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boo

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Posts posted by boo

  1. iv heard the theory that the binary system of the moon and earth is a result of an ancient collision with some rogue planet or some large object, which seems to have split the moon from the earth and set us in this rotating motion

    but that would mean the object itself was somehow absorbed into earth and became part of it

    so, im  just wondering, would it not make more sense that the moon itself might actually be that object? or the remains of it?

  2. 2 hours ago, Moontanman said:

    I think your larger just before a mass extinction effect is a bit of an illusion but there are some real world reasons this appears to be true even though currently I would say that mammals had their heyday around 2 million or more years ago and currently land animals are bit smaller on average than during Pliocene but Dinosaurs are or were "pre evolved" to be larger, this can be seen from modern living dinosaurs who have hollow bones and more advanced circulatory and lung systems compared to mammals. The largest mammal that ever lived was related to rhinoceros's and was as large as many dinosaurs. Mammals are burdened by heavier but less strong skeletons, less advanced breathing/circulatory systems, and a reproductive system that puts larger adults in a precarious place the larger they get.      

    this is fascinating information, i wasnt aware of it,  thankyou

     

    so, have the conditions also changed on earth since the dinosaur era ,  like is earth colder or something else that would make life impossible for such reptiles to live today?

     

  3. 20 minutes ago, Bufofrog said:

    Do you have any evidence to support this?  Large dinosaurs existed for more than 150 million years with no mass extinctions.  Large mammals have existed for tens of millions of years with no mass extinctions.  I do not think the evidence supports your proposition.

    It is certainly possible that large animals are more susceptible to dying off during an extinction event than small animals.  I don't think that large animals cause extinction events (with the possible exception of humans).

    i probably phrased my question badly.

    I was not suggesting that the large animals were the cause of the extinction.

    but rather, i was suggesting that it is a natural for animals to continue to grow larger and larger unless inhibited by mass extinction events , whatever the cause

  4. On 10/27/2020 at 3:42 PM, Janus said:

    That "Narrow band" is a lot wider than it looks to the naked eye. You are only seeing that part that is bright enough.

    As an example, consider the Andromeda galaxy.  To the naked eye it looks like a small fuzzy spot, but if you could see it in full, it would appear like this in the sky.

    andromeda+if+visible.jpg

    Several times wider than a full Moon. 

    What we see by naked eye is just the nucleus of the galaxy. But just because we don't see the disk by naked eye doesn't mean that it doesn't hide the light from galaxies behind it.

     

    its such a pity that andromeda doesnt actually look like this to the naked eye

  5. it seems that over the course of history, earths lifeforms tend to get very large before a mass extinction event happens, which reduces life back to small life forms again

    so,  would it be reasonable to believe that earth may be headed, over the course of millions of years, back to a dinosaurlike environment again at some point in the future with large animals of some description roaming the earth, weather they be reptiles, or mammals?

     and the human era is possibly just one of the early phases in that process.

    or is there some physical reason why earth can no longer support such a thing, such as weaker atmosphere, or colder planet temperature or something to do with how the eco system has been altered by us humans which makes it impossible?

  6. i heard about the phenomenon of rogue black holes which can get ejected when two galaxies collide in certain circumstances

    these black holes might carry no stars or planets with them and would therefore be invisible, i guess

    which gave me a frightening thought

    if one were hurtling through the abyss directly towards us, possibly about to enter our galaxy  near where earth is located

    would we know in advance?

  7. in terms of looking out of the milky way to the other galaxies in the outer universe 

    how much of it can we see from our location in the milky way?

    for exmaple, imagining the milky way disc was a clock

    if we are at 6 o clock now ,in the milky way,  that if we were at 7 o clock, or 3 o clock we would see a whole different selection of galaxies?

    or can we already see the full 360 degrees of the observable universe from where we are using the instruments we have?

    unless you guessed, im no scientist, so go easy please LOL

  8. On 10/16/2019 at 4:59 PM, Janus said:

    The acceleration of the expansion was discovered a couple of decades ago.  This was due to a study involving Type 1A supernovae.  We had learned that these types of supernovae always reach the same peak brightness.  This made them a "standard candle".  You could tell how far away one was by measuring how bright it appeared to us.

    It never really was thought that the rate of the expansion of the universe was constant.  That is because the gravitational attraction of everything in it was expected to slow the expansion over time.   The one thing we didn't know was if this would be enough to eve completely stop the expansion.

    The study's original intent was to answer this question.   Now the supernovae standard candle gave us a measure of a galaxy's distance and red-shift its speed of recession.  The other factor that comes into play is that the further the galaxy is from us, the further back in time the light we are seeing left it.   We are seeing a red-shift based on what was happening at that time.   If the universe was expanding at a constant rate, then the ratio between distance and red-shift would be the same for all galaxies no matter what distance they are.  If the expansion were slowing with time, it would not be a constant ratio with the ratio changing in a particular manner.  The magnitude of this change would give you a measure of the rate at which the universe's expansion.

    The study found such a deviation, but in the opposite direction than what they expected.  The red-shift/distance ratio changed in a manner that indicated that the universe was expanding slower in the past than it is now.  Instead of slowing down as time went by, it was speeding up.  "Dark energy" was the term coined for whatever was driving this acceleration.  The exact nature of Dark energy is still a mystery, and there are competing hypothesizes as to what it actually is. 

    thats fascinating

    could it be possible that the faster rate at which things are expanding, is a natural result of the fact that the universe is simply bigger now than it was before?  or is it moving even faster still?

     

  9. wow iv learned a lot in those two answers.  I didnt realise that dark matter and dark energy were two different things

    incidentally, how do we know that the expansion is increasing? and how is it increasing exactly?

    I always thought it was increasing at a steady rate,  but naturally that would mean the farther something is away, the faster it would move away simply because the space in between is expanding.

    is that it? 

    or am i to believe that things are expanding faster than they used to?   as in,  lets say you had two galaxies a certain distance from one another. would they move away from eachother at a faster rate now than they would have a billion years ago?  

     

  10. Quote

    Boo Said:  is dark matter nothing more than a wildcard thrown in to a mathematical equation to make the equation work?

     

    On 9/18/2019 at 2:49 PM, Strange said:

    I don't know what that means. Neptune was a "wildcard thrown in to a mathematical equation to make the equation work". The same could be said of electrons, photons, gravity, energy ...

    meaning that it was invented to explain the expanding universe, rather than because we detected it or "saw" it or otherwise proved it to be there.  thats what i meant, with the question. :-)

    reviving an old thread here, but thought i would clarify what i meant there.

  11. 34 minutes ago, Strange said:

    There are multiple lines of evidence for the existence of effects caused by something we label "dark matter". These include the orbital speeds within galaxies, the speeds of orbits with galaxy clusters, gravitational lensing, the spectrum of the CMB, the formation of large scale structures in the universe, and probably more.

    Nearly all of this evidence points to dark matter being a form of matter which does not interact electromagnetically. So, similar to neutrinos but it must be more massive because the distribution shows it to be moving more slowly.

    Not "see" it because it doesn't;t interact with light. I guess the question means will we ever have a more "direct" detection of the particles that make it up? Probably.

    It took over a decade to detect neutrinos "directly" before they were first detected. Obviously, it is harder to detect dark matter particles (otherwise we would have known what they were, perhaps even before observing the effects). It is rather inevitable that each new type of particle is going to be harder to detect.

    I don't know what that means. Neptune was a "wildcard thrown in to a mathematical equation to make the equation work". The same could be said of electrons, photons, gravity, energy ...

    Physics is described in terms of equations. When we discover new things, they are are included in those equations.

    That would be true whether dark matter is a modification to gravity or some form of matter. So the question doesn't really make sense.

    thanks for your response

    ok, very layman question here,  (and i do apologise if these questions appear nonsensical to those of you who study the subject), but it would clear a lot up for me.

    if you bumped into dark matter would you feel it?  or would you pass through it without feeling anything?

    and one more,  

    if there was dark matter in front of regular matter, would it obscure the light coming from it?  or would we see right through the dark matter as tough it was invisible?

  12. is dark matter nothing more than a wildcard thrown in to a mathematical equation to make the equation work?

    what evidence do we have for it other than that?

    will we ever be able to see it? 

    what do you ( or scientists) think it is exacly?

  13. 22 minutes ago, zapatos said:

    . All messages we hear from people appear to me to be coming from people, not God. A consistent message only tells me that those people began with a similar background.

    exactly.  arguably what you see is  exactly what you would expect to see if they were hallucinating, making it up etc.

    38 minutes ago, zapatos said:
    Would you mind providing a link? Primarily what I find is his doubt that Jesus really existed. Thanks.

    I will look for it

    1 hour ago, zapatos said:
    Would you mind providing a link? Primarily what I find is his doubt that Jesus really existed. Thanks.

    here  at  8:11  he makes the point.    

    yes it is assuming that the god cares what we think and wants us to follow him etc. but that is what the claim generally is.

  14. 1 minute ago, zapatos said:
     

    How does it weaken the case for them? What makes you believe Gods would provide a consistent message across place and time?

    you are missing the point.

    the god may or may not want to provide a consistent message, but if they did, it would make for very strong evidence of their existence. The fact that they don't, places the probability for their existence, far lower than the probability that a given individual who claims to have been visited by a god  is hallucinating.

     

  15. 2 minutes ago, zapatos said:

    Who exactly are we talking about that says that.

    How does that prove there is no God? Maybe that is proof that Gods always acts uniquely.

    Dr Richard carrier has made that point.

    Quote

    How does that prove there is no God? Maybe that is proof that Gods always acts uniquely.

    perhaps absolute proof is not obtainable, you can only work with probability,  it weakens the case for each of those gods considerably.

    5 minutes ago, Bufofrog said:

    God does not have communicate the same or consistent message, you just think he should.

    It would help if he did

  16. On 8/3/2019 at 3:15 AM, Trurl said:

    Michio Kaku is correct in saying we can’t prove or disprove God

    There are those who say you can disprove god.

    for example, different religions throughout history have been based upon revelations from a god or gods,  however the revelations and the religions that stem from them seldom have much in common with one another.  If this god had been real then we might see cases where the god was consistently saying the same things to these people regardless of their place in history or geography, but that isn't what we see.

     

     

  17. Is it possible that an extremely large comet or other such object could hit earth suddenly with little warning ?

     

    or is this something we would expect scientists to know about years /decades /centuries in advance?

     

    how much advance warning would we expect to have ? And how big and fast would it have to be to be catastrophic for human life ?

     

     

  18. you often hear the "why is there something rather than nothing?" idea being discussed with relation to the origins of the universe.

    but is "nothing" even possible? Our rudimentary brains tend to associate 'nothingness' with empty space , but apparently scientists have come to think that even empty space is "something" . there is activity there. there is something going on that is enabling that empty space to exist.  to me, a layman, that can only suggest that nothingness is not even possible. It is an abstract concept. than therefore that is why there is "something, rather than nothing"

    because there HAS to be. 

    am i on the right track?

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