Phil of Science Chapters 24, 23, 22

According to lecture, Darwin's theory of evolution undermined the belief that there was a qualitative difference between . . .

. . . humans and non-human animals.

The speed of light, in a vacuum, is approximately:

3.0 x 108 meters per second.

Based on lecture, which of the following best characterizes the reasons for time dilation in terms of a light clock?

A light clock moving relative to us must cover more distance, but since light moves at a constant rate, this implies that a clock moving relative to us will move more slowly.

Identify the correct statements about the diagram below:

A line along the vertical axis represents something we would normally describe as stationary in space. Any line from the the origin to any point outside the cone represent a physical impossibility in special relativity. Any line on the graph represents motion through spacetime.

What is this picture from lecture intended to illustrate?

A standard Galilean calculation that preserves the absolute nature of simultaneity, but which is not applicable to light.

According to DeWitt, which of these scientific discoveries caused problems for the biological vitalist view?

All of these

"Black body" is a technical term in physics that refers to, what?

An idealized object that absorbs all electromagnetic radiation.

DeWitt credits __________________ for popularizing the ___________ approach to chemistry.

Antoine Lavoisier . . . quantitative . . .

According to DeWitt, even though Einstein's relativistic theories represent space and time as a single entity, most scientists regard this as a convention, to be understood instrumentally, not realistically.

Fair

According to DeWitt, if we look at the Andromeda Galaxy in the night sky, we are seeing what the Andromeda Galaxy looked like eight minutes ago.

False

According to lecture, given Lord Kelvin's basic conservatism and resistance to ideas different than his own, it is not at all surprising that he regarded the problems of the ether and black body radiation as "minor clouds" for the future of Newtonian science.

False

According to lecture, it only took one attempt to replicate the Michelson-Morley experiment for physicists in general to be convinced that they should no longer believe in the existence of the ether.

False

According to lecture, just as in special relativity there is no preferred reference frame from which to judge whether something is moving at constant velocity or at rest, in general relativity there is no preferred reference frame from which to judge whether something is accelerating or moving at a constant velocity.

False

According to the vitalist view of biology, it was vital to understand that living substances were necessarily subject to the same laws (e.g. Newtonian) as non-living substances.

False

Einstein's theory of general relativity finally elucidates, explains and supports the notion of an attractive force that is at play between bodies, or "action at a distance"—something that Newton had difficulty explaining in his own theory of gravity.

False

Gravitational redshift refers to how light moving away from a strong gravitational field shifts away from the red end of the electromagnetic spectrum.

False

In general relativity, the principle of equivalence states roughly that all true physical descriptions of the universe are equivalent.

False

Suppose Frank and Flynn are twins, born at exactly the same time. You have never met Frank, but you know Flynn well. You know that Flynn is twenty years old. If you were asked how old Frank is, you would likely respond: "He is twenty years old." According to DeWitt, this judgement is a purely empirical claim, making no use of any hidden philosophical or conceptual belief.

False

The "ether" that DeWitt cites Deschanel as referring to in explanation of light's mode of travel shares many similarities with the "ether" of Aristotelian philosophy.

False

According to lecture, whose views about the nature of space and time reflected the most complete departure from the views of Aristotle?

Galileo

Which of the following is true?

In lecture it was suggested that the ether differs in important ways from other mysterious and undetected substances introduced for explanatory purposes because its existence was logically implied by our understanding of wave phenomena.

According to DeWitt, who argued that the behavior of gases could be best understood as "particles interacting under a repulsive force"?

John Dalton

According to DeWitt, which three surprising ideas, about space and time, must be accepted if one accepts the principle of relativity and PCVL?

Length contraction. Time dilation. The relativity of simultaneity.

What is the name given to equations that allow one to transform coordinates from a stationary spacetime coordinate system to a moving one?

Lorentz transformations.

As chemistry developed within the Newtonian worldview it gradually became clear that there is a class of organic compounds that can only be produced by living things.

No

"PCVL" refers to what?

Principle of the Constancy of the Velocity of Light.

According to DeWitt, it would take what to explain the problem of black body radiation?

Quantum theory

Which of the following are the two common misconceptions about the special theory of relativity mentioned in lecture?

Relativistic effects only occur near the speed of light. Everything is relative.

According to lecture, if the ether existed, we could say that to be truly at rest would be to be at rest in relation to the ether.

Right

According to lecture, how does Einstein say we can determine whether two remote events are simultaneous?

Send light beams triggered by the events to a detector situated at their midpoint.

In his discussion regarding the orbit of Mercury, DeWitt uses the term perihelion, what does it mean?

The closest point of an orbit, i.e. the point in a body's orbit in which it is the closest to the body it is orbiting.

"Time is time: the amount of time that passes is the same for everyone, everywhere, no matter for their motion, perspective or place." The statement above reflects which idea?

The idea of absolute time.

Which of the following is a principle of general relativity that is best seen as a generalized version of one of the principles of special relativity?

The principle of general covariance.

According to DeWitt, Which of the following principles are basic to the special theory of relativity?

The principle of the constancy of the velocity of light. The principle of relativity.

In representing gravity in terms of deformations of the fabric of spacetime curvature Einstein's theory of general relativity shows that . . .

The shortest path between two points in spacetime can sometimes be curved rather than straight. Gravitation is not a force that is propagated at a distance. Gravitation is not a force that is propagated instantaneously.

Which of the following is a true statement about this picture?

This is an inaccurate depiction of redshift due to the Doppler Effect. Since Einstein is moving toward the light, he will move past it more quickly, which effectively shortens the wavelength and increases the frequency. The phenomenon expected here would actually be a blue shift.

Which of the following are implications of the special theory of relativity?

Time dilation. Length contraction. The relativity of simultaneity.

According to lecture, prior to the results of the Michelson-Morley experiment, and it's consequences for the existence of the ether, scientific disagreement over whether or not there was such a thing absolute space didn't ammount to much beyond philosophical disagreement and differences. True

True

According to lecture, the "luminiferous ether" was postulated to make sense of light being a wave phenomenon (any wave, according to Newtonian mechanics, required a medium to pass through). If such an ether existed, it would follow that there would be a non-relative answer to the question: is this object really at rest, or in motion?

True

According to lecture, the Twin Paradox is a real paradox in special relativity, but it is resolved in general relativity.

True

According to lecture, the equivalence principle of general relativity essentially asserts the equivalence of gravitational and inertial mass, as presumed in Newtonan mechanics.

True

According to lecture, the perihelia of all planets in our solar system move, not just Mercury.

True

According to lecture, we can generally treat many non-inertial reference frame as inertial reference frames for practical purposes.

True

Dewitt: according to general relativity, when the planet Mars is in orbit around the Sun, it is following a "straight line."

True

In the Newton's Bucket thought experiment, an observer on the rim of the spinning bucket would not observe motion.

True

In the beginning of Newton's Bucket thought experiment, the bucket is spinning and the water is not, and the top of the water is predicted by Newton to remain flat.

True

Some of the pre-Netownian views (such as the alchemist's views on chemistry) may seem rather quaint to us. DeWitt suggests that our current science will probably look just as primitive to people living 500 years in the future.

True

According to DeWitt, Einstein started out with evidence in favor of the principle of relativity, and the principle of the constancy of the velocity of light. Given that these were well-evidenced positions, his contribution was to show what followed from these established facts.

Wrong

According to lecture, Einstein's defense of two theories with "relativity" in the title reveal his deep commitment to Galilean-style relativity, against absolutism about space and time.

Wrong

According to lecture, Newton thought that motion was always relative to a frame of reference—even from God's perspective.

Wrong

You compare a metal rod to a meter stick, laying them side by side. The metal rod is clearly the same length as the meter stick. You conclude that the metal rod is a meter long. I then tie a string to the end of the rod, and start spinning it around in circles over my head. Although you can't measure it again, since it is in motion, you probably still believe that it is one meter long. According to DeWitt, this belief is based on which two factors?

Your belief that space is absolute: space does not shrink or enlarge as a result of motion. Your belief from a moment before, when you compared the rod and stick.

Suppose Leslie and Lana are twins, born at exactly the same time. You have never met Leslie, but you know Lana well. You know that Lana is twenty years old. If you were asked how old Leslie is, you would likely respond: "Shee is twenty years old." According to DeWitt, which of the following beliefs would factor into your answer:

Your belief that time is absolute. Your belief that Lana is twenty years old. Your belief that Leslie and Lana are twins.

According to DeWitt, "spacetime" is . . .

a four-dimensional continuum.

According to DeWitt, at the very end of the 1800s, and in the early 1900s, Newtonian-based predictions of the radiation patterns emitted from a heated black body were . . .

accurate for longer wavelengths of radiation. inacurate for shorter wavelengths of radiation.

According to DeWitt, if we take a realist attitude towards the general theory of relativity, we are pushed to take . . .

an instrumentalist attitude towards Newton's notion of gravity.

According to lecture, the philosopher Ernst Mach . . .

believed that Newton erred in thinking that the surface of the water would remain flat when the bucket is moving relative to the water. believed that if the the stars were suddenly to start spinning around us, then the effect on us would be the same as when we begin spinning ourselves. believed that the concavity of the water in a spinning bucket, and inertia in general, is due to the distribution of mass in the universe.

The speed of light is generally represented, says DeWitt, by which letter:

c

Which aspect of this picture represents the path and distance a light clock would have to travel in a reference frame moving from left to right relative to us?

cDt

In lecture it was claimed that, when confronted with a phenomenon that we do not fully understand, it is common to . . .

claim that it is the result of the activity of a mysterious substance.

According to lecture, Inflationary Cosmology . . .

claims that the universe expanded for a very brief period at a speed faster than the speed of light. entails the creation of gravitational waves during the inflationary period. assumes the Big Bang theory of the early development of the universe.

According to lecture, the basic idea of time dilation is best expressed by the statement that . . .

clocks moving relative to us move more slowly than clocks in our own frame of reference.

DeWitt cites Lord Kelvin as having said, in 1900, that there were only a few "minor __________" in the otherwise brilliant sky of modern science.

clouds

According to lecture, the idea that every wave is a "disturbance propagated through a medium" is a __________________________ of the Newtonian worldview.

core conceptual fact

According to DeWitt, time dilation, length contraction, and the relativity of simultaneity are all _____________ consequences of the principle of the constancy of the velocity of light, and the principle of relativity.

deductive

In lecture it was stated that Max Planck's solution to the problem of black body radiation consisted partly in denying the Newtonian assumption that . . .

energy levels can vary continuously.

There are two twelve-inch rulers. Ruler A is stationary relative to us. Ruler B is moving past A at extremely high speeds. According to special relativity . . .

for us, Ruler B is shorter than A.

DeWitt, in regards to the "field lines" around a magnet: "The field lines suggest _________ that exist in space and, presumably, also in ________".

forces . . . time . . .

According to DeWitt, Einstein's theory of general relativity is often understood as primarily being a theory of _______.

gravity.

According to relativity theory, and as discovered by Minkowsky, the spacetime interval is a(n) _____________ property.

invariant

According to lecture, the idea that "like causes like" . . .

is a basic principle of "sympathetic magic". could incline one to believe in the effectiveness of voodoo dolls or alleged aphrodesiacs that resemble genitalia.

According to lecture, the fact that the notion of spacetime curvature strikes us as incoherent . . .

may be partially overcome by understanding that the mathematical models underlying this idea are coherent if difficult to visualize. may be overcome by imagining what it would be like for something that thinks its world is two-dimensional to be told that it is living on the surface of sphere.

According to DeWitt, special relativity applies so long as ___________ circumstances are met; general relativity ___________ these restrictions, and applies to ___________ frames of reference.

special . . . removes . . . all . . .

Eating certain foods as an aphrodisiac on the basis of their resemblance to genitalia is an example of . . .

sympathetic magic.

You are driving towards a siren. As you get closer to the siren, the pitch of the sound it makes raises in pitch. You then pass the siren and drive away from it. As you get further away, the pitch of the sound lowers. This is an example of . . .

the Doppler effect.

According to DeWitt, understanding the results of the Michelson-Morley experiment would specifically require . . .

the development of Einstein's theory of relativity.

According to the experimental setup of the Michelson/Morley experiment together with the assumption that all waves require a medium: If light waves are sent off at right angles to each other and then reflected back by mirrors set at equal distances from the source, then . . .

the light waves will return to the source at different times.

According to lecture, Einstein's theory of relativity is sometimes used to illustrate the advantages of operationalism, which is the view that . . .

the meaning of a term is the set of operations we used to measure it.

According to lecture, Newton devised other thought experiments meant to illustrate the same point as Newton's Bucket thought experiment. One, concerns identical spheres connected by a string rotating around each other in empty space. In this thought experiment . . .

the tension of the string is analogous to the concavity of the water in the bucket thought experiment. an observer positioned at the center of the string is analogous to a position on the rim of the bucket in the bucket thought experiment.

According to lecture, if you think of Galilean relativity as _______, then special relativity may actually be seen as the deepest form of Galilean relativity.

the view that there is no privileged position from which to determine whether you are truly at rest or in motion . . .

According to lecture, how does this picture help us to illustrate the "disagreement" that explains the phenomenon of length contraction?

v∆t for the stationary refence frame is v∆t' for the moving reference frame. Since ∆t' is shorter than ∆t, the length v∆t' must be shorter than v∆t.