Are Quark Stars Possible? - Space.com

Are Quark Stars Possible? - Space.com

Image credit: NASA/Goddard Space Flight Center

Image credit: NASA/Goddard Space Flight Center

Quark stars are one of those interesting edge cases in astrophysics. Bare hints that they might possibly populate our universe, and no major show stoppers to prevent them outright. So do they exist, or not? I explore in my latest Space.com article.

Statistics Brought to You by the Letter P - Notes from the Chief

Statistics Brought to You by the Letter P - Notes from the Chief

Image credit: SPD Swiss Precision Diagnostics GmbH [CC BY-SA 3.0]

Image credit: SPD Swiss Precision Diagnostics GmbH [CC BY-SA 3.0]

Last week I mentioned an odd term, p-value, which is commonly used in deciding whether your results are worth mentioning to your colleagues and the public. Of course it has a strict and narrow meaning, and of course that meaning is abused and misinterpreted in discussions about science. 

Let's say you're performing an experiment: a pregnancy test. The box claims 95% accuracy, and if you read the fine print it's referring to a p-value of 5%. You take the test and...it's positive! So are you really pregnant, or not?

Unfortunately your urgent question hasn't yet been answered. A p-value compares the hypothesis you're testing ("I'm pregnant") to what's called a null hypothesis (in this case, "no baby"), and a p-value of 5% says that if you were not pregnant, there would only be a 5% chance that the test would return a positive result.

You might be tempted to flip this around and state that there's a 95% chance you're actually pregnant, but you would be committing an egregious statistical sin - and this is the same sin committed wittingly or unwittingly by science communicators and sometimes scientists themselves.

Here's the problem: what if you're male? The test can still say you might have a baby, because it's not answering the question "Am I pregnant?" but rather "If I'm not pregnant, what are the chances of the test returning a positive result?" It's a low number - 5% - but not zero. Thus males can still get a positive result despite never being pregnant.

The p-value by itself was only ever intended to be a "let's keep digging" guidepost, not a threshold for believability. To answer the question you actually want answered, you have to fold in prior knowledge. Combined with a low p-value, a healthy female of reproductive age can begin to conclude that there might be a baby on the way. A male...not so much. In either case, the p-value alone wasn't enough, and announcements based solely on that number need to be viewed suspiciously.

Why We Believe the Big Bang - Ask a Spaceman!

Why We Believe the Big Bang - Ask a Spaceman!

What did Hubble really discover? Why does redshift imply an expanding universe? Why is the night sky dark? Why is there so much hydrogen, and how is that connected to the Big Bang? I discuss these questions and more in today’s Ask a Spaceman!

Support the show: http://www.patreon.com/pmsutter
All episodes: http://www.AskASpaceman.com

Follow on Twitter: http://www.twitter.com/PaulMattSutter
Like on Facebook: http://www.facebook.com/PaulMattSutter
Watch on YouTube: http://www.youtube.com/PaulMSutter

Go on an adventure: http://www.AstroTours.co

Keep those questions about space, science, astronomy, astrophysics, physics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE!

Big thanks to my top Patreon supporters this month: Robert R., Justin G., Matthew K., Kevin O., Justin R., Chris C., Helge B., Tim R., SkyDiving Storm Trooper, Steve P., Lars H., Khaled T., John F., Mark R., and David B.!

Music by Jason Grady and Nick Bain. Thanks to WCBE Radio for hosting the recording session, Greg Mobius for producing, and Cathy Rinella for editing.

Hosted by Paul M. Sutter, astrophysicist at The Ohio State University, Chief Scientist at COSI Science Center, and the one and only Agent to the Stars (http://www.pmsutter.com).

P-hacking the System - Notes from the Chief

P-hacking the System - Notes from the Chief

Image Credit: Santeri Viinamäki [CC BY-SA 4.0], via Wikimedia Commons

Image Credit: Santeri Viinamäki [CC BY-SA 4.0], via Wikimedia Commons

Science is hard. Scientists have to stare at mountains of data and try to figure out what secrets nature is whispering to them. There are innumerable blind alleys, dead ends, and false starts in academic research. That's life, and that's why over the centuries we've developed sophisticated statistical techniques to help lead us to understanding. But if you're not careful, you can fool yourself into thinking there's a signal when really you've found nothing but noise.

The problem is in correlations, or when two variables in your experiment or observation seem to be related to each other. Uncovering a correlation is usually the first step in "hey I think I found something," and so many researchers report a connection as soon as their experiment reveals one.

But experiments are often exceedingly complex, with many variables constantly changing - sometimes under your control and sometimes not. If you have, say, twenty variables that are all totally random, then by pure chance at least two of those variables will be correlated.

So when scientists fail to spot the correlation they were looking for, sometimes they start digging through the data until something pops up. And when it inevitably does - publish! But it was just a statistical fluke all along.

This practice is called "p-hacking", for reasons I'll get into another time, and it's a prime source of juicy headlines but faulty results.

Living in an Expanding Universe - Ask a Spaceman!

Living in an Expanding Universe - Ask a Spaceman!

What did Hubble really discover? Why does redshift imply an expanding universe? Why is the night sky dark? Why is there so much hydrogen, and how is that connected to the Big Bang? I discuss these questions and more in today’s Ask a Spaceman!

Support the show: http://www.patreon.com/pmsutter
All episodes: http://www.AskASpaceman.com

Follow on Twitter: http://www.twitter.com/PaulMattSutter
Like on Facebook: http://www.facebook.com/PaulMattSutter
Watch on YouTube: http://www.youtube.com/PaulMSutter

Go on an adventure: http://www.AstroTours.co

Keep those questions about space, science, astronomy, astrophysics, physics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE!

Big thanks to my top Patreon supporters this month: Robert R., Justin G., Matthew K., Kevin O., Justin R., Chris C., Helge B., Tim R., SkyDiving Storm Trooper, Steve P., Lars H., Khaled T., John F., Mark R., and David B.!

Music by Jason Grady and Nick Bain. Thanks to WCBE Radio for hosting the recording session, Greg Mobius for producing, and Cathy Rinella for editing.

Hosted by Paul M. Sutter, astrophysicist at The Ohio State University, Chief Scientist at COSI Science Center, and the one and only Agent to the Stars (http://www.pmsutter.com).

Rats - Notes from the Chief

Rats - Notes from the Chief

Image Credit: Irina Gelbukh [CC BY-SA 3.0]

Image Credit: Irina Gelbukh [CC BY-SA 3.0]

Once again there's a fresh round of blaring headlines and nervous chatter about potential links between cell phone use and cancer, this time based on a recent study purporting to show that a group of rats exposed to radio waves had greater incidents of tumors compared to a control group.

The radiation emitted by cell phones is not at the right frequency to ionize, excite, or even vibrate the stuff you're made of, so there's little to provide a causal link to cancer. So the standards of evidence for a study like this ought to be incredibly high. And then you read the study and find that the radiation-exposed rats lived longer, as a group, than the control rats. Since cancer rates correlate with age, something tells us that the research was not conducted well.

Sometimes scientists are their own worst enemies. There are the genuinely unscrupulous ones, willing to lie and cheat to advance their careers. And there are scientists who are, let's face it, inept at experimental design and statistical analysis. While we'll always have to be vigilant against those characters to make progress, they are thankfully in the minority and we can assume that most researchers, including the ones behind this study, have good intentions and are decent at their jobs.

But there are flaws in the modern scientific system that we must acknowledge. The unrelenting pressure to publish and the exhausting lifelong chase for funding create incentives for poor research to make it into journals and into the public discourse, muddying the waters and hurting science in the long run. This is especially harmful in fields that study extremely complex systems, like epidemiology, where good statistics are naturally hard to come by.

Scientists are just fighting for their careers, but when we need another round of discussions to (re)explain how to spot mistakes in metholodogy, something needs to be fixed.

Quantum Space Computers - Space Radio LIVE

Quantum Space Computers - Space Radio LIVE

Today on Space Radio:

  • Nobody wins the moon (yet),
  • what problems can we solve with quantum computers,
  • is it safe to contact aliens,
  • do all black holes spin,
  • Mike Brown in the house,
  • and of course listener questions!

Join the show recording every Thursday at 4pm ET by calling 888-581-0708. More info available at www.SpaceRadioShow.com.

Support the show on Patreon.

Follow on Twitter | Facebook | Instagram | YouTube.

Big thanks to my top Patreon supporters this month: Robert R., Justin G., Matthew K., Kevin O., Justin R., Chris C., Helge B., Tim R., SkyDiving Storm Trooper, Steve P., Lars H., Khaled T., John F., Mark R., and David B.!

Produced by Greg Moebius at WCBE Radio Columbus.

Hosted by Paul M. Sutter, astrophysicist at The Ohio State University, Chief Scientist at COSI Science Center, and the one and only Agent to the Stars.

Superbowl Asteroid | The Weather Channel AMHQ

Superbowl Asteroid | The Weather Channel AMHQ

Had a lot of fun, as usual, talking to Jim and Steph on The Weather Channel's AMHQ. This time about the "superbowl asteroid" that once again demonstrates that nature may try hard to wipe us out...but she has bad aim.

A Horoscopic Perspective - Notes from the Chief

A Horoscopic Perspective - Notes from the Chief

Image credit: NASA

Image credit: NASA

I feel incredibly sympathetic towards our ancestors for looking to the sky for answers. The dependable, regular movements of the heavens stand in stark contrast to the chaotic, unpredictable, and often violent Earthly world. It's not a huge stretch to imagine that perhaps the positions of the planets would tell us something important. Indeed, many of the early pioneers of what would become science were motivated not by understanding nature for the sake of it, but to build better tools for astrology.

Alas, the more we learned about the celestial realm the more we realized that it's just as chaotic, unpredictable, and often violent as it is down here. And while one of the great triumphs of scientific understanding was the realization that physics is universal throughout the cosmos, that same understanding places strict limits on what can influence what across the vast expanses of time and space that we call the universe. And it's very clear that the positions of the planets bear no relation to human activities.

So why does astrology persist even today? It's part confirmation bias - horoscopes and attributes are so vaguely written that you can give the exact same "prediction" to a hundred people and most will agree it applies to them, despite their sign. It's part cultural tradition - when humanity has been doing something for at least thousands of years it's hard to shake it off. And it's part comfort - who doesn't desire some form of control or knowledge over their lives?

It's this last part that puts science communicators in a tough spot. Obviously horoscopes fill a need in the lives of some people. If we're to (rightly) claim that they're bogus, what do we have to offer in replacement?

Very Large Objects! - Space Radio LIVE

Very Large Objects! - Space Radio LIVE

Today on Space Radio:

Join the show recording every Thursday at 4pm ET by calling 888-581-0708. More info available at www.SpaceRadioShow.com.

Support the show on Patreon.

Follow on Twitter | Facebook | Instagram | YouTube.

Big thanks to my top Patreon supporters this month: Robert R., Justin G., Matthew K., Kevin O., Justin R., Chris C., Helge B., Tim R., SkyDiving Storm Trooper, Steve P., Lars H., Khaled T., John F., Mark R., and David B.!

Produced by Greg Moebius at WCBE Radio Columbus.

Hosted by Paul M. Sutter, astrophysicist at The Ohio State University, Chief Scientist at COSI Science Center, and the one and only Agent to the Stars.