# Search results

1. ### Stargazing Assessment of astronomical numbers like those of Proxima Centauri

Proxima Centauri is 4.2 light years away. That is 24,673,274,438,400 miles. Going at the speed of the Sun through the Milky Way, 492,150 miles per hour, it would take 5,723 years to get there. In 100 years the Sun has only gone 431,123,400,000 miles, or 7 percent of 1 light year...
2. ### What is the largest an animal can be?

I know the blue whale is the largest known animal to have existed on Earth, but can animals conceivably grow larger, or is that pretty much the largest animal you can expect to find in the universe?
3. ### How do I factor polynomials?

I'm in desperate need of help with factoring. Basically, how do you do it? Below is an example of what I'm up against. 54c^2d^5e^3; 81d^3e^2 It wants me to find the greatest common factor. http://www.rempub.com/80-activities-...algebra-easier That is the book I'm working out of.
4. ### Getting to Habitable Exoplanets

According to Wikipedia, there could be as many as 11 billion planets in the habitable zone of sun-like stars, with the closest potentially 12 light years away. That number goes up to 40 billion if you include red dwarfs. How would we even go about getting to the nearest Exoearth?
5. ### Macroscopic Objects at Relativistic Speed

How much energy would be required to accelerate something the size of the space station to the same speed as protons colliding at the LHC?
6. ### Is there an unseen part of the universe older than the known universe?

The best theories have the universe arising from a singularity 13.8 billion years ago, and have it expanding, becoming increasingly dilute and frigid for eternity. Do you think the Copernican principle holds for the universe and that we inhabit a small part of a vaster cosmos permanently beyond...
7. ### Please recommend pop sci books

Here is what I have read: carroll, sean from eternity to here carroll, sean the particle at the end of the universe deutsch, david the fabric of reality gott, j. richard time travel in einstein's universe greene, brian the elegant universe greene, brian the fabric of the cosmos greene...
8. ### How much energy would it take

to accelerate a macroscopic object to the speeds reached by protons at the LHC? want to accelerate an object the size of the ISS to the speed of subatomic particles in a collider. I would like to know how much energy would be required.
9. ### Why does antimatter exist?

I don't understand why antimatter exists in the first place. Could you explain why and how an asymmetry developed between matter and antimatter?
10. ### Hypothetical Interstellar Spacecraft

I know of Project Daedalus, Project Icarus, and Project Orion. These basically utilize pulse propulsion. In Daedalus and Icarus helium 3 and deuterium are combusted by a laser to create thrust. And in Orion nuclear bombs explode behind the craft to get it moving. All of these designs only reach...
11. ### Recommended astronomy books

I'd like to read some layperson level materials about astronomy and astrophysics, what do you recommend?
12. ### The Limits of Math

I've been reading Brian Greene's books and he says the math for describing even the simplest physical phenomenon in the real world is wildly complex, thus physicist use vastly simplified models. Since current math is insufficient to describe everything in the universe and a final theory, will...
13. ### Why can't Wormholes exist?

I've read works by Kip Thorne, Brian Greene, Sean Carroll, Leonard Susskind and I get the impression that wormholes are highly problematic and are based on relativistic equations, but not reality. I want to know why wormholes are impossible.
14. ### Invasive Species in Hawaii

What flora and fauna currently in the islands didn't exist there before being introduced by man over the eons? What did the islands look like before humans first set foot on them? Basically, how different were they as compared with themselves today? Was ancient Hawaii even covered in vegetation...
15. ### How do Gravity and Acceleration affect Clocks?

I read that stationary clocks on Earth experience time more slowly than clocks on GPS satellites, so the GPS clocks are calibrated to run more slowly to compensate. Since the satellites are in orbit, wouldn't that mean their clocks would be slower since they were moving faster?
16. ### How strong is human stomach acid?

This may seem weird, but after a day of acid reflux here goes: Let's say you could shrink yourself down, and get swallowed alive by a healthy woman -- would her stomach be able to dissolve you bones and all? Or would you suffocate before feeling any considerable burning? Would you even feel...
17. ### Video Games and Their Basis in Theory

Are there any theories with which the mass effect fields of Mass Effect and the slipstream space of Halo draw inspiration from? Is there any scientific basis for either, or is it complete fantasy?
18. ### Some Questions

If you leave Earth traveling at .01c can you reach Saturn in 6 days? What type of presently conceptual craft could most realistically achieve this?
19. ### Fission Fragment Rocket

Fission-fragment rocket The wiki entry seems to paint this system in a positive light, so is it a workable propulsion system for high speed space missions? How long would a trip to Pluto take with something like this? How many years away is this from becoming a reality?
20. ### Is Fusion Practical for Spacecraft?

Would fusion make for practical applications in high speed interplanetary propulsion? Or would beamed propulsion be better?
21. ### Gaseous Core Nuclear Thermal Rocket

http://www.projectrho.com/rocket/enginelist.php#id--Gaseous_Core_Nuclear_Thermal_Rocket http://en.wikipedia.org/wiki/Gas_core_reactor_rocket How practical would this be? How much of a technological leap would be needed to achieve this? Would it make outer solar system missions possible...
22. ### 99% of Light speed

Is it possible to build a vehicle that can accelerate to .99 C? How would we go about doing something like this? If at all possible, how many centuries or millennia is it before this can be accomplished? Could a Bussard scramjet do it? How large would a laser/maser/gaser have to be...
23. ### Spaceship concepts from The Dream Machines

How plausible are these concepts? Thomas Ciesla's Centauri project utilizes a terraformed asteroid with antimatter propulsion that can travel at .30 c Alan Holt's interstellar transport system uses two field generators and 16 field amplifiers to create a space-time bubble around a vessel...