Progarchives.com has always (since 2002) relied on banners ads to cover web hosting fees and all.
Please consider supporting us by giving monthly PayPal donations and help keep PA fast-loading and ad-free forever.
/PAlogo_v2.gif "Progarchives.com Homepage") |
|
Post Reply 
|
Page <1 567 |
| Author | ||||
Dean 
Special Collaborator 
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
 Posted: April 24 2008 at 09:08 |
|||
|
Life has been found in the most inhospitable places on Earth including near volcanic vents, in sulphurous pools and under the Antarctic ice sheets. These examples are used to illustrate that life as initially created in the primordial soup 4 billion years ago has adapted as the environment changed (and will continue to do so). It is reasonable to assume that had our environment changed differently then life would have adapted differently, so even though the narrow environmental window we occupy and the random changes that got us here have resulted in our current physiology does not imply that any deviation from that would result in a non-viable environment. The 5 major mass extinctions since the Cambrian era illustrate how resilient and pervasive life is once established.
The SF (Science Fiction and Speculative Fiction) ideas of non-carbon lifeforms are based on reasonable scientific theory and are possible. Silicon-based is the most likely since it has similar properties to carbon and may be better suited to harsher environments than we are use to (such as high levels of sulfuric-acid). There are lifeforms on Earth that employ silica as part of their biochemistry. Throughout the Cosmos silicon is far more abundant than carbon but our environment favours carbon-based life, so in other environments silicon may win over carbon.
As far as I am aware none of the alleged microscopic life seen in meteors has been positively identified as being either life or extraterrestrial in origin - what has been found is the same chemical components that were present in the primordial soup, leading scientists to speculate that a) life could have been seeded from space and b) life could be more prevalent in the Universe than first assumed.
In terms of contact and intelligence - that is more of a problem and impossible to answer - from all the millions of species that have evolved on Earth only two have developed intelligence as we define it and they were of the same genus (Homo sapiens sapiens and Homo sapiens neanderthalensis) - Dolphins have have larger brains than us, (but so do elephants!) - because they are larger animals - in terms of encephalisation quotient (brain to body size) humans have a 30% larger brain than dolphins. Physical brain size is not a measure of intelligence. The probability that extraterrestrial life has developed intelligence and the power to communicate over interstellar distances is infinitesimal (but not zero) [Google: The Drake Equation].
|
||||
|
What?
|
||||
 |
||||
|
Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: April 24 2008 at 09:12 |
|||
and light has no mass, the mass of a photon is zero.
|
||||
|
What?
|
||||
|
||||
|
BaldFriede
Prog Reviewer 
Joined: June 02 2005 Location: Germany Status: Offline Points: 10266 |
Posted: April 24 2008 at 09:20 |
|||
Not quite; the rest mass of a photon is zero. That's a big difference. The mass of a photon is defined by the following equation: E=mc²=hν, from which follows that m=hν / c² E is the energy of the photon, ν the frequency , c the speed of light and h is Planck's constant. This follows from Einstein's mass-energy equivalence. Edited by BaldFriede - April 24 2008 at 09:37 |
||||
 BaldJean and I; I am the one in blue. |
||||
|
||||
|
Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: April 24 2008 at 09:44 |
|||
Accepted
 Moving photons have momentum (p) so E=mc²=hν=pc
(however, a photon is still not matter
 ) |
||||
|
What?
|
||||
|
||||
|
Padraic
Special Collaborator
Honorary Collaborator Joined: February 16 2006 Location: Pennsylvania Status: Offline Points: 31169 |
Posted: April 24 2008 at 10:25 |
|||
The EPR paradox does not lead to the conclusion that superluminal transfer of information is possible. http://en.wikipedia.org/wiki/No-communication_theorem |
||||
|
||||
|
BaldFriede
Prog Reviewer
Joined: June 02 2005 Location: Germany Status: Offline Points: 10266 |
Posted: April 24 2008 at 17:10 |
|||
It seems to depend on what you call "information". In my opinion knowing about the quantum state of a particle is information. Einstein called it "spukhafte Fernwirkung" ("spooky action at a distance"), which is why he did not accept quantum theory. |
||||
|
BaldJean and I; I am the one in blue. |
||||
|
||||
|
Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: April 24 2008 at 20:08 |
|||
Communication is the transfer of information. Having knowledge of something lightyears away is not the same as communicating that knowledge over that distance.
"information" is in this case the knowledge of the state of a particle, however this "knowledge" is only 100% predictable if the state of a corresponding paired particle is measured - which is a) perfectly reasonable and b) not faster than light. If it is noon in Amsterdam then I know it is midnight in Honolulu- I do not need to travel 11,000km to know this, but I do need prior knowledge of geography and world-time zones. Similarly the only reason I know the corresponding state of the other particle is because I had previous knowledge that the two particles were paired and their pairing was predetermined at the point of separation.
However, the paradox arises because we cannot know two things about a particle to any degree of certainty (Heisenberg's Uncertainty Principle) yet in these paired particles if we measure one parameter in one of the pair and the other parameter in the other then by inference we should know both parameters of both particles, which goes against what Quantum Mechanics says.
Now the "problem" I have with this is that the measurement (ie observation) is not a passive act - the reason we cannot measure momentum and position of a single particle simultaneously is because measuring one parameter affects the other, but the same is not true of the paired particles - measuring the momentum of particle A affects the position of that particle, but not of particle B. So we can now measure the position of B, but this is no longer the paired/mirrored position of A since that has been moved by the previous momentum measurement therefore cannot be used to predict the current position of A. There is no magic link between the two particles since the momentum and position of both are predetermined from their point of separation and "destroyed" by the respective acts of measurement (ie the pairing is broken). Even if the measurements were timed to be simultaneous, they no longer predict the current position and momentum of both particles.
If the particles happen to be a lightyear apart measuring the momentum of A tells you instantaneously the corresponding momentum of B but you still do not know the position of either. If observer B simultaneously measures the position of B, they know the corresponding position of A, but does not know the momentum of either. The only way for both observers to know both parameters of both particles is by subluminal communication between them. i.e. You have to wait a year to find out the position of B to be able to predict what the position of A was when you measured its momentum.... again, not what I would call faster than light communication.
|
||||
|
What?
|
||||
|
||||
|
tuxon
Forum Senior Member 
Joined: September 21 2004 Location: plugged-in Status: Offline Points: 5502 |
Posted: April 24 2008 at 20:18 |
|||
|
all fairly within the concept of truth, but one cannot explain the behavior of one particle based on the behavior of another partical ( be it the similar partical in another quantum reality).
|
||||
|
I'm always almost unlucky _ _ _ _ _ _ _ _ Id5ZcnjXSZaSMFMC Id5LM2q2jfqz3YxT
|
||||
|
||||
|
Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: April 24 2008 at 20:27 |
|||
You can if the two particles are entangled (Quantum Entanglement)
|
||||
|
What?
|
||||
|
||||
|
Atavachron
Special Collaborator
Honorary Collaborator Joined: September 30 2006 Location: Pearland Status: Offline Points: 65616 |
Posted: April 24 2008 at 20:33 |
|||
not unlike this discussion  kidding  |
||||
|
||||
|
tuxon
Forum Senior Member
Joined: September 21 2004 Location: plugged-in Status: Offline Points: 5502 |
Posted: April 25 2008 at 04:38 |
|||
but that doesn't explain it, does it?
 personally I feel that measuring itself has to much influence on the caracteristics, we only measure what we can measure, and we only measure what we want to measure, but never do we actually measure what is there, we can observe wave-particle duality by observing either the wave or the aprticle function, but we can't measure both.
if two counterpart particles (photon's) are measured simultaniously, by measuring one of those according to the wave structure, we will observe it's counterpart as a wave also, so there probably is a quantum entanglement, but for me the measurement itself determines the behaviour, and not the particles behaviour determine the outcome of the measurement.
I hope this makes sense.
 |
||||
|
I'm always almost unlucky _ _ _ _ _ _ _ _ Id5ZcnjXSZaSMFMC Id5LM2q2jfqz3YxT
|
||||
|
||||
|
The-Bullet
Forum Senior Member
Joined: January 23 2005 Location: United Kingdom Status: Offline Points: 401 |
Posted: April 25 2008 at 08:44 |
|||
Can you quote your source for these two points. It's generally accepted by scientists that the universe is 13.7 billion years old It is also believed that life began on earth as soon as conditions stabilized, about 3.5 billion years ago. Thanks.... |
||||
"Why say it cannot be done.....they'd be better doing pop songs?" |
||||
|
||||
|
Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: April 25 2008 at 08:45 |
|||
 )
|
||||
|
What?
|
||||
|
||||
|
tuxon
Forum Senior Member
Joined: September 21 2004 Location: plugged-in Status: Offline Points: 5502 |
Posted: April 25 2008 at 15:04 |
|||
|
not really convinced about the article, but it's a step further than when i left school. |
||||
|
I'm always almost unlucky _ _ _ _ _ _ _ _ Id5ZcnjXSZaSMFMC Id5LM2q2jfqz3YxT
|
||||
|
||||
|
Gamemako
Forum Senior Member
Joined: March 31 2006 Location: United States Status: Offline Points: 1184 |
Posted: April 30 2008 at 18:37 |
|||
I think we need a clarification here. I'm talking about carbon chains and nucleic acids. I'm pointing out that without a hot and reducing atmosphere (but not too hot), life as we know it cannot exist. Carbon has unique properties that are necessary for life as we know it to exist. I can't imagine any other basis for life (not to mention the question of elemental abundance -- heavy elements don't come from nowhere, and hydrogen and helium simply cannot feasibly form the basis of life). Given that life is just a self-replicating series of reactions, it's difficult to find another suitable catalyst for the creation of life. I'm not saying that it can't happen, I'm just saying that the candidates are few and somewhat lacking in abundance. Earth's atmosphere at the dawn of life had very little oxygen (think back to your chemistry: reduction is the opposite of oxidation, so, forgiving the dramatic oversimplification, what do you think would happen to oxygen molecules?). Think thousandths of a percent compared to the current 21%. As for going faster than the speed of light , you just suggested that there is life without mass.  //EDIT: Ignore that. Edited by Gamemako - April 30 2008 at 18:40 |
||||
|
Hail Eris!
|
||||
|
||||
|
Jim Garten
Special Collaborator
Retired Admin & Razor Guru Joined: February 02 2004 Location: South England Status: Offline Points: 14693 |
Posted: May 01 2008 at 03:39 |
|||
|
Having just read the last couple of pages, I think I need a lie down
|
||||
Jon Lord 1941 - 2012 |
||||
|
||||
|
BaldFriede
Prog Reviewer
Joined: June 02 2005 Location: Germany Status: Offline Points: 10266 |
Posted: May 01 2008 at 07:44 |
|||
If you take Bell's theorem to be correct, yes. However, I don't; his argumentation is in my opinion circular. The "spukhafte Fernwirkung" still exists. |
||||
|
BaldJean and I; I am the one in blue. |
||||
|
||||
|
Post Reply
|
Page <1 567 |
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
UFO's. Do you believe?
Topic Options
BaldFriede wrote: