Surveying dark energy across the universe - with Ofer Lahav

Join world-leading scientist Ofer Lahav as he reveals the narrative of the Dark Energy Survey (DES), an ambitious experiment designed to unravel the mysteries of the force shaping our universe.

Watch the Q&A here (exclusively for our Science Supporters):

Discover what the 3D map spanning 300 million galaxies and extensive supernovae has so far revealed, including its confirmation of the prevailing model of cold dark matter and a remarkably accurate cosmological constant.

But this remarkable survey doesn’t just advance our scientific understanding – Ofer sheds light on the human dimension of this project, sharing anecdotes of the long-term commitment and collaboration of the hundreds of scientists involved and the resilience they’ve shown in overcoming challenges along the way.

Join Ofer to explore the global nature of scientific progress, where teamwork and perseverance shape groundbreaking discoveries. The DES not only helps to reveal the mysteries of dark energy but also highlights the collective dedication and collaborative spirit that fuels scientific exploration.

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Ofer Lahav holds the Perren Chair of Astronomy at University College London (UCL) and is Vice-Dean (International) of the UCL Faculty of Mathematical and Physical Sciences (MAPS). Additionally, he co-directs the STFC Centre for Doctoral Training in Data Intensive Science. Specialising in Observational Cosmology, Lahav focuses on probing Dark Matter and Dark Energy, utilising Machine Learning for Big Data applications. Having served as the Head of Astrophysics at UCL from 2004 to 2011 and as Vice-Dean (Research) of UCL's Faculty of Mathematical and Physical Sciences from 2011 to 2015, Oher has played key roles in academic leadership. He served as Vice-President of the Royal Astronomical Society from 2010 to 2012 and played a pivotal role in founding the Dark Energy Survey (DES). His multi-faceted roles and groundbreaking research highlight his commitment to advancing the field of observational cosmology and understanding the fundamental properties of the universe.

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[togeiin]

They should just spend five bucks and read the comments on this video, I'm sure they've found the solution. /sarcasm

[tobysemler]

You wouldn't have to rush the actual topic if you didn't spend 45 minutes rehashing popular physics we've all heard 20 times.

[andycordy]

This channel has presented the development of cosmology to this point many times.

I was hoping to hear something more than talk of phenomena which are still unproven, presented as text book science.

[isatousarr]

The study of dark energy is crucial for understanding the accelerated expansion of the universe. As we develop more advanced observational tools and methodologies, our ability to survey and map dark energy improves significantly. This could offer profound insights into the fundamental forces shaping the cosmos. Given the challenges and complexities involved in observing and analyzing dark energy, what are the latest advancements in technology or methods that are enhancing our ability to survey it? How might these improvements impact our understanding of the universe's expansion and the nature of dark energy itself?

[ai]

love this topic, it's just fascinating how much we don't see!

[induchopra]

So our eyes csnt see smaller than photons. Or it can only see photons

[BarbaraYoung-nq]

Lewis Steven Hall Deborah Jones Jessica

[Dowskiify]

For those too lazy to watch: The survey clearly indicates that dark energy is somewhat disappointed by our understanding of it. There's some resentment about being called "something" or "unexplainable " and the respondent insisted they were more than "just a mistake by a guy named Einstein".

All in all dark energy feels misunderstood, misrepresented and therefore underappreciated. We need to do better people!

[GordonShuffell]

The oft used discription of universe as currents moving away from each other in a baking cake is ok . but I like the idea that the oven it's baking in could be a black hole

[Usrnet]

The galaxy’s rotation curves seem to result from them masses being tied but not a curved space all the way around the galaxies as spheres.

[SiqueScarface]

11:45 I know why I don't like raisins.

[q]

All we know for sure is it tastes like chicken

[daddust]

It took me a decade to understand why we can use stars as standardized candles. It wasn’t in the text books or in videos I watched. It wasn’t explained here either unfortunately. Candles aren’t a good explanation, I wondered why a dimmer star wasn’t just one that was smaller, not necessarily further away.

[maexchef]

I really dont get why the royal institution thinks its reasonable to accompany their fabulous talks with commercials on youtube.

[edstauffer]

Redshift = redshift +- the difference between the measured gravity well and the measuring gravity well. Almost everything is in a deeper gravity well and light redshifts as it climbs out of a gravity well.

[DanielMasmanian]

"and the results of the survey are in, but just need another trillion dollars to count them"

[jimdenzler]

Dark energy… matters! So does consciousness… (The Bad Luck Tree)

[Returntotruereality]

One night i saw the sky open and i can only describe what i saw was a lazer like beam of dark energy that hit me.
Since then my way of thinking has changed and much more. I left my body when the dark energy hit.
Believe it or not, im trying to write down the understandings i have received since. Knowledge is a word i have written about alot. What we think to be true does not mean that it is true. The Truth is out there.

[shawns]

There is only one reason to postulate dark energy, to explain the exponential expansion rate of the universe. The expansion was discovered in 1929. In 1998 it was discovered that the expansion is accelerating, this is when the concept of dark energy became mainstream.
If something accelerates at a constant rate it will get faster and faster. If a spaceship travels at a constant 1g acceleration rate it would achieve about 95% light speed in 1 year.
Electricity is drawn towards potential and the universe as a whole behaves the same way. Electricity comes into our homes because the neutral circuit provides the potential.
Physicists in the last century did not postulate dark energy because they understood that the expansion is a fundamental property of the universe. The fact that the expansion is accelerating does not invalidate their reasoning, it's what the known laws of physics would predict provided gravitational forces are not strong enough to counteract the process.
All studies to find dark energy have been fruitless because it doesn't exist. To say there is dark energy is to say there is 5 fundamental forces, there is 4

[chrwi]

Carl Sagan has never said "billions and billions".