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Old 16-02-2016, 00:18
atg
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Hi whatjoethinks , if you are happy with your previous comment, sometimes there is no need to keep explaining, as sometimes that takes one in circles.

For what it is worth I attach the following for atg, which provides adequate description of the various terminologies associated with prefixes used with the SI system of metrics:
https://en.wikipedia.org/wiki/Metric_prefix
Well thank you so much. I was really pointing out the slight inconsistency of using "Gya", to "avoid the confusion between different meanings of billion", while using billion in the same post. But thanks anyway.
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Old 16-02-2016, 00:19
MinaH
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46 billion! That's a lot of Melson's Columns.
Bill Gates is worth 78 billion ($).
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Old 16-02-2016, 00:21
MinaH
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Well thank you so much. I was really pointing out the slight inconsistency of using "Gya", to "avoid the confusion between different meanings of billion", while using billion in the same post. But thanks anyway.
I was sort of getting lost in the side stream this thread had taken. Apologies.
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Old 16-02-2016, 00:39
WhatJoeThinks
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Well thank you so much. I was really pointing out the slight inconsistency of using "Gya", to "avoid the confusion between different meanings of billion", while using billion in the same post. But thanks anyway.
I used "Gya" because that's the standard abbreviation (and I wanted to abbreviate). The rationale behind the standard abbreviation (that it avoids confusion) is not the same thing as my reason for using it. Is this really so confusing, or are you just being obtuse?
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Old 16-02-2016, 00:42
WhatJoeThinks
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46 billion! That's a lot of Nelson's Columns.


I'll never forgive Michio Kaku for claiming that if all the stars in the galaxy were turned into peas they'd fill a stadium.
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Old 16-02-2016, 11:36
The 12th Doctor
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I still haven't got it clear in my mind why these gravitational waves travel at the speed of light

Are they thought to be some kind of electro-magnetic wave ?

I don't think that's the case as I understood the science has been trying for a century to find a relationship between gravity and electromagnetism and the other forces

I suspect that these waves not actually composed of waves of gravity but ripples in the fabric of the universe.........in the same way that 'gravity' doesn't really exist but is merely a handy description of the distortions in spacetime caused by mass

Does this sound as though I'm on the right track ?
I know what you mean, this does puzzle me, too. Especially since the existence of gravitational waves, confirming Einstein, pretty much refutes the idea that gravity is a traditional "wave" carried by quanta of any kind, unless space itself is quantified and therefore, gravity is a disturbance in that spacetime field.
In other words, saying gravity is carried by gravitons is like saying waves in the ocean are unrelated to the ocean and the water, and actually consist of, say, oil slicks on the surface of, rather than part of, the water. For quantum gravity and general relativity to both be right, spacetime would need to be like water and gravity like waves in the water. Quantum spacetime rippling without a graviton in sight.
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Old 16-02-2016, 11:39
The 12th Doctor
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I'll never forgive Michio Kaku for claiming that if all the stars in the galaxy were turned into peas they'd fill a stadium.
The more I see of that dude, the more he reminds me of a lot of so-called experts on TV. I don't doubt his qualifications but I suspect he reads from a script written by a Star Trek fanclub.
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Old 16-02-2016, 12:00
RobinOfLoxley
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I don't mind a bit of dumbing down every now and again.

It's annoying when channels and whole series change their rationale though.
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Old 16-02-2016, 19:55
WhatJoeThinks
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I still haven't got it clear in my mind why these gravitational waves travel at the speed of light
Generally I think anything will travel at the speed of light unless there is a reason for it not to, such as having mass.
I know what you mean, this does puzzle me, too. Especially since the existence of gravitational waves, confirming Einstein, pretty much refutes the idea that gravity is a traditional "wave" carried by quanta of any kind, unless space itself is quantified and therefore, gravity is a disturbance in that spacetime field.
It makes much more sense to think of c as the speed of causality. If instantaneous action at a distance was possible then all sorts of paradoxes would occur, and that wouldn't make for a very orderly Universe, would it?

[Edit] PBS did a decent video about this a few months ago.
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Old 17-02-2016, 11:18
The 12th Doctor
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It makes much more sense to think of c as the speed of causality. If instantaneous action at a distance was possible then all sorts of paradoxes would occur, and that wouldn't make for a very orderly Universe, would it?

[Edit] PBS did a decent video about this a few months ago.
My point still stands - ripples in spacetime pretty much refutes the idea of gravitons. Gravity must be a disturbance in a quantified spacetime field rather than be a quantified wave or field itself.
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Old 17-02-2016, 12:08
njp
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My point still stands - ripples in spacetime pretty much refutes the idea of gravitons.
No, it doesn't. As I pointed out to you before, if quantum gravity theorists had made any predictions that were invalidated by the detection of gravitational waves, they would have to change or abandon their theories. But they haven't, so they don't. In fact, there isn't a consistent theory of quantum gravity, so predictions from it are a bit thin on the ground!

LIGO cannot tell us anything about the existence of gravitons, in the same way as the aerial of your TV set cannot tell you anything about the existence of photons.
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Old 17-02-2016, 19:40
Keyser_Soze1
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The top 10 astronomical discoveries of all time.

http://news.discovery.com/space/astr...tos-160217.htm
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Old 20-02-2016, 04:16
FIN-MAN
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NASA moves ahead with its next space telescope - Wide-Field Infrared Survey Telescope (WFIRST)
Hopefully we will finally be able to get those nude Alien shots everyone has been waiting for.

http://www.sciencemag.org/news/2016/...pace-telescope
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Old 24-02-2016, 21:32
Keyser_Soze1
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We really could be alone in the observable Universe.

If that it true what a really wonderful job Humanity has done in f****** up the planet for every other living thing.

Even so the point is moot.

If there were millions of advanced civilisations in the galaxy we will never be able to communicate with them in any meaningful way (if such a thing were possible with beings of a vastly different evolutionary and biological history).

The distances are far too great.

Why bother to ask a question when you will not get the answer for many millennia (and that is being optimistic)?

Humanity does not work on such timescales.

http://www.scientificamerican.com/ar...ial-after-all/

http://blogs.discovermagazine.com/d-.../#.Vs38rPmLTIU

On the other hand Homo sapiens is capable of true greatness and science is the light in a world of superstitious darkness.

http://www.smithsonianmag.com/smart-...way-180958206/

This video is breathtaking and so wonderfully relaxing.

https://www.youtube.com/watch?v=Ip3YHk0gu0I
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Old 24-02-2016, 22:56
FIN-MAN
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We really could be alone in the observable Universe.

If that it true what a really wonderful job Humanity has done in f****** up the planet for every other living thing.

Even so the point is moot.

If there were millions of advanced civilisations in the galaxy we will never be able to communicate with them in any meaningful way (if such a thing were possible with beings of a vastly different evolutionary and biological history).

The distances are far too great.


Why bother to ask a question when you will not get the answer for many millennia (and that is being optimistic)?

Humanity does not work on such timescales.

http://www.scientificamerican.com/ar...ial-after-all/

http://blogs.discovermagazine.com/d-.../#.Vs38rPmLTIU

On the other hand Homo sapiens is capable of true greatness and science is the light in a world of superstitious darkness.

http://www.smithsonianmag.com/smart-...way-180958206/

This video is breathtaking and so wonderfully relaxing.

https://www.youtube.com/watch?v=Ip3YHk0gu0I
The only way I could see human beings able to interact with other intelligent beings is if 1) They came here, or 2) we build large space ships/societies in the FAR FAR future that people just lived on traveling through space, kind of like nomads (think Battlestar Galactica). And then it would just be sheer coincidence that they bumped into each other. God help those poor aliens if that happens.
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Old 25-02-2016, 00:32
Keyser_Soze1
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The only way I could see human beings able to interact with other intelligent beings is if 1) They came here, or 2) we build large space ships/societies in the FAR FAR future that people just lived on traveling through space, kind of like nomads (think Battlestar Galactica). And then it would just be sheer coincidence that they bumped into each other. God help those poor aliens if that happens.
It probably would be God help us if any Alien intelligence ever visited Earth (and we probably would never even know about it).

One look and they could decide to quickly and painlessly fumigate the planet of Homo sapiens for the greater good of the biosphere!
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Old 25-02-2016, 02:37
FIN-MAN
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It probably would be God help us if any Alien intelligence ever visited Earth (and we probably would never even know about it).

One look and they could decide to quickly and painlessly fumigate the planet of Homo sapiens for the greater good of the biosphere!
Nah we don't have anything to worry about, remember we have the common cold. If Tom Cruise taught me anything it's that. I guess highly advanced aliens that are so technologically advanced to reach us and the equipment to take over earth in a blink of an eye have no medical advancement.
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Old 25-02-2016, 19:59
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We really could be alone in the observable Universe.

If that it true what a really wonderful job Humanity has done in f****** up the planet for every other living thing.

Even so the point is moot.

If there were millions of advanced civilisations in the galaxy we will never be able to communicate with them in any meaningful way (if such a thing were possible with beings of a vastly different evolutionary and biological history).

The distances are far too great.

Why bother to ask a question when you will not get the answer for many millennia (and that is being optimistic)?

Humanity does not work on such timescales.

http://www.scientificamerican.com/ar...ial-after-all/

http://blogs.discovermagazine.com/d-.../#.Vs38rPmLTIU
I am disappointed by those two highly "we're special and at the centre of things" anthropocentric BS articles which is what they are. It's not good science because only a minute fraction of this galaxy's planets have been observed so far so they cannot at this stage extrapolate to a wider position or principle. Furthermore, the current observing techniques are still too early and primitive and they are biased in favour of big planets and against Venus/Earth/Mars ones where the life might be.

As detection methods improve over the next few decades, many more Earth-sized planets will be found and before the end of this century, it will be possible to see pixellated continents on some of the nearer worlds and planetary atmospheres [CO2, H20, CH4, O2, O3] that are consistent with at least bacterial life will have been discovered.

This galaxy is so huge, let alone the rest of the universe, that there are almost certainly other intelligences and civilisations residing in the Milky Way Galaxy right now.

Every time the (primitive and arrogant) humans think that they are the centre of everything and that they are unique they have been proved wrong.
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Old 25-02-2016, 20:14
snukr
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I am disappointed by those two highly "we're special and at the centre of things" anthropocentric BS articles which is what they are. It's not good science because only a minute fraction of this galaxy's planets have been observed so far so they cannot at this stage extrapolate to a wider position or principle. Furthermore, the current observing techniques are still too early and primitive and they are biased in favour of big planets and against Venus/Earth/Mars ones where the life might be.

As detection methods improve over the next few decades, many more Earth-sized planets will be found and before the end of this century, it will be possible to see pixellated continents on some of the nearer worlds and planetary atmospheres [CO2, H20, CH4, O2, O3] that are consistent with at least bacterial life will have been discovered.

This galaxy is so huge, let alone the rest of the universe, that there are almost certainly other intelligences and civilisations residing in the Milky Way Galaxy right now.

Every time the (primitive and arrogant) humans think that they are the centre of everything and that they are unique they have been proved wrong.
How will they be able to see planetary atmospheres and know what they consist of, and why do they think they will be made up from gases which exist on earth? Do they not consider the possibility, indeed likelihood there are other gases in the Universe which don't exist on Earth? Do they seriously believe that there are no other minerals, metals or gases outside of those which exist in Earth's periodic table?
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Old 25-02-2016, 20:43
TelevisionUser
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How will they be able to see planetary atmospheres and know what they consist of, and why do they think they will be made up from gases which exist on earth? Do they not consider the possibility, indeed likelihood there are other gases in the Universe which don't exist on Earth? Do they seriously believe that there are no other minerals, metals or gases outside of those which exist in Earth's periodic table?
There's a whole lot of questions in that very sensible and inquiring post of yours so here goes.

The technique of astronomical spectroscopy [see http://everything.explained.today/As..._spectroscopy/] allows us to examine the composition of stars, planetary atmospheres and galaxies without the requirement to travel to these places. That is how part of the atmospheric compositions of Venus, Mars and Titan, etc. were determined before any close up space probes ever visited those places.

Elements like hydrogen and helium were formed in the big bang and all the rest were formed in the cores or the end of life explosions of stars so the elements that we know about are pretty much the same as occur elsewhere in the universe because they were generated by the same means. It is possible by laboratory experiments to create additional new heavy elements but they tend to be unstable and short lived and don't occur in nature [see https://en.wikipedia.org/wiki/Transuranium_element].

Since the building block elements are the same wherever you go in the universe, the compounds that result from the joining up of those elements will also be pretty much the same as the compounds that we know about or could predict. For example, the volcanic mineral olivine [see https://en.wikipedia.org/wiki/Olivine] has been found on Earth where it's pretty widespread and it's now been found too on the Moon and Mars and the obvious extrapolation is that it will be found on worlds in other solar systems where there has also been volcanic activity.

Regarding the detection of life on other worlds, the evolution and spread of microorganisms changed the composition of Earth's atmosphere [see https://en.wikipedia.org/wiki/Stromatolite] and the presence of life can be inferred if another world has a distinct and varied atmospheric composition similar to that of Earth and we can (or will be able to) determine that by spectroscopy which brings us back to the very first point in this thread. I hope that all helps.
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Old 26-02-2016, 21:20
Keyser_Soze1
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http://www.space.com/32038-cubesat-s...en-worlds.html

http://www.space.com/29320-cubesats-...fographic.html

http://www.livescience.com/53857-5d-...elativity.html
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Old 27-02-2016, 09:09
Eddie Badger
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Nah we don't have anything to worry about, remember we have the common cold. If Tom Cruise taught me anything it's that. I guess highly advanced aliens that are so technologically advanced to reach us and the equipment to take over earth in a blink of an eye have no medical advancement.
And they don't use anti-virus software and their computer systems can be hacked into by a Mac laptop.
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Old 27-02-2016, 10:59
RobinOfLoxley
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And they don't use anti-virus software and their computer systems can be hacked into by a Mac laptop.
Don't we mean Jeff Goldblum? http://scifi.stackexchange.com/quest...dependence-day
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Old 29-02-2016, 09:52
Keyser_Soze1
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Photon propulsion.

http://www.space.com/32026-photon-pr...hree-days.html
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Old 29-02-2016, 11:52
codeblue
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Do they seriously believe that there are no other minerals, metals or gases outside of those which exist in Earth's periodic table?
There are not.
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