GostHacked Posted July 29, 2009 Report Posted July 29, 2009 Is that your no expert opinion? And a visionary one as well. Flight, bah, impossible. Space travel, bah impossible. Star trek like cell phone communicators, bah impossible !!!. Quote
DogOnPorch Posted July 29, 2009 Author Report Posted July 29, 2009 But meh, no use arguing concepts of relativity here really. Can go to the physics forums for that ;p Arguing...no. But education...yes! You're obviously a very smart dude and we'd all benefit from a little Relativity 101. On a humorous note: This new learning amazes me Sir Bonam. Explain to me again how sheeps' bladders can be used to predict earthquakes. Quote Nothing cracks a turtle like Leon Uris.
Bonam Posted July 29, 2009 Report Posted July 29, 2009 Faster than light communications will eventually be possible. That may be true, but if it is, it will be a technology based on physics unknown to us today. You're obviously a very smart dude and we'd all benefit from a little Relativity 101. Unfortunately I'm not really qualified to give Relativity 101. My understanding of special relativity is decent, but certainly not exceptional nor complete, and general relativity I only have been exposed to in qualitative terms. Quote
DogOnPorch Posted July 29, 2009 Author Report Posted July 29, 2009 That may be true, but if it is, it will be a technology based on physics unknown to us today. Maybe with the technological singularity such concepts will emerge? Unfortunately I'm not really qualified to give Relativity 101. My understanding of special relativity is decent, but certainly not exceptional nor complete, and general relativity I only have been exposed to in qualitative terms. Fine...but if we get shipwrecked, I still say we call you "Professor". Quote Nothing cracks a turtle like Leon Uris.
CANADIEN Posted July 30, 2009 Report Posted July 30, 2009 Actually that is a flawed concept, arising from a lack of understanding of the principles of relativity. There is no absolute time frame in which to define simultaneity. For us, what we see happening on Betelgeuse, is what is happening NOW, for us, because any possible effects of the occurrence can only be felt now. One can do a thought experiment where one instantly transports themselves to Betelgeuse and from there observes that the events we are now seeing on Earth are 600 years old, but this is impossible in practice. For an observer on Earth, the only present is the present that is observable from Earth. Anyway my words are hopelessly inadequate to what I'm trying to explain I guess, relativity takes a bit of time to explain and to wrap one's head around. But the concept is to do with the relativity of simultaneity. I understand relativity... kind of. We could debate this for years and still fubd ways to claim both approaches are right in their own distict way or only the relativist approach is right. Quote
CANADIEN Posted July 30, 2009 Report Posted July 30, 2009 faster than light travel? Who knows? A few months back, PBS had something on an experiment in which light was actually slowed. Quote
Bonam Posted July 30, 2009 Report Posted July 30, 2009 Maybe with the technological singularity such concepts will emerge? I certainly look forward to finding out. Fine...but if we get shipwrecked, I still say we call you "Professor". Haha sure. Long as you don't expect me to build a radio out of coconuts... faster than light travel? Who knows? A few months back, PBS had something on an experiment in which light was actually slowed. Light is slowed all the time, whenever it passes through a medium besides vacuum. Various media have been developed that slow light to an extreme extent, such that it travels at speeds on the orders of just a few cm/s, I believe. However, the speed of light in these media is not a fundamental constant, it does not restrict the rate at which information can travel through that medium, nor through the universe in general. Certainly a gravitational wave would still travel through such a medium at the vacuum speed of light, c, 300000 km/s. And sound waves generally travel through such media faster than light as well. Quote
DogOnPorch Posted July 30, 2009 Author Report Posted July 30, 2009 I understand relativity... kind of. We could debate this for years and still fubd ways to claim both approaches are right in their own distict way or only the relativist approach is right. You can bounce the ball on the flatbed railcar...we'll watch. Quote Nothing cracks a turtle like Leon Uris.
Wild Bill Posted July 30, 2009 Report Posted July 30, 2009 "There was a young lady named Bright Who traveled much faster than light! She started one day, in the relative way And returned home the previous night!" Sorry. I just couldn't resist! Quote "A government which robs Peter to pay Paul can always depend on the support of Paul." -- George Bernard Shaw "There is no point in being difficult when, with a little extra effort, you can be completely impossible."
Jerry J. Fortin Posted August 1, 2009 Report Posted August 1, 2009 Are we positive about the polar axis of Betelgeuse? Is it not possible that massive energy discharges can cause axis shifts due to reduced volume and therefore mass? Quote
Bonam Posted August 1, 2009 Report Posted August 1, 2009 Are we positive about the polar axis of Betelgeuse? Is it not possible that massive energy discharges can cause axis shifts due to reduced volume and therefore mass? Angular moment is conserved. Quote
Jerry J. Fortin Posted August 3, 2009 Report Posted August 3, 2009 Angular moment is conserved. Sure as it applies to rotation, but what about the loss of volume at a particular point in the case of a mass eruption. Will that not adversely impact the magnetic field? If a large enough mass is ejected during some monster sizes flare or eruption is not the probable result going to be a magnetic pole shift? Does that not follow? I know it will not be a large shift in terms of degree but I am thinking that it MUST happen, but only with a sufficient discharge of volume. I mean this thing is going nova right? At some point the entire mass collapses, compresses and explodes. Quote
Sir Bandelot Posted August 3, 2009 Report Posted August 3, 2009 The general consensus amongst rational scientists is that there is no threat from a supernova beyond about 100 light years from Earth. Betelgeuse is something like 650 light years. But it would certainly be an impressive show! Quote
Jerry J. Fortin Posted August 3, 2009 Report Posted August 3, 2009 The general consensus amongst rational scientists is that there is no threat from a supernova beyond about 100 light years from Earth. Betelgeuse is something like 650 light years. But it would certainly be an impressive show! Good news! That doesn't answer the question though. The reason I ask is because from what I have been able to understand the most dangerous radiation will come from the centre axis of the star. I have read that as far as 4-500 light years will be adversely impacted by the explosion, along that axis. Quote
DogOnPorch Posted August 3, 2009 Author Report Posted August 3, 2009 I guess the ultimate answer is we really don't know. It's a very big explosion...boggles the mind. I'm still just reminded about the picture posted earlier of SN1994D...lol. That be big... Quote Nothing cracks a turtle like Leon Uris.
Jerry J. Fortin Posted August 3, 2009 Report Posted August 3, 2009 I guess the ultimate answer is we really don't know. It's a very big explosion...boggles the mind. I'm still just reminded about the picture posted earlier of SN1994D...lol. That be big... Should the axis of the supernova be aligned with the earth we may in fact have a problem. Quote
Bonam Posted August 4, 2009 Report Posted August 4, 2009 Sure as it applies to rotation, but what about the loss of volume at a particular point in the case of a mass eruption. Will that not adversely impact the magnetic field? If a large enough mass is ejected during some monster sizes flare or eruption is not the probable result going to be a magnetic pole shift? Does that not follow? I know it will not be a large shift in terms of degree but I am thinking that it MUST happen, but only with a sufficient discharge of volume. I mean this thing is going nova right? At some point the entire mass collapses, compresses and explodes. I'm not sure. I suppose that given the colossal violence of the explosion, many things are possible. If mass was ejected in a highly asymmetric fashion for some reason, perhaps that could have an effect of the type you describe. I don't know what would cause extreme asymmetry in the ejection to begin with though. In any case, consider how tiny the "target" angle for it would have to be to "hit" the Earth compared to the entire range of angles it could be pointing at (a full sphere, or 4 pi steradians) - the probability of it lining up like that is very small. Anyway, if we're gonna start worrying about cosmic threats, I think we should start with the asteroids and comets. The chance of one of those hitting the Earth is a lot higher than getting hit by harmful supernova radiation, plus we can actually realistically do something about it, and detect it with sufficient warning to react. I have read that as far as 4-500 light years will be adversely impacted by the explosion, along that axis. Where did you read that? Quote
DogOnPorch Posted August 4, 2009 Author Report Posted August 4, 2009 Some supernova remnants are very symetrical while others are all over the place. Maybe it depends on what type of supernova... Quote Nothing cracks a turtle like Leon Uris.
GostHacked Posted August 5, 2009 Report Posted August 5, 2009 Some supernova remnants are very symetrical while others are all over the place. Maybe it depends on what type of supernova... Yeah, I am not going to worry over the improbable chance of the pulsar or whatever comes off it affecting our planet. Even off a couple degrees, at that distance it would have a target path that is far beyond our solar system. Quote
gc1765 Posted August 6, 2009 Report Posted August 6, 2009 (edited) For anyone confused by special relativity, or whether things happened in the past or present, I strongly recommend reading pages 139-142 of this book Then answer the question, did the cows jump all at the same time or not?? If you've never heard of special relativity it will blow your mind. Edited August 6, 2009 by gc1765 Quote Almost three thousand people died needlessly and tragically at the World Trade Center on September 11; ten thousand Africans die needlessly and tragically every single day-and have died every single day since September 11-of AIDS, TB, and malaria. We need to keep September 11 in perspective, especially because the ten thousand daily deaths are preventable. - Jeffrey Sachs (from his book "The End of Poverty")
Sir Bandelot Posted August 6, 2009 Report Posted August 6, 2009 (edited) -Deleted- sb Edited August 6, 2009 by Sir Bandelot Quote
Sir Bandelot Posted August 6, 2009 Report Posted August 6, 2009 Houston, we have a problem... Dying Star Has Deadly Potential Wolf-Rayets are fiery, hot, dynamic stars, but WR 104 also has a sinister side... it could explode as a gamma-ray burst. Not only that, but recent observations of the system suggest it is facing right at us. If that thing blows, and it fires a deadly beam of gamma-rays in our direction, it could do serious damage to our planet. Alright, so who can sleep well at night now, hmm? Quote
Bonam Posted August 6, 2009 Report Posted August 6, 2009 (edited) Houston, we have a problem...Dying Star Has Deadly Potential Wolf-Rayets are fiery, hot, dynamic stars, but WR 104 also has a sinister side... it could explode as a gamma-ray burst. Not only that, but recent observations of the system suggest it is facing right at us. If that thing blows, and it fires a deadly beam of gamma-rays in our direction, it could do serious damage to our planet. Alright, so who can sleep well at night now, hmm? Reading further down in the article, note: Although, from the infrared observations, it's hard to see how WR 104 could possibly be facing anywhere other than right at us, Hill has uncovered something of a conundrum."Having said that, there are several reasons why I am not so sure," Hill continued. "First, I have been able to measure velocities for both the WR star and its companion." "With those velocities I can calculate the orbit and by extension say something about the orbital inclination if I assume reasonable masses for the stars. Doing that implies the inclination is at least 30 or 40 degrees." This analysis makes use of data gathered by another Keck instrument called the Low Resolution Imaging Spectrograph (LRIS). Dr. Hill decided to work with LRIS as it is sensitive to the spectral emission line of ionized carbon. It turns out that the carbon emission is a good diagnostic for the compressed wind regions where the stellar winds collide between WR 104 and its O-type partner (causing the infrared-emitting dust spiral), making it a great target for Hill to gain velocity readings from the spectrograph. and: There's another nagging doubt in his mind that WR 104 may not actually be facing us, and it's a question of statistics. "I think that about a half a dozen of these spiral pinwheels have now been imaged," Hill pointed out. "If I recall correctly, all but one of them look to the eye as if they are nearly face on. Statistically that raises a red flag to me."Artist impression of a Wolf-Rayet star (NASA) Okay, so the infrared observations by the NIRC and the spectroscopic results from LRIS don't appear to agree, and there's the statistical question that 5 times out of 6, the spiral pinwheels are facing us. What possible explanation could there be for WR 104? Referring to Peter Tuthill's website, Dr. Hill suggested that WR 104 has more of a 3D structure than meets the eye. "Take some three dimensional object like a fish bowl and tilt it. It is hard to figure out exactly what the tilt is," he said. Basically, it may very well be pointing up to 30-40 degrees away from us and they can't really tell. I'm not gonna lose any sleep over this one. Edited August 6, 2009 by Bonam Quote
DogOnPorch Posted August 8, 2009 Author Report Posted August 8, 2009 Reading further down in the article, note:and: Basically, it may very well be pointing up to 30-40 degrees away from us and they can't really tell. I'm not gonna lose any sleep over this one. Indeed...this star appears to be boiling so much it isn't so much a sphere as a churning blob of plasma. Quote Nothing cracks a turtle like Leon Uris.
wyly Posted November 2, 2009 Report Posted November 2, 2009 nothing we can do about exploding stars so I'm not going to worry about it, just enjoy life as best we can... Quote “Conservatives are not necessarily stupid, but most stupid people are conservatives.”- John Stuart Mill
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