Time Travel?

Kurt_ · Post by **Kurt_** » Mon Jul 17, 2006 12:12 pm

If you think about it, (regarding speed and time) we age less during the night than we do during the day, due to the Earth's rotation.

A) During the day, the Earth is rotating AGAINST the Orbit around the sun, moving us slower.

B) During the night, the Earth is rotating with the orbit, moving us faster.

sam fisher · Post by **sam fisher** » Mon Jul 17, 2006 12:24 pm

Unidentified Assilant wrote:I thought this was a screw joke.

In our lifetime, none of us will travel through time. Period.

Ha ha. Seriously, we are travelling throuagh it now, all at slightly different speeds due to proximity to the earths gravitational field and our velocity.

@Kurt:

We move the same speed round the sun at day and night as it is a constant. The earth also rotates at the same speed meaning that we move at the same speed, day or night. The only tiny difference would be the distance change between oour proximity to the Suns gravity during daylight and night time cycles.

joevennix · Post by **joevennix** » Mon Jul 17, 2006 12:39 pm

Unidentified Assilant wrote:I thought this was a screw joke.

In our lifetime, none of us will travel through time. Period.

We are only discussing the possiblities of time travel, limited to our knowledge of physics (for me this is very small).

Also, 'suspended animation' would count as a form of time travel, right? Like our body's processes are slowed down, and we sleep through twenty years, even though it only feels like a day.

timmeh87 · Post by **timmeh87** » Mon Jul 17, 2006 12:46 pm

sam fisher wrote:
joevennix wrote:
sam fisher wrote:AS VELOCITY INCREASES, THE SPEED AT WHICH TIME PASSES DECREASES
Ech, I mixed up my words. I was thinking about time in relation to everyone else. It would move faster for them, but... well I'm not really sure what I was thinking. I don't take physics for another two years

It is possible to go faster than the speed of light, even if it involves cheating a bit. We learned this in Bio 1 one day when the professor went into a rant. Scientists sent light through a thick fluid, slowing it down, then they shot small particles through the fluid, moving faster than the light. The effect gives off some kind of radiation.
Yup, the denser the medium the light travels through, the faster C becomes.

you mean slower? (and techincally C is a constant, it never changes. the speed of light in anythign other than a vacuum isnt C)

its also more closely realted to index of refraction than to density. although denser things tend to have higher refractive indicies.

joevennix · Post by **joevennix** » Mon Jul 17, 2006 1:03 pm

Somewhere I read that researchers shone a laser that traveled over 10 times the speed of light. Let me find the article...

Here it is.

sam fisher · Post by **sam fisher** » Mon Jul 17, 2006 4:50 pm

I don't actually know about refraction index's. I just know what I read. I read that as the denisty of the medium that light travels through increases, so does the speed of light. I just put C as I used it to represent the standard speed of light and If i said :

As the object gets denser the speed of light gets faster than the speed of light

That that could easily confuse people who cannot grasp the basic concept's of time dilation.

Kurt_ · Post by **Kurt_** » Mon Jul 17, 2006 4:52 pm

You...should stop talking now.

sam fisher · Post by **sam fisher** » Mon Jul 17, 2006 4:53 pm

Why, because I said that I used C as an abbreviation for the speed of light in any medium while technically C is a constant value of the speed of light in a vacuum? Or because I said that I did it so people who cannot grasp the basic concept of time dilation wouldn't become confused?

vskid · Post by **vskid** » Mon Jul 17, 2006 4:54 pm

sam fisher wrote:I don't actually know about refraction index's. I just know what I read. I read that as the denisty of the medium that light travels through increases, so does the speed of light. I just put C as I used it to represent the standard speed of light and If i said :

As the object gets denser the speed of light gets faster than the speed of light
That that could easily confuse people who cannot grasp the basic concept's of time dilation.

I think your backwards or something, if I try running in a vacuum and a brick wall, I'll go faster in the vacuum.

joevennix · Post by **joevennix** » Mon Jul 17, 2006 6:18 pm

Sam, shutup.

I'm sorry if I mixed up something. Apparently you did it too, a few posts ago. I know what I meant, and what I meant was correct. The words I described it in weren't. And, accordingly, I have never taken a physics class in my life. All I know is from reading. In the end, my words were wrong. I'm sorry if I offended you in any way. Honestly, can we just get past that, and on with the discussion of this topic.

Anyways, now for my next question: What effect does gravity have on time? I asked this before but Luc never really gave me a direct answer.

ganonbanned · Post by **ganonbanned** » Mon Jul 17, 2006 6:22 pm

[urlhttp://www.lifesci.sussex.ac.uk/home/John_Grib ... l_possible[/url]

sam fisher · Post by **sam fisher** » Tue Jul 18, 2006 6:06 am

vskid wrote:
sam fisher wrote:I don't actually know about refraction index's. I just know what I read. I read that as the denisty of the medium that light travels through increases, so does the speed of light. I just put C as I used it to represent the standard speed of light and If i said :

As the object gets denser the speed of light gets faster than the speed of light
That that could easily confuse people who cannot grasp the basic concept's of time dilation.
I think your backwards or something, if I try running in a vacuum and a brick wall, I'll go faster in the vacuum.

I didn't mix anything up, I just put it in simple terms. You just dont get it do you! YOU ARE NOT LIGHT.

Light travels, normally, at a maximum speed, known in physical equations as C. This is the speed of light in a vacuum.

However, in a denser medium, LIGHT TRAVELS FASTER. You don't neccisarily travel faster. Light does, Vskid, unless you are made up of waves of energy that normally travel at C through a vacuum, YOU WILL NOT RUN THROUGH A WALL.

Light can travel through a diamond, and due to the density I am pretty sure that it travels around 3 times C. IDIOT. I don't need to shut up.

Oh, vskid, you wont really move much at all in the vacuum of space, as there is nothing to cause friction. Therefore there is no equal and opposite reaction to allow you to move. Double Idiot.

codeman · Post by **codeman** » Tue Jul 18, 2006 6:26 am

sam fisher wrote: Light travels, normally, at a maximum speed, known in physical equations as C. This is the speed of light in a vacuum.

However, in a denser medium, LIGHT TRAVELS FASTER. You don't neccisarily travel faster. Light does, Vskid, unless you are made up of waves of energy that normally travel at C through a vacuum, YOU WILL NOT RUN THROUGH A WALL.

Light can travel through a diamond, and due to the density I am pretty sure that it travels around 3 times C. IDIOT. I don't need to shut up.

Ok...get some solid facts before you go throwing names around dude. Every material has something called a refractive index, n. For a vacuum, n=1 and for air n is very close to 1. In water for example, n=1.33. And guess how n is calculated?! n = c/v where you obviously know what c is because you are so high and mighty, but v in this case is the speed of light in that particular medium. Now...to get something bigger than one with a fraction, what has to happen to the denominator with respect to the numerator??? Hmm...i dont know, maybe it has to be SMALLER.

This is also why light bends when passing through a junction of different mediums, because the speed the light wave is travelling changes. I'd try to explain it further, but since you cant even grasp the basic concept i'm not even going to try. Before you try to come back and yell at me and call me an idiot, look up "refractive index" you smug bastard.

sam fisher · Post by **sam fisher** » Tue Jul 18, 2006 6:37 am

I can't be bothered to read that as it mentions refractive indexes that I have learned nothing about. All I know is that I read that THE DENSER THE MEDIUM THAT LIGHT IS TRAVELLING THROUGH THE FASTER IT IS. There we go.

I do understand why light bends.

codeman · Post by **codeman** » Tue Jul 18, 2006 6:57 am

sam fisher wrote:I can't be bothered to read that as it mentions refractive indexes that I have learned nothing about. All I know is that I read that THE DENSER THE MEDIUM THAT LIGHT IS TRAVELLING THROUGH THE FASTER IT IS. There we go.

I do understand why light bends.

You can't possibly understand why light bends if you have everything mixed up. If you haven't even bothered to learn about refractive indices then why are you acting like an expert in the field? Take it from someone who has learned about optics...a more dense medium has a higher refractive index. The speed of a light wave in a medium is proportional to C and inversely proportional to n, which means with a higher n, a lower speed. The speed of a light wave is indeed slower in a more dense medium.

Also, i can read...there's no need to put things in all caps, just makes you look more pathetic that you have to resort to "shouting"...rather than actually back up your arguments. Light travels slower in a more dense medium.