Why falsifiability is a false guide to what is and isn’t science

I had a liberal arts education, which means that I mostly use what I learned to post nonsense on Twitter. However, thanks to my advisor, I got a solid grounding in the philosophy of science. While I’m certainly no philosopher myself, I also (hopefully) have a less simplistic view of how science works and doesn’t work than what is often presented as the “scientific method” and suchlike. For Symmetry, I got a chance to talk a little about how “falsifiability” is widely promoted as a way to tell what is scientific and what is not, and why it’s actually a poor criterion, both from a philosophical and scientific point of view.

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Falsifiability and physics

Can a theory that isn’t completely testable still be useful to physics?

For Symmetry Magazine:

What determines if an idea is legitimately scientific or not? This question has been debated by philosophers and historians of science, working scientists, and lawyers in courts of law. That’s because it’s not merely an abstract notion: What makes something scientific or not determines if it should be taught in classrooms or supported by government grant money.

The answer is relatively straightforward in many cases: Despite conspiracy theories to the contrary, the Earth is not flat. Literally all evidence is in favor of a round and rotating Earth, so statements based on a flat-Earth hypothesis are not scientific.

In other cases, though, people actively debate where and how the demarcation line should be drawn. One such criterion was proposed by philosopher of science Karl Popper (1902-1994), who argued that scientific ideas must be subject to “falsification.”

[Read the rest at Symmetry Magazine]

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Why physicists hate time

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Wait a second: What came before the big bang?

Not everyone thinks the universe had a beginning.

This story originally appeared in the print edition of the September issue of Popular Science. This week, it appeared online with enhanced graphics. The text is by PopSci editor Rachel Feltman and me; the art is by Matei Apostolescu.

Cosmologists used to think the universe was totally timeless: no beginning, no end. That might sound mind-melting, but it’s easier on the scientific brain than figuring out what a set starting point would mean, let alone when it would be. So some physicists have cooked up alternative cosmological theories that make time’s role seem a little less important. The concepts are as trippy as those black-light posters you had in college.

[read the rest at Popular Science]

The search for magnetic monopoles, the truest north

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The hunt for the truest north

Many theories predict the existence of magnetic monopoles, but experiments have yet to see them

For Symmetry Magazine:

If you chop a magnet in half, you end up with two smaller magnets. Both the original and the new magnets have “north” and “south” poles.

But what if single north and south poles exist, just like positive and negative electric charges? These hypothetical beasts, known as “magnetic monopoles,” are an important prediction in several theories.

Like an electron, a magnetic monopole would be a fundamental particle. Nobody has seen one yet, but many—maybe even most—physicists would say monopoles probably exist. (Read the rest at Symmetry Magazine…)

BICEP3: Revenge of the telescope

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Dusting for the fingerprint of inflation with BICEP3

A new experiment at the South Pole picks up where BICEP2 left off

For Symmetry Magazine:

When researchers with the BICEP2 experiment announced they had seen the first strong evidence for cosmic inflation, it was front-page news around the world. Inflation is the extremely rapid expansion of space-time during its first split second of existence, proposed to explain a number of puzzling properties of the universe, making the BICEP2 results a really big deal. Over the following months, though, the excitement evaporated: After combining their data with other experiments, the BICEP2 team showed that most or all of the signal attributed to inflation was likely produced by galactic dust inside the Milky Way.

But traces of inflation could still be hiding in the data, and that’s why scientists haven’t given up yet. BICEP3, the upgraded version of BICEP2, began collecting data yesterday. The first observations using the fully updated equipment will run through November. [Read the rest at Symmetry Magazine]

Listening to the sounds of the cosmos

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Last year, I went to a conference in Florida to hear — and in some cases meet — some of the leading thinkers in the study of gravitational waves. These waves are disturbances in the structure of spacetime itself, and could provide information about some exciting phenomena, if we can learn to detect them. The universe as heard in gravitational waves includes colliding black holes, white dwarfs locked in mutual orbits, exploding stars, and possibly chaotic disturbances from the very first instants after the Big Bang. This story marks one of my first big magazine articles, which I wrote for Smithsonian Air & Space magazine.

The Universe is Ringing

And astronomers are building observatories to listen to it

For Smithsonian Air & Space:

Think of it as a low hum, a rumble too deep to notice without special equipment. It permeates everything—from the emptiest spot in space to the densest cores of planets. Unlike sound, which requires air or some other material to carry it, this hum travels on the structure of space-time itself. It is the tremble caused by gravitational radiation, left over from the first moments after the Big Bang.

Gravitational waves were predicted in Albert Einstein’s 1916 theory of general relativity. Einstein postulated that the gravity of massive objects would bend or warp space-time and that their movements would send ripples through it, just as a ship moving through water creates a wake. Later observations supported his conception. [Read the rest at Air & Space….]

Now it can be told: I will be writing a weekly post for The Daily Beast (making me The Weekly Beast?), on space, astronomy, and such things. My first column is about inflation, and why it’s a big deal:

If you compare any two points on the night sky, their temperature as measured in microwave light is identical to a few millionths of a degree. That light, known as the cosmic microwave background, comes to us from nearly the beginning of the Universe, so it has been traveling for 13.8 billion years. Even with the expansion of the cosmos, two points on opposite sides of the sky were never in the same place, yet they have the same temperature… assuming the current rate of the expansion of the Universe has been roughly the same since the beginning.

But maybe it hasn’t. The cosmic temperature coincidence (which would be a great band name), along with several other annoying aspects of the Universe, led a group of researchers to propose the theory of inflation. [read more…]

The Daily Beast’s latest astronomy columnist is…me!

The BICEP2 telescope (foreground) with the South Pole Telescope (SPT) behind. [Credit: Steffen Richter (Harvard University)]

The BICEP2 telescope (foreground) with the South Pole Telescope (SPT) behind. [Credit: Steffen Richter (Harvard University)]

Today was an exciting and stimulating day: the BICEP2 collaboration announced the first measurement of the cosmic microwave background that might tell us whether or not inflation happened. Inflation is the hypothetical rapid expansion of the Universe during its first instants, which explains a lot about why the cosmos appears the way it does. However, data on inflation itself, as opposed to its side-effects, are hard to come by. This new observation could help resolve that…assuming we can figure out why some of its aspects don’t agree with prior observations.

While they do not constitute a direct detection of either primordial gravitational waves (the distortions causing the light polarization) or inflation, the BICEP2 results could provide the best evidence for both that could not be easily explained away by other theories. This observation cannot be the end of the story, however. The measurement of polarization is significantly larger that what is seen in the results of prior observations in a way that cannot be immediately dismissed. Whether the problems are with the interpretation and analysis of the BICEP2 data, or if something more subtle is at work, remains to be seen. [Read more….]

New data offer a peek into the Universe’s first instants