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User: barakn

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  1. Re:The Moon doesn't offer much, but Mars... on The Case for the Moon · · Score: 1
    Getting to Mars actually takes less energy that getting to the Moon so I don't see much of a gain as using the Moon as a stepping stone.

    Oh really? Then you'll be happy to provide proof. What's that? You don't have proof? You were on crack when you wrote that, you say? Well, ok. we'll let you off just this once. But don't let it happen again.

  2. Re:What X?? class would cook Earth on Sun Produces Strongest Flare Ever Recorded · · Score: 1

    Since you're talking about x-rays, the magnetosphere numbers are meaningless. X-rays pass through the magnetosphere without noticing it. The atmosphere is remarkably efficient at absorbing them, though.

  3. Re:Other source on Sun Produces Strongest Flare Ever Recorded · · Score: 2, Interesting

    Saturated the SXI imager as well. For those of you who don't know, SXI is a sun-pointed x-ray imaging device on a weather satellite.

  4. Re:Impressive, on Sun Produces Strongest Flare Ever Recorded · · Score: 4, Informative

    Beryllium, not barium.

  5. Re:Historic Period? on Three More Solar Flares · · Score: 1
    Direct observations of sunspots go back to the early 17th century, corresponding to the invention of the telescope.

    Who makes this shit up? It doesn't take a telescope to observe sunspots, which is why the Chinese were doing it as early as 28 B.C.. Eurocentric bastards....

  6. Re:Here comes ANOTHER one... on Three More Solar Flares · · Score: 1
  7. Re:Almost on Three More Solar Flares · · Score: 1

    Yeah, "of the times." And I'd probably be going out on a limb if I connected the Medieval Warm Period (10th to 14th century) with the solar activity of the time. But since the connection of the sun and climate is still not understood very well, a blanket statement like "which has very little to do with sunspots of course" doesn't sit easily with me.

  8. Re:It's not the # of flares .. it's on Three More Solar Flares · · Score: 1

    The science of observing sunspots is thousands of years old. Accurate and mostly continuous records have been kept for centuries. So "a few years ago" is a meaningless statement. The only necessary equipment is an eye.

  9. Re:It's not the # of flares .. it's on Three More Solar Flares · · Score: 2, Insightful
    The number of sunspots is about normal for this time in the 11 year solar cycle

    No. Here's the monthly averaged daily SSNs and here's the last six daily SSNs (scroll a third of the way down to see 'em). The daily SS numbers for the six day period ending on Oct. 28 were 122, 160, 139, 191, 238, and 230. The number dropped to 76 today, which is roughly normal this late in the cycle, but that's because the huge spots are rotating out of view (not to worry, they'll be back in 2 weeks). Once the monthly averages are updated, we'll see that this solar cycle has a peculiar third peak (and even a second peak is somewhat unusual).

  10. Re:Almost on Three More Solar Flares · · Score: 1
    Western European history of the times got kindof complicated - which as very little to do with sunspots of course...

    So you're saying the Maunder Minimum and the resultant Little Ice Age didn't effect Western European history?

  11. Re:Hacking And Overclocking - What? on Hackers On Atkins · · Score: 1
    the diet explicitly tells you that you need to be drinking twelve to sixteen glasses of water a day, to keep flushing your system. You'll note that the FDA says you should drink twelve of them, and most people don't even do that.

    To quote from Dr. Atkins' New Diet Revolution (p. 230) "You must drink at least eight 8-ounce glasses of pure water daily." He never mentions kidney stones as a problem. You were probably thinking of gallstones, which aren't caused by the Atkins diet. The diet can cause the gallbladder to contract, which will cause previously unnoticed gallstones to become painful. In fact, low-fat diets are blamed for inactive gallbladders and thus for forming the gallstones in the first place.

    The FDA certainly did not recommend 12 glasses of water a day. This is another urban myth that just won't die. Anecdotes are not as useful as they seem, but I'll relate one anyway. A friend of mine who exercised heavily, ate an extremely low-fat diet, and drank up to a gallon of water a day had to have surgery on his gallbladder at the age of 25.

  12. Re:SXI online, but too late on NASA's Earth Observatory Shows Solar Flare · · Score: 1

    Well, gosh, you're right. I think I was trying to include a link to the extreme proton event we're experiencing. This page is great for geosynch orbit, this for an L1 halo orbit.

  13. SXI online, but too late on NASA's Earth Observatory Shows Solar Flare · · Score: 4, Informative

    New images of the xray sun are being taken by the SXI imager once again. Use of the imager had stopped because of an unexpected over-current problem. The SXI team decided that they could safely operate the instrument at a lower voltage, albeit at the expense of a lower signal to noise ratio. The decision was hastened by the dramatic solar events today.

  14. Re:Should be interesting on The 'Perfect Space Storm' Of 1859 · · Score: 2, Informative

    This causes drag to increase on satellites; they slow down and gravity pulls them in towards earth.They actually speed up. But they still fall in. Basically, the drag allows them to trade gravitational potential energy for kinetic energy.

  15. Re:Is it just me on Mystery Spot on Jupiter Baffles Astronomers · · Score: 1

    of course now i've gotta clarify some things i said. I assumed inverting involved flipping the image, but rotating the image will also turn it upside down but without changing the handedness. Typically the main optics of a telescope will rotate the image upside-down. It's those of us that choose to use a diagonal that get our images with their handedness reversed as well. Cameras are usually mounted on the optical axis, not a diagonal, and so should take images that are merely rotated, like the Jupiter photos.

  16. Re:Is it just me on Mystery Spot on Jupiter Baffles Astronomers · · Score: 2, Informative
    Something that is upside-down AND left-right reversed has merely been rotated 180 deg (its 'handedness' changes every time you flip it, whether it's right-left or upside-down, and two flips will rectify it). If you rotate the aforementioned Jupiter photos, the red spot appears in the appropriate southern hemisphere and the surface features rotate in the right direction.

    In fact, anybody who images Jupiter through a telescope isn't likely to catch it with its equator nicely aligned with with the CCD's pixel matrix, so somebody had to rotate Jupiter's image just to get its axis to appear straight up & down. I'm curious as to why they choose the north-down perspective, but it's not to be mean. 'Cause I'm left-handed. That's the hand I use, well, never mind......

  17. Is it just me on Mystery Spot on Jupiter Baffles Astronomers · · Score: 3, Informative

    or did anybody else notice that Jupiter's north pole is pointing down in these photos. Oh, yeah, and look at this page for some photos of dark spots caused by comet Shoemaker-Levi 9.

  18. which makes it worthless.... on Not Your Father's Periodic Table · · Score: 1, Insightful

    because it strips out the color-coded information on what sort of 'phile the element is. Iron, for example, is obviously an unusual element when looking at the pdf, as the colors indicate it likes hanging out with everything but atmospheres. In the html version, you don't see it.

  19. Re:They look rather dubious to me on Stonehenge Discovery using 3D Laser Scanning · · Score: 1
    it produces perfectly circular shadows on the two solstice days, which implies that not only did they realise that the sun was at the center of the solar system, but they had correctly estimated the earth-sun distance to within .5%

    It seems like all it would take is knowledge of which days were solstices (a simple observational matter). I can find no references to the "circular shadow' theory either. Most mentions of archeoastronomy in regards to Stonehenge are of solstice sunsets and sunrises framed by stones or aligned above marker stones. These kind of alignments would merely require the builders to remember what points on the horizon these few special events occur on. Links to the "circular shadow" theory would be greatly appreciated, as would an explanation of why it is insufficient to know the path the sun takes through the sky.

  20. Re:that's great but on Stonehenge Discovery using 3D Laser Scanning · · Score: 1

    ... or massive amounts of tourons (sorry, tourists) rubbing the stone with their hands, thanks to the convenient motorway built nearby.

  21. Re:right on! on Could 'Fire Paste' Replace Shuttle Tiles? · · Score: 2, Informative

    Actually, I made enough simplifications that there could be something exponential lurking in a more detailed analysis. My model works for either a good conductor that remains isothermal as it cools, or for a perfectly bad conductor being heated from the outside (it radiates all the energy away from its surface without any of it working its way inside). Also implied was a near vacuum and heat sinks cold enough compared to the temperature of the object that they are essentially zero. As such, it works best for insulating tiles on the Shuttle during the period of reentry when there is still little atmosphere (space = 2.7 K, Earth ~ 300 K, tiles up to 2700 K). In case you care, there is a much more sophisticated analysis of shuttle skin here.

  22. Re:that's great but on Stonehenge Discovery using 3D Laser Scanning · · Score: 1
    it is strange they are able to last 2000+ years and then erode away in the last 50 !

    Try using your imagination. The Great Smog of London in 1952 was responsible for killing 4000 people. Levels of sulfur dioxide jumped dramatically and the smog pH dropped to 1.4-1.9, more acid than battery acid. Symptomatic of a society heavily dependent on coal after they chopped all their forests down.

  23. Re:Incredible claims on Could 'Fire Paste' Replace Shuttle Tiles? · · Score: 1

    It had absolutely nothing to do with the quality of the insulation or its bond to the metal frame. No insulation available on this planet would have survived the scrubbing action of tons of high velocity metallic debris, and any large fire afterwards would melt the exposed frame.

  24. Re:right on! on Could 'Fire Paste' Replace Shuttle Tiles? · · Score: 1
    All things dissipate heat at an exponential rate - heat flow is usually related to a difference in temperatures, so as an object reaches the temperature of its surroundings, the heat flow slows down to aproach zero.

    Careful. This substance is claimed to have virtually no heat conductance, so it dissipates heat either by convection or by radiation (which will dominate at hight T). Luminosity (dE/dt) goes as T^4 and T is proportional to the thermal energy (E=c1*T). A little calculus shows that the temperature T of a high temperature object radiating into a heat sink (i.e. 2.7 Kelvin outer space) goes like (c+t)^(-1/3), where the constant c is determined by the initial T (at t=0), and t is time. The heat dissipation rate thus goes like (c+t)^(-4/3), which is certainly not exponential but does slow down as it approaches the temperature of the heat sink.

  25. Incredible claims on Could 'Fire Paste' Replace Shuttle Tiles? · · Score: 1
    From the article:

    He adds that fire paste can handle such high temperatures, that had the steel skeleton holding up the World Trade Towers been sprayed with it, the buildings wouldn't have imploded after being hit by two airliners Sept. 11

    The WTT skeleton had insulation that could withstand high temperatures, but it didn't withstand the mechanical stripping caused by tons of metal careening into the building at hundreds of miles per hour. His 'paste' would fare no better.

    "It dissipates heat at an exponential rate, it's beyond belief, and I have no idea why it does, all I know is that it does."

    Its energy dissipation varies as T^4, (Stefan-Boltzmann law), and he hasn't tested it well enough to differentiate between an e^T curve and a T^4 curve.