Lightspeed, Spontaneous Human Combustion

ha ha! Good one, U.J.

I was at a backyard barbeque a couple years ago, and a high school teacher and I got into it. He stated categorically that time travel is impossible. He said that if TT is possible, then where is everyone? Why no HG Wells? It's a technological hurdle even quantum theorists admit to being difficult and only impossible from a point of view that our own technological devlopment does not allow for it. But to rule out technological development of ourselves in the future let alone those of other civilizations would be to doubt Darwinian evolution. Tech advancement, like human evolution, is just a matter of time. And our state of tech is in its infancy. As Arthur Clarke once said about it, a sufficiently advanced technology would be indiscernable from magic as far as a less evolved civilization is concerned. So I asked the wise guy how far off we are from the technology for invisibility? He had to admit that the science for that is not so far away. Then I said to him, Well there you are. They could be all around us everywhere, and we wouldn't even notice. 

According to quantum gurus Einstein through Deutsch and Kaku, the space-thyme continuum is a river that flows with branches, eddys and oxbows. The philosophy of presentism is probably incompatible with quantum reality. Apparently if we were able to go back in time and visit ourselves in the past, it would have to be to a fork in the river of time belonging to another universe. In another universe, Hitler and the Nazis were not defeated at Stalingrad and Leningrad and proceeded to takeover the world and every other historical scenario imaginable. In another universe, you are typing this post not me. In the multiverse, every evolutionary chance and chaotic happenstance possible and the seemingly impossible has occurred and will continue on for infinity. That's a long time.

The Cat: We're all mad here. 

The Hatter: Why is a raven like a writing desk?

Multivac: Insufficient data for meaningful answer...

I read this book a while back and I found it fascinating. I agree with the premise of the book that consciousness is the great unknown and the central key to understanding the universe.  The authors are scientists and they make a biological argument not a religious one.  So the book is not about intelligent design but rather the bilogical and physical design of intelligence.  

Quote:

Consciousness is not just an issue for biologists; it’s a problem for physics. There is nothing in modern physics that explains how a group of molecules in a brain creates consciousness. The beauty of a sunset, the taste of a delicious meal, these are all mysteries to science — which can sometimes pin down where in the brain the sensations arise, but not how and why there is any subjective personal experience to begin with. And, what’s worse, nothing in science can explain how consciousness arose from matter. Our understanding of this most basic phenomenon is virtually nil. Interestingly, most models of physics do not even recognize this as a problem.

http://www.msnbc.msn.com/id/31393080/ns/technology_and_science-science/t...

Cloak's on you: Scientists create 'invisible' object  

Well, it's not quite 'invisible man' invisibility just yet. In another thread someone asked, if time travel is possible, then where are all the visitors from the future? And one possibility is that time travellers could be here and milling around, like time travellers often do, and that they are invisible? 

I have my towel, but before entering this discussion I need a pangalacticgargleblaster.  Or two.

Excited sesium molecules can travel faster than light, under certain conditions (like in a massive particle collider) .  We can't.

Those are possibilities. Another could be that, as Einstein said, time is a river, and we exist in a forked stream of time. Perhaps this tributary of it is yet to be visited. Perhaps we have been visited in a parallel carbon copy of this world.

if time travel existed - we could only travel forward not back

What if they have been coming for some time? The TV character Deepthroat said to Mulder that they have been here for a long, long time. Not only could UFOs be "von Neumann probes" piloted by self-replicating robots designed by a race of beings in a galaxy far-far away and who became extinct long ago - why couldn't they also be inter-dimensional time travelers? Perhaps in a parallel universe, the singularity could have expanded all of 9 or 10 spatial dimensions at birth instead of the measly three we have in this one. The truth is out there, because scientists have estimated the number of possibilities for the physical nature of this universe at approximately 10^500. That's a huge number of possibilities. I can only suggest that anything is possible.

I hear ya. And I can't help but be pessimistic myself with what Lord Rees of the Royal Astronomers said about it - that our brains might simply not be big enough to understand the universe and everything in it. Is it a case that our five senses have evolved in a part of the universe where atomic matter, or 4% of all matter, dictates the laws of physics in this part of it? Science textbooks are changing at a rapid pace compared to when I went to school. According to some scientists there will be discoveries of new laws of nature between now and the next five to ten years if things work out with CERN in Switzerland. These discoveries if made might lead to new science and technologies comparable to Newton's discovery of gravity that lead to the industrial revolution. I am hopeful for this and the next generations of young people.

I think anything is possible. Look at evolution and technology. Our stone tools gave way to rockets that took us into space. A Royal astronomer in the 19th century once said that trans-Atlantic voyages by heavier than water steamships would be impossible, and that we might as well try flying to the moon.

And scientists once mocked the idea of air travel. It was science fiction.

Another scientist once estimated that the fuel needed to carry men to the moon would require millions more tons of fuel than was eventually used in the Apollo 11 moonshot.

A sufficiently advanced technology, another scientist in the last century once said, would be indistinguishable from magic. Therefore it could be said that evolution and magic are just a matter of time. Now imagine that it's happened somewhere in the universe for some sufficiently evolved species of beings long ago. Carl Sagan once pondered that there could be millions of technically advanced beings in just our own galaxy. Anyone coming here from afar would probably not be just a few decades or a century more advanced than ourselves. And they might be as unnoticable to us as Charles Darwin would have been to the strange animals he observed on the Galapagos.

Charles Yu's top ten time travel books 

Uncle John wrote:

The past does not exist because it is gone. The future does not exist because it has not happened yet.

This is essentially what the philosophy of presentism says: that the past has already occurred, and that the future is yet to happen. And it is incompatible with modern theory of relativity.

Uncle John wrote:

Still, "what if"s are fun, and a great way to waste time. Others of us have to worry about putting our kids through school, having a decent place to live, and having enough to eat.

Excuse me, then. And I suspect that the world is more politically aware than it once was. But this isn't a politics thread - it's just banter. There is no rule against proposing what ifs in my version of revolution at any given point in the time-space continuum. I won't allow it.

If youre on a  fast train travelling 100 m/s, and you walk 10 m/s toward the liquor bar in the caboose, you would be moving a cumulative total of 110 m/s according to math and common sense.

And so if you are on a super-duper fast train moving 3 million m/s, and you walk 10 m/s toward the caboose, you should be moving a total of 3, 000, 010 m/s, no? And if not, why not?

Spoiler.

ETA:

Okay I can't help myself here's another, and Spector, you've been promoted to referee. No blurting out the answer.

Another train is moving at 110 m/s to the west. Someone on that train is sprinting down the aisle at 10 m/s in the same direction the train is moving and shining a 1000 watt halogen spotlight infront of them while sprinting.

A tall woman on a horse is travelling alongside the train at 30 km/hr and sensing she might be travelling 10 km/hr faster due to a tail wind.

Question: The speed of the light emitted from the 1000 W halogen spotlight according to the woman on horseback is:

a) 110 m/s + c

b) 110 m/s + 10 m/s + c

c) c

d) -c + 120 m/s

e) ∞

c = speed of light

I doubt if the woman on horseback would be able to see the light anyway. The train would be rushing past her at 396 km/h relative to the ground, and 366 km/h relative to her.

The idea that we cannot travel faster than light I believe stems from the basic E=mc2 of mass energy conversion.

Energy is mass and mass is energy.

If you take something with mass, and accelerate it, you are giving it energy.  Since energy is mass, you are giving the object mass.  As the speed of the object increases, so too does it mass, reducing the ability to accelerate it.  So the closer one gets to the speed of light, the closer to zero acceleration the object gets, theoretically reaching an impass at the speed of light.

This is just my simple understanding.  If I've err'd or if someone cares to elaborate, please speak up.

M. Spector wrote:

So how does an experiment with a 16% margin of error prove that neutrinos can travel 299,798,454 ÷ 299,792,458 = 1.00002 times the speed of light?

[url=http://www.bbc.co.uk/news/science-environment-17139635]It doesn't.[/url]

Quote:

... they found a problem in the optical fibre connection between the GPS signal and the experiment's main clock - quite simply, [b]a cable not quite fully plugged in.[/b]