Interesting Science Stuff Thread

[Easy Bakes 253]

Rainbow Toad Rediscovered, Photographed for First Time

thought to be Extinct for 87 years.

Taste the Rainbow

[astronelson 339]

It's always nice to hear of Lazarus taxons.

While slightly larger than a toad, there is still hope for the Thylacine (Tasmanian Tiger) yet, then. It's only been presumed extinct for 75 years.

There have been hopes of cloning it floating around since 1999, just in case we actually did kill all of them. There are a few troubles to be expected along the way though - it was the last member of the family Thylacinidae, so a suitable surrogate mother would be rather hard to find. In addition to this the only genetic samples we have are all at least three-quarters of a century old, so the DNA has deteriorated somewhat.

Despite these, there are projects underway that show some promise. Perhaps someday we will be able to reintroduce the Tasmanian Tiger to Tasmania. It's not often we get a chance to fix our worst mistakes, so I hope this works.

[A Nonny Moose 8,261]

Well, the New Guinea jungles hold many surprises for self-assured scientists who take other people's word for things.

The Tassie is a pretty beastie. Imagine a cat-like carnivorous marsupial. What a prize. I suppose they were a bit of a nuisance and were stamped out by the farmer crowd. Getting one up from old DNA has overtones of Jurassic Park. I don't think they should even try. Let her rest with the Dodo.

  Edited July 15, 2011 by A Nonny Moose  

[Easy Bakes 253]

Great White Jumps into Research Boat

They were counting GW Sharks

wonder if someone said "Here's One !"

[A Nonny Moose 8,261]

Thanks for the daily smile. The poor shark was following the line of "chum". Those guys are pretty fearless.

[A Nonny Moose 8,261]

Limit of c in vacuuo confirmed. The conclusion that time travel is impossible is not necessarily fact, as there may be some work around not yet discovered. Let us pray for the understanding of the elusive graviton.

[Easy Bakes 253]

Limit of c in vacuuo confirmed. The conclusion that time travel is impossible is not necessarily fact, as there may be some work around not yet discovered. Let us pray for the understanding of the elusive graviton.

So they proved light can not exceed the speed of light.

[A Nonny Moose 8,261]

Limit of c in vacuuo confirmed. The conclusion that time travel is impossible is not necessarily fact, as there may be some work around not yet discovered. Let us pray for the understanding of the elusive graviton.

So they proved light can not exceed the speed of light.

Actually confirmed one of the conjectures in special relativity. The LHC may write a few new words on that with the anti-matter experiments. Besides, don't we already have a pretty good idea that there is a time-dilation on the event horizon of a black hole?

[Easy Bakes 253]

Limit of c in vacuuo confirmed. The conclusion that time travel is impossible is not necessarily fact, as there may be some work around not yet discovered. Let us pray for the understanding of the elusive graviton.

So they proved light can not exceed the speed of light.

Actually confirmed one of the conjectures in special relativity. The LHC may write a few new words on that with the anti-matter experiments. Besides, don't we already have a pretty good idea that there is a time-dilation on the event horizon of a black hole?

yes light( or visible light photons ) cannot escape/pass thru but Xrays can and i think positrons can also escape. but that just may be an effect of observation of the matter passing beyond the event horizon, no real time dialtion occurs at the point of impact just in the observation of the effect on light escaping from the event.

Also The Black Hole movie was not that bad.

  Edited July 26, 2011 by Easy Bakes  

[A Nonny Moose 8,261]

When a black hole eats too much, the radiation escapes from both ends (poles), but what happens to the stuff that remains? Theory says it can grow as long as it can attract matter (and energy) into the gravity well, but sometime there must be a limit. Does it become a white hole or a kind of little big bang?

[astronelson 339]

Let's deal with these in order, shall we?

When a black hole eats too much, the radiation escapes from both ends (poles),

Not quite - the jets coming out the poles are because of the accretion disc interacting with the magnetic field, twisted by the black hole's intense effect on spacetime. Some matter passing close to the black hole is caught up in the magnetic field and ejected out perpendicular to the disc.

but what happens to the stuff that remains?

It stays there until the black hole decays through Hawking radiation, which is another thing entirely. Hawking radiation comes from the electron-positron pairs forming all the time. Usually these recombine and there's no net change to the universe, but near a black hole, the intense gravity can make one fall in while the other stays out. Since an electron (or positron) seems to have come from nowhere, there must be a corresponding decrease in the energy of the universe somewhere else. This happens to be the spacetime near the black hole, which means the black hole has become slightly lighter.

Theory says it can grow as long as it can attract matter (and energy) into the gravity well, but sometime there must be a limit. Does it become a white hole or a kind of little big bang?

There's no limit, and no reason why there must be one. It can just keep growing and being a black hole until nothing falls into it any more, or at least falls in slower than Hawking radiation escapes. The biggest black hole we know of is in OJ287, with a mass of 18 billion suns. That beauty's 3.5 billion light-years away.

[Easy Bakes 253]

Let's deal with these in order, shall we?

When a black hole eats too much, the radiation escapes from both ends (poles),

Not quite - the jets coming out the poles are because of the accretion disc interacting with the magnetic field, twisted by the black hole's intense effect on spacetime. Some matter passing close to the black hole is caught up in the magnetic field and ejected out perpendicular to the disc.

but what happens to the stuff that remains?

It stays there until the black hole decays through Hawking radiation, which is another thing entirely. Hawking radiation comes from the electron-positron pairs forming all the time. Usually these recombine and there's no net change to the universe, but near a black hole, the intense gravity can make one fall in while the other stays out. Since an electron (or positron) seems to have come from nowhere, there must be a corresponding decrease in the energy of the universe somewhere else. This happens to be the spacetime near the black hole, which means the black hole has become slightly lighter.

Theory says it can grow as long as it can attract matter (and energy) into the gravity well, but sometime there must be a limit. Does it become a white hole or a kind of little big bang?

There's no limit, and no reason why there must be one. It can just keep growing and being a black hole until nothing falls into it any more, or at least falls in slower than Hawking radiation escapes. The biggest black hole we know of is in OJ287, with a mass of 18 billion suns. That beauty's 3.5 billion light-years away.

Don't know if they have proved it yet but the astrophysics crowd think that most galaxies

have black holes at their centers, eventually it will probably consume the whole galaxy.

[astronelson 339]

Don't know if they have proved it yet but the astrophysics crowd think that most galaxies

have black holes at their centers, eventually it will probably consume the whole galaxy.

Black holes don't actually suck things in like a cosmic vacuum cleaner. Most of the galaxy will be quite stable. We're certainly unlikely to fall into Sagittarius A* (the supermassive black hole at the centre of our galaxy). We've got the conservation of angular momentum to thank for that.

The 18 billion solar mass black hole I mentioned before would "only" have a radius of 53.1 billion kilometres (2.05 light-days). Quite small compared with the average separation of stars.

[A Nonny Moose 8,261]

But then, that was 3.5 billion years ago. Wonder what it is like now? It might have even dissipated, eh? That thing we see now is much older than our puny little solar system.

[astronelson 339]

But then, that was 3.5 billion years ago. Wonder what it is like now? It might have even dissipated, eh?

Since it'll stick around for about 1.22*10⁹⁸ years (assuming Hawking radiation is correct, and we haven't any good reason to think otherwise), I'd say it's roughly the same size as it was a mere 3.5 billion years ago.

[A Nonny Moose 8,261]

But then, that was 3.5 billion years ago. Wonder what it is like now? It might have even dissipated, eh?

Since it'll stick around for about 1.22*10⁹⁸ years (assuming Hawking radiation is correct, and we haven't any good reason to think otherwise), I'd say it's roughly the same size as it was a mere 3.5 billion years ago.

In that case, maybe we'll be able to pop over and check on it in person, not too close, someday. Cosmic events sometimes are really hard to get your head around.

[Easy Bakes 253]

Water flowing on mars.

http://www.bbc.co.uk/news/science-environment-14408928

[Terring 6,473]

A crazy idea from the past. In 1933, Science & Mechanics magazine proposed the installation of gigantic wind turbines on top of every skyscraper in the city!

[Easy Bakes 253]

A crazy idea from the past. In 1933, Science & Mechanics magazine proposed the installation of gigantic wind turbines on top of every skyscraper in the city!

imagine the noise and vibrations inside the building.

[A Nonny Moose 8,261]

A crazy idea from the past. In 1933, Science & Mechanics magazine proposed the installation of gigantic wind turbines on top of every skyscraper in the city!

<illustration deleted>

imagine the noise and vibrations inside the building.

Modern technology would find a way to silence them.

[Jamesrules90 133]

People don't go on the top of buildings, only the rich illuminati live up there (oops I said too much). It wouldn't be that much of a problem the top floors are mainly observation floors and meeting rooms for people who want to feel big and they are so well sound proofed it wouldn't be a problem.

[Easy Bakes 253]

What would the vibration do to the structure of the buildings?

[Jamesrules90 133]

What would the vibration do to the structure of the buildings?

Attach a mass damper to the skyscraper and the vibrations are negated.

[Ocram's Razr 964]

Many buildings have wind turbines.

[A Nonny Moose 8,261]

I don't think a mass damper has the effect of killing waves of such short wavelength.

[Jamesrules90 133]

Oh well if not they can always stick the wind turbines are airships.

[A Nonny Moose 8,261]

Oh well if not they can always stick the wind turbines are airships.

Huh?

[Jamesrules90 133]

I meant on balloons attached to the buildings, I was distracted when I typed that.

[A Nonny Moose 8,261]

I meant on balloons attached to the buildings, I was distracted when I typed that.

So I gathered. I should think a damper of some kind could be included in the turbine structure, but they could always use a sky hook.

[Jamesrules90 133]

Maybe it would just be easier to build them out at sea. Having them high up would cause problems with all the high wind speeds as that kind of thing causes break failure as seen here. If we increased funding on nuclear fusion research we could have near unlimited power. We could just stick biomass digestors in them instead and then get gas and stuff.

Edit summary: I changed the youtube link since I didn't realize it would become a full video.

  Edited August 6, 2011 by Jamesrules90