What If Dark Energy is a New Quantum Field?

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What is Quintessence? Well we know that something is up with the way the universe is expanding - there’s some kind of anti-gravitational effect that’s causing the expansion to accelerate. We don’t know what it is - just that it competes against the inward-pulling effect of gravity. And it’s winning - it looks like the universe will expand forever, at an ever-increasing rate. We call this mysterious influence dark energy, but while we’ve talked a lot about how it behaves, we’ve never really explored what it is. So, what is dark energy, really?

One strong possibility is quintessence. Quintessence is a hypothetical form of dark energy, more precisely a scalar field. Watch the episode to learn more.

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Hosted by Matt O'Dowd
Written by Matt Caplan & Matt O'Dowd
Post Production by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Caique Oliveira, Adriano Leal & Stephanie Faria
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Directed by Andrew Kornhaber
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Executive Producers: Eric Brown & Andrew Kornhaber
Executive in Charge for PBS: Maribel Lopez
Director of Programming for PBS: Gabrielle Ewing
Assistant Director of Programming for PBS: John Campbell

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[pbsspacetime]

A few of our eagle-eyed Space Time fans have noted that 3:48 what is labeled as Dark Matter and should be labeled as Dark Energy. They are all technically correct, the best kind of correct.

[pinfarmer]

This show has been on a roll for YEARS. Amazing that we get this level of content on such a regular basis.

[brianmessemer]

Matt and Space Time team: I'm not a scientist, I'm a music teacher. I don't fully understand most of what is discussed on this show; especially the math. But just because we don't fully understand something doesn't mean we can't be fascinated by it and appreciate it. I feel like a child listening to adults when I watch Space Time, and I mean that in good way. What a humbling and satisfying thing, to be able to even partially follow discussions concerning the farthest edges of humanity's understanding of the universe. Thank you, Space Time!

[Vhourgannox]

I don't usually understand all of the content in these videos, but I've noticed that over time, if I go back and rewatch older ones, I understand a lot more than I did the first time I watched it. I'm subtly learning about physics while hardly noticing the change.

[kudaj]

If even a grain of sand can overcome dark energy influence, does it mean that the expansion might be vastly uneven? Especialy in regions of the universe rich in megastructures, like the great attactor, or very empty, like the great void?

[Myth-zdko]

I saw a physisict saying "After 30 years of thorough research and studying of Dark energy we have come so far that we have a name for it."😀

[IAmNumber]

I never thought videos so difficult to understand could be so addictive 😂

Edit: Now that this is top comment I should say that I actually think this is a really fascinating way to learn. Even if it sounds like gibberish at first, if you watch enough of these videos, patterns emerge and even high-level concepts begin to make sense in relation to one another.

[TheKaylich]

You know it's gonna be good when Matt looks tired. Your hard work is much appreciated. Thoroughly enjoyed this new (to me) perspective. Does it make sense to think of scalar fields as constant accelerations of values in other fields? In other words: We measure a constantly accelerating force, could such a force be always explained by a new field?

[claironaut]

This show has caused me to become so immersed in astronomy and physics. Introduced me to new channels and ideas regarding different fields. At first I thought I'd never even grasp some of these ideas because they seemed like gibberish at first. As I kept up with the channel I found myself learning some of the theory in all of it. There's so much to learn for me and there always will be, but I'm grateful for PBS Spacetime for intriducing me this. After i graduate in engineering I plan to study more in the field of physics. Thank you.

[ZetaFuzzMachine]

I'm super hyped for this video! I'm writing my final degree project on the thermodynamics of dark energy!!
I'll apply the thermodynamic approach to the equation of state and see how do the different scenarios hold up!
It's so nice to see the topic explained by Matt, and so satisfying to know that I got it right through the papers ...
THANK YOU SO MUCH PBS SPACE TIME

[hugegamer]

I’m old enough to remember being taught space was either going to collapse back on itself, expand to a point but never get there, or keep expanding in size forever, more and more slowly but for sure one of those three. To learn space is actually accelerating came as a shock to everyone, it makes sense to me something like quintessence could actually be true as well. Reality is stranger than we think, even if we take that into account.

[Evan_Case]

It's wild that something so integral to the universe can be so hidden from us.

[tommylakindasorta]

This was one of the more mind-blowing videos you've done. I had to watch chunks over and over -- it felt like I was putting together a really tricky but amazing puzzle in my brain.

[peterkerr]

Love these videos. I think they're pitched at a decent level, really pushing my level of understanding.

[TheReal_ist]

Please never give up comment responses!!

So few people do it anymore and it really proves your integrity and willingness to change when shown your wrong.

So proud of u guys keep it up!!

[crowlsyong]

Thank you Matt and PBS for another one. PBS Spacetime is among my most cherished productions of my life so far.

[Jamndude]

Serious consideration, is it possible that the quintessential and gravitational fields, if the exist, might be a single unified field that excites omega to a positive value in the presence of mass carrying particles of other fields? They both seem to work on such a strangely similar mechanism, one constricting space time while the other causes its expansion when unchecked.

[Raptorman]

Come on, everyone knows the fifth element is Leeloo...

[RedDadRedemption]

As it is known that particles can pop in and out of existence as the vacuum of space is filled with potential/energy. What would the effect on space time be if trillions of particles are popping in and out of existence between the galaxies? Could they add weight (each briefly but overall massively) to the universe as each individual particle is invisible? The pressure of each 'pop' outweighing the gravity of each particle popped.

[Uvuv]

I’m not gonna lie, I go out of my way to not watch any corporate or “big group content”. I only watch those who started from the bottom. PBS is the exception. Never thought