Author Topic: Episode #725  (Read 4034 times)

0 Members and 1 Guest are viewing this topic.

Offline Steven Novella

  • SGU Panel Member
  • Well Established
  • *****
  • Posts: 1854
    • http://www.theskepticsguide.org
Episode #725
« on: June 01, 2019, 01:30:48 PM »
News Items: Hyperloop Update, Smart Clothing, Misreporting Medical News, Murray Gell-Mann Dies, HappinessWho's That NoisyYour Questions and E-mails: BandwidthName That Logical FallacyScience or Fiction
Steven Novella
Host, The Skeptics Guide
snovella@theness.com

Offline brilligtove

  • Too Much Spare Time
  • ********
  • Posts: 7679
  • Ignorance can be cured. Stupidity, you deal with.
Re: Episode #725
« Reply #1 on: June 01, 2019, 04:21:18 PM »
Steve got me on WTN.
(click to show/hide)
evidence trumps experience | performance over perfection | responsibility – authority = scapegoat | emotions motivate; data doesn't

Offline 2397

  • Frequent Poster
  • ******
  • Posts: 3097
Re: Episode #725
« Reply #2 on: June 01, 2019, 05:48:45 PM »
I'm glad they ended up going into the matter of trains instead of just planes and hyperloops. But there is also the option of not traveling. Why do people need to travel quickly between cities all the time? What is your city missing? What is your workplace missing? And then there's the tourism, which is the least benefit for the fuel spent. Can't even eat them.

Offline Quetzalcoatl

  • Stopped Going Outside
  • *******
  • Posts: 5404
Re: Episode #725
« Reply #3 on: June 01, 2019, 05:59:44 PM »
But there is also the option of not traveling. Why do people need to travel quickly between cities all the time? What is your city missing? What is your workplace missing? And then there's the tourism, which is the least benefit for the fuel spent. Can't even eat them.

This is a very unusual approach I have not seen before.
"I’m a member of no party. I have no ideology. I’m a rationalist. I do what I can in the international struggle between science and reason and the barbarism, superstition and stupidity that’s all around us." - Christopher Hitchens

Offline daniel1948

  • Happy Man in a Boat
  • Reef Tank Owner
  • *********
  • Posts: 9561
  • I'd rather be paddling
Re: Episode #725
« Reply #4 on: June 01, 2019, 08:24:32 PM »
I got SoF right!

(click to show/hide)

I lived for a year and a half in Spain, which has a high-speed train (half the speed of the French and Japanese). Even at these moderate speeds, the run between Madrid and Seville is killing air travel between those two cities. The distance is 360 km and the flight time is an hour and five minutes. The train trip is two and a half hours. But you can get to the train station, which is in the middle of the city, just minutes before your train leaves, rather than 90 minutes before your flight, after driving or taking the subway all the way out to the suburb. When you arrive there is no wait to get off and you have your luggage with you, and you are in the middle of the city, not out in the suburb. And the train is far more comfortable, and even in coach the seats are bigger.

City center to city center the train is faster than the plane.

Of course, we don't need a hyperloop. Or even maglev. We just need decent trains that run on time, on dedicated passenger rail lines.
Daniel
----------------
"Anyone who has ever looked into the glazed eyes of a soldier dying on the battlefield will think long and hard before starting a war."
-- Otto von Bismarck

Offline daniel1948

  • Happy Man in a Boat
  • Reef Tank Owner
  • *********
  • Posts: 9561
  • I'd rather be paddling
Re: Episode #725
« Reply #5 on: June 01, 2019, 08:30:51 PM »
For the happiness study, I think they need to divide the married women into two groups: Those who are married to men who are assholes, and those who are married whose spouses are not assholes. So many men are assholes, that it could unfairly bias the results against marriage when (perhaps) being married to someone who is not an asshole would not make a woman unhappy.

I have a purpose in life: To have as much fun as I possibly can. Since for me this means being active (nowadays that's mostly paddling, but also walking on the beach) I figure I should be in the long-lived group, since we know that being active promotes health.
Daniel
----------------
"Anyone who has ever looked into the glazed eyes of a soldier dying on the battlefield will think long and hard before starting a war."
-- Otto von Bismarck

Offline stands2reason

  • Empiricist, Positivist, Militant Agnostic
  • Poster of Extraordinary Magnitude
  • **********
  • Posts: 10838
Re: Episode #725
« Reply #6 on: June 01, 2019, 09:26:26 PM »
Naturally aspired engines (i.e. not electric or turbo) will get a decrease in power and efficiently correlating with air pressure drop, just like driving at altitude. Also, removing air resistance won't on its own won't allow normal cars to go that much faster efficiently.

One thing to point out is that the numbers Jay gave (speed vs economy) are averages. The more aerodynamic the vehicle, and the smaller the frontal area, the faster you can go before aerodynamic drag starts to increase quadraritically or worse with speed. (Boxier shapes have a worse-than-quadratic ramp-up in drag.) It is an "empirical law" meaning most aerodynamic stuff that we makes experiences approximately quadratic increased in drag at the speeds we typically use them.The other thing is that until recently, most vehicles had a 4-speed auto with one overdrive gear. This means the engine revs unnecesarily to travel at the desired freeway speed.
« Last Edit: June 01, 2019, 09:29:17 PM by stands2reason »

Offline Alex Simmons

  • Well Established
  • *****
  • Posts: 1072
Re: Episode #725
« Reply #7 on: June 02, 2019, 03:04:10 AM »
Naturally aspired engines (i.e. not electric or turbo) will get a decrease in power and efficiently correlating with air pressure drop, just like driving at altitude. Also, removing air resistance won't on its own won't allow normal cars to go that much faster efficiently.

Keep in mind I haven't yet listened to the podcast for context, but on flat terrain, air drag is by far the largest resistance factor (>90%), and so anything that reduces aerodynamic drag will result in an increase in speed for same power, or reduced power demand for the same speed. If you remove air resistance (while not hampering ability to generate power), a vehicle will be able to travel a huge amount faster for the same power output.

One thing to point out is that the numbers Jay gave (speed vs economy) are averages. The more aerodynamic the vehicle, and the smaller the frontal area, the faster you can go before aerodynamic drag starts to increase quadraritically or worse with speed. (Boxier shapes have a worse-than-quadratic ramp-up in drag.) It is an "empirical law" meaning most aerodynamic stuff that we makes experiences approximately quadratic increased in drag at the speeds we typically use them.

Putting aside any funkiness with the relationship between CdA* and Reynolds number**, then the function of drag with air velocity is a quadratic equation no matter the speed of the car and wind, nor the shape of the vehicle. There is no speed it cuts in or cuts out (unless and until the relationship between CdA and Reynolds number changes - which is the sort of thing that occurs over orders of magnitude changes in velocity).

All that happens with vehicles with a less streamlined shaped is they have a higher CdA. As a result at the same air velocity (ceteris paribus) they present a greater drag, and hence require more power to sustain such a velocity. Since the drag is a quadratic relationship with velocity (and linear with CdA), then there is a cubic relationship between power and velocity (and it's still linear with CdA).

IOW, a doubling of the velocity requires 2³ = 8 times the power to overcome the additional aerodynamic drag.
A doubling of CdA requires a doubling of power to overcome the additional aerodynamic drag. The CdA change can be as a result of changes in size and/or shape.


* Cd = Coefficient of Drag (dimensionless)
A = Effective Frontal Area (SI units m²)
CdA = Cd x A (SI units m²)

** assuming CdA is constant over the range of Reynolds numbers in consideration for vehicles - which is a reasonable assumption for most motor vehicles and speeds.

Offline 2397

  • Frequent Poster
  • ******
  • Posts: 3097
Re: Episode #725
« Reply #8 on: June 02, 2019, 04:51:24 AM »
For the happiness study, I think they need to divide the married women into two groups: Those who are married to men who are assholes, and those who are married whose spouses are not assholes. So many men are assholes, that it could unfairly bias the results against marriage when (perhaps) being married to someone who is not an asshole would not make a woman unhappy.

Also how do single men compare to single women?

Women live longer in general. If they live shorter lives being married in exchange for men living longer lives being married, what is it about single life for men that is inherently more difficult for their bodies to cope with, vs. single life for women?

They mentioned children, but didn't really discuss that part. I could imagine that pregnancy and childbirth would have more of an impact than domestic chores and gender roles. It doesn't take that many women outright dying or suffering long term injuries due to reproduction to noticeably lower the average lifespan and happiness.

Offline lucek

  • Not Enough Spare Time
  • **
  • Posts: 138
Re: Episode #725
« Reply #9 on: June 02, 2019, 07:38:07 AM »
Steve's quote was from futurama season 2 episode 14 how hermes requisitioned his groove back.
"You are technically correct. The best kind of correct."

My 2 cents on the bandwidth data rate throughput thing. Use the analogy of a truck. You are told the truck has x cubic feet in the back. That is your bandwidth. What you load into it is your throughput. What makes it to the destination intact is your data rate.

And to fill out my meme bingo card put the truck in a hyperloop and it's a series of tubes.

One finally one. I think the rogues are underselling abiogenisys research. Yes experiments done 70 years ago kicked off the feild but today we have made all the amioacids allvthe nuclear bases sugars and phosphate groups etc. Required for life in plausible brebiotic conditions. We have shown how they could polimerize. We have even found autocatalitic rna sequences that are fairly short. Furthermore on the other side when we don't concern ourselves with prebiotic condition of earth we can create synthedic organisms with fully synthetic only being too time-consuming to bother with not impossible.
« Last Edit: June 02, 2019, 08:15:19 AM by lucek »
You have the power, but. . .
Power is just energy over time and. . .
Energy is just the ability to do work.

Offline daniel1948

  • Happy Man in a Boat
  • Reef Tank Owner
  • *********
  • Posts: 9561
  • I'd rather be paddling
Re: Episode #725
« Reply #10 on: June 02, 2019, 11:31:52 AM »
Hyperloop makes no sense for individual passenger cars. Of course, Elon Musk is not concerned about naturally-aspirated cars. But cars would still have to be pressurized. Hyperloop only makes sense for trains. And even then a conventional train or maglev makes more sense, since for a train, the air resistance has a much smaller effect because of the minuscule frontal area vs total volume.

The Boring Company could build a tunnel for a conventional high-speed train, and forget about the economically-inefficient low-pressure aspect. A high-speed train would be competitive with the airlines because of the convenience, the location of terminals vs. airports, and eliminating the 90-minute requirement as well as the half-hour waiting for checked bags. Of course, such a train would have to be operated the way European trains are operated, since Amtrak is a disaster.

For the happiness study, I think they need to divide the married women into two groups: Those who are married to men who are assholes, and those who are married whose spouses are not assholes. So many men are assholes, that it could unfairly bias the results against marriage when (perhaps) being married to someone who is not an asshole would not make a woman unhappy.

Also how do single men compare to single women?

Women live longer in general. If they live shorter lives being married in exchange for men living longer lives being married, what is it about single life for men that is inherently more difficult for their bodies to cope with, vs. single life for women?

If they fail to control for marriages where the man is an asshole vs. marriages without an asshole man, then a possible explanation is that with the woman doing more than her share of the work, her stress level is higher than for a single woman, and the man doing less than his share his stress level is lower. Also (if the man is an asshole) sex becomes a pleasure and enjoyment for him but a chore for her, again increasing her stress and reducing his.

In an egalitarian marriage (where the man is not an asshole, or there is no man involved) the work load is shared evenly and sex is managed for the equal enjoyment of both, and the stress levels would be much less disparate. Only the physical stress of pregnancy and childbirth itself is unilaterally on the woman, but a non-asshole spouse could compensate, at least in part, by taking on more of the other work and being more supportive of the woman.

This, of course, is just a hypothesis, but I think it's worth considering.
Daniel
----------------
"Anyone who has ever looked into the glazed eyes of a soldier dying on the battlefield will think long and hard before starting a war."
-- Otto von Bismarck

Offline brilligtove

  • Too Much Spare Time
  • ********
  • Posts: 7679
  • Ignorance can be cured. Stupidity, you deal with.
Re: Episode #725
« Reply #11 on: June 02, 2019, 01:39:13 PM »
I still think everyone is missing the point with Musk and his ventures. I think he's been trying to build a set of sustainable businesses that can produce the critical components of a moon base (solar power, battery storage, airtight pod-style transportation, rockets, efficient tunnelling...). Assuming he doesn't completely mess up his whole portfolio, I expect him to start a company or consortium working on sealed undersea habitats or similar - something to do with long term terrarium-style life support - in the next couple years.
evidence trumps experience | performance over perfection | responsibility – authority = scapegoat | emotions motivate; data doesn't

Offline brilligtove

  • Too Much Spare Time
  • ********
  • Posts: 7679
  • Ignorance can be cured. Stupidity, you deal with.
Re: Episode #725
« Reply #12 on: June 02, 2019, 01:44:53 PM »
In an egalitarian marriage (where the man is not an asshole, or there is no man involved) the work load is shared evenly and sex is managed for the equal enjoyment of both, and the stress levels would be much less disparate. Only the physical stress of pregnancy and childbirth itself is unilaterally on the woman, but a non-asshole spouse could compensate, at least in part, by taking on more of the other work and being more supportive of the woman.

This, of course, is just a hypothesis, but I think it's worth considering.

Anecdote: I have had many years to observe many relatively intimate details of lesbian marriages, most with children. So far I have never seen any relationship where both partners think housework and related duties are fairly distributed. The closest I've seen is where both feel about the same degree of being taken advantage of. The overall degree of imbalance does appear to be a bit less than in hetero couples, in terms of the number of hours each partner dedicates to various aspects of their relationship and family. But not by much.
evidence trumps experience | performance over perfection | responsibility – authority = scapegoat | emotions motivate; data doesn't

Online Harry Black

  • International Man of Mystery
  • Global Moderator
  • Poster of Extraordinary Magnitude
  • *****
  • Posts: 16939
Re: Episode #725
« Reply #13 on: June 02, 2019, 03:28:39 PM »
For the happiness study, I think they need to divide the married women into two groups: Those who are married to men who are assholes, and those who are married whose spouses are not assholes. So many men are assholes, that it could unfairly bias the results against marriage when (perhaps) being married to someone who is not an asshole would not make a woman unhappy.

Also how do single men compare to single women?

Women live longer in general. If they live shorter lives being married in exchange for men living longer lives being married, what is it about single life for men that is inherently more difficult for their bodies to cope with, vs. single life for women?

They mentioned children, but didn't really discuss that part. I could imagine that pregnancy and childbirth would have more of an impact than domestic chores and gender roles. It doesn't take that many women outright dying or suffering long term injuries due to reproduction to noticeably lower the average lifespan and happiness.
Perhaps it has something to do with how labour is distributed in the home? It seems that in most relationships the man gets help with the chores and admin of his life, making appointments etc etc while the woman gets less time for looking after herself and probably less sleep?

Offline Ah.hell

  • Poster of Extraordinary Magnitude
  • **********
  • Posts: 13443
Re: Episode #725
« Reply #14 on: June 03, 2019, 10:18:02 AM »
Hyper-loop and the boring company are two different things.  The hyper-loop is is an absurd idea for a train that won't ever be built at scale.  As Steve notes, it doesn't offer an improvement over conventional rail in proportion to the extra cost. 

The boring company is just an attempt to build tunnels that will allow personal vehicle travel underground.  There's not much revolutionary about it except that Musk thought he could build a tunnel in half the time and a 1/10 the price of experts in the field of building tunnels. 

In both cases, Musks estimate of the cost and time to build are about 1/2 to 1/10 of what they actually will be. 

Way to easy on Musk on this episode. 

There's all sorts of possible reasons why married men might live longer.  Less risk tacking when you feel responsibility for a family.  Your partner almost certainly exerts pressure on you to generally live a healthier lifestyle.  (in my experience men are some what less free to tell there wives to exercise than women are to tell there husbands.)  There's evidence that the presence of children, babies anyway, suppress testosterone production in men.  Care taking by wives......

Why women live shorter lives, there wasn't any mention if it was controlled for child birth which would almost certainly have a significant impact.  Men likely to less care taking of partners and probably exert less pressure for living healthier lifestyles.... 
« Last Edit: June 03, 2019, 10:23:21 AM by Ah.hell »

 

personate-rain