Slitherine

quote:

ORIGINAL: CRations

If, while traveling at the speed of light, I turn on a radio will it work? And if the radio does work, what would I hear?

CR

Kirk Lazarus: I know who I am. I'm the dude playin' the dude, disguised as another dude!
Ron Swanson: Clear alcohols are for rich women on diets.

quote:

ORIGINAL: Nikademus

If a man talks in a forest and there's no woman around to hear him.....is he still wrong?

(my fav.)

quote:

ORIGINAL: CRations

If, while traveling at the speed of light, I turn on a radio will it work? And if the radio does work, what would I hear?

CR

quote:

I could give a serious answer, but the smart ass comments are too good.

Bill

quote:

ORIGINAL: wdolson

If you were traveling at the speed of light, time would essentially stop and you would hear nothing. Another way to look at it would be the radio waves would be traveling exactly the same speed you were.

If you were traveling a little less than the speed of light, you would pick up radio, but it would be stuff broadcast after you left (you would be going slower than the radio waves), but it would be dramatically downshifted in frequency to a point where you would probably need a computer to speed it back up again, and collecting an hour's worth of programming would take a few years.

If you were able to exceed the speed of light, with some kind of drive only known to science fiction today, you would outrun the radio and most likely hear nothing while you were traveling, but when you stopped, you would be able to pick up broadcasts from many years ago, depending on how far away you were. The radio waves would also be very diffuse, the strength of the signal declines at the cube of the distance (the signal is radiating out from Earth in a sphere), so you would need a super sophisticated receiver to be able to pick up anything. Radio noise put out by our sun would probably drown out much of the signal after some distance. You might be able to pick up a bit of a radio hot spot where Earth was when the broadcasts you are picking up were sent, but all you would be able to do is pick up that something was transmitted.

SETI tries to pick up coherent radio patterns in signals from other stars. So far they haven't found anything definitive. They do have some pretty sophisticated receiver arrays (and would like to build even more sophisticated arrays). I doubt you'd be able to pick up anything coherent with commercially available equipment even if planets around nearby stars were broadcasting.

And always remember 285,000 miles per second, it's not only a good idea, it's the law.

Bill

quote:

ORIGINAL: wdolson

Light always travels at the speed of light relative to the frame it's traveling within. Hence the reason the theory is called relativity. If you are in a craft traveling near the speed of light, light will travel within the craft at the speed of light.

This is why a lot of Physicists resisted the theory of relativity when it was introduced. It's hard to get to your mind around it when you first encounter it.

Bill

quote:

ORIGINAL: wdolson
I'm also not so sure that the world is going to end up over crowded. We're pushing the carrying capacity of the world's food growing capabilities now. We're managing, but some years of bad grain crops in the main grain exporting countries sent the price of grain worldwide off the peg. The impact in the developing world was heavy. The Arab Spring was fueled in part by people mad at the high cost of food in economies that have no room for more expensive food.

India and China are right now keeping their people fed by mining their ground water. China has already exhausted most of their shallow aquifers and are working on the deepest water they can recover to grow crops. India is only a few years behind them in the use of their ground water. Estimates are by 2020, those two countries will not have enough water to grow their crops. What will happen when 2.5 billion more people are buying grain on the international markets?

It will be terrible, but I expect the world's population is going to drop sharply when that happens. It won't be pleasant. The developed countries that can grow enough to feed themselves will fare the best, but we'll all get some impact.

Personally I think the long term carrying capacity of the Earth's eco system is about 2-3 billion. If an ice age starts, that may drop to about 500 million. Those are just my back of an envelope guesses.

Anyway, that's a major tangent...

Bill

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ORIGINAL: zzodr

Yes, sadly, we won't be going anywhere beyond our solar system with manned spacecraft. As much as discovery of other planets intrigues and excites us.
Voyager 1 has been cruising at @60,000km/h for around 34 years and has gone 0.002 light years - our nearest star Proxima Centauri is around 4.2 light years away.
On rough scale, if the Sun was a beach ball, and the Earth a pea - 110metres away, Proxima Centauri would be around 32,000km away on scale. 

quote:

ORIGINAL: Phanatik

These discussions refer to light traveling through a vacuum.

If your radio is traveling through a vacuum, you won't hear anything regardless of how fast it's traveling.

Has anyone heard anything lately about the Swiss experiment where the particle traveled faster than C? Last I heard some folks were pooh poohing the results.

WitP AE - Test team lead, programmer

quote:

ORIGINAL: LoBaron
Great read Bill, thank you!

I´d just like to comment on your analysis of population developement and it´s implications.
It very much depends on what you define as "overcrowded".

If you define it as "more people than sutainable with current technology relying on
renewable ressources" it already is.

The problem with the scenario you describe is, that when prices for a ressource are increasing - not
because of increased production cost but because of increased demand and low availability - the attractiveness
to profit from the production of those ressources increases in direct proportion.

Now, the best way to increase production of mentioned ressources is to increase the area where those ressources
can be harvested. The only places left on earth where this expansion still is possible are the rainforests which
are responsible for a high percentage of oxygen production and CO² binding.

By reducing the area of rainforests we are at the same time reducing the sustainable number of people by renewable
ressources. We are, sadly, moving in a fast spinning devil´s circle fuelled by the global market and free economy.

Just hope my post is not interpreted as too political, just extending on your really interesting major tangent.

Best regards,

Lenny

WitP AE - Test team lead, programmer

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ORIGINAL: wdolson

quote:

ORIGINAL: Phanatik

These discussions refer to light traveling through a vacuum.

If your radio is traveling through a vacuum, you won't hear anything regardless of how fast it's traveling.

Has anyone heard anything lately about the Swiss experiment where the particle traveled faster than C? Last I heard some folks were pooh poohing the results.

Without some kind of radio receiver, you won't hear anything regardless of whether you are in an atmosphere or not. Radio waves travel and can be picked up just as easily in vacuum as in an atmosphere. Signals broadcast from vacuum to vacuum can potentially have less noise because there will be no atmospheric interference.

Earth communicates with unmanned craft in vacuum all the time with no problems.

Bill