Unraveling the Mysteries of Dark Energy with NASA's WFIRST

Scientists have discovered that a mysterious pressure dubbed "dark energy" makes up about 68 percent of the total energy content of the cosmos, but so far we don't know much more about it. Exploring the nature of dark energy is one of the primary reasons NASA is building the Wide Field Infrared Survey Telescope (WFIRST), a space telescope whose measurements will help illuminate the dark energy puzzle. With a better understanding of dark energy, we will have a better sense of the past and future evolution of the universe.

Astronomers have measured the rate of of the universe's expansion by using ground-based telescopes to study relatively nearby supernova explosions. The mystery escalated in 1998 when Hubble Space Telescope observations of more distant supernovae helped show that the universe actually expand ed more slowly in the past than it does today. The expansion of the universe is not slowing down due to gravity, as everyone thought. It's speeding up.

While we still don't know what exactly is causing the acceleration, it has been given a name -- dark energy. This mysterious pressure remained undiscovered for so long because it is so weak that gravity overpowers it on the scale of humans, planets and even the galaxy. It is only on an intergalactic scale that dark energy becomes noticeable, acting like a sort of weak opposition to gravity.

What exactly is dark energy? More is unknown than known, but theorists are chasing down a couple of possible explanations. Cosmic acceleration could be caused by a new energy component, which would require some adjustments to Einstein's theory of gravity -- perhaps the cosmological constant, which Einstein called his biggest blunder, is real after all.

Alternatively, Einstein's theory of gravity may break down on cosmological scales. If this is the case, the theory will need to be replaced with a new one that incorporates the cosmic acceleration we have observed. Theorists still don't know what the correct explanation is, but WFIRST will help us find out.

Discovering how dark energy has affected the universe's expansion in the past will shed some light on how it will influence the expansion in the future. If it continues to accelerate the universe's expansion, we may be destined to experience a "Big Rip." In this scenario, dark energy would eventually become dominant over the fundamental forces, causing everything that is currently bound together -- galaxies, planets, people -- to break apart. Exploring dark energy will allow us to investigate, and possibly even foresee, the universe's fate. Watch this video to learn more about dark energy and how WFIRST will study it.

Music: "Searching Everywhere" from Universal Production Music

Credit: NASA's Goddard Space Flight Center
Scott Wiessinger (USRA): Lead Producer
Krystofer Kim (USRA): Lead Animator
Chris Smith (USRA): Animator
Sophia Roberts (AIMM): Narrator
Francis Reddy (University of Maryland College Park): Lead Science Writer
Claire Andreoli (NASA/GSFC): Lead Public Affairs Officer

Follow NASA’s Goddard Space Flight Center

[cordatusscire]

Fantastic presentation! Thank you for the video and update.

[scrionycoronaruiz]

Animation so good i thought this was a Ted Ed video...twice

[crkakde]

Makes james Webb w'FIRST'!!🤐

[duran]

Oooh..the background music 🎶 somthing 🎼

[masaharumorimoto]

The waves in the early universe corresponding to locations now warps my brain so hard... If I keep thinking about it I might poof out of existence.

[joeldenney]

Hold on, now. Gravity is stronger than DE, except where mass is really far away, like between galaxies. So then, within galaxies space may be expanding, but gravity is keeping both the masses themselves (the Earth, say) intact, as well as the distances between masses in our galaxy, (e.g. Earth's orbit). Yes?


Alternately, is there any measurement of how far our galaxy has expanded? I don't recall seeing one. In any case, where's the point where DE overcomes G in our galaxy, and how has that changed, if at all? (In the "local group", say)?


Is alpha Centauri supposed to eventually become so far away, its light will take too long to reach us vs. DE? Then it must be drifting away right now, shouldn't it? So, how fast?


Anybody know of a theory that will allow the story of DE overpowering G to be explained step-by-step?


What about overcoming the Strong Force? Let's see the details.



The Big Rip sounds fishy to me. I don't pretend to be smarter than cosmologists; my suspicion is that this is some artifact of the popular press' need for drama.

[youxkio]

Excellent presentation, simple and easy to understand.

[CHAS]

Is the possibility ruled out that light itself loses energy as it travels billions of light years? That would explain the redshift in frequency of a photon if true. Is the redshift the same for all directions from earth? Or is there a spherical variation as you measure around the globe? If the redshift as a function of distance is the same in all directions, then that would put earth dead center of the expansion. There are a lot of unanswered questions, and unquestioned answers.

[anandrajsingh]

Spirals I saw here was very relatable to my sister's cartoon network graphics.

[sheep.herder]

Getting kind of desperate...dark matter 😂😂😂 where are all the sheep 🐑🐑🐑

[CaptainNero]

First thought that came to mind was looking at the sun. Maybe the interactions between the two.

[kellyviolette]

we will never know everything ~ that's the matrix of it.

[FinnBearOfficial]

They solved this dark matter/energy malarkey in the Safire Project, haven't you heard?

[enriqueatentar]

Sometimes people must live in the place that unfamiliar in him you cannot learn things in just seeing it we need to go live there without returning in earth don't fear death because we are immortals in spirit when humans die they become angels but imprisoned in Hades but Space don't have this place so we can clone our genes and back to space expeditions mission.

[jshafer]

Is electricity involved in any of the dark energy theories?

[MozartificeR]

I don't believe that stars can explode or ever go out...

[worksmartpaul]

1st off there's no such thing as evolution.