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Comment Re:Someone doesn't understand basic relativity (Score 0) 81

And I don't mean the speed of light kind.

At 14 stories tall and traveling upwards of 1300 m/s (nearly 1 mi/s), stabilizing the Falcon 9 first stage for reentry is like trying to balance a rubber broomstick on your hand in the middle of a wind storm.

EXACTLY the same as takeoff. NO difference.

Same amount of fuel? No, so not the same moments of inertia. During launch the engine is pushing in the direction of travel, during re-entry no. During launch, the aerodynamics include that nice fairing on the nose, which should be a bit less chaotic than coming engine first down. The period of 1300 m/s travel that you quote and compare to launch is not during launch (0 m/s) - it is probably closer to the period of maximum dynamic load and clearly during super sonic travel. The reverse part of that travel, the period of maximal dynamic load during re-entry in a non-aerodynamic configuration is rather more difficult than getting off the pad.

Comment Re:The video game crash of 1983 (Score 1) 191

The crash happened across platforms, though I have a limited view of it - I co-wrote Repton for Sirius Software, available on Apple II, C-64, and Atari 400/800. Sirius went out of business because 20th Century Fox failed a promised payment of $20mil. But I also worked for Infocom around '85 - and they were also crushed - maybe due to being text based.

Comment Re:Nothing? (Score 1) 429

As long as there's no faster-than-light travel, "X happens before Y" is an invariant - it's true in all reference frames.

No. http://math.ucr.edu/home/baez/... and for the longer version http://en.wikipedia.org/wiki/L.... In these examples, the doors either close at the same time for the observer stationary with respect to the barn, or at different times for the observer running with the pole.

OK, sorry, should have said ""X doesn't happen after Y" is an invariant" (there don't exist reference frames such that X happens before Y in one frame and X happens after Y in another frame).

Again no. A running coming from the other direction would see the doors close in the other order. I think the AC parallel to this post explains it pretty well.

Comment Re:Nothing? (Score 4, Informative) 429

As long as there's no faster-than-light travel, "X happens before Y" is an invariant - it's true in all reference frames.

No. http://math.ucr.edu/home/baez/... and for the longer version http://en.wikipedia.org/wiki/L.... In these examples, the doors either close at the same time for the observer stationary with respect to the barn, or at different times for the observer running with the pole.

Comment Re:Science is not about trust (Score 1) 460

Always enjoy reading his lectures - thanks. Had the pleasure of hearing a couple as well.
Maybe I was not clear in my statement - the LHC itself is not so much an experiment as a source of high energy collisions - the experiments are the detectors placed in the beam line, and with respect to the detection of the Higgs, there are the two: http://en.wikipedia.org/wiki/A... http://en.wikipedia.org/wiki/C.... While they are similar in that they detect collisions and take careful account of the collision products they do so differently. So they are effectively in a position to reproduce each others results as they have done with the detection of the Higgs.

Comment Re:Science is not about trust (Score 3, Informative) 460

Science is about reproducible results. Publish the details of your experiment, so I can perform your experiment (and variations on it) myself. Your claim is strengthened if I get the same results you do.

But I don't have a Large Hadron Collider! How am I supposed to reproduce this?

The fact is that many experiments are expensive to reproduce and will not be; and there are scientists who do poor work either intentionally or due to institutional reasons. The desire to do great science is only part of the motivation of a scientist; the desire to feed one's family can influence anyone thinking, as can the desire for fame, or other desires.
Addressing the LHC argument - The LHC requires thousands of scientists, the results will be examined to see if they match previous results at the appropriate energies, and it is worth noting that the LHC has detectors ATLAS and CMS which effectively check each others results regarding detection of the Higgs. And there are other detectors looking for new physics, that are not presently worth the cost of double coverage.

I suspect that there are backwaters of science, where someone may find gain in having published many papers, and have low risk of being caught because the value of the results is such that they will not be replicated; but when you cheat like Jan Hendrik Schön with results that would be quite valuable then you can expect work attempting to extend the experiment to be done, and when it fails the original work will be re-checked.

Comment Re:Hmmm ... (Score 2) 356

Read the conclusion where the author directly addresses your concerns. But, I will also point out that at the stage of collapse the authors are talking about the star more closely resembles a neutron star rather than a hydrogen fusing star. Because a neutron star is supported by Pauli exclusion, it seems to me that the density may well be close to constant through out a majority of the star.

Comment Re: Alright smart guy (Score 1) 504

I use safari too - which is what is failing to load all kinds of things - I'm going to give tenfourfox a try. I mostly like to have a 'puter that the two year old can tear the keys off of and I don't get stressed out. But it would also be nice if the browser worked well enough for the seven year old to run his blog.

Comment Re:Just do it. (Score 2) 234

To add to the Galaxy Zoo suggestion:
Have a look at this book: "Statistics, data mining and machine learning in astronomy" http://www.britastro.org/journ...
I have my BS in Physics, but I write software. I think it would be pretty hard at 10 hours a week to pick up the math of most of the advanced topics - even mechanics. But, learning statistics and data mining and having public access to data like the Sloan Survey would put you in the position to make real discoveries as an amateur. And, a modicum of competence in statistics and data mining may give you some good options for paying gigs.

Comment Re:Thermodynamic equilibrium is not required (Score 1) 211

There's this "Sun" bombarding the planet with energy, constantly.

Then take the two-body system given by the Earth and the Sun as the closed system.

If it was a closed system the Earth would have cooked by now coming to equilibrium with the Sun - fortunately we have the cold bath of the rest of the universe to which most of the Sun's energy flows, as well as some heat from the night side of the Earth - so it is not a closed system.

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