Dark Stars, Dark Energy & Gravitons Explained by Brian Greene

Everything you see, everything you ever loved, every object you look at in the night sky, including comets, moons, planets, and stars, are made of ordinary matter. Which consist of only about 5% of the Universe. And that's the bit of the universe we understand.
The remaining 95% however, we have no idea what it truly is.
But we've given this mystery a name. And we know just about enough that it's two separate things. Dark matter & dark energy.

Theoretical physicist, Brian Greene explains in great detail what we know about dark matter, dark energy and gravitons.

In theories of quantum gravity, the "Graviton" is the hypothetical quantum of gravity, an elementary particle that mediates the force of gravitational interaction.

If gravitons exist, they are expected to be massless because the gravitational force has a very long range, and appears to propagate at the speed of light.

It's extremely counterintuitive that the vast majority energy distribution in the universe is invisible to us, especially when we gaze the night sky and observe trillions of stars. But there could be also stars that are partially made of dark matter.

The early universe may have harbored so called "dark stars". These types of cosmic objects would be composed mostly of normal matter, like modern stars, but a high concentration of neutralino dark matter present within them would generate heat via annihilation reactions between the dark-matter particles.

Under this model, a dark star is predicted to be an enormous cloud of molecular hydrogen and helium ranging between 4 and 2,000 astronomical units in diameter and with a surface temperature and luminosity low enough that the emitted radiation would be invisible to the naked eye.

In theories of quantum gravity, the "Graviton" is the hypothetical quantum of gravity, an elementary particle that mediates the force of gravitational interaction.

#bgreene #universe #space

[agaba]

Neil, Greene helped me understand why i choose to study something as complicated as physics

[nelson_rebel]

Just out of curiosity. Instead of matter we dont see or understand. Could our understanding of gravity be incomplete? Like how the fabric of reality works with fast moving mass in the universe?

[mikemcfadden]

If gravity is mediated by a quantum particle, the graviton, wouldn't that particle have to exceed the speed of light for black hole gravity to extend beyond the event horizon?

[brett_kendrick]

I thought gravitons didn't exist once we found out that gravity was an actual wave like every other form of energy in the universe

[Jonnysboxing]

Thanks Brian. Neil and yourself run the Science Media. Very appreciative.! It's truly amazing how yall can repeat the same thing everyday. I'd have a heart attack 😆.

[hazelvoss]

When Physics and Metaphysics play around with one another, discoveries of our relationship to the Universe, and to ourselves, becomes increasingly interesting. Looking forward to more of your informative videos! 🙌

[michaelccopelandsr]

TIME is fascinating. I worked the subway stations for nearly 10 years. From one end of the city to the other. Every so often I would notice the city would be saying that, "Today just flew by" or "The day was just dragging along."  How can an entire city complain about the same TIME paradox unless it was effected by it. Maybe a TIME distorted bubble the earth passes through in its revolution around the sun. Maybe random waves of TIME distortion hitting the earth? Maybe they're randomly given off by the sun. Maybe they're from outside our Terran system and reach us in intervals. ???? There is SO MUCH MORE to TIME than we realize.  TI-I-I-IME, is on my side. Yes, it is!

[mikemcfadden]

If dark matter interacts with visible matter gravitationally do the Earth and Moon have dark matter associated with them? Does the Sun? By how much does the presence of dark matter in solar systems change the calculations for orbital velocities and planetary interactions? Or does dark matter only come into play on the galactic scale?

[margaretford]

The narrator who sounds like Warwick Davis is a delight to the ears. I don’t see his name in the credits anywhere, but his diction and pacing is absolutely perfect for this video. 👍 👍 👍

[michaelccopelandsr]

I believe quantum particles are particles that exist in past, present and future at the same time. That's why quantum particles that do not connect in any way, react the same way. It's the same particle.  How do these particles come to exist in all of time, at the same time, you ask. Maybe the same way all of matter gets focused to one point. This is how all the TIME this particle wasn't there,   exists in the same TIME it is there.  See, quantum reality.
I believe the TIME Force/quantum reality/quantum realm is fluid.  When it takes 500k of our years for one millionth of a second to pass inside a black hole. (Heavy Time)  Then you have a white hole's ENTIRE existence flashing by in an instant. (Light Time)  You can imagine time being a fluid force. I mean, if it walks like a duck and quacks like a force, it might not be just a causality.

[Zelink]

“Dark Energy” is nonsense, check out the Thunderbolts Project and Electric Universe instead.

[richardblakely]

A basis for gravity theory comes from the fact that photons emit gravity shockwaves. That is because photons have a small amount of gravity, which is obvious because photons cannot escape a black hole. So, billion-year-old photons have lost a large portion of their energy as gravitons. Gravitons must, therefore, form a large part of the universe. We can probably call this dark energy because it can escape black holes. Probably, dark matter is actually old photons that are travelling randomly in the universe, and they do actually have gravity despite what "liberals" claim. For example, some "liberals" imagine global warming is being caused by CO2, but we know that convection limits warming, and so they are wrong in that theory also.

[KaliFissure]

Neutron Decay Cosmology. Neutrons which contact event horizons become the vacuum energy for one single Planck second then reemerge in lowest density points of space where they decay into amorphous atomic hydrogen.
This decay process includes a volume increase, energy density decrease, of over 10^54 times. Expansion. Dark energy. Lambda.
Perfectly compensating the compression it will experience in its world line.
The decay product, amorphous atomic hydrogen, doesn't have stable orbital electron so can't emit or absorb photons. Dark matter.
In time the hydrogen stabilizes and follows usual evolution pathway from gas to nebula to proto star to star until in distant future it is again at edge of event horizon.

Event horizons act as energy pressure release valves venting from highest energy density conditions to lowest energy density points of space.

[solapowsj]

Obviously cooked up by dropouts who didn't comprehend physics. Dark 🌑.

[darthagaddadavida]

I've been asking this question on a few other channels but not too many replies. Is it possible that dark matter gets it's mass from the other energy state of the Higgs field/boson?

[mikejones]

Maybe the reason we haven't found an acceptable boson equivalent for gravity has to do with gravity being less 'time-dependent' than the other forces. That is, it isn't mediated by particles whose velocities are delimited by the speed of light, which is finite, and thus require time to travel from one position to another.

[pranjallkumar]

Can't understand 50% of things what they say... But something keeps me hooked...

[jamesritter]

Perhaps the other half we cannot see is connected to the alternate reality. That we simply cannot see. So we see ordinary matter where as the parallel universe sees dark matter but not ordinary matter. But they are linked together via quantum physics. The Ying and the yang or all the other philosophical quotes are ancestors had an idea of

[WolfStarsDream]

Ah I love watching these videos and then not recalling a single sentence of it

[igorastral]

-Did you like this video?
-Yes. Yes I did.