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The Physics of Starship Battles: Energy, Waves, and Sound UPGRADED By Bernard Finnigan

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The Physics of Starship Battles: Energy, Waves, and Sound UPGRADED By Bernard Finnigan

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The Physics of Starship Battles: Energy, Waves, and Sound UPGRADED  By Bernard Finnigan

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Interstellar - Trailer - Official Warner Bros. UK

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Apollo Moon Mission display in the National Air and Space museum

There is no oxygen in space, so all crewed spacecraft carry a life-support system. This supplies air for people to breathe. The system also includes equipment to keep the air at a comfortable temperature and pressure and to remove carbon dioxide and odors.

Gravity in space is much weaker than it is on Earth. When people travel in space, they seem to become weightless. This often makes them feel sick. Their bodies do not have to work as hard, because they are not fighting gravity to sit or stand up. If they stay in space for a long time, the lack of gravity makes their muscles start to waste away. Exercise and a special diet help to combat these effects.

Astronauts on the APOLLO PROJECT traveled to the Moon, about 239,000 miles (385,000 km) away. Russian cosmonaut Valeri Poliakov traveled a distance of about 174 million miles (280 million km) around Earth while in the Mir space station.

In the space race of the 1960s, the US Apollo Project beat the Soviet Union by landing the first astronauts on the Moon. The first Moon landing, by Apollo 11, took place on July 20, 1969, when Neil Armstrong and Buzz Aldrin became the first humans to set foot on another world.

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There is no oxygen in space, so all crewed spacecraft carry a life-support system. This supplies air for people to breathe. The system also includes equipment to keep the air at a comfortable temperature and pressure and to remove carbon dioxide and odors. Gravity in space is much weaker than it is on Earth.

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How Interstellar Space Travel Works (Infographic)

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How Interstellar Space Travel Works (Infographic)

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(Image credit: Karl Tate, SPACE.com)

Even the fastest humans and spacecraft launched thus far would take many thousands of years to reach the closest stars. Speeds about 75 times faster than this would be required if we hope to make an interstellar trip in less than a hundred years.

To understand the difficulty of interstellar travel, one must comprehend the incredible distance involved. Even the closest star is more than 266,000 times farther away than our own sun. Consider the speed of light. Light, the fastest thing known, takes only 8 minutes to travel to us from the sun, but requires more than four years to get to the nearest star.

A handgun bullet travels at 720 miles per hour, but would take nearly 4 million years to get to the nearest star. The fastest object ever launched into space is the Voyager 1 probe, and it would take nearly 75,000 years to make the trip.

Today's chemical rockets are far too slow for interstellar travel. To have a hope of reaching the closest star in less than a hundred years, we would have to accelerate a starship to nearly 30 million mph.

Rockets using nuclear fusion or antimatter propulsion could do the job, but they would have to be developed. It is theoretically possible that by warping space, a starship might travel faster than light without violating the laws of physics within its own bubble of space-time.
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How Interstellar Space Travel Works (Infographic)

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(Image credit: Karl Tate, SPACE.com) Even the fastest humans and spacecraft launched thus far would take many thousands of years to reach the closest stars. Speeds about 75 times faster than this would be required if we hope to make an interstellar trip in less than a hundred years.

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Since the year 2000, humanity has maintained a continuous presence in space aboard the International Space Station (ISS).

People from 18 different countries have spent time at the ISS. The record for longest continuous stay is held by U.S. astronaut Mark Kelly, who spent nearly one year there.

But despite such achievements, space travel still involves a myriad of health risks for people.

From DNA damage caused by radiation exposure to the bone loss, muscle loss, and blood pressure changes that occur when living in microgravity, to name a few.

And the longer a person is in space, the greater the toll on their health.

It's a major challenge for the National Aeronautics and Space Administration (NASA), which hopes to send humans to Mars someday.

NASA conducts extensive research on how to make space travel safer.

As part of this effort, NASA requested that the National Academies of Sciences, Engineering and Medicine provide an independent review of more than 30 evidence reports on the human health risks of long-duration and exploration spaceflights.

Today, a committee of experts at the National Academies released a new letter report - the fourth in a series of five - with their findings.
Read more: Get the facts on radiation therapy "
Radiation risks

The latest review examines eight NASA evidence reports, with half of the topics focused on the health risks of radiation exposure in space.

"The radiation problem is the toughest one to solve and the most concerning," Valerie Neal, Ph.D., a historian at the National Air and Space Museum, told Healthline.

Neal spent 10 years working at NASA, but she was not involved in the current research.

On Earth, Neal explained, we are shielded by the planet's magnetic field and the protective gases in the atmosphere.

However, there's no effective way to shield astronauts from some types of radiation present in space, especially on a long journey such as a trip to Mars.

In particular, there is no technology to protect against galactic cosmic rays, a type of ionizing radiation likely produced by supernovae, or exploding stars.

That type of radiation can pass right through the hull of a spacecraft and the skin of people on board.

Astronauts also face radiation risks from solar particle events, which are difficult to predict.

In its current review, the National Academies' committee looked at NASA's evidence reports on radiation exposure and increased risk of cardiovascular disease, cancer, central nervous system disorders, and acute radiation syndrome.

For the conditions covered in each report, the committee noted that NASA has well-documented evidence of the risks, although some studies rely heavily on animal models.

One area of growing interest is the link between radiation and cardiovascular disease.

The committee found that there's now enough evidence, "to support the conclusion that the risk of degenerative diseases from long-term exposure to space radiation may be of much greater concern than previously believed."

Another major area of concern is cancer.

Radiation exposure can cause genetic damage that may increase an astronaut's risk of developing cancer years after their mission.

Currently, NASA sets the radiation limit for astronauts at a 3 percent cancer fatality probability.

For a mission on the ISS, where proximity to Earth provides some protection from radiation, women can stay about 18 months and men can stay about 24 months before exceeding the limit.

But on a mission to Mars, astronauts would be way over the limit, according to Francis Cucinotta, Ph.D., a professor of health physics at University of Nevada, Las Vegas, who authored the research on exposure limits.

Cucinotta worked for NASA for more than a decade, and developed a database that tracks astronauts' exposure to radiation and cancer risk estimates.

He told Healthline it would be a question of ethics whether to raise the risk limit to allow astronauts to travel to Mars.

"It requires a good discussion of whether you would accept that risk. And then how high of a risk would you accept?" Cucinotta said.
Read more: "toxic masculinity" leads to mental health issues for men "
Risks on top of risks

But the hazards of space aren't the only risks astronauts face on a long voyage.

They also have to put up with each other, while maintaining their own sanity in a small, cramped space.

The National Academies also examined NASA's evidence reports on mental health issues related to space travel and "behavioral health decrements" when team members aren't working well together.

Another report focused on the health risks associated with sleep loss, circadian rhythm issues, and work overload.

Lastly, the committee reviewed evidence on risks related to "vestibular/sensorimotor alterations," which include issues like space motion sickness.

Overall, the committee noted that all of NASA's reports were quite thorough, but recommended that NASA pay more attention to the interactions between different types of risks.

For example, lack of sleep and being overworked could have a big impact on how well a team of astronauts works together.

Teamwork issues are especially important to consider on long-duration missions, according to Neal.

"On a one- to two-week mission you are so busy, you don't have time for interpersonal issues to form," Neal told Healthline. But on longer missions, more psychological factors come into play.

She noted that being able to call family and friends back home and talk in real time has made a world of difference for astronauts' mental health and well-being.

But those immediate connections wouldn't be possible on a long mission to Mars - which could be a real source of stress for astronauts.

At the end of a mission, Neal explained, "No matter how productive they feel they've been, they all say they are eager to rejoin family and friends."
Read more: Get the facts on motion sickness "
Health risks of space tourism

While NASA's evidence reports focus on the risks of long-duration space travel for astronauts, there's growing public enthusiasm about short-term space tourism for civilians.

But even a brief sojourn in space comes with health risks.

Neal noted that most of the risks of a long-duration spaceflight, like radiation exposure, wouldn't be an issue for the brief commercial trips proposed by space tourism companies like Virgin Galactic.

On these trips, people are in outer space for only a few minutes.

However, space tourists could still experience the immediate side effects of being in a microgravity environment, such as space motion sickness.

"If the ratio among astronauts proves to be true of the general population, about half the people would experience some space motion sickness," said Neal. "For some people it's like queasiness and for some it's nonstop vomiting."

Neal said another pressing issue would be the safety of the commercial spacecraft itself.

The OECD Observer notes that the U.S. space program faced two crashes out of 113 departures, for a failure rate of 1.8 percent.

That's far higher than would be allowed in commercial airlines, which have an accident rate of about 0.4 per 100,000 flights.

But for many, the risks are well worth the chance to see Earth at a distance.

So far, the only space tourists have been wealthy people who made trips to the ISS lasting between eight and 15 days.

For Neal, who has devoted much of her career to supporting space travel, the opportunity to do an orbital tour of Earth would be a dream come true.

If the price of a visit ever dropped low enough, she said she would do it - despite the risks.

"I would be just so thrilled at the view that I probably wouldn't even think about it," she said. "Everybody who has had that view says it is life altering, and it gives you such a different view of life and the cosmos."

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Since the year 2000, humanity has maintained a continuous presence in space aboard the International Space Station (ISS). People from 18 different countries have spent time at the ISS. The record for longest continuous stay is held by U.S. astronaut Mark Kelly, who spent nearly one year there.

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What happens to the unprotected human body in space?

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What happens to the unprotected human body in space?

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Image public domain

It's a recurring horror in sci-fi: the hull is pierced, a human is trapped without equipment in an airlock about to open, a door needs to be opened in order to expel something undesirable. With no air and almost zero pressure, the human body isn't going to last long without some form of protection.

But what does happen, exactly? Do your eyes explode outward while your blood evaporates? Well, no. The truth is both less dramatic and far more fascinating -- as we have discovered through accidents in space and in test chambers, and animal experimentation in the 1960s.

The first thing you would notice is the lack of air. You wouldn't lose consciousness straight away; it might take up to 15 seconds as your body uses up the remaining oxygen reserves from your bloodstream, and -- if you don't hold your breath -- you could perhaps survive for as long as two minutes without permanent injury.

If you do hold your breath, the loss of external pressure would cause the gas inside your lungs to expand, which will rupture the lungs and release air into the circulatory system. The first thing to do if you ever find yourself suddenly expelled into the vacuum of space is exhale.

The other things, you can't really do much about. After about 10 seconds or so, your skin and the tissue underneath will begin to swell as the water in your body starts to vaporise in the absence of atmospheric pressure. You won't balloon to the point of exploding, though, since human skin is strong enough to keep from bursting; and, if you're brought back to atmospheric pressure, your skin and tissue will return to normal.

It also won't affect your blood, since your circulatory system is able to keep your blood pressure regulated, unless you go into shock. The moisture on your tongue may begin to boil, though, as reported by Jim LeBlanc, who was exposed to near vacuum in a test chamber in 1965. LeBlanc's suit sprung a leak, and he remained conscious for about 14 seconds; his last sensation was bubbling on his tongue (he was safely revived, as the researchers began repressurising the chamber almost immediately -- after about 15 seconds).

Because you will be exposed to unfiltered cosmic radiation, you can expect some nasty sunburn, and you'll probably also get a case of decompression sickness.You would not, however, freeze straight away, despite the extremely cold temperatures; heat does not leave the body quickly enough for you to freeze before you suffocate, due to the lack of both convection and conduction.

If you do die in space, your body will not decompose in the normal way, since there is no oxygen. If you were near a source of heat, your body would mummify; if you were not, it would freeze. If your body was sealed in a space suit, it would decompose, but only for as long as the oxygen lasted. Whichever the condition, though, your body would last for a very, very long time without air to facilitate weathering and degradation. Your corpse could drift in the vast expanse of space for millions of years.

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What happens to the unprotected human body in space?

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It's a recurring horror in sci-fi: the hull is pierced, a human is trapped without equipment in an airlock about to open, a door needs to be opened in order to expel something undesirable. With no air and almost zero pressure, the human body isn't going to last long without some form of protection.

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Over the decades, Hollywood has exposed many hapless characters to the frigid, unforgiving vacuum of outer space, much to the guilty viewing pleasure of the audience. We, as members of that audience, have been fed countless cinematic, special effects treats involving flash-freezing, in-suit explosions, and -- my personal favorite -- a bulbous, ballooning Arnold Schwarzenegger. But, as entertaining as these gruesome scenes may be, they aren't entirely accurate.
First You Bloat, Then You Burst.
In the 1981 sci-fi jaunt, Outland, an unfortunate construction worker ruptures his space suit, begins to swell inside his apparel like batter filling a waffle iron, and finally explodes into smithereens. Though scintillating on the silver screen, this scene would never play out in real life. There have actually been cases of astronauts' body parts being briefly exposed to vacuums when their suits were damaged with no explosive or disastrous outcomes.

Even if a suit-less human was exposed to outer space, they would neither excessively balloon nor burst. The air in one's lungs would expand, potentially causing tissue tearing, and water in soft tissues would vaporize, inducing swelling, but the tight seal of your skin would inhibit any biological fireworks.

Hollywood take note: Just like cars don't always explode after being flung from cliffs, nor do humans explode when exposed to a vacuum.
Quick Freeze? Oh Please!

The 2007 indie sci-fi flick, Sunshine, showcased Danny Boyle's prodigious directorial talents, but not his knowledge of heat transfer. In a dramatic and memorable scene, one of the characters is killed by rapidly freezing to death when exposed to the cold vacuum of space. This would not happen.

Though space is typically very cold -- most floating objects have a surface temperature of -454.8 degrees Fahrenheit -- a person would not instantly freeze because heat does not transfer away from the body very quickly. On earth, heat can be transferred via convection, but outer space is mostly nothingness. The only way to transfer heat is via infrared radiation.
The Grim Reality
If you became gripped with an uncontrollable urge to go for a quick, unprotected pleasure float in outer space, here's what would likely happen:

First off, the gas in your lungs and digestive tract would rapidly expand, inducing swelling. If you choose this inopportune chance to hold your breath, your lungs would likely burst and you'd be a goner.

Any water directly exposed to the environment, such as the liquid on your eyes or tongue would boil off in a matter of seconds. About ten seconds into the ordeal, you would lose vision. Moments later, you would likely lose consciousness, a result of gas exchange working in reverse and oxygen being dumped from your blood. Your skin would discolor to a pallid shade of blue. After about one minute, circulation would stop altogether. After another minute, you'd be dead by asphyxiation.

There is some good news to take away from this morbid message. You can likely survive unprotected in space for as long as 90 seconds, which is plenty of time to be rescued!

Expiring in space is no picnic. In fact, a Hollywood ending might be preferable.

( Image: Astronaut via Shutterstock)

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How Would You Die in Outer Space? | RealClearScience

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Over the decades, Hollywood has exposed many hapless characters to the frigid, unforgiving vacuum of outer space, much to the guilty viewing pleasure of the audience. We, as members of that audience, have been fed countless cinematic, special effects treats involving flash-freezing, in-suit explosions, and -- my personal favorite -- a bulbous, ballooning Arnold Schwarzenegger.