The Universe

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

Anybody else intrigued by the sheer phenomenal distances/speeds/timescales that exist on a Universal scale?

At school I did a course in Cosmology, mega interesting topic but even now there's snippets of info that still amaze me.

Our galaxy, the Milky Way is 100,000 light years in circumference.... that's just impossible to comprehend, that's 100,000 years travelling at 186,000 miles per SECOND!

When you consider that our 100,000 light year-long galaxy is just one of billions of other galaxies out there.... just reminds you how insignificant we are really!

Here's another amazing rationalisation I've read about the Milky Way and our Solar System:

If you imagine the Milky Way as a circle of 80 miles circumference, the relative circumference of our Solar System within that 80 mile galaxy is just 2 millimetres! 2 MILLIMETRES WITHIN 80 MILES!

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

yeah I love it as well.

tbh to get away from everyoen else I'd happily be fired off into space.

I like to watch programs on it, was watching something last night, well the tail end of it about ice planets.

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

More interesting facts:

- It takes the Sun 250 million years to complete one orbit of the Milky Way. In realtive terms, the Sun has completed 0.0008 of a galactic orbit since the existence of mankind.

- It is now commonly though that a black hole exists at the centre of every spiralling galaxy.

- The Solar System orbits within the Milky Way in the middle of the galactic plane. As a result, beautiful images can be captured like the one below:

[IMG:1024:680:cab9086acf]http://upload.wikimedia.org/wikipedia/en/4/4e/Milkywayfromchile.jpg[/img:cab9086acf]

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

The Earth....

- Has a mass of 5,980,000,000,000,000,000,000,000 kilograms.

- Is 4,500,000,000 years old

- Orbits the Sun at a speed of ~ 67,000mph

- Looks like this at night:

[IMG:700:350:539ca4f7f4]http://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Earthlights_dmsp.jpg/700px-Earthlights_dmsp.jpg[/img:539ca4f7f4]

Level 9 User Joined: 03 Jul 2006 Posts: 412

Damn, i knew i left a light on at home.

But the earth is getting ever lighter, older and slowing down. Wink

What's your theory on dark matter, is this just an excuse to make the maths work??

Level 10 User Joined: 04 Nov 2005 Posts: 575

It's one of these topics I can spend hours looking into tbh. One thing I always think of though is where any of it came from. If you know what I mean, at some point there MUST have been NOTHING at all, not even space, but somehow from nothing something has been created - it's just mindbogling imo, and is something that will probably never be answered.

I also think that it will one day be discovered that the whole thing of the speed of light being the uppermost limit of speed will be disproved and by some means or another it will be possible. I'm not saying it's going to happen anytime in our liftime or anything, but I do believe it will happen.

Level 9 User Joined: 03 Jul 2006 Posts: 412

Where it came from? That's easy, it, erm, came from what was there before! Just a load of pent-up energy Wink

According the the pattern of our universe, the speed of light cannot be exceeded - how would you know if it was faster anyway? Any kind of signal or beam could only travel this fast at best. Besides, any fool knows the laws of physics can only be beaten by a well-cared for Renault 19 16v. (Newton's 2nd Law of Ignition Module Unreliability, Heisenberg's Under-Sill Rust Uncertainty Principle to name but a few)

Level 10 User Joined: 04 Nov 2005 Posts: 575

yeah, I know they say that it can't be exceeded and I have looked at all the theory behind it etc (though can't remember it all, lol). I'm just saying that I believe in the future it will be possible by some means or other.

Btw, where did this energy come from? Wink

Site Subscriber Joined: 02 Oct 2004 Posts: 1575

Gentle Ben";p="106385 wrote:

The Earth....

- Has a mass of 5,980,000,000,000,000,000,000,000 kilograms.

- Is 4,500,000,000 years old

- Orbits the Sun at a speed of ~ 67,000mph

- Looks like this at night:

[IMG:700:350:fa8b401800]http://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Earthlights_dmsp.jpg/700px-Earthlights_dmsp.jpg[/img:fa8b401800]

look at the light polution northern hemisphere is really bad. lol look at oz only 2 lights on there perth and sydney.

anyway we all know the answer is 42

Level 9 User Joined: 03 Jul 2006 Posts: 412

best not to think about it... Wink

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

Someone explain why you can't go faster than light...surely its just another velocity.

Ppl thought they would never travel faster than sound.

I wish we would get our arses moving and get out into space more often...its a shame its so expensive that even for the benefit of mankind, ppl have to make money out of it, hindering progress.

I've heard talk of going back to the moon, but the timescales and planning makes it sound dubious that they ever managed it in the freaking sixties.

I love watching and reading about the spacecraft tbh...watching the massive engines of the space shuttle just fascinates me.

Level 9 User Joined: 03 Jul 2006 Posts: 412

Because... we know this from Einstein's Special Theory Of Relativity! (still just a theory mind, not proven Wink

)

Wikipedia:

Quote:

It is important to realise that the speed of light is not a "speed limit" in the conventional sense. An observer chasing a beam of light will measure it moving away from him at the same speed as a stationary observer. This leads to some unusual consequences for velocities.

Most individuals are accustomed to the addition rule of velocities: if two cars approach each other from opposite directions, each travelling at a speed of 50 kilometres per hour (31 miles per hour), one expects that each car will perceive the other as approaching at a combined speed of 50 + 50 = 100 km/h (62 mph) to a very high degree of accuracy.

At velocities at or approaching the speed of light, however, it becomes clear from experimental results that this rule does not apply. Two spaceships approaching each other, each travelling at 90% the speed of light relative to some third observer between them, do not perceive each other as approaching at 90% + 90% = 180% the speed of light; instead they each perceive the other as approaching at slightly less than 99.5% the speed of light.

Contrary to one's usual intuitions, regardless of the speed at which one observer is moving relative to another observer, both will measure the speed of an incoming light beam as the same constant value, the speed of light.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

dark matters quite a subject. I watched a program on it and just thought it was funny how it was exactly the number needed to make all their sums add up.

Ity makes sense but they can't explain it, its to small to see, we are being washed by dark matter as we sit here etc.

As for the speed of light, in a shuttle or whatever doing he speed of light and you throw a tennis ball forward, that would excede the speed of light. But would you see it?

All the light in the uk is from london and what appears to be manchester! Oz has 2 lights cos theres nothign in the middle of ther place.

Canada is dark as well.

As always japan is shining like a mofo.

Level 9 User Joined: 03 Jul 2006 Posts: 412

That's the point of dark matter, it's made up by scientists to make their equtions work (in terms of mass and energy in the universe) - nothing wrong with this in itself, it may as well exist. Trouble is no-one's been able to detect it yet Confused

And if you throw a tennis ball forward in a space shuttle which is travelling at the speed of light (relative to Earth or whatever), on board it will look normal, from Earth you won't see it since the light coming off it will be be travelling away from you (the shuttle's speed)

Level 10 User Joined: 04 Nov 2005 Posts: 575

The whole dark matter thing, I don't know much about tbh. However all I was saying is that at some point there had to be nothing at all, not even this dark matter, absolutely nothing whatsoever. The thing is that really from that it would, in the way we look at things, be impossible for ANYTHING to form but now we have the whole universe. I just fail to get my head around it as it really is impossible for something to form out of nothing, and by nothing I mean there wouldn't even have been space or anything at all.

Posted: Thu Aug 31, 2006 12:48 pm

My brain hurts

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

The speed of light will never be exceeded by man, animal, atom, or anything else that has an inherent mass associated with it.

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

As regards the amount of dark matter being the exact amount needed to make sums add up etc, there are a number of similar 'coincidental' observations.

I mean, what are the chances of the moon being exactly the same size as the Sun when observed from Earth to enable eclipses to be seen, the superimposition of the moon over the Sun is perfect enough to allow solar prominences to be seen!

[IMG:702:522:8810513bc1]http://antwrp.gsfc.nasa.gov/apod/image/9908/augeclipse_pasternak_big.jpg[/img:8810513bc1]

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

The maths behind the physics is also a little self-contradictory.

Things like interconvertability of mass and energy as shown by Einstein. Normally anything that has motion has kinetic energy, but since kinetic energy of a moving body requires it to have a mass and an associated velocity to return a value, it kind of says that light shouldn't be able to travel since it is massless, therefore cannot have an associated KE etc.

I heard that the fundamental and classical maths and laws of Physics are actually being rewritten by the governing bodies to take into account unexplained observations of the universe and contradictions that have arisen from contradictions between certain laws in Physics.

Level 9 User Joined: 03 Jul 2006 Posts: 412

so now we're getting into wave-particle duality... there's an argument for light being made up of a stream of photons which do of course have energy (and associated mass, from E=mc.c)... my brain hurts too Confused

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

Its all just theories tho yeah? Thats called guessing. I don't like to believe in guessing.