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Books and Articles by Daniel Robbins
Articles & Books From Daniel Robbins
Article / Updated 09-14-2023
The multiverse is a theory that suggests our universe is not the only one, and that many universes exist parallel to each other. These distinct universes within the multiverse theory are called parallel universes. A variety of different theories lend themselves to a multiverse viewpoint.Not all physicists really believe that these universes exist.
Article / Updated 04-27-2023
General relativity was Einstein’s theory of gravity, published in 1915, which extended special relativity to take into account non-inertial frames of reference — areas that are accelerating with respect to each other.General relativity takes the form of field equations, describing the curvature of space-time and the distribution of matter throughout space-time.
Article / Updated 04-14-2023
General relativity was Einstein’s theory of gravity, published in 1915, which extended special relativity to take into account non-inertial frames of reference — areas that are accelerating with respect to each other. General relativity takes the form of field equations, describing the curvature of space-time and the distribution of matter throughout space-time.
Article / Updated 02-07-2023
Many physicists feel that string theory will ultimately be successful at resolving the hierarchy problem of the Standard Model of particle physics. Although it is an astounding success, the Standard Model hasn’t answered every question that physics hands to it. One of the major questions that remains is the hierarchy problem, which seeks an explanation for the diverse values that the Standard Model lets physicists work with.
Article / Updated 12-14-2022
For most interpretations, superstring theory requires a large number of extra space dimensions to be mathematically consistent: M-theory requires ten space dimensions. With the introduction of branes as multidimensional objects in string theory, it becomes possible to construct and imagine wildly creative geometries for space that correspond to different possible particles and forces.
Article / Updated 03-26-2016
In 1905, Albert Einstein published the theory of special relativity, which explains how to interpret motion between different inertial frames of reference — that is, places that are moving at constant speeds relative to each other.
Einstein explained that when two objects are moving at a constant speed as the relative motion between the two objects, instead of appealing to the ether as an absolute frame of reference that defined what was going on.
Article / Updated 03-26-2016
At energy levels where predictions from string theory and general relativity match up, D-branes and p-branes are equivalent. Though Polchinski was aware of Strominger’s work on p-branes — they discussed their projects over lunch regularly — both scientists thought that the two types of branes were distinct. Part of Polchinski’s 1995 work on branes included the realization that they were actually one and the same object.
Article / Updated 03-26-2016
No matter how complex modern physics concepts get, they have their roots in basic classical concepts. To understand the revolutions leading up to string theory, you need to first understand these basic concepts. You’ll then be able to understand how string theory recovers and generalizes them.
The question of matter’s meaning dates back to at least the Greeks and Chinese philosophers, who wondered what made one thing different from another.
Article / Updated 03-26-2016
In trying to understand the universe, two major problems remained: the flatness problem and the horizon problem. To solve these, the big bang theory is modified by the inflation theory, which states that the universe expanded rapidly shortly after it was created. Today, the principles at the heart of inflation theory have a profound impact on the way that string theory is viewed by many physicists.
Article / Updated 03-26-2016
Causal dynamical triangulations’ biggest flaw in comparison to string theory is that it doesn’t tell us anything about where matter comes from, whereas matter arises naturally in string theory from the interactions of fundamental strings.
The causal dynamical triangulations (CDT) approach consists of taking tiny building blocks of space, called 4-simplices (sort of like multidimensional triangles), and using them to construct the space-time geometry.
