Ask Mr. Science

[erush1345]

Ok, I'm starting this lame thread for you to ask me any science/math related questions. Don't ask things like how Shego throws fireballs, that's just fiction. Try to stay realistic with the questions and I'll see what I can do for you. Ask away.




Please note, any answers/responses here are not necessarily my opinions, its just the facts. How you interpret the responses is up to you. I will try my best to keep my own ideas out of the responses.

[Ashley Benlove]

So... why is Chemistry and Physics so hard?

[erush1345]

ashleybenlove said:

So... why is Chemistry and Physics so hard?

It would depend on a person's ability to grasp the subjects and their ability and amount of studying done. Most concepts in both subjects are rather simple in nature, but have few real-world examples that most people can relate to (more so on Chemistry than Physics).

[Ashley Benlove]

I barely passed both of those classes with a 70.

The chances of me taking them in college? NONE!

[erush1345]

Well, that would be a good thing. In college, you really should focus on something that you're good at and that will help you in your life after college.

[nabusan]

Erm, is time travel possible?

What can wormholes really do?

[Ashley Benlove]

Would you time travel?

[erush1345]

nabusan said:

Erm, is time travel possible?

What can wormholes really do?

Black holes are involved in both of your questions. A bit of trivia, black holes are not completely black, particles created just on the edge of the event horizon (the point where light no longer has energy to escape, the escape speed is higher than the speed of light), by pair production can actually have one of the pair form outside of the hole, while the other is formed inside the hole, thus, there is a small amount of energy that leaks from black holes. This discovery by Stephen Hawking lead to the radiation being named Hawking radiation.

Theoritically, time travel is possible in some solutions of equations in general relativity. When quantum effects are added in, for the most part, these solutions fail to work. However, quantum gravity has not been integrated into the theorums, thus, it might still be possible. However, Stephen Hawking says that the surest sign that time travel is not possible is that we don't have time visitors from the future with us now.

Wormholes are a theoretical idea that basically is a shortcut from one area of spacetime to another area of spacetime. As seen in the picture below, you would go a much shorter distance getting somewhere through the wormhole as opposed to moving along normal spacetime (depicted here in pretty much 2D to make the image easier to comprehend). That's what the theory says. Unfortunately, you encounter the problem of what exactly a singularity is in the middle of black hole. We just don't know. One solution in Einstien's general relativity allows for travel through the wormhole. Others say everything ceases to exist. Since the nearest black hole we know of is in the center of our galaxy, it would be rather hard to find out which is correct.




Overall, both experiences would kill you (well, you'd proably die from old age first) by the pull of gravity of the black hole streching you lengthwise (otherwise known as spaghettification. If that didn't kill you, the radiation levels would, since matter swirls around the singularity in a disc. That disc is accellerated to near the speed of light, where synchrotron radiation is released (along with other forms of radiation).

In any case, you are dead. No time travel for joo.


In reply to Ashley's question, as a scientist, I would observe things as they happened, not changing anything. [AN: remember, not exactly my opinion, but, in the case of being completely neutral . . .]

[USS Columbia]

Actually, there is a closer black hole to Earth: V4641. It's "only" 1500 light years away, and I'm pretty sure there are others. (I know because I was toying with the idea of having the ship in my sci-fi comic encounter one, until I found out that the closest one was 1500 ly away.)

antwrp.gsfc.nasa.gov/apod/ap000117.html

(Sorry to be nitpicky, but as a scientist you probably understand. )

One question though: Is synchronoton radiation lethal? What are its effects?

[erush1345]

Thanks for the assist Columbia ;D (for the life of me, I don't know what I was thinking when I wrote that.)

As for synchrotron radiation being lethal, yes, it is. If you read the link, you find that the radiation comes in all sorts of flavors: infrared, optical, ultraviolet, and x-rays. The infrared, ultraviolet and x-rays would be emitted in such quantities that the total dose you would receive would be lethal very, very quickly. In fact, Jupiter's magnetosphere accelerates the solar wind to relavistic speeds, causing synchrotron radiation to be released. The Galileo probe that orbited Jupiter for about 8 years absorbed several times the lethal dose of radiation to humans. Fortunately, the electronics onboard were hardened in anticipation for it. The shielding worked for longer than was expected.


Opps, missed the second part of your question.

There's different levels of radiation exposure and the amount of time needed for biological effects to manifest.

In this case, you would be dead pretty quickly due to the extrememly high doses and short period of time that you would be exposed (before you were dead). At a 50 rad level instantaneously, human cells start to die (see link). For you guys, at 350 rads, you become sterile. A cell is affected by the amount that the cell divides. Fast dividing cells, like skin, are more susceptable to problems than slower dividing cells, like nerves. A good link would be this for some general information. As a former Navy Nuke, I do have a slight increase in the risk for some cancers. Also, not proven, but pretty accepted amongst nukes is that I will have a lot larger chance to have a female kid as opposed to a male kid, since the Y-chromosone is more susceptable to being damaged due to low level radiation exposure. [FYI - my combined dose that I received while in the military was around 500 mrem, believe it or not, that amount is less than the people sitting on the flight deck receive due to the sun/cosmic background and shielding effects of all the steel on the ship to the part that I worked in].

A good chart that we had was this:

Rem - Effect(s)
5-20 slight increased risk for developing some types of
cancers
25-100 first able to see changes in blood chemistry due to
radiation exposure
>50 temporary sterility in males
100 double the normal instance of genetic defects
100-200 vomiting, diarrhea, reduction in immune system, bone
growth retardation
200-300 serious radiation poisoning, extreme nausea
>300 permenant sterility in males and females
300-400 bone marrow and intestinal destruction
400-1000 acute illness, death within days

[Imperial General Someguy]

Is hyperspace from Star Wars (or slipspace from Halo) faster than light travel, or the creation of a wormhole, or something else?

[USS Columbia]

So gas giants, black holes, and particle accelerators are sources of this radiation...what else? And does standard radiation shielding work against it? (Questions for my comic and ship---I try to keep it relatively realistic.)

[Ashley Benlove]

So... how far is 1500 light years?

[erush1345]

usscolumbia said:

SO gas giants, black holes, and particle accelerators are sources of this radiation...what else? And does standard radiation shielding work against it? (Questions for my comic and ship---I try to keep it relatively realistic.)

Anything that has a huge mass or strong magnetosphere would be able to produce it. The mass or magnetic field causes normal particles to be accelerated to the relavistic speeds that would release the large amounts radiation. Believe it or not, there are areas around Earth that have this problem. The Van Allen Belts are not places you would want to spend much time. In fact, each trip through them to the Moon, the astronauts received around 2 rem (if I recall correctly, so around 4-5 rem total for each mission). That is spread over time, the chart I listed above is mainly for instantaneous exposures. As they say in nuclear power, any exposure increases your risks. Standard radiation shielding would work, but we are talking lead and steel for some types (gamma, alpha and beta). Polymers and water for other types (neutrons). The amounts needed for travelling inside a black hole would be cost prohibative (in size, mass, energy consumption to move said mass, and lastly cost). A standard nuclear reactor has around 5 feet of shielding around the core itself and around 3-5 feet of shielding around the reactor compartment.

[AN: The core (see below)is never exposed except in refueling and that is done quite carefully with cranes.

The reactor compartment (see below) is the room that surrounds the core. You cannot enter a reactor compartment with a reactor critical and not have some bad exposure, think Spock dies in Star Trek, just over a lot longer time (like a few weeks, you might live).

It is safe to enter while the core is shutdown to do maintenance, just minimize exposure and time in there. The room around the reactor compartment is normally called the reactor auxillaries room (see above, it is labeled turbine building there, since this is a sketch of Three Mile Island), where the components for operating the reactor are (I get to sit in front of a panel here, called the reactor plant control console, like this, except a bit smaller with about 100x the gages on it for a naval nuclear control panel:

which is located in the Enclosed Operating Space). A reactor core has several tons of uranium dioxide fuel (and other stuff). Think this times a whole bunch for orbiting around Jupiter. Hopefully, that explains something to you.]

[erush1345]

someguy21 said:

Is hyperspace from Star Wars (or slipspace from Halo) faster than light travel, or the creation of a wormhole, or something else?

It would have to be creation of a wormhole (or similar type thing), nothing can travel faster than the speed of light in a vacuum (you can go faster than the speed of light in other substances, like water. That's where you see the blue glow from nuclear reactors, which is Cherenkov Radiation.)

[USS Columbia]

It does, thank you.

Hmm...I wonder if a nuclear fusion process would release Cherenkov radiation...but then again, one cannot see the engine core of my ship for the reasons you described.

[erush1345]

usscolumbia said:

It does, thank you.

Hmm...I wonder if a nuclear fusion process would release Cherenkov radiation...but then again, one cannot see the engine core of my ship for the reasons you described.

Cherenkov radiation would be produced if something was propagating (moving) through another material (like water) faster than the speed of light is in that material (that's what causes the glow).

I would believe that your ship using fusion could, since you are combining two atoms in an extremely hot and dense environment (of course that is somehow controlable ;D ). The speed of light in this case would be less than the speed of light through a vacuum, thus it is possible it would (light takes around 100,000 years to leave the core of the Sun to the surface due to the density of the materials). I wouldn't wanna stand anywhere near it however.

[erush1345]

ashleybenlove said:

So... how far is 1500 light years?

1 light second is around 186,000 miles (300,000 km). So, in a year (31,536,000 seconds), light would travel 5,865,696,000,000 miles. So, 1,500 light years is around 8,798,544,000,000,000 miles. Don't try to make it in one trip.


For size comparision, the Sun is around 24,000,000,000,000 miles away from us. So 1,500 ly is 366.06 times the distance from the Earth to the Sun.

Another comparision, the closest star to us, Alpha Centauri C (otherwise known as Proxima Centauri) is 4.22 ly away from us. Thus, 1,500 ly is 355.45 times the distance from us to the closest star.

Last comparision. The space shuttle orbits at a speed of around 8 km/sec. The fastest man-made probe is travelling at the speed of 70.2 km/sec. That would take around 18,000 years to get to Proxima Centauri and around 6.4 million years to get 1,500 ly to the nearest black hole using current technology.

[Ashley Benlove]

MAN, WE SUCK!

You would think we could go better than that.

[USS Columbia]

Wat's the most interesting proposal for an FTL drive that you've heard? It doesn't matter if it's not possible right now, because of course no FTL drive is (that I know of.)