Dark Energy

Cypress said:
Einstein was at the forefront transforming long-accepted scientific dogma into something entirely new.

I believe he would be the first to say scientific knowledge and theories are provisional and subject to modification or change.
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E=MCsquared will never change,or the theory of relatively
 
Celticguy said:
yes its present in a number of different cultures with different spellings.

I would argue the scientific confirmation mainly because science has not figured out how to define and measure it. But I've seen it and people I know far more extensively.

Its real and it could well be this dark energy.
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I for one do not necessarily think we have to have a scientific answer for everything. I do not think we need, nor does one necessarily exist, a scientific explanation for art, imagination, charity, mercy, justice.

In the Neo-confucian Chinese tradition, the Cosmos is held together by both Qi and Li.

They are complementary, and both are necessary for harmony and existence. I have never been crystal clear on their meaning and significance, but Qi is supposed to be a vital life force, and Li is the order or principle reflected in the natural order.
 
Cypress said:
I for one do not necessarily think we have to have a scientific answer for everything. I do not think we need, nor does one necessarily exist, a scientific explanation for art, imagination, charity, mercy, justice.

In the Neo-confucian Chinese tradition, the Cosmos is held together by both Qi and Li.

They are complementary, and both are necessary for harmony and existence. I have never been crystal clear on their meaning and significance, but Qi is supposed to be a vital life force, and Li is the order or principle reflected in the natural order.
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yeah but its so much more. of course the fun aspect is that its so very basic and elemental.
 
Sock Sockinski said:
E=MCsquared will never change,or the theory of relatively
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E=MC2 is a mathematical consequence of the theory of special relativity, it is not, strictly speaking, the theory itself.

The accelerating expansion of the universe discovered in the 1990s contradicts the predictions of general relativity and the Newtonian laws of gravity.

Either there is something wrong with our understanding of gravity and general relativity, or we need to modify them to account for a hitherto unknown force, aka dark energy.
 
Cypress said:
The normal matter and energy we can see or detect - aka, atoms, photons, radiation and the electromagnetic spectrum - only account for about 5 percent of the universe.

We don't know what the other 95 percent of the universe is, but we know something else is there by indirect evidence.
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Just what IS 5% of infinity?
 
Cypress said:
Basically the universal contants just are what they are...

We cannot derive them from any laws of physics or chemistry

We only know about them from experimental measurement.

It just is what it is.


That is what I mean by scientifically unsatisfactory. We have no deeper understanding of these Universal constants. I guess it ultimately becomes a philosophical question.

But some people wonder when you start having 20 or 25 universal constants holding the universe together, and which cannot be independently derived from physical laws, if it means we are missing something deeper and more fundamental about reality.
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They are each derived from physical laws.
A universal constant is nothing more than a constant to convert a relation to our units of measurement.
 
Dutch Uncle said:
Yet, without those constants, NASA wouldn't be able to put the James Webb telescope up and predict it's orbit.

IMO, and again my math stops at Trig, it's like calling gravity a "theory". Theory or not, throwing bowling balls off the roof of a 10 story building has a single outcome; all the balls will hit the ground.
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Gravity is not a theory. It's a force. How fast the balls hit the ground is easily predicted by Newton's law of gravition, assuming the mass of the Earth and the mass of the bowling ball are known.
The mass of the Earth was first measured by Cavendish.
 
Into the Night said:
They are each derived from physical laws.
A universal constant is nothing more than a constant to convert a relation to our units of measurement.
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Nope.

You would think in an ideal universe, physical laws could be derived simply from first principles, aka mass, acceleration, momentum, energy, wavelength, frequency. Newton's second law, for instance, just involves mass and acceleration.

But the universal gravitational constant, Plank's constant, and other constants had to be derived by measurment or empirical calculation. There is nothing self-evident about them.
 
Into the Night said:
Gravity is not a theory. It's a force. How fast the balls hit the ground is easily predicted by Newton's law of gravition, assuming the mass of the Earth and the mass of the bowling ball are known.
The mass of the Earth was first measured by Cavendish.
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Wrong again.

Newton and Cavendish were displaced by Einstein and General Relativity, who showed in 1916 that gravity is not a force strictly speaking, it is a geometry, specifically a curvature of spacetime.
 
Cypress said:
Into the Night said:
No. They are simply constants that convert a relation to our units of measurement.
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Nope.

You would think in an ideal universe, physical laws could be derived simply from first principles, aka mass, acceleration, momentum, energy, wavelength, frequency. Newton's second law just involves mass and acceleration.

But the universal gravitational constant, Plank's constant had to be derived by meassure or empirical calculation. There is nothing self-evident about them.
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Agreed there's nothing self evident about the universal constants.

Sure, following off a cliff gives a person a lesson in the effects of gravity, but understanding the gravitational constant requires a measurement system. Some measurements are arbitrary or ego centric. Cubits and Astronomical Units (AU) being two.

Despite Sybil's typical oversimplification, he's correct about converting some Universal Constants into human numbers. Regardless, the constant in question, regardless of what it is, exists whether we measure it or not.

https://www.nist.gov/si-redefinition
The units in the revised SI are based completely on seven unchanging quantities or “universal constants,” including the speed of light, the amount of electric charge in an electron, and the Planck constant. Learn more about each of these “invariants of nature” and how they come into play in the revised SI.
 
Dutch Uncle said:
Agreed there's nothing self evident about the universal constants.

Sure, following off a cliff gives a person a lesson in the effects of gravity, but understanding the gravitational constant requires a measurement system. Some measurements are arbitrary or ego centric. Cubits and Astronomical Units (AU) being two.

Despite Sybil's typical oversimplification, he's correct about converting some Universal Constants into human numbers. Regardless, the constant in question, regardless of what it is, exists whether we measure it or not.

https://www.nist.gov/si-redefinition
The units in the revised SI are based completely on seven unchanging quantities or “universal constants,” including the speed of light, the amount of electric charge in an electron, and the Planck constant. Learn more about each of these “invariants of nature” and how they come into play in the revised SI.
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Agreed, that's why I was saying that the universal physical constants seem like a basic, underlying fabric of reality, an ultimate truth perhaps. The universe cannot exist without them, we just translate them into units we can understand
 
Cypress said:
Agreed, that's why I was saying that the universal physical constants seem like a basic, underlying fabric of reality, an ultimate truth perhaps.
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Agreed. They are fundamental operating rules of the Universe. They exist regardless if we understand them or not. They exist even if we are not aware of them like Dark Energy and Dark Matter.
 
Into the Night said:
No. They are simply constants that convert a relation to our units of measurement.
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No, Dutch Uncle's statement is entirely reasonable and plausible.

The point of searching for a long-hoped for Theory of Everything is based on the premise that there should be less of these messy little physical constants, and the cosmos should supposedly be able to be explained from first principles involving the direct properties of energy and matter.

The fact that we are basically no closer to a Theory of Everything than we were 50 years ago, could suggest the universe is less elegant than we hoped for, and these messy little physical constants just really do represent something fundamental about the fabric of reality.
 
Cypress said:
No, Dutch Uncle's statement is entirely reasonable and plausible.

The point of searching for a long-hoped for Theory of Everything is based on the premise that there should be less of these messy little physical constants, and the cosmos should supposedly be able to be explained from first principles involving the direct properties of energy and matter.

The fact that we are basically no closer to a Theory of Everything than we were 50 years ago, could suggest the universe is less elegant than we hoped for, and these messy little physical constants just really do represent something fundamental about the fabric of reality.
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Or we are missing a key part of the puzzle. :)

This thread mentions one of them; Dark Energy. We can see the effects but the cause is still unknown.

I still favor the idea that a Unified Field Theory will come about...and it'll have to include both Dark Energy and Dark Matter. Something Einstein didn't know about AFAIK.


https://www.thegreatcoursesdaily.com/what-is-einsteins-unified-field-theory/
A unified field theory, Einstein hoped, would combine and merge the theory of general relativity with the theory of electromagnetism, fusing them together into a singular physical and mathematical framework. The theory that Einstein had hoped to discover would be far more powerful, and more far-reaching, than either of these individual theories could ever be alone.

Unification has played a very important role in the history of physics. In fact, arguably, many of the greatest accomplishments in physics are examples of unification. By unification in this context, it means uniting two or more ideas that were thought to be as completely distinct, proving their different aspects as the same underlying phenomenon.
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Dutch Uncle said:
Or we are missing a key part of the puzzle. :)

This thread mentions one of them; Dark Energy. We can see the effects but the cause is still unknown.

I still favor the idea that a Unified Field Theory will come about...and it'll have to include both Dark Energy and Dark Matter. Something Einstein didn't know about AFAIK.


https://www.thegreatcoursesdaily.com/what-is-einsteins-unified-field-theory/
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Good stuff.
I think we need a viable quantum theory of gravity to merge it with EM and the nuclear forces.

One of the strongest theories of dark energy is just the cosmological constant: that even empty space has a latent energy imbued within it. That just adds another universal physical constant into the cosmos, and to me is somewhat unsatisfying scientifically. But it really would be a reasonably simple and elegant solution.

The nightmare scenario is that dark energy implies we do not fundamentally understand gravity, and it's back to the drawing board!
 
Cypress said:
Good stuff.
I think we need a viable quantum theory of gravity to merge it with EM and the nuclear forces.

One of the strongest theories of dark energy is just the cosmological constant: that even empty space has a latent energy imbued within it. That just adds another universal physical constant into the cosmos, and to me is somewhat unsatisfying scientifically. But it really would be a reasonably simple and elegant solution.

The nightmare scenario is that dark energy implies we do not fundamentally understand gravity, and it's back to the drawing board!
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While I'm familiar with the concepts, that doesn't mean I understand them. LOL

How does dark energy negate the theory of gravity or alter it? Because it appears to be massless?
 
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