Amazing Light Show, with NO 'audience scanning' (just a few gamma-rays! ;)

[skulpture]

He's an interesting scientist... One that can both understand the complexity and still break most of it down in easy-to-understand terms for the layman.

Yup thats why I liked him. Made sense about a subject that doesnt make sense to me... if that makes sense!

[buffo]

I know we've already discussed it, but I found this comic that sums up string theory quite nicely. Have a look...

Adam

[steve-o]

Interstellar travel. Hmmm. How fast could we go, and what is prohibiting us from achieving near-light velocities in the semi-vacuum of space? Friction? I think we could go a lot faster if the right propulsion system was integrated into the right ship...

[buffo]

Interstellar travel. Hmmm. How fast could we go,

In theory, we could go nearly as fast as light. But even that isn't really fast enough for true interstellar travel. The distances involved are just too large.

what is prohibiting us from achieving near-light velocities in the semi-vacuum of space? Friction?

No, not friction. Relativity. And it's a real bitch. As you go faster, your mass increases, you are compressed in the direction of motion, and time slows down. You don't notice these changes at the slow speeds that humans normally experience, but as you get closer to the speed of light, these changes become more and more pronounced.

Once you reach roughly 90% of the speed of light, these changes are significant enough that it requires serious engineering to compensate for them. This is why particle accelerators are so complex. As the particle beam gets faster and faster, the particles themselves get heavier! Eventually they'll smash into the curved walls of the accelerator ring! So the steering magnets have to be made stronger and stronger as speed increases to compensate for this.

Remember that Force = Mass x Acceleration. So if you rearrange that, you get Acceleration = Force/Mass. Now, as you get close to the speed of light, you mass approaches infinity. So given a constant force, your acceleration slows down. This is why you can never accelerate matter to the speed of light. You'd need infinite force.

I think we could go a lot faster if the right propulsion system was integrated into the right ship...

Google "Bussard Ramjet" for an idea as to what this would look like. It's a spaceship that is essentially a giant propulsion machine; it would be nearly a third of a mile long! But even if we could build such a ship, it would still be limited by the speed of light. (Still, even 90% of the speed of light is a hell of a lot faster than we're able to travel now.)

Adam

[steve-o]

Very nice response Adam. Thanks.
I was thinking of one of these (Radiometer) (a stationary mile-wide vane or 2) to propel thru space. The device is archaic, but it's a neat device, Though I really like the concept of bending time and space so you dont have to fool with trying to approach light-speed...
At 1/2 light-speed, though, we could reach the nearest star (Proxima Centauri) in about 8 years . Telemetry and communications might be a problem tho...

[sunbear]

Spectacular ！
Horsehead Nebula， Eskimo Nebula .......sooo beautiful the pictures are ! And the pictures reminds me of that once upon a time i was big Astronomy enthusiasts ! time went on , but i am not the little child handed a telescope any more

[steve-o]

That's beautiful! It's amazing that space (and nature) contain more beauty than every man-made apparatus or contraption ever invented.. I still love lasers tho.. it's the best we can do without competing with nature.. (we'd lose every time)... but we still try.. and it is nice..
.. and awesome to look at a 5Watt 'tube' of light through still air..

[tendril]

The structure of universe theoretically very simple. Galaxies form meta galaxies they form mega meta galaxies...But what I don't believe is that universe is infinite. Makes no logical sense.

If space is the distance between 2 points then space only exists because of matter. So as the universe expands it creates space where there was none. We also live in a very 3 dimensional existence and find it difficult to comprehend any other way of imagining it.

[Ian]

The biggest mistake anyone can make is thinking they "knew" anything in the first place.

[steve-o]

Yes, I agree that there is no way that we can understand the complexity and dynamics of the universe using only the known information at our disposal at the present time ..