Black holes are some of the most mysterious and fascinating objects in the universe. These are objects whose gravitational pull is so intense that nothing, not even light can escape once it enters a region at the boundary of the black hole known as event horizon. Once anything crosses the event horizon there is no force in the universe that can help it from falling inside the black hole. There are mainly three kinds of black holes. The smallest known black holes are ‘Primordial black holes’- that are thought to have formed in the early universe, the medium sized black holes known as ‘Stellar black holes’- that are formed when the center of a big star collapses and then there are the largest known black holes called the ‘Supermassive black holes’ that were formed at the same time as the galaxies they reside in.
Black holes by themselves have been a field of research for decades. People are down to Black holes because of their mysterious nature. There are a few things about black holes that make them unique and so mysterious.
- Black holes are powerful engines of nature
Black holes are probably the most efficient and powerful engine in the universe. Much of matter swirling into a black hole doesn’t fall in but is spit out outward at speeds close to the speed of light. These giant jets of matter have been observed to shoot out from Galaxies core. Giant spinning black holes are the only powerful known source that can produce such jets. This happens because some of the materials that don’t reach the event horizon get trapped in the Black hole’s powerful magnetic field. These jets of materials shooting out of the black hole emit huge amounts of energy.
- There is a Black hole at the center of our Milky way Galaxy
Yes, like most galaxies, there is a supermassive black hole at the center of our own Milky Way galaxy. The black hole, known as Sagittarius A has a mass of about four million times the mass of our Sun.
The supermassive black hole Sagittarius A* (Sgr A*), located in the centre of the Milky Way galaxy, is shown in these images.
The image in the figure shows X-ray in blue color taken from Chandra X-ray observatory and infrared emissions are shown in red and yellow taken from Hubble Space telescope. The zoomed in view shows the black hole in X-rays.
- Black holes slows down time
According to Einstein’s theory, if you get closer to any massive body, times slows down. This effect can be observed on earth only by using very sensitive instruments because earth’s gravity is too weak to show any noticeable effect.
But since black holes are so dense and the gravitational pull is so strong that it literally distorts space-time. And that’s why near a black hole the slowing of time is extreme. If you can manage to orbit near the event horizon of a black hole for a while and then turn your spaceship round and fly back to earth – you will have travelled to the future! Depending on how long you stayed in orbit, you will find most people you knew are older or probably not alive!
- Trip to a black hole is a one way trip
The extreme gravitational pull of a black hole makes it impossible for anyone or anything to escape from it once it has crossed a certain region called the event horizon. Not even light can escape from this gravitational pull. You may be able to survive a trip (well at least for a while) through the event horizon of a supermassive black hole. But for a stellar mass black hole tidal forces are large even outside the event horizon. And so you will be ripped apart before you try to cross the horizon. In any case, once you cross the event horizon there is no turning back.
- Inside a black hole
So what’s inside this black hole? Well, that’s still a mystery.
Our understanding of laws of physics breaks down at the center of the black hole. A singularity lies at the center; it’s a point that contains infinite mass in an infinitely small amount of space. Einstein’s theory suggests that time is destroyed at the center, i.e. time as we know it ends there. We don’t know why time would come to end at the center of the black hole.
- If you fall into a black hole you will be spagettified
Lets say you survive your trip long enough inside the event horizon of a supermassive black hole. At first you will experience weightlessness i.e. you will be in a state of free fall. But as get closer to the center of the black hole you will start to feel tidal ‘stretching’, meaning if you legs would feel a much stronger pull than your head as it is closer to the center. You will experience this extreme stretching until you are ripped apart or spagettified. For a stellar mass black hole you will experience this even before you cross the event horizon.
- Black holes evaporate
Black holes do evaporate although we are not entirely sure how. Stephen Hawking showed in 1974 that black holes are not entirely black, they do emit radiation and as a result black hole shrink. Eventually they will vanish completely. And this process is known as black hole evaporation. However, this is a very slow process and some of the very small primordial black holes evaporate over long periods of time and massive black holes can live for billions of years.
- Black holes do not suck or at least not if you keep your distance
A very common misconception about black hole is that many people think black holes suck everything around them. Yes, they are undoubtedly very weird objects in space but they definitely do not suck things into them like a monster. As long as you keep a safe distance from the event horizon you are safe like any other place in space. In fact, the black holes gravitational field is the same as any other object of the same mass.
- Universe inside a Black hole
Some scientists claim that inside a black hole there is one-way door between two universes. If somehow you manage to survive a trip through the center black hole of our Milky Way galaxy, you may end up in another universe. If that’s true, then we might be living inside a black hole right now. It can be hard to believe at first, but it may actually be the best explanation of how our universe came into existence. Unfortunately, there is no way to do a direct experiment to prove this theory since no information can get back out of a black hole. The only thing we can do is to study black holes from outside and develop theories about what lies inside a black hole.
- Its possible to see a black hole form
Yes! It is possible to see the beginning of its formation of stellar black holes. Stellar black holes form when the center of a massive star collapses in upon itself. This causes the star to explode and huge amount of energy is released during this process emitting a flash of gamma rays. This happens when a star goes supernova. This is the last view of the stars core that can be detected using telescopes before it collapses into a black hole. Telescopes can detect the fading of the dying star and the formation of a black hole.
If you would like to know more about black holes, there are many books out there. My personal favourite is Kip Thorne’s Black Holes and Time Warps: Einstein’s Outrageous Legacy, if you are interested.
Do you know of any other mind-blowing facts about black holes? Then share your knowledge in the comments below.
New data from NASA’s MRO(Mars Reconnaissance Orbiter, a satellite) shows strong evidence that liquid water flows on Mars.
NASA’s research and observations of this Red planet indicates that once a primitive ocean on Mars had more water than Earth’s Arctic ocean. It is also expected that water may still be present on Mars but there was no evidence until recently.
Dark narrow streaks on the walls of Garni crater on Mars (Photo credit : NASA/JPL/University of Arizona)
Mysterious darks streaks appear on Mars slopes during Martian summer, and then disappear during winter season. As you can see in the picture, these downhill flows (known as Recurring Slope Lineae RSL) have a correlation with the presence of liquid water. An imaging spectrometer aboard the satellite MRO has recently detected signatures of hydrated salts at multiples locations near these dark streaks (when the dark streaks were relatively wide). The hydrated salts are believed to be perchlorates. Some perchlorates have characteristics that can keep liquids from freezing. Since the dark streaks only form during the summer, higher temperatures most probably drive water to the surface. The source of this water is still a mystery, which can be surface or subsurface ice or something else.
So why are we so excited about the presence of liquid water on Mars? Well, water is a key ingredient for life and it is also believed that once Mars was a warm and wet world that was suitable for life; Mars’ geological evolution was comparable to Earth’s. Understanding the geology of Mars can help us understand Earth’s past and future, and may help answer the age-old question of whether life exists beyond our home planet.
Interested to know more? The new results were published online on September 28 in Nature Geoscience.
Who doesn’t want to save some money, specially when you are a student? Its hard enough to pay for tuition fees, living costs and other extras that come along the way. You should grab any chance to save money whenever you can. Here we are going to list the top 15 ways a student can save money during their time at school.
- Carry your Student ID or sign up for a Student advantage card:
Many times you will come across retailers who have seasonal offers for students. When you go out for shopping it’s a very good idea to keep your Student ID in your wallet so that if you happen to come across such an offer you can use your student card. Some stores just require a student ID, while others may want a little extra. For example, in the UK many retailers give discount to students only if they have NUS (National Union of Students) card. In Canada, there is SPC (Student Price Card) card that provides discounts and deals at stores and restaurants etc. It’s a good idea to sign up for these cards if you like shopping.
- Opt for no/lowest fee banking:
As an international student you may have different options for banking depending on where you are studying. Most banks usually offer an annual student rate that can sometimes be free or cheaper than other options. You also want to check out other banks and compare all their service charges. When I was a student in the UK, I had a bank account with no annual fees. You can also open a savings account that earns interest.
Most bank accounts in Canada/US have the option for student chequing account. Most of the banks offer a student chequing account. There are also other options. My personal favourite Canadian bank is Tangerine (which has no annual fees or service charges). In fact if you sign up using my Orange key (42358105S1) you will get $50 bonus for just signing in. However, keep in mind before you can open an account with Tangerine you need an external account.
- Use Student discount offered by public Transport companies:
As a student you will almost always enjoy student pricing for travel costs in most countries/cities around the world. For example, in London (UK) you can apply for 18+ student oyster photo card and can get 30% off the price of adult-rate Travel cards and also in bus and tram passes. In Toronto, Canada, you can also get Post-Secondary Students Metropass for a discounted rate. These are just examples, no matter where you study just make sure you use these discounts whenever available.
- Walk or bike:
If you live in a place where everything is close by, including your School, why not walk or bike? It will save you a lot of money and will keep you healthy as well.
5. Get a part-time job/summer internships:
Instead of taking expensive vacation during summer, get a summer job or better yet try to secure a summer internship. It will not only help you save a lot of money but also look good for your CV. Along with some extra cash you get a chance to meet people outside school and get some real life experience along the way. But be careful not to overdo it. You don’t want to end up distracted from your schoolwork. Also, for international students there is always some kind of restriction of how many hours (if at all) they are allowed to work in a week. Make sure you follow the rules.
6. Apply for scholarships:
Applying for scholarships is another way to get some extra cash. You want to keep an eye for these. Many of my friends in College missed out on some very good opportunities for not paying attention. Look for all kinds of scholarships, apply for even the smaller ones. There is almost always some kind of scholarship available based on merit, need or ethnicity (or other kinds). I remember securing small scholarships, bursaries and other big scholarships during my College life, which undoubtedly helped my savings account look better. Check out the financial Aid office or posters at your College to get to know more about these scholarships.
7. More student pricing:
As I was saying, always pay attention to the student pricing everywhere. If you shop online pay attention to the online offers a well. If you are a student in the UK, sign up for https://www.studentbeans.com. You can find about all kinds of offers and discounts on travel, food and drink, clothing, school supplies and what not! You can also get discounts on many of the well-known attractions in the UK and sometimes even for movies!
There are also many other discounts available for students during ‘back to school’ season (which is usually right before the fall semester). Apple does student pricing on new MacBooks and iMacs, so don’t forget to take advantage of some discount if you plan to buy a new Macbook. Some students also wait for black Friday to arrive since they get discounts from many retailers on that day.
8. Avoid specialty stores, instead shop in superstores:
Sometimes products in a specialty store (such as Staples for school supplies) can be more expensive than that of a general superstore (for example Walmart/Asda). Chances are you will find the same brand product at a cheaper price if you shop at the general stores.
- Opt for Dollar or pound stores:
Many times you will find essential stuffs with a bargain at dollar stores (such as Dollarama/Dollar stores in Canada/ US) or Pound stores (in the UK). Bigger version of these stores almost have everything including kitchen utensils, school supplies, cleaning products, and everyday essentials with a bargain.
- Cook your own food:
Okay, this one sounds like easier said than done. But believe me, if you start out with the habit of takeaway or eating ready-made food all the time, it starts to get very expensive. Also, when you cook your own food that’s usually much healthier. Try to bring your own lunch to College.
If you are sharing with other students, it can be a good idea to share the cost of big purchases such as buying a big bag of rice (buying in bulk usually saves a lot of money).
- Save money on Books:
You don’t have to buy all the books that are recommended for your courses. Check your library first to see if the book is. If not, the look for used books that can be bought for a cheaper price. Some times there can be facilities or shops in your own College that sell used books. You can also rent books if that is cheaper. Other options include checking out Amazon’s market place at amazon, you will almost always find used books from their website www.amazon.ca.
- Live with other students:
If you are going to live off campus, get a place with your friends or other students and split the rent. Sharing is always cheaper than living on your own.
- Make a budget:
If you make a budget for a certain period of time (say for a week or a month), it always helps you to stay away from impulse buying. You need to stick to your budget plan and make sure you do not spend more than you earn. You should know how much you are spending on your living costs, say on rent, food, utilities, internet, phone bills, transportation etc. Always keep a track of where your money goes in spending.
- Use automated service for bill payments:
If you forget to pay bills on time, you will encounter late charge fees. The best way to make sure it never happens is to automate your bill payments. That way you will never have to worry about paying bills on time. This applies to credit card bills as well.
- Use Campus services or Student Union offers:
Instead of spending a lot of money going out, check out your campus activities. Get to know what your Student Union has to offer. Most Colleges arrange many social events that are usually cheaper to participate or almost free. Sometimes joining your campus gym will also be cheaper than an external one.
One of the most stressful time in a students life is when they start to apply for colleges or universities. And the fact that there are so many choices with so many courses at different universities with each having different requirements does not make it any easier. How do you know which school is good for what you want to study and how should you know about the application process?
When I started applying for schools, I had no idea what I was doing back then and I was very confused with the whole application process. I wish I could go back and tell myself a few things that I know now. So, I decided to share a few things that may help some future students. Here are a list of things that every student in my opinion should keep in mind when applying for colleges.
1. Check out the University ranking:
If you are going to study a fairly demanding subject, you should always check out the ranking of the university. Don’t just trust any ranking on any website though. Look for ranking from reliable sources. Time higher education is a good place to start and is quite reliable. What’s more is that they usually show the analysis of what their ranking is based on. You can also find rankings by reputation of the school, area or subject. Another reliable source is the QS world university ranking. You can use other sources; just make sure that their rankings are based on reliable data.
However, keep in mind just because a university didn’t make it to the ranking table does not mean that the school is not worth checking out. There are many good schools that may not have an overall good ranking but may be specialised in one, two or a few subjects.
2. Check out the financial commitment:
One of the many mistakes that students do is that they don’t plan for their finances in advance. While many students get help from home, others opt for bank loans or credit cards. Whichever way you decide to pay for schools, try to plan ahead and get a clear picture of how you will pay for the years coming ahead. Students also need to take other things like living costs or emergencies into account. I have seen many bright students dropping out half way through due to financial situations. You don’t want to get to a point where you used your money and energy only to find out that you cannot afford to go to college anymore. That can be very frustrating.
So, I can’t stress enough…PLAN your finances. Check and compare fees of different colleges.
3. Read the entry requirements
One of the other important things to keep in mind is that you should check the entry requirements of the school you are applying to very carefully. Many schools in the US or Canada require SAT/GRE or some other kind of exams, while schools in the UK do not have a lot of entry exams. However, for international students there is almost always a requirement for the english language test. You HAVE to take some sort of English language test depending on the school you are going to. Most schools in the US prefer TOEFL or IELTS, while schools in Canada or the UK usually prefer IELTS. However, you should always check with the school to find out what kind of tests they accept. There could be some other kind for entry tests that they may want you to take depending on the subject or school you are applying to.
Also always check that your GPA meets the minimum GPA requirement or you meet the minimum score requirement for the standardised tests. You want to apply for schools where you have a score well above the minimum requirement, then your chances of getting in will be much higher.
4. Check the deadlines:
You should check the deadline for application well ahead. Before the deadlines you need to take care of the required tests (if any) and get the results in hand so that you can apply in time. This is a vital part, many students end up missing deadlines for the schools they were interested in and then ending up in a somewhere they didn’t plan to go. Last think you want is to regret about not applying to your dream school just because yo missed the deadline.
5. Have backup plans:
May be you always wanted to go to Harvard or Caltech, or may be Oxford or Cambridge. Whatever your dream school is, don’t just apply to just one place. Apply to several other schools at the same time, it’s always good to have backup plans. If you are applying to good ranking universities, also apply for some medium ranked and small universities. However, avoid applying to schools where you never plan to go even if you get in; this will save your time, money and energy.
6. Write your Statement of Purpose (SOP) early:
Your Statement of Purpose/ interest is one of the most important part of your application. This is where the admissions committee get to know ‘YOU’. You should start writing it as early as possible and proofread many times. Show your friends who can help you pointing out your mistakes or even your teacher/ professor at school who you think can help you with that. There will probably be many other students with similar grades like yourself; writing an exceptional SOP is a good way to make your application stand out. Just be honest and be yourself. A key to getting into good schools is a very good SOP along with your grades and scores or standardised tests.
7. Getting letters of recommendations:
Just like SOP, letters of recommendation is another vital part of your application. Admissions committee takes this very seriously. You should get this letter from someone who is well-aquainted with your work. This could be your teacher or professor from your current school or your employer. Some universities ask for an additional reference from someone who knows you in a personal capacity, so make sure you check what kind of reference you need to provide and how many.
8. Visit if possible:
Most schools organise open days for prospective students. If possible go and visit the school you are interested in. You get to meet the professors and get to know about their research (this is specially helpful for prospective graduate students). You can find out more about the facilities, clubs, transportation, social life and about their accommodations. I know it is not very practical for international students, but you can always get in touch with the department via email or phone. Even better, get in touch with current students or alumni to learn more about the department, social life etc.
9. Waiting for decision:
Fingers crossed, now that you have applied, its time to wait. If you have applied online, you will usually get an email confirmation or login information to check the status of your application. If you are anxious, its very normal. Try to focus on other things and make the most of your time remaining before college starts.
10. Getting accepted:
Its going to be all worth it when you get those acceptance letters in your hands, trust me. There is no joy like getting into the college you have always wanted to go.
And if you didn’t get accepted into your dream college, don’t kick yourself. Most good colleges receive thousands more applications from students than they can actually admit, and so they have to reject many of the brilliant ones. Don’t feel bad about not getting in where you wanted. You will still have other colleges as option and you will definitely get into one of those.
11. Apply for Visa (for international students):
For international students, this can be one of very stressful task depending on which country you are applying from and which country you are applying to. However, if done correctly and if the documents are prepared carefully, this process can be made much easier and less time consuming. Try to apply for student visa as early as you are allowed to. I will post a few things regarding students visa processes in a few days. So, stay tuned.
You should prepare yourself for the most amazing experience of your life. While going to college may seem like a lot of work, in the end its worth it. You will get to have friends from all around the world with different backgrounds and learn many new things. This can be a very rewarding experience. So relax and enjoy the time in college while keeping a balance between schoolwork and other things in life.
An end note : Its very important to keep calm and focus on the applications in an efficient way. Many students get overwhelmed with the amount of work they have to do while applying. The best way to avoid this is to get organised, makes lists of schools if necessary, research them one by one. Once you are done choosing follow the application process and start gathering your documents.
During this time, if you have any questions or confusions regarding the admissions process, requirements or anything else always contact the relevant admissions office or international office of the college you are interested in. They will be able to provide you with the most updated information.
This is my first post. I have been thinking about blogging about student life for a while. Well, finally the day came when I decided to jump to my computer and start writing it. Let’s just hope my posts are useful to some students. I have been student for a long time and I help many students everyday. So I decided to write about my experiences as a student to help others. I will be talking about student life in general, tips to survive through college life, application processes, tips for applying for visas, applying for scholarships, maintaining your finances, getting part-time jobs, internships, and many other things that will hopefully be helpful for students. So keep an eye on my blog as I will be posting new things regularly.
Feel free to comment on my posts. Share your views and tips as well to help our fellow students.