Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).


Comment: Re:Inexpensive way to send up inert objects (Score 1) 131

by danhaas (#42559653) Attached to: The Science Behind Building a Space Gun

The necessity of momentum to circularize the orbit is clear if your model consists of only the Earth and the satellite, but I wonder if the gravitational pull of the moon could be used.
What if we could shoot something up to a Lagrange point? Would we still need engines in our satellite?

Comment: Re:no grey goo? (Score 1) 274

by danhaas (#42095481) Attached to: Cambridge University To Open "Terminator Center" To Study Threat From AI

The grey goo apocalypse has already happened. Bacteria are trying to do it for billions of years, and have had some nice accomplishments:


I really doubt we could do better than billions of years of evolution iterations.

Biological warfare, though, is another beast, since it targets human specifically.

Comment: Re:Hold your head high ! (Score 1) 684

by danhaas (#42041819) Attached to: Young Students Hiding Academic Talent To Avoid Bullying

I think there is some truth in his "head games", but your argument is good too.

One thing that helped me get through bullying was martial arts; after a few months of practice, I wouldn't be able to outright beat the bullies, but I would at least be willing to put up a fight.

The boost in self-confidence that martial arts gave me made me a tougher target and they moved on.

But I was an easy target also because I didn't really belong there, with those people. I was naturally isolated.

It doesn't matter how tough you are, if you think differently, you will be a target.

Comment: Feasibility of Strikes (Score 2) 761

Petroleum Engineer here, working with research.

I can tell for myself, engineers don't have much reason to strike. Why? Because it's usually pointless, there's no short-term damage to the employer. If an engineer doesn't show up, work simply goes on.

An engineer on the field has to strike for a few weeks/months to even begin to be noticed. In my case, working with research, I would have to strike for at least one year to do some real harm to my employer.

Engineers aren't useless; the most I know are well worth what they earn. But they influence mainly the future profits of the company, while blue-collar works have a direct influence on the daily profits, not to mention the quarter results.

Striking just isn't a nice strategy for white-collar workers. Threatening to go to a competitor is.

Now if people could threaten to move entire work groups to a competitor... that would be a negotiation I would like to see.

Comment: Re:Not so fast (Score 1) 580

by danhaas (#41706333) Attached to: Scientists Turn Air Into Petrol

CO2 filtering is indeed tricky. Maybe ammonia fuel production would be more viable.

Ammonia as a fuel:

Production process:

This process requires pure hydrogen, which could be made with high temperature electrolysis. I think this setup could work very well with solar thermal plants.

Other than the trouble that your fuel would really stink, it could be easier to produce than gasoline.

Ammonia is also extensively used for agriculture, so this process may be important even if fuel production doesn't take off.

Comment: Re:Got to love public services... (Score 1) 91

Recirculation patterns are pretty common when the fluid flows through an expansion, specially if it's a sharp cut.

You can see it clearly in this case because of the gas bubbles, but this happens everywhere: next time you walk behind a building on the shore, watch the huge recirculation that the wind forms. This is usually how people with umbrellas end up wet "because of the crazy wind".

Comment: Re:Still Wrong (Score 1) 926

That's right, the raw material isn't the problem, but energy. Fossil fuels just happen to be the cheapest source of energy for that.

In fact, many, many problems can be solved if there is free, clean, abundant energy. It's possible to just vaporize any piece of land, separate each atom individually and produce pratically anything out of it.

Of course, that's insanely inefficient. But an even crazier idea is to manufacture the atoms you need with nuclear reactions, and it would be viable with infinite energy.

Energy is the ultimate resource. Fossil fuels are just the easiest source to tap, which would be best used to develop the next not-so-easy energy source, if we were wise.

Yes, we will be going to OSI, Mars, and Pluto, but not necessarily in that order. -- Jeffrey Honig