All Questions
Tagged with cosmology quantum-mechanics
132
questions
16
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6
answers
2k
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Question on Roger Penrose's argument on using particles as clocks
In Roger Penrose's book Cycles of Time under section 2.3 (space-time, null cones, metrics, conformal geometry), Penrose makes the following argument which states that only particles with mass can be ...
- 498
3
votes
2
answers
163
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Uncertainty of the past
If the future today can be described as a complex set of probabilistic wave functions which collapse to form our reality, is it possible that the past history of the universe could also be ...
- 533
0
votes
1
answer
77
views
Does kinetic energy qualify as negative energy in the wormhole of Kip Thorne and Mike Morris?
Referring to Lagrangian methods if potential energy of gravity is considered as positive energy, then kinetic energy should be considered negative.
Recent publications on frame dragging could suggest ...
- 111
1
vote
0
answers
153
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Does the 'No-Superdeterminism' assumption of the 2020 Wigner's friend experiment excl backwards/block-wise/holistic consistency & limited nonlocality?
In "A strong no-go theorem on the Wigner’s friend paradox" authors conclude that one of three possible options is necessary for reconciling quantum physics with more classical physical ...
- 341
7
votes
1
answer
511
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Does zero point energy really contribute to the cosmological constant?
The zero point energy is usually supposed to contribute to the cosmological constant. And the mismatch between the small cosmological constant compared with the huge zero point energy is deemed as one ...
- 4,452
0
votes
0
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19
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Constant Internal energy of universe and its original source [duplicate]
While I was studying thermodynamics I am confused about internal energy of universe. here a question confused me. "If the internal energy of the universe is constant then where did all energy ...
1
vote
1
answer
147
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Can we make a machine that create same amount of positive and negative energy?
I'm in 11th standard. I was studying the chapter work, energy and power. In between, gradually I started taking interest in energy. Then I search for energy of the universe. I was surprised that total ...
- 17
5
votes
0
answers
82
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Bargmann–Wigner equations in NP formalism
Bargmann-Wigner equations describe free particles of arbitrary spin $j$, namely
$$(-\gamma^{\mu}\partial_{\mu}+m)_{\alpha_r \alpha_{r’}}\Psi_{\alpha_1,..,\alpha_{r’},...,\alpha_{2j}}=0$$
where we have ...
- 341
1
vote
1
answer
69
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Is the inflation theory based on the inflaton field or electronuclear force carriers decay? [duplicate]
Some sources introduce the inflaton field as the cause of the inflation period in the big bang theory, and some others relate it to the decay of electronuclear bosons. Which one of these is ...
- 11
0
votes
0
answers
60
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What does Dr. Krauss mean by a universe from "nothing." [duplicate]
I have read for a couple weeks now about a universe from nothing. I understand that the gluon field supports quarks in a proton. I understand that the universe has zero total energy. I'm confused ...
- 11
1
vote
1
answer
73
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What is Quantum Cosmology [closed]
I understand that quantum behavior is only apparent on the microscopic level, what then is the subject of Quantum Cosmology?
0
votes
0
answers
114
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Did Stephen Hawking propose that the universe arised from truly nothingness?
Stephen Hawking giving a lecture describing how the universe would have arisen from his model (developed with James Hartle) or "no boundary" conditions, once said:
Unlike the black hole pair ...
- 2,462
0
votes
0
answers
49
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What are the more important effects or consequences of gamma-ray bursts for the cosmos?
I would like to know what are, in general, the consequences/effects of the known gamma-ray bursts. I refer gamma-ray bursts from the Wikipedia Gamma-ray burst that shows how are classified and the ...
2
votes
0
answers
72
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Would the nightsky be bright (filled with starlight) without accelerating space expansion?
As I currently understand, if a photon was emitted from a far away point in the Universe, beyond the event/particle horizon, so that the space inbetween the emitter and us is expanding faster then ...
- 29k
3
votes
0
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Entanglement and cosmological eras
I'm checking this paper: https://arxiv.org/abs/1405.7834
In the context of quantum cosmology, they assume that the universe evolves in an entangled state between the two epochs considered, i.e.$$\...
