriving 1.7 seconds after the arrival of the gravitational wave. The 1.7 second difference is attributed to a 1.7 time gap from the event to the start of production of light. (For instance, matter accelerated to high speed colliding with surrounding matter; the resulting heating then gives emission of light.)

@Michael75579

17 күн бұрын

@@georgenorris2657 In relativity, c is not just the speed of light but the fastest speed at which any interaction can travel. This means that gravitational waves can travel at a maximum of c, and observations of events which produce both gravitational waves and gamma rays have constrained the difference between the speed of gravitational waves and the speed of light to be extremely small if it's not zero. Gravitational waves are travelling changes in the shape of space-time. If the Sun somehow instantaneously vanished then space-time where the Sun was would lose the curvature that was caused by the Sun and this flattening would travel outwards. Since it's the curvature of space-time that causes the Earth to orbit the Sun, the Earth's orbit wouldn't change until this flattening reached us 8 minutes later.

Great lecture, respect. I had this thought the other day: is the observable edge of the universe, the age of the universe, really a time dilation barrier; where time stops to the observer, us, in this case. I wrote my idea in a paper (original thought and no AI added); I think it solves the problems JWST is presenting us. Comments

I wonder how he might deal with some boffin at a party who is holding forth that some supreme being said “let there be light”

@user-wr4uz8pg7m

11 күн бұрын

How would u handle such a statement if you were well versed in cosmology?

Still grouping in the dark

The Hubble tension will be resolved by realising that the Milky Way is around 26 million light years from the centre of a finite universe with a space boundary. This theory matches all observations and explains dark matter and dark energy. Richard

@jonathonjubb6626

22 күн бұрын

Nobody likes a smartarse! The HT will be resolved when scientists realise they do not fully understand red shift and probably gravity... (Halton Arp and also Mond)

@JohnBeeblebrox

22 күн бұрын

​@@jonathonjubb6626MOND does have some interesting aspects. Still not been completely ruled out...

@bipolarminddroppings

22 күн бұрын

No. It won't be. Your hypothesis is provably wrong with type 1a supernova. You don't know enough to know why you're wrong...

@bipolarminddroppings

22 күн бұрын

​@jonathonjubb6626 it's actually much more likely that the problem will be solved because lamda isn't a constant. You don't have the first clue what I mean when I say lamda isn't a constant, and thats why you should be quiet and learn something instead of thinking you know better than actual experts.

Use Metric, its science! Now your using Miles, feet and the Metric system in this video...its a chaos..

@user-wr4uz8pg7m

11 күн бұрын

Though your brief statement includes at least four errors, so ... :)

Здравия всем. Испытаем ❤фонарь для гравитационных квантов❤ посмотрим на Вселенную? И возможно квантами гравитации (цифровым способом) измерим Вселенную? Соберём учебное пособие для школ и ВУЗ, с помощью «ГИБРИДНОГО гироскопа». Вы сможете совершать научные открытия; по астрономии, астрофизике, космологии, высшей теоретической физике,... Обращаюсь к Вам с предложением на совместное изобретения ГИБРИД гироскопа из некруглых, ДВУХ катушек с новым типом оптического волокна с «полой сердцевиной из фотоно-замещенной вакуумной зоной или (NANF)», где - свет в каждом плече проходит по 250000 метров при этом, не превышает параметры 84/84/84 см., и вес - 24кг. Предприятия по выпуску "Волоконно-оптических гироскопов" может выпускать ГИБРИД гироскопы, для учебно практического применения в школах и высших учебных заведений. Эйнштейна мечтал измерить скорость поезда, самолёта - через опыт Майкельсона Морли 1881/2024 г., и только тогда, опыт будет выполнен больше чем 70%. Это возможно выполнить с помощью оптоволоконного ГИБРИД гироскопа. Вот исходя из выполненного более 70% опыта Майкельсона, возможно доказать постулаты: Свет - это упорядоченная вибрация гравитационных квантов и доминантные гравитационные поля корректируют скорость света в вакууме. (Мы, не ищем эфир, мы увидим работу квантов гравитации) В итоге увидите *теорию всего* в простом учебном устройстве.

Why on earth are so many wasting their life studying how old the universe is, how it started and how big it is??? It is. It works. It’s amazing. ITS ENOUGH.

@lafenelson3212

22 күн бұрын

So that people can say things like "earth" and know what they're talking about.

@steveclark2996

21 күн бұрын

"It works. It’s amazing" - when will it stop working and why?

@margaretbloomer9001

20 күн бұрын

It's because it's amazing that we want to know more. If we don't look or ask questions, we stagnate. It's because we ask questions (we're human beings, an inquisitive species), we gain knowledge and understanding. We develop technologies. Durrr!

@Sandbar1914

19 күн бұрын

I cannot think of a more rewarding life than advancing knowledge. What is it you do?

@gsb5012

19 күн бұрын

@@Sandbar1914 advancing knowledge of useful stuff like disease, protecting our own planet and its incredible resources, its wildlife and science, discovering what we still don’t know about it all.