Hard Science Help

[Inu]

Re: Hard Science Help

 

It's also psosible that Relativity is completely correct... until you hit lightspeed. In my scifi games, I state that a new model of physics has come in that sit 'above' relativity in the same way that relativity sits 'above' Newton. Newton is still 100% (or, well, 99.99999etc%) correct at speeds significantly below c. Relativity doesn't alter Newton... until you get fast. So this new model only replaces relativity at or above lightspeed.

 

It usually involved hyperdimensional/subspace/hyperspatial/etc properties. The kind of thing that Einstein simply couldn't have taken into account, just like Newton couldn't have taken relativity into account given the instruments of the day.

[eternal_sage]

Re: Hard Science Help

 

of course, again, thats what i was trying to get at, but failed my Eloquence Roll.

[Clonus]

Re: Hard Science Help

 

It's also psosible that Relativity is completely correct... until you hit lightspeed. .

 

If it is, then you can't hit lightspeed.

[Maur]

Re: Hard Science Help

 

Maur: not sure on all that' date=' but mass has nothing to do with gravity, weight does.[/quote']

 

Weight is the effect of gravity on mass. The basic SI units are Kilogram, Meter and Second. Weight is Mass * Gravity which is Newtons in SI or Pounds Force in English. Your weight on the moon is 1/6 of what it is on the Earth, but you mass is the same...

[Cancer]

Re: Hard Science Help

 

So far, relativity, both special and general, has passed every experimental and observational test we've been able to put to it. That includes a broader regime than you might guess. We lack the tech to get macroscopic objects up to relativistic speeds, but subatomic particles are another thing entirely. One of the problems in particle physics is that the standard model does pretty well in those energy regimes we can access....

[eternal_sage]

Re: Hard Science Help

 

Maur: of course, i suppose i misunderstood what you said, as you mention gravity and mass, i assumed you meant their was a connection (other than an objects mass determines its gravity field, and mass*gravity is, as you said, weight) misunderstanding on my part. please continue!

[SteveZilla]

Re: Hard Science Help

 

Here's some more thoughts/suestions:

 

1. Photons are energy, and the amount of energy contained within determines their frequency.

2. Photons travelling "uphill" against gravity loose energy and are red-shifted.

3. Where does that energy go? AFAIK, it can't just be lost.

4. What happens when the last quanta of energy from an "uphill"-travelling Photon is lost due to the gravity (I.e., inside a Black Hole)?

5. Prior to loosing that last quanta of energy, what is the frequency (Kenneth ) of the Photon?

6. How do the time-dialating effects of intense gravity affect these frequencies?

[Clonus]

Re: Hard Science Help

 

So far' date=' relativity, both special and general, has passed every experimental and observational test we've been able to put to it. That includes a broader regime than you might guess. We lack the tech to get macroscopic objects up to relativistic speeds,[/quote']

 

Just blatantly relativistic. I have heard of people putting atomic clocks on supersonic jets to test for the nanosecond's loss of time.

[Cancer]

Re: Hard Science Help

 

Just blatantly relativistic. I have heard of people putting atomic clocks on supersonic jets to test for the nanosecond's loss of time.

 

Well, yeah. Actually, if you leave out the general relativity terms, then your GPS readings will be off by at least 50 meters, so this bites you in unsuspected ways.

[Cancer]

Re: Hard Science Help

 

Here's some more thoughts/suestions:

 

1. Photons are energy, and the amount of energy contained within determines their frequency.

2. Photons travelling "uphill" against gravity loose energy and are red-shifted.

3. Where does that energy go? AFAIK, it can't just be lost.

It gets paid to the local gravitational well; it costs energy to go up.

4. What happens when the last quanta of energy from an "uphill"-travelling Photon is lost due to the gravity (I.e., inside a Black Hole)?

The photon doesn't have enough energy to be able to buy itself out of the gravity well. The black hole forecloses, takes all its energy. Since all there is to a photon is its energy, that destroys it and it's gone and you don't have to worry about it any more. Kinda like how the banking system wants to handle subprime mortgages: they take everything and that's the end.

5. Prior to loosing that last quanta of energy, what is the frequency (Kenneth ) of the Photon?

A small number. E = h f for photons, where h is Planck's constant.

6. How do the time-dialating effects of intense gravity affect these frequencies?

You've changed topics, believe it or not. In 1-5 you're talking about general relativity; in 6 you're talking special relativity. Still, the answer is, it doesn't matter. Photons travel at c. Things that travel at c don't have time pass for them.

[McCoy]

Re: Hard Science Help

 

Personally, I think that time travel is impossible, because of the following thoughts:

 

1. Man Invents Time Machine -- both are both made out of matter contained within the universe.

2. Man uses Time Machine and travels into the past.

3. When Man arrives, the universe now has over 100% of the mass of the universe.

 

A similar reason would IMO prevent travel into the future (meaning you don't occupy space-time continuously from start to end of trip). For the period between "leaving" and "arriving", the universe has less than 100% of the mass of the universe.

You can't break the laws of Physics.

 

But you can bend them a little!

 

One hypothesis I have heard of is that you can make changes to the system as long as you change it back before the system reacts.

 

As an example, no responsible person would knowingly write a check on an account with insufficent funds on deposit. But let's say some other person, neither you nor I, had to mail a bill today to avoid a late fee. He writes a check, knowing (a) there is insufficent amount of money in the account as he writes and mails the check but ( his paycheck will be directly deposited in that accound day after tommorrow, same day the other company gets the check he mailed. By the time the check reaches the bank the funds are on deposit, no harm, no foul.

 

Now our irresponsible person had to pay the bill three days ago to avoid the late charge. He gets cash out of his account, and steps into the Wayback machine, and comes out a week ago. The universe, as he left it, is minus his mass and the currency he was carrying. The universe as he arrives is over by the same amount. He buys a money order and mails it, avoiding the late charge. He then comes back to the moment he left. The universe is over by the currency he used to pay for the money order until it catches up to the point wenre he took that currency into the past. So the currency was in two places at the same time for about a week there, and as long as no one noticed two bills wit identicale serial numbers no harm done.

 

So while for that week there were minor fluxuations in the mass-energy of the universe, on the average it all evened out. Don't KNOW if this is the way a Wayback machine would work, but makes sense to me.

 

But Photons have (are) energy. And energy and mass are equivalent (E=MC^2). So don't they have "effective" or "equivalent" mass?

Yes, photons have "equivalent" mass, or gravity could not affect them. The question is do they have "rest" mass.

[McCoy]

Re: Hard Science Help

 

Photons travel at c. Things that travel at c don't have time pass for them.

Wow. That means, from the photon's point of view, its creation and destruction are the same event, it comes into existance and is snuffed out literally in no time at all.

 

I think my brain just melted.

[SteveZilla]

Re: Hard Science Help

 

It gets paid to the local gravitational well; it costs energy to go up.

 

So the Gravity field gets stronger by the same amount of energy lost by the photon?

 

The photon doesn't have enough energy to be able to buy itself out of the gravity well. The black hole forecloses' date=' takes all its energy. Since all there is to a photon is its energy, that destroys it and it's gone and you don't have to worry about it any more. Kinda like how the banking system wants to handle subprime mortgages: they take everything and that's the end. [/quote']

 

I was wondering if physics gives some different status to the event of the Photon ceasing to exist as opposed to that when the Photon looses energy but is still around.

 

A small number. E = h f for photons' date=' where h is Planck's constant.[/quote']

 

Actually, I was concerned with it's it's wavelength (I guess I should have asked that first time around). In a way, I was essentially asking what is the minimum possible energy of a photon, and from that, what's the maximum possible wavelength. And is that wavelength longer than the universe or smaller?

 

I have derived the following formula from what you stated here and a helping from Wikipedia:

 

λ = Ch/E

 

λ = Wavelength, C = Speed of Light In A Vacume, h = Planck's constant, and E = Energy. But it still doesn't tell me just how small E can become without reaching zero.

 

You've changed topics' date=' believe it or not. In 1-5 you're talking about general relativity; in 6 you're talking special relativity. Still, the answer is, it doesn't matter. Photons travel at [i']c[/i]. Things that travel at c don't have time pass for them.

 

But it oscillates -- it has a frequency. Frequency is a measure of cycles per unit of time. If time is slower in that region of space due to gravity, wouldn't the frequency of any photon in that region also be lower?

[SteveZilla]

Re: Hard Science Help

 

Wow. That means' date=' from the photon's point of view, its creation and destruction are the same event, it comes into existance and is snuffed out literally in no time at all.[/quote']

 

Which has interesting implications upon the "distance" the photon "travelled" during that "time".

 

I think my brain just melted.

 

Um, McCoy? You've got something dribbling out your left ear...

[AmadanNaBriona]

Re: Hard Science Help

 

ever seen Jeff Dunham's ventriloquist routine?

 

*neeeeeeowwwwwww*

(The sound made as information goes whizzing by, totally over my head)

[Cancer]

Re: Hard Science Help

 

So the Gravity field gets stronger by the same amount of energy lost by the photon?

Presumably, but we're on slippery ground here. If we're talking about a black hole, and the photon is inside the black hole, then (1) the photon had to "borrow" its initial energy from the energy of the black hole in order to exist in the first place and (2) strictly speaking, you shouldn't ask questions about what goes on inside a black holes, because you can't learn the answers (no information can escape the event horizon). In fact, you can't be certain whether the same laws of physics operate inside a black hole as outside, because no information escapes to let you know.

I was wondering if physics gives some different status to the event of the Photon ceasing to exist as opposed to that when the Photon looses energy but is still around.

Virtual particles (of which photons are certainly included) come into existence and are destroyed all the time. This situation probably fits into that process, modulo the problems of discussing the inside of black holes already mentioned.

Actually, I was concerned with it's it's wavelength (I guess I should have asked that first time around). In a way, I was essentially asking what is the minimum possible energy of a photon, and from that, what's the maximum possible wavelength. And is that wavelength longer than the universe or smaller?

Actually, I never considered that before. There's no fundamental limit on the minimum energy in a photon, but you have practical problems making very low energy photons. The black-body spectrum goes to zero as energy/frequency goes to zero/wavelength goes toward infinity. Also, in a non-vacuum, photons interact with the particles around them, which tends to increase the photon energies, though I forget the dependencies of the strengths of the interactions as a function of photon energy (it's a constant value at low energy, though).

But it oscillates -- it has a frequency. Frequency is a measure of cycles per unit of time. If time is slower in that region of space due to gravity, wouldn't the frequency of any photon in that region also be lower?

Remember, you're changing frames of reference. Not only do the clocks slow down as your speed increases, but your meter sticks contract, also. With photons, the total photon energy is conserved as you change reference frames ... it was arguments about electromagnetic waves and energy conservation that make the entirety of "On the electrodynamics of moving bodies" which was Einstein's initial paper on special relativity.