Episode #688

[Steven Novella]

What's the Word: Trophic
News Items: Bogus Personality Tests, Pluto Revisited, Light Sails, Growing Brains
Who's That Noisy
Science or Fiction

[DevoutCatalyst]

Better looking pee or your money back,

[PSXer]

Nitpick: You mentioned that if the only criteria for being a planet was that it was round, 7 moons would be considered planets. Actually, according to Wikipedia, the count would be all the way up to 19. Maybe Dysnomia would be included too? We'll probably never know for sure. https://en.wikipedia.org/wiki/List_of_gravitationally_rounded_objects_of_the_Solar_System#Satellites

If they were all listed as planets, that would be a lot of planets. But if they're moons, they won't come up in the list of planets and will be mostly ignored. I guess kids will never learn how cool Titan is because it happens to be orbiting Saturn. 

As to Haumea, I believe the current understanding for it not being round is not that it doesn't have enough mass to be squished into a ball. It's elongated because it rotates so damn fast- 1 rotation every 4 hours. Earth isn't perfectly spherical either. Is there a certain "roundness quotient" that Earth is on one side of and Haumea is on the other? I guess the does it look round by eye method you mentioned in the podcast.

Any way you stack it, you're either going to have a LOT of planets or you're going to be missing some interesting objects. Probably the only thing that really matters about something being classified as a 'planet' or not is if they teach about it in schools. I'm reminded of some guy on Slashdot who said they should reclassify rivers so that only the 8 largest are real rivers and the rest are 'dwarf rivers'. That way the kids wouldn't have too many rivers to memorize.

[lonely moa]

Not the first time I have heard a doctor make a totally wrong diagnosis, but I thought everyone knew that beetroot turns one's urine "pink".  I await the next podcast after Steve eats asparagus.

[CarbShark]

Nitpick: You mentioned that if the only criteria for being a planet was that it was round, 7 moons would be considered planets.

If you were referring to my comment, it included directly orbiting the sun, which excludes satellites.

So no moons. A total of 9 known planets and possibly one more

(If you were not referring to my comment, the paper arguing  Pluto be classified a planet specifically eliminated satellites. I haven’t listened to this episode yet and probably shouldn’t be commenting yet, but we discussed this at length in another thread)
Sent from my iPhone using Tapatalk

[PSXer]

Sorry should have been more clear, I was talking to the podcast. Steve said that Philip Metzger wants to change the definition of a planet to anything that's gravitationally rounded. He then said that under Metzger's definition, 7 moons would classify as planets. One of those two statements must be wrong. I guess I could see what Metzger actually said about it. I'm guessing the 7 number came about because 7 of the moons are larger than Pluto.

[The Latinist]

I’ve long advocated the same definition for planet that’s Steve does in this episode. To me, it strikes the perfect balance between tradition and science.

My impression is that planetary scientists are the main people who advocate a position that would make moons of Jupiter and Saturn planets.  From their perspective, the only things that matter are the characteristics of bodies that they study...and I think that they also believe that promoting such bodies to planetary status will give them greater priority in research funding.

Finally, since there seems to be some confusion about what exactly would count as gravitationally rounded, I’ll drop this wiki page here: https://en.m.wikipedia.org/wiki/List_of_gravitationally_rounded_objects_of_the_Solar_System.  Note that this page includes some objects which are believed formerly to have been in hydrostatic equilibrium even if they are not currently so (due, for instance, to impacts or other loss of material). Which ones will make the cut depends on where one draws the line.

[elert]

I'm sorry, but the 100 days ground zero fire bit from Science or Fiction is a bit too press-release-perfect for me. Ground zero had its own local weather for awhile. I was seeing and smelling this on my way to work every day after until some random day in November. Here's where the trouble begins. In my memory, the fire was declared out around THAT time — roughly 60 days later. I remember hearing it on either the radio or TV or both. I also remember the smell stopping around that time. I have no recollection of anyone discussing this in December 2001. More importantly, how does a fire know that a prominent base 10 number of days has passed?

[mabell_yah]

I think "Steve's law" is an improvement, and I'm happy to learn the word "barycenter." However, I don't think the concept of binary planet (and above) is meaningful. The term "planet" should refer to the important bodies of a solar system with minor refinements.

Pluto's diameter is 2372km with the barycenter 960km above the surface. Charon's diameter is 1208km with a semi-major axis (which I take to mean closest orbit) of 17,536km.  So the barycenter is 95% of Charon's orbital distance away from Charon. Furthermore, the barycenter is within a planetary diameter of Pluto, whereas it's around 14 Charon diameters away from Charon. This is s severely lopsided relationship. Calling the Pluto system a double planet and putting Charon in the same classification as Jupiter waters down the definition of planet to the point it is almost meaningless. Therefor, I suggest we refine Steve's definition to say that a planet must have it's barycenter within the planet body. Keeping it within a planetary diameter of the surface is also acceptable.

I would add a fourth rule: a planet cannot be tidally locked. Pluto and Charon are tidally locked, so out they go.

Finally, I would add a fifth rule: a planetary orbit must enter the heliosphere. Remember when Voyager passed though the heliopause and was said to have left the solar system. If it's outside the solar system, it's not a planet. It's something else. The recently-proposed planet 9 is so far out that it never enters the heliosphere. It's something else. Maybe an epi-planet.

[sylvano]

Greetings all.

Is there a URL to the WTN bird call website mentioned in the episode? I didn't notice one in the show notes.

thanks
Sylvano

[lucek]

Loved the description of starwisps.

[CookieMustard]

As a borscht lover the first thing that occured to me when Steve talked about his pinkish urine was beets. I used to make large pots of borscht which would last several days and my urine would be pinkish for the duration. Plus my wife likes making pickled beets.
I once talked about this to a friend and he mentioned that at one time he had been eating a large amount of carrots for several days and his urine had an orange tint for a while.

[DevoutCatalyst]

As a borscht lover the first thing that occured to me when Steve talked about his pinkish urine was beets. I used to make large pots of borscht which would last several days and my urine would be pinkish for the duration. Plus my wife likes making pickled beets.
I once talked about this to a friend and he mentioned that at one time he had been eating a large amount of carrots for several days and his urine had an orange tint for a while.

Sweet potatoes being my staple, I switched to light yellow fleshed varieties. The orange flesh cultivars make the skin look positively covfefe eaten daily. That was a decade ago. Nobody knows my sweet potato habit today excepting you and the greengrocer.

[PabloHoney]

My employer uses a personality test called https://www.rembrandtadvantage.com/index.html|Rembrandt. 
It's always bugged the shit out of me because it's self-reported and there are sites that talk about how to respond to the questions to achieve X profile that would be better for your career and increase the likelihood of getting hired/promoted etc.. 

From what I understand though, the Rembrandt test it at least based on the accepted psychological categories and it provides values within the spectrum rather than the false dichotomies.  I've bitched about it to my boss, but find myself dialing it back a bit since it's at least quite a bit better than Myers Briggs. 

[Alex Simmons]

I would add a fourth rule: a planet cannot be tidally locked. Pluto and Charon are tidally locked, so out they go.

I'm not sure why tidal locking should be a factor as tidal locking is an inevitability of enough time passing.

With enough time (about 50 billion years) the Earth will become tidally locked to the Moon but the Sun may have vapourised the Earth or caused other gravitational interactions before that happens. Depends on how big the Sun gets in its dying stages.

Many exoplanets are tidally locked to their host star.

Mercury is tidally locked in a 3:2 spin orbit resonance.