Author Topic: Episode #586  (Read 3812 times)

0 Members and 1 Guest are viewing this topic.

Online Friendly Angel

  • Frequent Poster
  • ******
  • Posts: 2996
  • Post count reset to zero in both forum apocalypses
Re: Episode #586
« Reply #15 on: October 03, 2016, 06:32:50 PM »

Sufficiently large thermonuclear reactors explode at the end of their life. Below some specific size, they don't explode, but merely get really, really big.

I don't think you know what you're talking about here.

Chernobyl and the Army reactor both had steam explosions - nothing like a thermonuclear bomb explosion.

Power reactors don't have the fissionable material density to be explosive.  Navy reactors have a high enrichment of the uranium for long life, but it's mixed in with enough non fissionable material in the meat that it's still not explosive.

There has never been a nuclear reactor that turned into a nuclear bomb.

Amend and resubmit.

Offline Swagomatic

  • Frequent Poster
  • ******
  • Posts: 2370
Re: Episode #586
« Reply #16 on: October 03, 2016, 06:40:10 PM »

Sufficiently large thermonuclear reactors explode at the end of their life. Below some specific size, they don't explode, but merely get really, really big.

I don't think you know what you're talking about here.

Chernobyl and the Army reactor both had steam explosions - nothing like a thermonuclear bomb explosion.

Power reactors don't have the fissionable material density to be explosive.  Navy reactors have a high enrichment of the uranium for long life, but it's mixed in with enough non fissionable material in the meat that it's still not explosive.

There has never been a nuclear reactor that turned into a nuclear bomb.

I thought the same thing at first, but I think he may have been alluding to a supernova explosion for big stars and a red giant for sun-sized stars. 
Beware of false knowledge; it is more dangerous than ignorance.
---George Bernard Shaw

Online Friendly Angel

  • Frequent Poster
  • ******
  • Posts: 2996
  • Post count reset to zero in both forum apocalypses
Re: Episode #586
« Reply #17 on: October 03, 2016, 06:42:01 PM »

Sufficiently large thermonuclear reactors explode at the end of their life. Below some specific size, they don't explode, but merely get really, really big.

I don't think you know what you're talking about here.

Chernobyl and the Army reactor both had steam explosions - nothing like a thermonuclear bomb explosion.

Power reactors don't have the fissionable material density to be explosive.  Navy reactors have a high enrichment of the uranium for long life, but it's mixed in with enough non fissionable material in the meat that it's still not explosive.

There has never been a nuclear reactor that turned into a nuclear bomb.

I though the same thing at first, but I think he may have been alluding to a supernova for big stars and a red giant for sun-sized stars.

Ahh. OK.  Fusion reactors then.  Sorry I didn't get it Daniel.
Amend and resubmit.

Offline daniel1948

  • Stopped Going Outside
  • *******
  • Posts: 4657
  • Cat Lovers Against the Bomb
Re: Episode #586
« Reply #18 on: October 03, 2016, 06:59:17 PM »

Sufficiently large thermonuclear reactors explode at the end of their life. Below some specific size, they don't explode, but merely get really, really big.

I don't think you know what you're talking about here.

Chernobyl and the Army reactor both had steam explosions - nothing like a thermonuclear bomb explosion.

Power reactors don't have the fissionable material density to be explosive.  Navy reactors have a high enrichment of the uranium for long life, but it's mixed in with enough non fissionable material in the meat that it's still not explosive.

There has never been a nuclear reactor that turned into a nuclear bomb.

I thought the same thing at first, but I think he may have been alluding to a supernova explosion for big stars and a red giant for sun-sized stars. 

Yep. See the last paragraph in my first post in this thread, which is the first reply after the OP. See also reply #6 by Dan I.
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 Fast Eddie B

  • Frequent Poster
  • ******
  • Posts: 2501
Re: Episode #586
« Reply #19 on: October 03, 2016, 10:06:16 PM »
A gyroscope can measure changes in angular momentum independent of gravitational forces.  This is in fact how inertial guidance works.  Angular momentum is somewhat weird in that isn't relative in a Newtonian sense.

Changes, I guess.

But the angular momentum in a uniformly rotating universe would not be changing. Right?
"And what it all boils down to is that no one's really got it figured out just yet" - Alanis Morisette
• • •
"I doubt that!" - James Randi

Offline Skip Nordenholz

  • Off to a Start
  • *
  • Posts: 31
Re: Episode #586
« Reply #20 on: October 04, 2016, 02:31:22 AM »
On the whole hackable system being created because of bugs, thats not really a profound statement when you consider to a programmer that if a system has undesired behavior, like hack-able, then its defined as a bug.

Offline daniel1948

  • Stopped Going Outside
  • *******
  • Posts: 4657
  • Cat Lovers Against the Bomb
Re: Episode #586
« Reply #21 on: October 04, 2016, 10:12:00 AM »
To truly make a system unhackable you have to prevent social-engineering hacks. Is there a way to do that which would not effectively cripple the system?
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 amysrevenge

  • Baseball-Cap-Beard-Baby Guy
  • Stopped Going Outside
  • *******
  • Posts: 4978
  • The Warhammeriest
Re: Episode #586
« Reply #22 on: October 04, 2016, 10:16:08 AM »
To truly make a system unhackable you have to prevent social-engineering hacks. Is there a way to do that which would not effectively cripple the system?

WORD

We have a super-secure password setup at work, including being forced to change passwords every three months.  The only way I can get by is to leave a hint to what my current password is on a sheet of paper at my desk.  It would be much easier to hack my note (it's not like I just write down the password - I'm telling myself how I built the password) than to hack the password.  :P
Big Mike
Calgary AB Canada

Offline daniel1948

  • Stopped Going Outside
  • *******
  • Posts: 4657
  • Cat Lovers Against the Bomb
Re: Episode #586
« Reply #23 on: October 04, 2016, 10:36:45 AM »
To truly make a system unhackable you have to prevent social-engineering hacks. Is there a way to do that which would not effectively cripple the system?

WORD

We have a super-secure password setup at work, including being forced to change passwords every three months.  The only way I can get by is to leave a hint to what my current password is on a sheet of paper at my desk.  It would be much easier to hack my note (it's not like I just write down the password - I'm telling myself how I built the password) than to hack the password.  :P

You just hit on one of my pet peeves: Forced password changes.

On sites where there is nothing personal or critical or financial I use easy-to-remember passwords. On banking sites I use very difficult-to-guess passwords. I would say my passwords there are impossible to guess. I can construct a totally-secure password and memorize it. I cannot remember a new complex password every three months. Sites that force me to do that require me to write down the password somewhere, and that is less secure than allowing me to keep my password.

Why the holy fuck do those shithead morons think that changing my password every three months in the absence of any successful hack of the old one would make my account more secure??? It forces people to either write down their password or use simple easy-to-remember passwords.

I have actually closed out my accounts at two different banks because they required me to create a new password every three months. It was not worth it. If they are going to make it that hard on me, without any real security benefit then I'll take my business elsewhere.
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 Pusher Robot

  • Frequent Poster
  • ******
  • Posts: 2205
  • Do you have stairs in your house?
Re: Episode #586
« Reply #24 on: October 04, 2016, 11:22:53 AM »
I can construct a totally-secure password and memorize it. I cannot remember a new complex password every three months. Sites that force me to do that require me to write down the password somewhere, and that is less secure than allowing me to keep my password.

No, it isn't.  The main threat you are defending against when using strong password on internet-accessible services is from remote attacks.  They have access to time, computers, and dictionaries of weak or stolen passwords to plow through.  They don't have access to the pad of paper on your desk with your strong password written on it.
A novice was trying to fix a broken Lisp machine by turning the power off and on.
Knight, seeing what the student was doing, spoke sternly: “You cannot fix a machine by just power-cycling it with no understanding of what is going wrong.”
Knight turned the machine off and on.
The machine worked.

Offline amysrevenge

  • Baseball-Cap-Beard-Baby Guy
  • Stopped Going Outside
  • *******
  • Posts: 4978
  • The Warhammeriest
Re: Episode #586
« Reply #25 on: October 04, 2016, 11:38:40 AM »
Yeah, but how much less secure is my strong password after a year, compared to after 3 months?  Is 3 months some sort of optimized compromise between how often hackers get access to my mid-sized engineering consulting company's password list and how often I need to enter my password?  Or is it some arbitrary bullshit thing that makes upper management feel better, as per TSA theater at the airport?
Big Mike
Calgary AB Canada

Offline gebobs

  • Not Enough Spare Time
  • **
  • Posts: 199
  • Me like hockey!
Re: Episode #586
« Reply #26 on: October 04, 2016, 03:17:37 PM »
The rogues wondered what sort of life, if any, might be found on Europa. They finally settled on bacteria. Of course, if life exists there, it probably would be pretty simple. But wouldn't it be highly unlikely that it would be anything like bacteria? The only way it could possibly be bacteria is if some sort of panspermia is going on, right?
« Last Edit: October 04, 2016, 03:27:37 PM by gebobs »

Offline daniel1948

  • Stopped Going Outside
  • *******
  • Posts: 4657
  • Cat Lovers Against the Bomb
Re: Episode #586
« Reply #27 on: October 04, 2016, 03:26:45 PM »
I can construct a totally-secure password and memorize it. I cannot remember a new complex password every three months. Sites that force me to do that require me to write down the password somewhere, and that is less secure than allowing me to keep my password.

No, it isn't.  The main threat you are defending against when using strong password on internet-accessible services is from remote attacks.  They have access to time, computers, and dictionaries of weak or stolen passwords to plow through.  They don't have access to the pad of paper on your desk with your strong password written on it.

A lock on your door won't keep burglars out. It will just make the door a more difficult entry point than, say, breaking a window or cutting through a wall. Perhaps it will make the burglars decide that your neighbor's house is an easier target than yours.

There are various ways a hacker may gain access to my accounts. But if and when they do, it won't be by guessing my passwords, because those are more difficult to guess than other ways over which I have no control. As long as nobody has come close to guessing my password, there is no good reason to force me to change it.

Note also that standard good procedure for web sites is to block access entirely after a specific number of failed attempts. So a hacker can only try three or four, or maybe at most ten guesses before the account is locked and I am notified. If I was not the one who was trying wrong passwords (because I forgot mine) then the alert will let me know that something is going on. And even then, changing the password is not necessarily the best choice, since the hacker didn't get in.

Again, I don't use guessable passwords.

It would be much easier for someone to bribe a banker into turning over my social security number and then calling the bank and pretending to be me, as a reporter did with a friend of his (with permission) to show how easy it is to hijack someone's account using information about them that's easily available.

Strong passwords are not the weak link in account security. The problem with passwords is just the people who use weak ones, or who don't even bother to change the default password. And even then, social engineering is probably responsible for more hacked accounts than anything to do with passwords.
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

  • Stopped Going Outside
  • *******
  • Posts: 4657
  • Cat Lovers Against the Bomb
Re: Episode #586
« Reply #28 on: October 04, 2016, 03:31:27 PM »
The rogues wondered what sort of life, if any, might be found on Europa. They finally settled on bacteria. Of course, if it life exists there, it probably would be pretty simple. But wouldn't it be highly unlikely that it would be anything like bacteria? The only way it could possibly be bacteria is if some sort of panspermia is going on, right?

I thought the same thing: Life on another planet is bound to be completely different from anything on Earth. There probably won't be any analogy between the two. Bacteria, protozoa, and certainly jellyfish will have no analogues on Europa. If there is life there (as I think possible, and I hope is the case) it will be so unrecognizable that there will be controversy for a while as to whether it even qualifies as life. We'll have to get it in its own environment and watch it reproduce before we'll be able to confirm that it's actually life.
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

Online Ah.hell

  • Poster of Extraordinary Magnitude
  • **********
  • Posts: 10899
Re: Episode #586
« Reply #29 on: October 04, 2016, 04:02:56 PM »
IDK, convergent evolution is a thing.  If a plan worked once there's no reason why evolution would come up with something similar elsewhere.  On the other hand, there's no reason why it would.  As we only have sample size of one biosphere, we really have no way to guess how life might evolve elsewhere. 

 

personate-rain